Qiuwen Wu

Journal Article Med Phys · May 16, 2024 BACKGROUND: Seed implant brachytherapy (SIBT) is a promising treatment modality for parotid gland cancers (PGCs). However, the current clinical standard dose calculation method based on the American Association of Physicists in Medicine (AAPM) Task Group 4 ... Full text Link to item Cite

A novel AP/PA total body irradiation technique using abutting IMRT fields at extended SSD.

Journal Article J Appl Clin Med Phys · April 2024 PURPOSE: To develop a Total Body Irradiation (TBI) technique using IMRT at extended SSD that can be performed in any size Linac room. METHODS: Patients studied were placed on a platform close to the floor, directly under the gantry with cranial-caudal axis ... Full text Link to item Cite

Automatic planning for head and neck seed implant brachytherapy based on deep convolutional neural network dose engine.

Journal Article Med Phys · February 2024 BACKGROUND: Seed implant brachytherapy (SIBT) is an effective treatment modality for head and neck (H&N) cancers; however, current clinical planning requires manual setting of needle paths and utilizes inaccurate dose calculation algorithms. PURPOSE: This ... Full text Link to item Cite

A reinforcement learning agent for head and neck intensity-modulated radiation therapy

Journal Article Frontiers in Physics · January 1, 2024 Head and neck (HN) cancers pose a difficult problem in the planning of intensity-modulated radiation therapy (IMRT) treatment. The primary tumor can be large and asymmetrical, and multiple organs at risk (OARs) with varying dose-sparing goals lie close to ... Full text Cite

Long-term risk of carotid stenosis and cerebrovascular disease after radiation therapy for head and neck cancer.

Conference Cancer · October 28, 2023 BACKGROUND: Recipients of radiation therapy (RT) for head and neck cancer (HNC) are at significantly increased risk for carotid artery stenosis (CAS) and cerebrovascular disease (CVD). We sought to determine (1) cumulative incidences of CAS and CVD among H ... Full text Link to item Cite

Photon energy synthesis method on medical linac for radiotherapy

Journal Article Chinese Journal of Medical Physics · July 1, 2023 Objective To propose an energy synthesis method that can fit photons with any known intermediate energies through high- and low-energy photons and compare it with the existing method. Methods Percentage depth dose (PDD) and off-center ratio (OCR) are two i ... Full text Cite

Continuous photon energy modulation in IMRT of pancreatic cancer

Journal Article Frontiers in Physics · January 1, 2023 Purpose: To develop a novel IMRT optimization method based on the principle of photon energy synthesis that simultaneously optimizes fluence map and beamlet energy. The method was validated on pancreatic cancers to demonstrate the benefits of the additiona ... Full text Cite

Input feature design and its impact on the performance of deep learning models for predicting fluence maps in intensity-modulated radiation therapy.

Journal Article Phys Med Biol · October 21, 2022 Objective. Deep learning (DL) models for fluence map prediction (FMP) have great potential to reduce treatment planning time in intensity-modulated radiation therapy (IMRT) by avoiding the lengthy inverse optimization process. This study aims to improve th ... Full text Link to item Cite

Applying pytorch toolkit to plan optimization for circular cone based robotic radiotherapy.

Journal Article Radiat Oncol · April 20, 2022 BACKGROUND: Robotic linac is ideally suited to deliver hypo-fractionated radiotherapy due to its compact head and flexible positioning. The non-coplanar treatment space improves the delivery versatility but the complexity also leads to prolonged optimizati ... Full text Link to item Cite

Purposeful irradiation of the epidural space to enhance local control without compromising cord sparing in spine radiosurgery†.

Journal Article J Radiosurg SBRT · 2022 PURPOSE: The epidural space is a frequent site of cancer recurrence after spine stereotactic radiosurgery (SSRS). This may be due to microscopic disease in the epidural space which is underdosed to obey strict spinal cord dose constraints. We hypothesized ... Link to item Cite

Does radiation therapy need more than two photon energies from Linac?

Journal Article Front Oncol · 2022 PURPOSE: Modern Linacs are equipped with multiple photon energies for radiation therapy, and proper energy is chosen for each case based on tumor characteristics and patient anatomy. The aim of this study is to investigate whether it is necessary to have m ... Full text Link to item Cite

A novel continuous beam energy selector for photon intensity-modulated radiotherapy

Conference Proceedings - 2022 15th International Congress on Image and Signal Processing, BioMedical Engineering and Informatics, CISP-BMEI 2022 · January 1, 2022 A photon synthesis method was developed recently which can generate photon beam of any equivalent energy from only two energies. In this work, a novel continuous beam energy selector for photon intensity-modulated radiotherapy (IMRT) was proposed and valid ... Full text Cite

Transfer learning for fluence map prediction in adrenal stereotactic body radiation therapy.

Conference Phys Med Biol · December 6, 2021 Objective:To design a deep transfer learning framework for modeling fluence map predictions for stereotactic body radiation therapy (SBRT) of adrenal cancer and similar sites that usually have a small number of cases.Approach:We developed a transfer learni ... Full text Link to item Cite

Artificial intelligence applications in intensity modulated radiation treatment planning: an overview.

Journal Article Quant Imaging Med Surg · December 2021 Artificial intelligence (AI) refers to methods that improve and automate challenging human tasks by systematically capturing and applying relevant knowledge in these tasks. Over the past decades, a number of approaches have been developed to address differ ... Full text Link to item Cite

Assessing the robustness of artificial intelligence powered planning tools in radiotherapy clinical settings-a phantom simulation approach.

Journal Article Quant Imaging Med Surg · December 2021 BACKGROUND: Artificial intelligence (AI) based radiotherapy treatment planning tools have gained interest in automating the treatment planning process. It is essential to understand their overall robustness in various clinical scenarios. This is an existin ... Full text Link to item Cite

Insights of an AI agent via analysis of prediction errors: a case study of fluence map prediction for radiation therapy planning.

Journal Article Phys Med Biol · November 26, 2021 Purpose.We have previously reported an artificial intelligence (AI) agent that automatically generates intensity-modulated radiation therapy (IMRT) plans via fluence map prediction, by-passing inverse planning. This AI agent achieved clinically comparable ... Full text Link to item Cite

Introducing matrix sparsity with kernel truncation into dose calculations for fluence optimization.

Journal Article Biomed Phys Eng Express · November 12, 2021 Deep learning algorithms for radiation therapy treatment planning automation require large patient datasets and complex architectures that often take hundreds of hours to train. Some of these algorithms require constant dose updating (such as with reinforc ... Full text Link to item Cite

Technical note: A fast and accurate analytical dose calculation algorithm for 125 I seed-loaded stent applications.

Journal Article Med Phys · November 2021 PURPOSE: The safety and clinical efficacy of 125 I seed-loaded stent for the treatment of portal vein tumor thrombosis (PVTT) have been shown. Accurate and fast dose calculation of the 125 I seeds with the presence of the stent is necessary for the plan op ... Full text Link to item Cite

Collect Insights of an H&N IMRT Planning AI Agent Through Analyzing Relationships Between Fluence Map Prediction Error and the Corresponding Dosimetric Impacts.

Conference International journal of radiation oncology, biology, physics · November 2021 Purpose/objective(s)With many deep learning (DL) models being developed for clinical applications, it is important to understand their behavior and clinical consequence. This study aims to collect insights of the relationship between fluence map p ... Full text Cite

An AI-Enabled Virtual Hands-On Teaching Tool for Treatment Planning: A Pancreas SBRT Pilot Study.

Journal Article International journal of radiation oncology, biology, physics · November 2021 Purpose/objective(s)To develop a tutoring program to help physician and physics residents to learn pancreas stereotactic body radiation therapy (SBRT) treatment planning via carefully collected cases and a series of specially designed knowledge mo ... Full text Cite

An end-to-end deep convolutional neural network-based dose engine for parotid gland cancer seed implant brachytherapy.

A novel AP/PA total body irradiation technique using abutting IMRT fields at extended SSD.

Automatic planning for head and neck seed implant brachytherapy based on deep convolutional neural network dose engine.

A reinforcement learning agent for head and neck intensity-modulated radiation therapy

Long-term risk of carotid stenosis and cerebrovascular disease after radiation therapy for head and neck cancer.

Photon energy synthesis method on medical linac for radiotherapy

Continuous photon energy modulation in IMRT of pancreatic cancer

Input feature design and its impact on the performance of deep learning models for predicting fluence maps in intensity-modulated radiation therapy.

Applying pytorch toolkit to plan optimization for circular cone based robotic radiotherapy.

Purposeful irradiation of the epidural space to enhance local control without compromising cord sparing in spine radiosurgery†.

Does radiation therapy need more than two photon energies from Linac?

A novel continuous beam energy selector for photon intensity-modulated radiotherapy

Transfer learning for fluence map prediction in adrenal stereotactic body radiation therapy.

Artificial intelligence applications in intensity modulated radiation treatment planning: an overview.

Assessing the robustness of artificial intelligence powered planning tools in radiotherapy clinical settings-a phantom simulation approach.

Insights of an AI agent via analysis of prediction errors: a case study of fluence map prediction for radiation therapy planning.

Introducing matrix sparsity with kernel truncation into dose calculations for fluence optimization.

Technical note: A fast and accurate analytical dose calculation algorithm for 125 I seed-loaded stent applications.

Collect Insights of an H&N IMRT Planning AI Agent Through Analyzing Relationships Between Fluence Map Prediction Error and the Corresponding Dosimetric Impacts.

An AI-Enabled Virtual Hands-On Teaching Tool for Treatment Planning: A Pancreas SBRT Pilot Study.

Assessing the Robustness and Performance of Artificial Intelligence Powered Planning Tools in Clinical Settings.

Conference International journal of radiation oncology, biology, physics · November 2021 Purpose/objective(s)Artificial intelligence (AI) driven tools have been maturing in automating the radiation treatment planning process. To prepare for clinical deployment of these tools, it is essential to understand their robustness in clinical ... Full text Cite

The Reduction of Computational Cost by Introducing Kernel Sparsity and Truncation Into IMRT Optimization.

Conference International journal of radiation oncology, biology, physics · November 2021 Purpose/objective(s)Applications involving AI and Machine Learning are rapidly improving our ability to plan treatments efficiently and effectively by aiding human planners and physicians during the iterative process of planning. These algorithms ... Full text Cite

An artificial intelligence-driven agent for real-time head-and-neck IMRT plan generation using conditional generative adversarial network (cGAN).

Journal Article Med Phys · June 2021 PURPOSE: To develop an artificial intelligence (AI) agent for fully automated rapid head-and-neck intensity-modulated radiation therapy (IMRT) plan generation without time-consuming dose-volume-based inverse planning. METHODS: This AI agent was trained via ... Full text Link to item Cite

An Interpretable Planning Bot for Pancreas Stereotactic Body Radiation Therapy.

Journal Article Int J Radiat Oncol Biol Phys · March 15, 2021 PURPOSE: Pancreas stereotactic body radiation therapy (SBRT) treatment planning requires planners to make sequential, time-consuming interactions with the treatment planning system to reach the optimal dose distribution. We sought to develop a reinforcemen ... Full text Link to item Cite

Investigation of effect of filter on the stand-up technique for total skin irradiation by Monte Carlo simulation.

Journal Article J Appl Clin Med Phys · January 2021 PURPOSE: The aim of this study was to investigate dosimetric effects of scattering filter on the stand-up technique for total skin irradiation (TSI) with a single electron field by Monte Carlo (MC) simulation. METHODS: MC simulations were performed with BE ... Full text Link to item Cite

Clinical Experience With Machine Learning-Based Automated Treatment Planning for Whole Breast Radiation Therapy.

Journal Article Adv Radiat Oncol · 2021 PURPOSE: The machine learning-based automated treatment planning (MLAP) tool has been developed and evaluated for breast radiation therapy planning at our institution. We implemented MLAP for patient treatment and assessed our clinical experience for its p ... Full text Open Access Link to item Cite

Deep Learning-Based Fluence Map Prediction for Pancreas Stereotactic Body Radiation Therapy With Simultaneous Integrated Boost.

Journal Article Adv Radiat Oncol · 2021 PURPOSE: Treatment planning for pancreas stereotactic body radiation therapy (SBRT) is a challenging task, especially with simultaneous integrated boost treatment approaches. We propose a deep learning (DL) framework to accurately predict fluence maps from ... Full text Link to item Cite

Recumbent Total Skin Electron Beam Therapy.

Journal Article Adv Radiat Oncol · 2021 PURPOSE: Our purpose was to describe preliminary dosimetric and clinical results of a recumbent total skin electron beam therapy (TSEBT) technique and compare this to a conventional standing TSEBT technique. METHODS AND MATERIALS: A customized treatment pl ... Full text Link to item Cite

Early 18F-FDG-PET Response During Radiation Therapy for HPV-Related Oropharyngeal Cancer May Predict Disease Recurrence.

Journal Article Int J Radiat Oncol Biol Phys · November 15, 2020 PURPOSE: Early indication of treatment outcome may guide therapeutic de-escalation strategies in patients with human papillomavirus (HPV)-related oropharyngeal cancer (OPC). This study investigated the relationships between tumor volume and 18F-fluorodeoxy ... Full text Open Access Link to item Cite

Validation of the dosimetry of total skin irradiation techniques by Monte Carlo simulation.

Journal Article J Appl Clin Med Phys · August 2020 PURPOSE: To validate the dose measurements for two total skin irradiation techniques with Monte Carlo simulation, providing more information on dose distributions, and guidance on further technique optimization. METHODS: Two total skin irradiation techniqu ... Full text Link to item Cite

A patient-independent CT intensity matching method using conditional generative adversarial networks (cGAN) for single x-ray projection-based tumor localization.

Journal Article Phys Med Biol · July 20, 2020 A convolutional neural network (CNN)-based tumor localization method with a single x-ray projection was previously developed by us. One finding is that the discrepancy in the discrepancy in the intensity between a digitally reconstructed radiograph (DRR) o ... Full text Link to item Cite

Knowledge-Based Tradeoff Hyperplanes for Head and Neck Treatment Planning.

Journal Article Int J Radiat Oncol Biol Phys · April 1, 2020 PURPOSE: To develop a tradeoff hyperplane model to facilitate tradeoff decision-making before inverse planning. METHODS AND MATERIALS: We propose a model-based approach to determine the tradeoff hyperplanes that allow physicians to navigate the clinically ... Full text Link to item Cite

Real-time tumor localization with single x-ray projection at arbitrary gantry angles using a convolutional neural network (CNN).

Journal Article Phys Med Biol · March 19, 2020 For tumor tracking therapy, precise knowledge of tumor position in real-time is very important. A technique using single x-ray projection based on a convolutional neural network (CNN) was recently developed which can achieve accurate tumor localization in ... Full text Link to item Cite

Technical Note: A dose calculation framework for dynamic electron arc radiotherapy (DEAR) using VirtuaLinac Monte Carlo simulation tool.

Journal Article Med Phys · January 2020 PURPOSE: Dynamic electron arc radiotherapy (DEAR) is a novel dynamic technique that achieves highly conformal dose through simultaneous couch and gantry motion during delivery. The purpose of this study is to develop a framework integrating a Monte Carlo d ... Full text Link to item Cite

Knowledge Models as Teaching Aid for Training Intensity Modulated Radiation Therapy Planning: A Lung Cancer Case Study.

Journal Article Front Artif Intell · 2020 Purpose: Artificial intelligence (AI) employs knowledge models that often behave as a black-box to the majority of users and are not designed to improve the skill level of users. In this study, we aim to demonstrate the feasibility that AI can serve as an ... Full text Link to item Cite

Fluence Map Prediction Using Deep Learning Models - Direct Plan Generation for Pancreas Stereotactic Body Radiation Therapy.

Journal Article Front Artif Intell · 2020 Purpose: Treatment planning for pancreas stereotactic body radiation therapy (SBRT) is a difficult and time-consuming task. In this study, we aim to develop a novel deep learning framework to generate clinical-quality plans by direct prediction of fluence ... Full text Open Access Link to item Cite

Three IMRT advanced planning tools: A multi-institutional side-by-side comparison.

Journal Article J Appl Clin Med Phys · August 2019 PURPOSE: To assess three advanced radiation therapy treatment planning tools on the intensity-modulated radiation therapy (IMRT) quality and consistency when compared to the clinically approved plans, referred as manual plans, which were planned without us ... Full text Link to item Cite

Two Photon Dose Engines for Accurate and Fast Volumetric Modulated Arc Therapy

Conference 2019 Advances in Science and Engineering Technology International Conferences, ASET 2019 · May 14, 2019 Two photon dose computation engines based on pencil beam models were customized to meet the requirements of high conformity and fast computation for Volumetric Modulated Arc Therapy (VMAT) plans. The first model is designed to run through first VMAT iterat ... Full text Cite

Nonuniform Planning Target Volume Margins for Prostate Bed on the Basis of Surgical Clips on Daily Cone Beam Computed Tomography.

Journal Article Adv Radiat Oncol · 2019 PURPOSE: We hypothesized that the interfraction motions of the superior and inferior prostate beds differ and therefore require different margins. In this study, we used daily cone beam computed tomography (CBCT) to evaluate the motion of postprostatectomy ... Full text Open Access Link to item Cite

Convolutional Neural Network (CNN) Based Three Dimensional Tumor Localization Using Single X-Ray Projection

Journal Article IEEE Access · January 1, 2019 Accurate localization of lung tumor in real time based on a single X-ray projection is of great interest to the tumor-tracking radiotherapy but is very challenging. In this paper, a convolutional neural network (CNN)-based tumor localization method was pro ... Full text Cite

In modern linacs monitor units should be defined in water at 10 cm depth rather than at dmax.

Journal Article Med Phys · November 2018 Full text Link to item Cite

Machine learning and modeling: Data, validation, communication challenges.

Journal Article Med Phys · October 2018 With the era of big data, the utilization of machine learning algorithms in radiation oncology is rapidly growing with applications including: treatment response modeling, treatment planning, contouring, organ segmentation, image-guidance, motion tracking, ... Full text Link to item Cite

Improving Quality and Consistency in NRG Oncology Radiation Therapy Oncology Group 0631 for Spine Radiosurgery via Knowledge-Based Planning.

Journal Article Int J Radiat Oncol Biol Phys · March 15, 2018 PURPOSE: To use knowledge-based planning (KBP) as a method of producing high-quality, consistent, protocol-compliant treatment plans in a complex setting of spine stereotactic body radiation therapy on NRG Oncology Radiation Therapy Oncology Group (RTOG) 0 ... Full text Link to item Cite

A singular value decomposition linear programming (SVDLP) optimization technique for circular cone based robotic radiotherapy.

Journal Article Phys Med Biol · January 5, 2018 With robot-controlled linac positioning, robotic radiotherapy systems such as CyberKnife significantly increase freedom of radiation beam placement, but also impose more challenges on treatment plan optimization. The resampling mechanism in the vendor-supp ... Full text Link to item Cite

Using weighted power mean for equivalent square estimation.

Journal Article J Appl Clin Med Phys · November 2017 PURPOSE: Equivalent Square (ES) enables the calculation of many radiation quantities for rectangular treatment fields, based only on measurements from square fields. While it is widely applied in radiotherapy, its accuracy, especially for extremely elongat ... Full text Open Access Link to item Cite

Observation of different tumor motion magnitude within liver and estimate of internal motion margins in postoperative patients with hepatocellular carcinoma.

Journal Article Cancer Manag Res · 2017 AIMS: To assess motion magnitude in different parts of the liver through surgical clips in postoperative patients with hepatocellular carcinoma and to examine the correlation between the clip and diaphragm motion. METHODS: Four-dimensional computed tomogra ... Full text Open Access Link to item Cite

Comparisons of volumetric modulated arc therapy (VMAT) quality assurance (QA) systems: sensitivity analysis to machine errors.

Journal Article Radiat Oncol · November 7, 2016 BACKGROUND: In volumetric modulated arc therapy (VMAT), gantry angles, dose rate and the MLC positions vary with the radiation delivery. The quality assurance (QA) system should be able to catch the planning and machine errors. The aim of this study was to ... Full text Open Access Link to item Cite

A pencil beam dose calculation model for CyberKnife system.

Journal Article Med Phys · October 2016 PURPOSE: CyberKnife system is initially equipped with fixed circular cones for stereotactic radiosurgery. Two dose calculation algorithms, Ray-Tracing and Monte Carlo, are available in the supplied treatment planning system. A multileaf collimator system w ... Full text Link to item Cite

Diode-based transmission detector for IMRT delivery monitoring: a validation study.

Journal Article J Appl Clin Med Phys · September 8, 2016 The purpose of this work was to evaluate the potential of a new transmission detector for real-time quality assurance of dynamic-MLC-based radiotherapy. The accuracy of detecting dose variation and static/dynamic MLC position deviations was measured, as we ... Full text Open Access Link to item Cite

Diode-based transmission detector for IMRT delivery monitoring: a validation study.

Journal Article J Appl Clin Med Phys · September 2016 The purpose of this work was to evaluate the potential of a new transmission detector for real-time quality assurance of dynamic-MLC-based radiotherapy. The accuracy of detecting dose variation and static/dynamic MLC position deviations was measured, as we ... Full text Link to item Cite

TU-H-CAMPUS-IeP2-02: Four-Dimensional Coronary Artery Visualization Based On Image Propagation.

Journal Article Med Phys · June 2016 PURPOSE: 4D visualization of coronary artery using X-ray angiograms rotationally acquired on C-arm has many valuable applications, like dynamic roadmapping. In this work we propose and validate a method to visualize 4D artery based on 3D coronary image pro ... Full text Link to item Cite

SU-F-T-347: An Absolute Dose-Volume Constraint Based Deterministic Optimization Framework for Multi-Co60 Source Focused Radiotherapy.

Journal Article Med Phys · June 2016 PURPOSE: Treatment plan optimization in multi-Co60 source focused radiotherapy with multiple isocenters is challenging, because dose distribution is normalized to maximum dose during optimization and evaluation. The objective functions are traditionally de ... Full text Link to item Cite

SU-G-TeP1-08: LINAC Head Geometry Modeling for Cyber Knife System.

Journal Article Med Phys · June 2016 PURPOSE: Knowledge of the LINAC head information is critical for model based dose calculation algorithms. However, the geometries are difficult to measure precisely. The purpose of this study is to develop linac head models for Cyber Knife system (CKS). ME ... Full text Link to item Cite

SU-G-BRC-17: Using Generalized Mean for Equivalent Square Estimation.

Journal Article Med Phys · June 2016 PURPOSE: Equivalent Square (ES) is a widely used concept in radiotherapy. It enables us to determine many important quantities for a rectangular treatment field, without measurement, based on the corresponding values from its ES field. In this study, we pr ... Full text Link to item Cite

SU-F-T-283: A Novel Device to Enable Portal Dosimetry for Flattening Filter Free Beams.

Journal Article Med Phys · June 2016 PURPOSE: Varian's electronic portal imaging device (EPID) based portal dosimetry tool is a popular and effective means of performing IMRT QA. EPIDs for older models of the TrueBeam accelerator utilize a 40cmx30cm Image Detection Unit (IDU) that saturates a ... Full text Link to item Cite

TH-AB-BRB-02: ET-Reloaded.

Journal Article Med Phys · June 2016 Current state-of-the art digital C-arm medical linear accelerators are capable of delivering radiation treatments with high level of automation, which affords coordinated motions of gantry, couch, and multileaf collimator (MLC) with dose rate modulations. ... Full text Link to item Cite

SU-G-TeP4-01: A High Resolution Pre-Treatment VMAT QA Technique Based On EPID for Single Isocenter Multiple Mets Stereotactic Radiosurgery.

Journal Article Med Phys · June 2016 PURPOSE: For multiple mets radiosurgery, it is advantageous to use VMAT with a single isocenter for the ease in planning and efficiency in delivery. Insightful pre-treatment QA for these cases is difficult to obtain because (1) target size is often small a ... Full text Link to item Cite

SU-G-TeP2-14: Universal Function Form for Photon Open Field In-Water Output Ratio.

Journal Article Med Phys · June 2016 PURPOSE: In-Water-Output-Ratio (IWOR) plays a significant role in linac-based radiotherapy treatment planning, linking MUs to delivered radiation dose. For an open rectangular field, IWOR depends on both its width and length, and changes rapidly when one o ... Full text Link to item Cite

Establishing the feasibility of the dosimetric compliance criteria of RTOG 1308: phase III randomized trial comparing overall survival after photon versus proton radiochemotherapy for inoperable stage II-IIIB NSCLC.

Journal Article Radiat Oncol · May 4, 2016 BACKGROUND: To establish the feasibility of the dosimetric compliance criteria of the RTOG 1308 trial through testing against Intensity Modulation Radiation Therapy (IMRT) and Passive Scattering Proton Therapy (PSPT) plans. METHODS: Twenty-six lung IMRT an ... Full text Link to item Cite

Tomosynthesis Applications in Radiation Oncology

Chapter · April 19, 2016 Cite

WE-A-207-02: Electron Beam Therapy - Current Status and Future Directions.

Journal Article Med Phys · June 2015 UNLABELLED: In memory of the significant contribution of Dr. Jacques Ovadia to electron beam techniques, this session will review recent, advanced techniques which are reinvigorating the science of electron beam radiation therapy. Recent research efforts i ... Full text Link to item Cite

TU-CD-304-07: Intensity Modulated Electron Beam Therapy Employing Small Fields in Virtual Scanning Mode.

Journal Article Med Phys · June 2015 PURPOSE: Dynamic electron radiation therapies such as dynamic electron arc radiotherapy (DEAR) utilize small fields to provide target conformity and fluence modulation. The purpose of this study is to demonstrate the feasibility of virtual scanning mode us ... Full text Link to item Cite

SU-E-T-690: Sensitivity Analysis to Machine Error: Comparisons of VMAT QA Systems.

Journal Article Med Phys · June 2015 PURPOSE: In VMAT delivery, the gantry angles, dose rate and the MLC positions are all modulated. It is therefore necessary to perform pre-treatment QA to detect any possible errors either in the plan or machine delivery system. Previously we developed a QA ... Full text Link to item Cite

SU-E-T-344: Dynamic Electron Beam Therapy Using Multiple Apertures in a Single Cut-Out.

Journal Article Med Phys · June 2015 PURPOSE: Few leaf electron collimators (FLEC) or electron MLCs (eMLC) are highly desirable for dynamic electron beam therapies as they produce multiple apertures within a single delivery to achieve conformal dose distributions. However, their clinical impl ... Full text Link to item Cite

SU-E-T-317: Dosimetric Evaluation of Acuros XB Advanced Dose Calculation Algorithm in Head and Neck Patients.

Journal Article Med Phys · June 2015 PURPOSE: The Acuros XB photon dose calculation algorithm is a newly implemented calculation technique within the Eclipse treatment planning system using deterministic solutions to the linear Boltzmann transport equations. The goal of this study is to asses ... Full text Link to item Cite

SU-E-T-252: Developing a Pencil Beam Dose Calculation Algorithm for CyberKnife System.

Journal Article Med Phys · June 2015 PURPOSE: Currently there are two dose calculation algorithms available in the Cyberknife planning system: ray-tracing and Monte Carlo, which is either not accurate or time-consuming for irregular field shaped by the MLC that was recently introduced. The pu ... Full text Link to item Cite

A Monte Carlo simulation framework for electron beam dose calculations using Varian phase space files for TrueBeam Linacs.

Journal Article Med Phys · May 2015 PURPOSE: To develop a framework for accurate electron Monte Carlo dose calculation. In this study, comprehensive validations of vendor provided electron beam phase space files for Varian TrueBeam Linacs against measurement data are presented. METHODS: In t ... Full text Link to item Cite

Quality assurance for online adapted treatment plans: benchmarking and delivery monitoring simulation.

Journal Article Med Phys · January 2015 PURPOSE: An important challenge facing online adaptive radiation therapy is the development of feasible and efficient quality assurance (QA). This project aimed to validate the deliverability of online adapted plans and develop a proof-of-concept online de ... Full text Link to item Cite

Point/Counterpoint. Online adaptive planning for prostate cancer radiotherapy is necessary and ready now.

Journal Article Med Phys · August 2014 Full text Link to item Cite

Incorporating single-side sparing in models for predicting parotid dose sparing in head and neck IMRT.

Journal Article Med Phys · February 2014 PURPOSE: Sparing of single-side parotid gland is a common practice in head-and-neck (HN) intensity modulated radiation therapy (IMRT) planning. It is a special case of dose sparing tradeoff between different organs-at-risk. The authors describe an improved ... Full text Link to item Cite

Dynamic electron arc radiotherapy (DEAR): a feasibility study.

Journal Article Phys Med Biol · January 20, 2014 Compared to other radiation therapy modalities, clinical electron beam therapy has remained practically unchanged for the past few decades even though electron beams with multiple energies are widely available on most linacs. In this paper, we present the ... Full text Link to item Cite

Strategies for automatic online treatment plan reoptimization using clinical treatment planning system: a planning parameters study.

Journal Article Med Phys · November 2013 PURPOSE: Adaptive radiation therapy for prostate cancer using online reoptimization provides an improved control of interfractional anatomy variations. However, the clinical implementation of online reoptimization is currently limited by the low efficiency ... Full text Link to item Cite

A novel technique for VMAT QA with EPID in cine mode on a Varian TrueBeam linac.

Journal Article Phys Med Biol · October 7, 2013 Volumetric modulated arc therapy (VMAT) is a relatively new treatment modality for dynamic photon radiation therapy. Pre-treatment quality assurance (QA) is necessary and many efforts have been made to apply electronic portal imaging device (EPID)-based IM ... Full text Link to item Cite

Dynamic Electron Arc Radiation Therapy (DEAR): A New Conformal Technique in Delivering Electron Beam Therapy

Conference International Journal of Radiation Oncology*Biology*Physics · October 2013 Full text Cite

SU-E-T-143: Dosimetric Characteristics of TrueBeam STx System with High Definition Multi-Leaf Collimator: Commissioning of Stereotactic Radiosurgery.

Journal Article Med Phys · June 2013 IntroductionDosimetric characteristics of one TrueBeam STx treatment unit with a 120-leaf high definition multileaf collimator (HD120MLC) are systematically measured for commissioning of stereotactic radiosurgery (SRS). Due to limited data available, it is ... Full text Link to item Cite

WE-G-108-08: A Novel Technique for VMAT QA with EPID in Cine Mode On Varian TrueBeam.

Conference Med Phys · June 2013 PURPOSE: Volumetric modulated arc therapy (VMAT) is a relatively new treatment modality for dynamic photon radiation therapy. Pre-treatment quality assurance (QA) is necessary and many efforts have been taken to apply electronic portal imaging device (EPID ... Full text Link to item Cite

SU-E-T-560: A Method to Determine Optimal Dynamic MLC Parameters for Varian Truebeam with Millennium MLC and HDMLC.

Conference Med Phys · June 2013 PURPOSE: Correct MLC modeling is essential to the accurate IMRT delivery. Most TPSs use simplified models with parameters of leaf transmission (LT) and dynamic leaf gap (DLG). The common way to determine them is through extrapolation from measurements. In ... Full text Link to item Cite

SU-E-T-553: Measurement of Incident Electron Spots On TrueBeam.

Conference Med Phys · June 2013 PURPOSE: Lateral dimensions of the incident electron beam (spot sizes) are essential for accurate modelling of x-ray fields, especially for small field output factors and penumbrae. We present spot sizes measured on the Varian TrueBeam linac and propose an ... Full text Link to item Cite

SU-E-T-602: Dynamic Electron Arc Radiotherapy (DEAR): A Planning Study.

Conference Med Phys · June 2013 PURPOSE: Electron beam therapy is under-utilized in radiation treatment of cancer and has remained practically unchanged for decades. We propose a new technique, Dynamic Electron Arc Radiotherapy (DEAR) with synchronized couch motion. In DEAR, gantry rotat ... Full text Link to item Cite

Adaptive dose-compensation technique for image-guided radiotherapy of prostate cancer

Journal Article IFMBE Proceedings · April 16, 2013 Background: For image-guided radiotherapy (IGRT) of prostate cancer, the current standard is online image guidance which can effectively correct setup errors and inter-fraction rigid organ motion. However, planning margins are still necessary for deformati ... Full text Cite

TU‐C‐108‐07: Transmission Detector Array System for RT Delivery Monitoring: Validation Testing

Conference Medical Physics · January 1, 2013 Purpose: To quantify the influence of the gantry‐mounted Delta4‐AT detector array on beam quality, and the detection sensitivity to machine output and MLC position deviations. Methods: A Delta4‐AT prototype was attached to the accessory holder mount of a V ... Full text Cite

SU‐E‐T‐707: Evaluation of the Quality of Organs‐At‐Risk Dose Sparing in Anorectal and Prostate IMRT Plans

Conference Medical Physics · January 1, 2013 Purpose: To evaluate the quality of organs‐at‐risk (OARs) dose sparing in IMRT plans for anorectal and prostate cancer cases utilizing organ‐based knowledge models to predict OAR DVHs.MethodsThe quality of OAR dose sparing in IMRT plans are evaluated by or ... Full text Cite

TH‐C‐137‐08: Dosimetric Quality of An Automatic IMRT Planning Method for Head and Neck Cancer Cases

Conference Medical Physics · January 1, 2013 Purpose: To evaluate the dosimetric quality of an automatic IMRT planning method for Head and Neck (HN) cancer cases. Methods: Eighteen HN cancer patients are planned with nine equally spaced IMRT beams. The OAR dose sparing objectives for each plan (prima ... Full text Cite

SU‐E‐CAMPUS‐T‐05: Quality Evaluation of An Automatic VMAT Planning Method for Head and Neck Cancer Cases

Conference Medical Physics · January 1, 2013 Purpose: To evaluate the dosimetric quality of an automatic volumetric‐modulated arc therapy (VMAT) planning method for Head and Neck (HN) cancer cases. Methods: Eighteen HN cancer cases are planned automatically by 2‐arc VMAT. An OAR DVH prediction model ... Full text Cite

TU‐E‐108‐02: Dynamic Electron Arc Radiotherapy (DEAR): A Feasibility Study

Conference Medical Physics · January 1, 2013 Purpose: Electron beam therapy is under‐utilized in radiation treatment of cancer and has remained practically unchanged for decades. We propose a new technique, Dynamic Electron Arc Radiotherapy (DEAR) with synchronized couch motion. DEAR utilizes modulat ... Full text Cite

Commissioning and dosimetric characteristics of TrueBeam system: composite data of three TrueBeam machines.

Journal Article Med Phys · November 2012 Featured Publication PURPOSE: A TrueBeam linear accelerator (TB-LINAC) is designed to deliver traditionally flattened and flattening-filter-free (FFF) beams. Although it has been widely adopted in many clinics for patient treatment, limited information is available related to ... Full text Link to item Cite

Dosimetric Evaluation of Flattening Filter-free (FFF) Photon Beams for Lung SBRT

Conference International Journal of Radiation Oncology*Biology*Physics · November 2012 Featured Publication Full text Cite

Study of Prostate Bed Motion Using Daily CBCT and Surgical Clips

Conference International Journal of Radiation Oncology*Biology*Physics · November 2012 Featured Publication Full text Cite

Evaluation of IMRT and VMAT for Head-and-Neck Cancer With Flattening Filter-free (FFF) Beams

Conference International Journal of Radiation Oncology*Biology*Physics · November 2012 Featured Publication Full text Cite

Partial Breast Extracranial Radiosurgery: A Dosimetric Evaluation of Treatment Delivery Accuracy

Conference International Journal of Radiation Oncology*Biology*Physics · November 2012 Featured Publication Full text Cite

Independent verification of gantry angle for pre-treatment VMAT QA using EPID.

Journal Article Phys Med Biol · October 21, 2012 Featured Publication We propose a method to incorporate independent verification of gantry angle for electronic portal imaging device (EPID)-based pre-treatment quality assurance (QA) of clinical volumetric modulated arc therapy (VMAT) plans. Gantry angle is measured using pro ... Full text Link to item Cite

Evaluation of the accuracy of a 3D surface imaging system for patient setup in head and neck cancer radiotherapy.

Journal Article Int J Radiat Oncol Biol Phys · October 1, 2012 Featured Publication PURPOSE: To evaluate the accuracy of three-dimensional (3D) surface imaging system (AlignRT) registration algorithms for head-and-neck cancer patient setup during radiotherapy. METHODS AND MATERIALS: Eleven patients, each undergoing six repeated weekly hel ... Full text Link to item Cite

SU-E-T-104: Commissioning and Dosimetric Characteristics of TrueBeam System: Composite Data of Three TrueBeam Machines.

Journal Article Med Phys · June 2012 Featured Publication INTRODUCTION: A TrueBeam linear accelerator (TB-LINAC) is designed to deliver standard flattened and flattening-filter-free (FFF) beams. In our institute, three TB-LINAC units are installed. In this work, composite data of the three units and multi-unit co ... Full text Link to item Cite

SU-E-J-23: Prostate Bed Motion Study Using Surgical Clips Based on Daily CBCT.

Journal Article Med Phys · June 2012 Featured Publication PURPOSE: To study prostate-bed motion after prostatectomy using the surgical clips as a surrogate. METHODS: On the treatment planning CT, surgical clips within the PTV are identified and contoured. They are also identified and contoured in each daily CBCT. ... Full text Link to item Cite

SU-E-J-16: Prostate Bed Motion during Post-Prostatectomy Radiotherapy.

Journal Article Med Phys · June 2012 PURPOSE: To report the inter-fractional prostate bed motion (PBM) during post-prostatectomy radiotherapy using cone-beam CT (CBCT). The correlations between PBM, anterior rectal wall and posterior bladder wall shifts were also investigated. METHODS: Sevent ... Full text Link to item Cite

MO-D-BRB-09: Treatment Delivery QA for Online Adaptive Radiation Therapy Based on Dynamic Machine Information (DMI): A Feasibility Study.

Journal Article Med Phys · June 2012 Featured Publication PURPOSE: To implement a quality assurance (QA) system for the treatment delivery of online adaptive radiation therapy utilizing Dynamic Machine Information (DMI). MATERIALS AND METHODS: DMI provides the expected/actual MLC leaf-positions, delivered MU, and ... Full text Link to item Cite

SU-E-T-559: Evaluation of Flatening Filter Free (FFF) Beams in Radiotherapy of Head and Neck Cancer.

Journal Article Med Phys · June 2012 Featured Publication PURPOSE: To investigate th applicability of the flattening filter free (FFF) to fractionated radiotherapy of head and neck cancer. METHODS: Twelve patients previously treated with IMRT were selected. A SIB protocol was chosen so that 66/54 Gy were prescrib ... Full text Link to item Cite

SU-E-T-406: Online Image-Guidance for Prostate SBRT: Dosimetric Benefits and Margin Analysis.

Conference Med Phys · June 2012 PURPOSE: To evaluate the dosimetric benefits of online image guidance during prostate stereotactic body radiotherapy (SBRT) and the potential on margin reduction. METHODS: 28 prostate SBRT patients were retrospectively studied, each treated with 37Gy in 5 ... Full text Link to item Cite

SU-E-T-626: Individualized Trade-Off of Dose Coverage and Sparing in IMRT Planning.

Conference Med Phys · June 2012 PURPOSE: We present an evidence-based approach to quantifying the dose sparing trade-offs between different Organs-at-risk (OARs) and the trade-off between OAR dose sparing and target dose coverage in IMRT plans. METHODS: The interaction between dose spari ... Full text Link to item Cite

MO-D-BRB-10: Modeling Inter-Patient Variation of Organ-At-Risk Sparing in IMRT Plans: An Evidence-Based Plan Quality Evaluation.

Conference Med Phys · June 2012 PURPOSE: To develop a predictive model to assess the quality of critical organ dose sparing in IMRT plans by providing patient specific dose sparing references, based on an array of patient anatomical features and prior planning experience. METHODS: Contri ... Full text Link to item Cite

Comparison of 3D conformal breast radiation treatment plans using the anisotropic analytical algorithm and pencil beam convolution algorithm.

Journal Article Radiother Oncol · May 2012 Featured Publication PURPOSE: To investigate (1) dosimetric differences between plans calculated using the anisotropic analytical algorithm (AAA) and pencil beam convolution (PBC) algorithm, (2) the plan quality achieved using AAA compared to PBC based on dosimetric parameters ... Full text Link to item Cite

A "rolling average" multiple adaptive planning method to compensate for target volume changes in image-guided radiotherapy of prostate cancer.

Journal Article J Appl Clin Med Phys · January 5, 2012 Featured Publication For prostate cancer radiotherapy, the interfractional organ motion can have several forms: changes in position, shape, and volume. The interfractional motion can be managed through either online or offline image guidance (IG). The position changes are comm ... Full text Link to item Cite

Assessing Effects of Ion Collection Efficiency in Flattening Filter-Free (FFF) Beams On Three TrueBeam Machines

Conference MEDICAL PHYSICS · 2012 Featured Publication Full text Cite

Benchmarking Flattening-Filter Free Photons for IMRT/VMAT

Conference MEDICAL PHYSICS · 2012 Featured Publication Full text Cite

On-Board Digital Tomosynthesis: An Emerging New Technology for Image-Guided Radiation Therapy

Chapter · January 1, 2012 External-beam radiation therapy is a common treatment modality for cancers. e treatment course typically consists of 30-40 daily fractions of 180-200 cGy over several weeks. On-board imaging (OBI) guidance is oen designed to track shis in patient positioni ... Full text Cite

Evaluations of an adaptive planning technique incorporating dose feedback in image-guided radiotherapy of prostate cancer.

Journal Article Med Phys · December 2011 Featured Publication PURPOSE: Online image guidance (IG) has been used to effectively correct the setup error and inter-fraction rigid organ motion for prostate cancer. However, planning margins are still necessary to account for uncertainties such as deformation and intra-fra ... Full text Link to item Cite

The Role of Offline Adaptive Planning in Online Image Guided Radiation Therapy of Prostate Cancer

Journal Article International Journal of Radiation Oncology*Biology*Physics · October 2011 Featured Publication Full text Cite

Dosimetric and geometric evaluation of a hybrid strategy of offline adaptive planning and online image guidance for prostate cancer radiotherapy.

Journal Article Phys Med Biol · August 7, 2011 Featured Publication For prostate cancer patients, online image-guided (IG) radiotherapy has been widely used in clinic to correct the translational inter-fractional motion at each treatment fraction. For uncertainties that cannot be corrected online, such as rotation and defo ... Full text Link to item Cite

Dosimetric effect of intrafraction motion and residual setup error for hypofractionated prostate intensity-modulated radiotherapy with online cone beam computed tomography image guidance.

Journal Article Int J Radiat Oncol Biol Phys · June 1, 2011 Featured Publication PURPOSE: To quantify the dosimetric effect and margins required to account for prostate intrafractional translation and residual setup error in a cone beam computed tomography (CBCT)-guided hypofractionated radiotherapy protocol. METHODS AND MATERIALS: Pro ... Full text Link to item Cite

WE‐E‐BRB‐07: EPID Based Verification of Delivered Fluence for VMAT with High Angular Resolution

Conference Medical Physics · January 1, 2011 Purpose: In VMAT, the dose rate, MLC position, and gantry angle change simultaneously, it is important they follow their predefined trajectories to ensure correct dose delivery. Our purpose is to develop an efficient VMAT QA strategy using EPID that is cap ... Full text Cite

WE‐E‐301‐01: Practical Tips for VMAT Implementation

Conference Medical Physics · January 1, 2011 Volumetric modulated arc therapy (VMAT) is an arc‐based dose delivery approach that produces highly conformal dose distributions similar to those generated with static gantry intensity modulated radiation therapy. Like many existing IMRT approaches, this t ... Full text Cite

SU‐E‐T‐419: Clinical Protocol for the Use of Scrotal Shields in IMRT Treatment of Anal Cancer

Conference Medical Physics · January 1, 2011 Purpose: To implement a clinical protocol for the use of scrotal shields for anal cancer IMRT treatment. Methods and Results: (1) Simulation The patient is immobilized in a full‐body alpha‐cradle mold in the frog‐leg position. Further, the mold is built up ... Full text Cite

SU‐E‐T‐99: A Patient Specific QA Protocol for Verification of 4D Dosimetry

Conference Medical Physics · January 1, 2011 Purpose: Presently, there is no patient specific dosimetric QA for radiation treatment of moving targets. Here we present a patient specific QA protocol for verification of 4D dosimetry delivered to a moving target in SBRT of lung and liver tumors. Methods ... Full text Cite

SU‐E‐T‐773: Dosimetric and Geometric Evaluation of a Hybrid Strategy of Online Image Guidance and Offline Adaptive Planning for Prostate Cancer Radiotherapy

Conference Medical Physics · January 1, 2011 Purpose: In fractionated radiotherapy of prostate cancer, both online and offline image‐guided strategies have been used to manage uncertainties such as setup errors and organ motions. In general, online image guidance is more effective than offline image ... Full text Cite

SU‐E‐T‐782: A Novel Geometric Index to Evaluate Image Guidance Strategies for Prostate Cancer Adaptive Radiotherapy

Conference Medical Physics · January 1, 2011 Purpose: Margin has been commonly used to evaluate different image guidance (IG) strategies in prostate cancer radiotherapy. However, it becomes cumbersome when applied to adaptive radiotherapy. In this study, a new index, cumulative index of target volume ... Full text Cite

SU‐E‐T‐270: A “Rolling Average” Adaptive Planning Technique to Compensate Target Volume Changes in Prostate Cancer Radiotherapy

Conference Medical Physics · January 1, 2011 Purpose: In external beam radiotherapy of prostate cancer, the inter‐fractional motion can have several forms: changes in position, shape and volume. The changes in position can be corrected by online image guidance, while the shape and volume changes are ... Full text Cite

SU‐C‐110‐01: Strategies for Online Plan Re‐Optimization: Objective Settings and Starting Stage

Conference Medical Physics · January 1, 2011 Purpose: To find the most robust strategies of objective setting and starting stage for online plan re‐optimization, so it can be automatically executed within 1 min while providing high quality adaptive plans. Methods: 10 prostate cancer patients, each wi ... Full text Cite

SU‐E‐T‐854: Key Anatomical Factors Influencing OAR Dose‐Volume Distribution in Prostate IMRT Plans

Conference Medical Physics · January 1, 2011 Purpose: To identify the key factors of patient anatomy that influence the optimal dose volume histograms (DVHs) for the organs‐at‐risk (OARs) and to explore the tradeoffs between different OAR sparing goals. Methods: 88 prostate IMRT plans were studied re ... Full text Cite

TH‐E‐BRB‐05: Modeling the Correlation Between OAR Dose Sparing and Patient's Anatomy in Head and Neck IMRT

Conference Medical Physics · January 1, 2011 Purpose: To summarize the knowledge of the dependence of organ‐at‐risk (OAR) dose‐volume distribution on patient's anatomy by machine learning techniques from a database of previous expert plans. Methods: 35 head‐and‐ neck IMRT plans were studied retrospec ... Full text Cite

Treatment Plan Optimization for Adaptive Radiation Therapy

Chapter · January 1, 2011 In current standard radiation therapy process, patient anatomy is represented by the snapshot of computed tomography (CT) images at the simulation for treatment planning. The planned radiation dose distribution, obtained from either three-dimensional (3D) ... Full text Cite

Adaptive radiation therapy: technical components and clinical applications.

Journal Article Cancer J · 2011 Featured Publication In current standard radiation therapy process, patient anatomy is represented by the snapshot of computed tomographic images at the simulation for treatment planning. However, patient anatomy during the treatment course is not static, and the changes can b ... Full text Link to item Cite

Prostate intrafraction motion assessed by simultaneous kilovoltage fluoroscopy at megavoltage delivery I: clinical observations and pattern analysis.

Journal Article Int J Radiat Oncol Biol Phys · December 1, 2010 Featured Publication PURPOSE: To describe prostate intrafraction motion using kilovoltage fluoroscopy at treatment delivery for a hypofractionated radiotherapy protocol. METHODS AND MATERIALS: Kilovoltage images were acquired during treatment delivery, as well as pre- and post ... Full text Link to item Cite

Prostate intrafraction motion assessed by simultaneous kV fluoroscopy at MV delivery II: adaptive strategies.

Journal Article Int J Radiat Oncol Biol Phys · December 1, 2010 Featured Publication PURPOSE: To investigate potential benefits of adaptive strategies for managing prostate intrafractional uncertainties when interfraction motion is corrected online. METHODS AND MATERIALS: Prostate intrafraction motion was measured using kV fluoroscopy duri ... Full text Link to item Cite

Breast Cancer Radiation Treatment Planning: A Comparison of Anisotropic Analytical Algorithm (AAA) and Pencil Beam Convolution (PBC) Algorithm

Conference International Journal of Radiation Oncology*Biology*Physics · November 2010 Featured Publication Full text Cite

Variation of Clinically Relevant Dose Indices for 3DCRT of Lung with Respect to Dose Calculation Algorithm

Conference International Journal of Radiation Oncology*Biology*Physics · November 2010 Featured Publication Full text Cite

Generating arbitrary one-dimensional dose profiles using rotational therapy.

Journal Article Phys Med Biol · October 21, 2010 Featured Publication Conformal radiation therapy can be delivered using several methods: intensity-modulated radiotherapy (IMRT) at fixed gantry angles, through the continuous gantry rotation of linac (rotational arc therapy), or by a dedicated treatment unit such as tomothera ... Full text Link to item Cite

Dosimetric assessment of rigid setup error by CBCT for HN-IMRT.

Journal Article J Appl Clin Med Phys · May 28, 2010 Featured Publication Dose distributions in HN-IMRT are complex and may be sensitive to the treatment uncertainties. The goals of this study were to evaluate: 1) dose differences between plan and actual delivery and implications on margin requirement for HN-IMRT with rigid setu ... Full text Open Access Link to item Cite

A hybrid strategy of offline adaptive planning and online image guidance for prostate cancer radiotherapy.

Journal Article Phys Med Biol · April 21, 2010 Featured Publication Offline adaptive radiotherapy (ART) has been used to effectively correct and compensate for prostate motion and reduce the required margin. The efficacy depends on the characteristics of the patient setup error and interfraction motion through the whole tr ... Full text Link to item Cite

SU‐GG‐T‐136: Treatment Plans Comparison with Static‐Gantry IMRT and RapidArcTM for Head‐And‐Neck Cancers Involving Cervical Lymph Nodes

Conference Medical Physics · January 1, 2010 Purpose: To compare the dosimetric results and treatment efficiency of intensity modulated arc therapy using RapidArc™ to static‐gantry IMRT plans for conventional fractionation treatment of head‐and‐neck cancer. Materials and Methods: This study evaluated ... Full text Cite

SU‐GG‐T‐225: Gantry‐Angle Dependence of a 2D Ion Chamber Array for IMAT QA

Conference Medical Physics · January 1, 2010 Purpose: Gantry‐angle dependence of dose measurement for intensity‐modulated arc therapy (IMAT) quality assurance (QA) using a two‐dimensional ion chamber array may be significant. A new device, the gantry angle sensor, has been provided to compensate for ... Full text Cite

SU‐GG‐T‐137: Similarities between Static and Rotational Intensity Modulated Plans

Conference Medical Physics · January 1, 2010 Purpose: To explore similarities between intensity modulated radiotherapy (IMRT) and intensity modulated arc therapy (IMAT) techniques in the context of the number of multi‐leaf collimator (MLC) segments required to achieve plan objectives, the major facto ... Full text Cite

SU‐GG‐T‐583: Dosimetric Comparison of Anisotropic Analytical and Pencil Beam Convolution Algorithms in Breast Cancer Radiation Treatment Planning

Conference Medical Physics · January 1, 2010 Purpose: The anisotropic analytical algorithm (AAA) has been shown to provide more accurate dose calculation due to 3D scatter and inhomogeneity corrections than the pencil beam convolution algorithm (PBC) for inhomogeneous anatomical regions such as lung ... Full text Cite

SU‐EE‐A1‐03: Arc Modulated Radiation Therapy Based on Linear Models

Conference Medical Physics · January 1, 2010 Purpose: The challenge for implementing promising Arc Modulated Radiation Therapy (AMRT) is its effectiveness of treatment planning tools to find optimal multileaf collimator (MLC) sequence and the fluence map. This study provides a new approach to the abo ... Full text Cite

WE‐B‐BRA‐03: Adaptive Image‐Guided Radiation Therapy (AIGRT) for Hypo‐Fractionated Prostate Cancer Treatment

Conference Medical Physics · January 1, 2010 Purpose: The large fractional dose of hypo‐fractionated prostate treatment requires high accuracy of daily treatment delivery. This study analyzes the performance of an adaptive IGRT (AIGRT) technique, which combines image guidance and adaptive re‐planning ... Full text Cite

TU‐E‐BRB‐03: A Planning Quality Evaluation Tool for Adaptive IMRT Treatment Based on Machine Learning

Conference Medical Physics · January 1, 2010 Purpose: To monitor the quality of adaptive IMRT plans, especially dose sparing for the organs‐at‐risk (OARs), a plan evaluation tool is developed to predict the dose volume histogram (DVH) based on patient's anatomical information and a database of high q ... Full text Cite

TU‐B‐BRA‐01: Total Body Irradiation (TBI): Looking from Differrent Angles

Conference Medical Physics · January 1, 2010 Purpose: To explore the new degree of freedom of VMAT to design a novel technique for TBI, in which patient is positioned supine/prone on the floor and an arc field is delivered with variable dose rate and/or dynamic collimators. Method and Materials: A fo ... Full text Cite

Quantitative evaluation of cone-beam computed tomography in target volume definition for offline image-guided radiation therapy of prostate cancer.

Journal Article Radiother Oncol · January 2010 Featured Publication PURPOSE: To quantitatively evaluate cone-beam CT (CBCT) in target volume definition in an offline image guidance environment. METHODS AND MATERIALS: Fifteen patients each with five helical CTs (HCT) and eight CBCTs were included. A single physician manuall ... Full text Link to item Cite

Dosimetry challenges for implementing emerging technologies.

Journal Article J Phys Conf Ser · 2010 Featured Publication During the last 10 years, radiation therapy technologies have gone through major changes, mainly related introduction of sophisticated delivery and imaging techniques to improve the target localization accuracy and dose conformity. While implementation of ... Full text Link to item Cite

On-line adaptive radiation therapy: feasibility and clinical study.

Journal Article J Oncol · 2010 Featured Publication The purpose of this paper is to evaluate the feasibility and clinical dosimetric benefit of an on-line, that is, with the patient in the treatment position, Adaptive Radiation Therapy (ART) system for prostate cancer treatment based on daily cone-beam CT i ... Full text Open Access Link to item Cite

Dosimetric assessment of rigid setup error by CBCT for HN-IMRT

Journal Article Journal of Applied Clinical Medical Physics · January 1, 2010 Featured Publication Dose distributions in HN-IMRT are complex and may be sensitive to the treatment uncertainties. The goals of this study were to evaluate: 1) dose differences between plan and actual delivery and implications on margin requirement for HN-IMRT with rigid setu ... Full text Cite

Adaptive replanning strategies accounting for shrinkage in head and neck IMRT.

Journal Article Int J Radiat Oncol Biol Phys · November 1, 2009 Featured Publication PURPOSE: Significant anatomic and volumetric changes occur in head and neck cancer patients during fractionated radiotherapy, and the actual dose can be considerably different from the original plan. The purposes of this study were (1) to evaluate the diff ... Full text Link to item Cite

Adaptive Management of Intrafraction Motion in Online Image Guided Prostate Cancer Radiotherapy

Conference International Journal of Radiation Oncology*Biology*Physics · November 2009 Featured Publication Full text Cite

Inferences about prostate intrafraction motion from pre- and posttreatment volumetric imaging.

Journal Article Int J Radiat Oncol Biol Phys · September 1, 2009 Featured Publication PURPOSE: To evaluate the ability of rectal filling, bladder filling, and prostate localization from pre- and posttreatment volumetric imaging to predict prostate intrafraction motion. METHODS AND MATERIALS: Pre- and posttreatment cone beam computed tomogra ... Full text Link to item Cite

Parameter optimization in HN-IMRT for Elekta linacs.

Journal Article J Appl Clin Med Phys · April 28, 2009 Featured Publication Planning and delivery in HN-IMRT has been challenging for the Elekta linac because of numerous machine limitations. Direct aperture optimization (DAO) algorithms have had success in simplifying the planning process and improving plan quality. Commercial ad ... Full text Open Access Link to item Cite

Ice as a water-equivalent solid medium for brachytherapy dosimetric measurements.

Journal Article Radiat Environ Biophys · April 2009 Precise positioning of source and dosimeters is essential in the experimental determination of dosimetric characteristics of brachytherapy sources. Various near-water equivalent solid phantoms have been used to achieve the necessary precision in the positi ... Full text Link to item Cite

The role of seminal vesicle motion in target margin assessment for online image-guided radiotherapy for prostate cancer.

Journal Article Int J Radiat Oncol Biol Phys · March 1, 2009 Featured Publication PURPOSE: For patients with intermediate- and high-risk prostate cancer, the seminal vesicles (SVs) are included in the clinical target volume (CTV). The purposes of this study are to investigate interfraction motion characteristics of the SVs and determine ... Full text Link to item Cite

Optimizing monoscopic kV fluoro acquisition for prostate intrafraction motion evaluation.

Journal Article Phys Med Biol · January 7, 2009 Featured Publication Monoscopic kV imaging during radiotherapy has been recently implemented for prostate intrafraction motion evaluation. However, the accuracy of 3D localization techniques from monoscopic imaging of prostate and the effect of acquisition parameters on the 3D ... Full text Link to item Cite

SU‐FF‐T‐620: Assessment of Dose Reconstruction Methods for Prostate Image Guided Radiotherapy Protocols

Conference Medical Physics · January 1, 2009 Purpose: Many dosimetric evaluations of prostate intrafraction motion disregard effects of treatment duration and translations of the surrounding body per fraction. However the probability of motion has been shown to increase with time and image guidance s ... Full text Cite

TU‐C‐303A‐08: A Hybrid Strategy Using Discriminant Analysis for Prostate Intrafraction Motion Management

Conference Medical Physics · January 1, 2009 Purpose: Prostate intrafraction motion has been shown to be patient specific; however most current compensation strategies are population wide. We evaluate the feasibility of applying margins based on a subpopulation of patients with similar intrafraction ... Full text Cite

SU‐FF‐T‐309: Quality Assurance for Imaging Guided Stereotactic RadioSurgery with Novalis Tx™ System

Conference Medical Physics · January 1, 2009 Purpose: To present QA measurements over extended periods at our institute and recommend a QA program for image‐guided radiosurgery on Novalis Tx system. Method and Materials: Novalis Tx system is developed based on a Trilogy linear accelerator featuring B ... Full text Cite

SU‐FF‐T‐130: Radiotherapy Treatment Plans with RapidArc for Head‐And‐Neck Cancer

Conference Medical Physics · January 1, 2009 Purpose: The purpose of this study is to compare RapidArc plans and conventional IMRT plans for head‐and‐neck cancer treatment involving bilateral nodes. Methods and Materials: This study included 10 locally advanced head‐and‐neck cancer patients. The plan ... Full text Cite

SU‐EE‐A3‐02: Imaging Guided Frameless Stereotactic RadioSurgery Using CBCT 6D Image Registration and 6D Couch On Novalis Tx™ System

Conference Medical Physics · January 1, 2009 Purpose: To investigate localization accuracy for image‐guided frameless stereotactic‐radiosurgery (IG‐SRS) using CBCT 6D image registration and 6D‐couch on Novalis Tx system. Method and Materials: Novalis Tx system is a powerful radiosurgery system featur ... Full text Cite

SU‐FF‐T‐548: Comparison of Cone‐Beam CT and Frame‐Based Localizations for Stereotactic Radiosurgery with Fixed Head Rings and Removable Frames

Conference Medical Physics · January 1, 2009 Objectives: To compare localization accuracy using both conventional frame‐based localizers and cone‐beam CT (CBCT) images for stereotactic radiosurgery (SRS). Methods: A SRS geometric phantom was used to verify the localization accuracy based on a SRS loc ... Full text Cite

SU‐FF‐T‐301: Clinical Implementation and Commission of Volumetric Modulated Arc Therapy

Conference Medical Physics · January 1, 2009 Purpose Volumetric modulated arc therapy (VMAT) is a rotational IMRT modality that combines dose rate modulation with gantry and MLC motion, thereby increasing the complexity of IMRT delivery. Effective implementation of this technology is still quite new ... Full text Cite

SU‐FF‐T‐314: Patient‐Specific Quality Assurance Techniques for RapidArc Radiotherapy

Conference Medical Physics · January 1, 2009 Purpose: To develop a patient‐specific quality assurance protocol for RapidArc™ radiotherapy. Method and Materials: Following the commissioning of RapidArc™ treatment delivery, we tested several methods of patient‐specific quality assurance (QA). Ion chamb ... Full text Cite

SU‐FF‐J‐56: Integrating Real‐Time Tracking Into Image Guided Radiation Therapy for Prostate Cancer Treatment

Conference Medical Physics · January 1, 2009 Purpose: To investigate how a real‐time tracking technique, based on implanted transponders, could be effectively integrated into the current process for image‐guided radiation treatment of prostate cancer. Method and Materials: Current prostate IGRT proce ... Full text Cite

TH‐A‐211A‐01: Digital Tomosynthesis for Target Localization

Conference Medical Physics · January 1, 2009 Any deviation between treated and planned volumes for 3‐D conformal therapy, such as IMRT, may cause an adverse clinical outcome. It is therefore critical to minimize all potential deviations using an on‐board (or real‐time) imaging procedure immediately p ... Full text Cite

SU‐FF‐T‐567: Volumetric Modulated Arc Therapy for Spine Body Radiotherapy: Comparison with Static Intensity Modulated Treatment

Conference Medical Physics · January 1, 2009 Purpose: Volumetric modulated arc treatment (VMAT) reduces treatment time over static beam intensity modulated treatment (IMRT) by delivering IMRT using arcs. This clinical study evaluates the feasibility of using VMAT for spine stereotactic body radiother ... Full text Cite

SU‐FF‐J‐55: Acceptance Testing and Quality‐Assurance Protocols for the Calypso® 4D Localization System™ and Q‐Fix®/Calypso® Couchtop

Conference Medical Physics · January 1, 2009 Purpose: To develop quality‐assurance (QA) protocols for the Calypso® 4D Localization System including acceptance testing, commissioning, daily QA, monthly QA, and annual QA. Method and Materials: The following acceptance testing/commissioning/QA protocols ... Full text Cite

SU‐FF‐J‐105: Is Offline Adaptive Planning Necessary for Online Image‐Guided Radiotherapy of Prostate Cancer?

Conference Medical Physics · January 1, 2009 Purpose: In online image‐guided radiation therapy of prostate cancer, the inter‐fractional translational motion is corrected at each fraction. However, rotation and deformation can only be accounted for using planning margins. Offline adaptive strategy has ... Full text Cite

SU‐FF‐T‐80: Hybrid Image Guided Radiation Therapy for Hypofractionated Prostate IMRT: Feasibility Study

Conference Medical Physics · January 1, 2009 Purpose: In prostate IGRT employing hypofractionation, two methods are commonly used: patient re‐positioning and re‐planning. We propose a hybrid IGRT technique in this study. The dosimetric benefits and efficiency improvement of the technique is quantitat ... Full text Cite

TH‐C‐303A‐04: Evaluation of 3D Surface Camera System in Patient Setup for HN RT

Conference Medical Physics · January 1, 2009 Purpose: To evaluate the usefulness of a 3D surface camera system (AlignRT) in detecting rigid and non‐rigid setup errors during head and neck radiotherapy. Methods and Materials: To evaluate the accuracy of AlignRT's surface registration algorithm, both t ... Full text Cite

SU‐FF‐T‐574: Radiotherapy Treatment Plans with RapidArc for Prostate Cancer Involving Seminal Vesicles

Conference Medical Physics · January 1, 2009 Purpose: The purpose of this report is to compare RapidArc plans and conventional IMRT plans for prostate cancer involving seminal vesicles. Methods and Materials: This study included 10 patients. The planning‐target volume (PTV) contained the prostate and ... Full text Cite

MO‐D‐BRB‐08: A Hybrid Strategy of Offline Adaptive Planning and Online Image Guidance for Prostate Cancer Radiotherapy

Conference Medical Physics · January 1, 2009 Purpose: In online image‐guided radiotherapy of prostate cancer, the setup error and inter‐fractional motion is eliminated through pre‐treatment imaging and couch correction at each fraction. However, the rotation and deformation is not corrected and only ... Full text Cite

SU‐FF‐J‐95: Dosimetric Margin Assessment for Rigid Setup Error by CBCT for HN‐IMRT

Conference Medical Physics · January 1, 2009 Purpose: High dose gradients offered by IMRT increase the sensitivity of treatment to setup errors compared to conventional treatments. We evaluated the dosimetric effects of setup error on HN‐IMRT using actual patient CBCT measurements. The purposes were ... Full text Cite

SU‐FF‐T‐102: Is Average Fractional Dose Representative of Cumulative Dose for HN‐IMRT?

Conference Medical Physics · January 1, 2009 Purpose: Use of on‐board cone‐beam CT (CBCT) imaging during HN‐IMRT treatment course allows for calculation and reconstruction of the dose delivered to the patient daily. The purpose of this study was to investigate whether the average fractional dose repr ... Full text Cite

Parameter optimization in HN-IMRT for Elekta linacs

Journal Article Journal of Applied Clinical Medical Physics · January 1, 2009 Featured Publication Planning and delivery in HN-IMRT has been challenging for the Elekta linac because of numerous machine limitations. Direct aperture optimization (DAO) algorithms have had success in simplifying the planning process and improving plan quality. Commercial ad ... Full text Cite

Prostate intrafraction motion evaluation using kV fluoroscopy during treatment delivery: a feasibility and accuracy study.

Journal Article Med Phys · May 2008 Featured Publication Margin reduction for prostate radiotherapy is limited by uncertainty in prostate localization during treatment. We investigated the feasibility and accuracy of measuring prostate intrafraction motion using kV fluoroscopy performed simultaneously with radio ... Full text Link to item Cite

TU‐C‐351‐03: Can Pre‐ and Post‐Imaging Determine Prostate Intrafraction Motion?

Conference Medical Physics · January 1, 2008 Purpose: Recent studies of prostate intrafraction motion have been inconclusive. One cine‐MRI study demonstrated that pre‐treatment rectal filling status is a significant predictor of intrafraction motion magnitude. However, studies using the Calypso syste ... Full text Cite

TU‐FF‐A3‐05: Optimizing KV Fluoro Acquisition for Prostate Intrafraction Motion Evaluation

Conference Medical Physics · January 1, 2008 Purpose: Commercially available gantry mounted kV imagers are currently restricted to manual fluoroscopy acquisitions with fixed mAs & frame rate, limiting use of fluoroscopy for prostate intrafraction motion measurement. For consideration in future acquis ... Full text Cite

SU‐GG‐T‐446: Dosimetric Characteristics of High Definition Multi‐Leaf Collimator

Conference Medical Physics · January 1, 2008 Purpose: A new type of high‐definition multi‐leaf collimator (HD 120 MLC, Varian Medical Systems) is being introduced into clinical practice to improve the conformality of stereotactic radiation therapy and radiosurgery. Its leaf width at isocenter is 2.5 ... Full text Cite

SU‐GG‐T‐454: Localization Accuracy of Cone‐Beam CT Guided Radiosurgery as Investigated Utilizing a Geometric Phantom

Conference Medical Physics · January 1, 2008 Purpose: While the advantage of imaging guidance with cone beam CT (CBCT) guided radiosurgery is obvious, the localization accuracy of CBCT guided radiosurgery still remains a concern. This study utilized a geometric phantom with known target positions to ... Full text Cite

SU‐GG‐J‐81: Efficacy of Patient Setup Correction Procedure in Prostate Radiotherapy

Conference Medical Physics · January 1, 2008 Purpose: Using an on‐board cone‐beam CT (CBCT) based statistical margin model to determine whether a prostate center‐of‐mass (COM) based translation correction procedure can significantly reduce the CTV‐to‐PTV margin required for prostate patients who were ... Full text Cite

SU‐GG‐I‐52: Conversion of On‐Board Digital TomoSynthesis (DTS) to HU Values

Conference Medical Physics · January 1, 2008 Purpose: To investigate a method to convert the pixel values of DTS images to HU values with reference HU values from CT images. Method and Materials: This study included CT and DTS images of two phantoms (Catphan and a chest phantom) and three patients (p ... Full text Cite

SU‐GG‐I‐53: The Impact of Scan Angles On the Visibility of Anatomy in On‐Board Digital Tomosynthesis (DTS) Images for Head and Neck Cancer Patients: A Single‐Observer Study

Conference Medical Physics · January 1, 2008 Purpose: To assess the impact of scan angles on the visibility of anatomy in on‐board digital tomosynthesis (DTS) images as a means to optimize this technique. Method and Materials: Head and neck cancer patients undergoing intensity‐modulated radiotherapy ... Full text Cite

SU‐GG‐T‐53: Integrating An Online Adaptive IMRT Process to the Prostate IGRT

Conference Medical Physics · January 1, 2008 Purpose: To investigate the feasibility of a novel online IMRT re‐optimization process. This online process can be an integral part to the current prostate IGRT paradigm to augment the existing patient alignment techniques for cases with complex daily orga ... Full text Cite

SU‐GG‐T‐13: Fast Seed Localization On MR Images For Post‐Prostate Implant Dosimetry

Conference Medical Physics · January 1, 2008 Purpose: Accurate and reliable post‐prostate implant dosimetric analysis requires optimal identification of the seeds on CT and optimal description of soft tissues on MRI. We present a fast seed localization technique for MRI that is also robust from motio ... Full text Cite

SU‐GG‐T‐54: On‐Line Adaptive IMRT for Prostate Cancer

Conference Medical Physics · January 1, 2008 Purpose: This study proposes a novel on‐line IGRT technique that can modify the original IMRT plan to match with the “anatomy‐of‐the‐day” within few minutes. The performance of this technique is compared with current on‐line IGRT strategies using bone/soft ... Full text Cite

SU‐GG‐J‐47: Clinical Implementation of An Integrated System for Image‐Guided Radiation Therapy (IGRT) and Adaptive Radiation Therapy (ART)

Conference Medical Physics · January 1, 2008 Purpose: It is critical that image‐guided radiation therapy (IGRT) and adaptive radiation therapy (ART) are performed with clearly defined goals without abusing the technologies. This study illustrates the current integrated system that provides efficient ... Full text Cite

SU‐DD‐A1‐02: Parameter Optimization in Head and Neck IMRT for Elekta Linacs

Conference Medical Physics · January 1, 2008 Purpose: Planning and delivery in HN‐IMRT is challenging for Elekta linacs because of numerous constraints on beam delivery systems. The purpose of this study is to find a set of planning parameters that are applicable to most patients and optimal in terms ... Full text Cite

Evaluation of three types of reference image data for external beam radiotherapy target localization using digital tomosynthesis (DTS).

Journal Article Med Phys · August 2007 Digital tomosynthesis (DTS) is a fast, low-dose three-dimensional (3D) imaging approach which yields slice images with excellent in-plane resolution, though low plane-to-plane resolution. A stack of DTS slices can be reconstructed from a single limited-ang ... Full text Link to item Cite

Effect of the first day correction on systematic setup error reduction.

Journal Article Med Phys · May 2007 Featured Publication Treatment simulation is usually performed with a conventional simulator using kV X-rays or with a computed tomography (CT) simulator before the treatment course begins. The purpose is to verify patient setup under the same conditions as for treatment plann ... Full text Link to item Cite

WE‐E‐M100F‐07: Prostate Intrafraction Motion Measurement Using KV Fluoroscopy During Treatment Delivery

Journal Article Medical Physics · January 1, 2007 Purpose: Margin reduction for prostate radiotherapy is limited by uncertainty in prostate localization during treatment. We investigate the feasibility and accuracy of measuring prostate intrafraction motion using kV fluoroscopy performed simultaneously wi ... Full text Cite

SU‐FF‐J‐64: The Role of Seminal Vesicle Motion in Target Margin Assessment for Online Image Guided Prostate Cancer Radiotherapy

Journal Article Medical Physics · January 1, 2007 Purpose:. For intermediate and high risk prostate cancer, both prostate gland and seminal vesicle (SV) should be included in CTV. However, motion patterns of prostate and SV could be different resulting in different margin requirement. Our purposes are to ... Full text Cite

SU‐FF‐J‐73: Non‐Rigid Setup Errors in HN‐IMRT Patients and Their Dosimetric Effect

Journal Article Medical Physics · January 1, 2007 Purpose: Dose distribution in head and neck IMRT plan is highly conformal and therefore sensitive to setup error. Rigid setup error measurements and its dosimetric effects have been reported previously. In this study, we investigate the non‐rigid component ... Full text Cite

SU‐FF‐T‐163: Dose Calculation On Cone Beam CT (CBCT)

Journal Article Medical Physics · January 1, 2007 Purpose: CBCT provides useful information for image guidance, however, uncertainty in CT number prevents it from being used for accuracy dose calculation. The purpose of this study is to quantify the accuracy of dose calculation using different CT to densi ... Full text Cite

SU‐FF‐J‐58: Clinical Evaluation Using Digital Tomosynthesis for Positioning Verification of Breath‐Hold Liver Treatment

Conference Medical Physics · January 1, 2007 Purpose: To demonstrate clinical feasibility of generating digital tomosynthesis (DTS) in a single breath‐hold (BH) period compared to multiple BH periods for CBCT acquisition and to examine on‐board BH‐DTS as an efficient alternative to BH‐CBCT for target ... Full text Cite

SU‐FF‐J‐48: Three‐Dimensional MRI and Cone‐Beam CT Matching for Localization of Prostate Cancer Treatment

Conference Medical Physics · January 1, 2007 PURPOSES: There is a growing interest using MRI only for prostate cancer treatment planning. This study is aimed to investigate clinical feasibility of matching 3D planning MRI to on‐board cone‐beam CT (CBCT) images for target localization. Materials and M ... Full text Cite

SU‐FF‐T‐252: Improvement of Localization Accuracy by Using 3D Cone Beam CT for Stereotactic Body Radiation Therapy of Liver, Lung and Spine Lesions

Conference Medical Physics · January 1, 2007 Purpose: To compare treatment isocenter placement based on OBI 2D kV imaging and OBI 3D‐CBCT imaging for patients undergoing SBRT, and compare the CBCT based isocenter shifts among liver, lung and spine lesions. Material and Methods: 119 SBRT fractions wer ... Full text Cite

SU‐FF‐T‐326: On the Use of Ice as a Water‐Equivalent Solid Medium for Brachytherapy Dosimetry Measurement

Conference Medical Physics · January 1, 2007 Purpose: It is well‐known that fluctuation in chemical compositions can lead to significant errors in the dosimetry of low‐energy brachytherapy sources using the traditional “water‐equivalent” solid phantoms. The aim of this work was to investigate the fea ... Full text Cite

SU‐FF‐T‐14: A High MU Efficiency Dynamic MLC Leaf Sequencing Algorithm

Conference Medical Physics · January 1, 2007 Purpose: MU efficiency is a major figure of merit for dMLC leaf sequencing. However, leaf sequencing is often generated with focus on other constraints and the MU efficiency is taken as a byproduct. This work is to develop a new dMLC leaf sequencing algori ... Full text Cite

TH‐E‐M100F‐07: Amplitude Gated Breath‐Hold Treatment for Upper Abdominal Lesions with On Board Imaging Guidance

Conference Medical Physics · January 1, 2007 Purpose: To apply on‐boardmdash;image (OBI) guided amplitude gating for breath‐hold treatment and to assess treatment margin adequacy by analyzing the isocenter placement based on orthogonal 2D kV radiographs and 3D cone‐beam CT (CBCT) acquired under ampli ... Full text Cite

SU‐DD‐A3‐04: On‐Line Re‐Optimization of Prostate IMRT Plans for Image Guided Adaptive Radiation Therapy

Conference Medical Physics · January 1, 2007 Purpose: This study proposes a novel on‐line adaptive planning technique for the prostate treatment by directly re‐optimizing the IMRT plan based on both the “anatomy‐of‐the‐day” and the original plan information. Method & Materials: Using a commercial tre ... Full text Cite

WE‐E‐M100F‐01: 3D Interfraction Position Verification for Patients Undergoing Partial Breast Irradiation: Comparing Digital Tomosynthesis to Cone‐Beam CT

Conference Medical Physics · January 1, 2007 Purpose: This clinical study evaluates digital tomosynthesis (DTS) technology for daily imaging guidance for partial breast irradiation (PBI) and compares its positioning accuracy to the 3D CBCT technique. Compared to CBCT, DTS offers lower imaging dose an ... Full text Cite

TU‐EE‐A3‐03: Performing Concurrent Kilovoltage Imaging While Delivering Megavoltage Treatment Beams

Conference Medical Physics · January 1, 2007 Purpose: To investigate the clinical feasibility of performing concurrent kilovoltage (kV) x‐ray imaging while the patient at the treatment position was irradiated by megavoltage (MV) beams. Method and Materials: Anatomical visibility and contrast details ... Full text Cite

On relating the generalized equivalent uniform dose formalism to the linear-quadratic model.

Journal Article Med Phys · December 2006 Featured Publication Two main approaches are commonly used in the literature for computing the equivalent uniform dose (EUD) in radiotherapy. The first approach is based on the cell-survival curve as defined in the linear-quadratic model. The second approach assumes that EUD c ... Full text Link to item Cite

Geometric and dosimetric evaluations of an online image-guidance strategy for 3D-CRT of prostate cancer.

Journal Article Int J Radiat Oncol Biol Phys · April 1, 2006 Featured Publication PURPOSE: To evaluate an online image-guidance strategy for conformal treatment of prostate cancer and to estimate margin-reduction benefits. METHODS AND MATERIALS: Twenty-eight patients with at least 16 helical computed tomography scans were each used in t ... Full text Link to item Cite

Application of dose compensation in image-guided radiotherapy of prostate cancer.

Journal Article Phys Med Biol · March 21, 2006 Featured Publication In image-guided radiation therapy (IGRT), volumetric information on patient anatomy at treatment conditions is made available with in-room imaging devices capable of cone-beam CT. Setup error and inter-fraction rigid motion can be corrected online. The pla ... Full text Link to item Cite

Monte Carlo-based dosimetry of head-and-neck patients treated with SIB-IMRT.

Journal Article Int J Radiat Oncol Biol Phys · March 1, 2006 Featured Publication PURPOSE: To evaluate the accuracy of previously reported superposition/convolution (SC) dosimetric results by comparing with Monte Carlo (MC) dose calculations for head-and-neck intensity-modulated radiation therapy (IMRT) patients treated with the simulta ... Full text Link to item Cite

SU‐FF‐J‐51: Dosimetric Evaluations of Organs at Risk for Head and Neck Cancer Patients During Entire IMRT Treatment Course

Conference Medical Physics · January 1, 2006 Purpose: Significant anatomic changes occur during radiotherapy treatment course for head and neck cancer patients. The purpose of this study is to evaluate the dosimetric changes by estimating the cumulative doses to critical organs. The finding will help ... Full text Cite

TU‐C‐ValB‐09: Setup Error Analysis of HN‐IMRT Patients Using Electronic Portal Images and Cone‐Beam CTs

Conference Medical Physics · January 1, 2006 Purpose: It is important to monitor and correct patient setup during treatment course for head and neck IMRT because highly conformal dose distribution is sensitive to setup uncertainties. Setup for HN region is unstable because patient is usually uncomfor ... Full text Cite

SU‐FF‐T‐263: Imaging with Brachytherapy Sources

Conference Medical Physics · January 1, 2006 Purpose: To demonstrate the concept of 2D projection and 3D volumetric imaging using brachytherapy treatment sources in patient prior to or during treatment. Method and Materials: As shown Figure 1, an Ir‐192 HDR catheter is placed at 15 cm depth (a reason ... Full text Cite

SU‐FF‐T‐151: Conservation of Integrated Reference Air Kerma

Conference Medical Physics · January 1, 2006 Purpose: To demonstrate the conservation rule of the integrated reference air kerma (IRAK). Method and Materials: For a brachytherapy photon source whose radial dose functions is flat over the clinical distance range, the dose falls off with the inverse sq ... Full text Cite

SU‐EE‐A1‐04: Verifying Internal Target Volume Using Cone‐Beam CT for Stereotactic Body Radiotherapy Treatment

Conference Medical Physics · January 1, 2006 Purpose: The internal target volume (ITV) could be determined using 4D CT simulation images and be verified in the treatment room using on‐board cone‐beam CT (CBCT) since the CBCT projection images are acquired over approximately 10 breathing cycles. This ... Full text Cite

SU‐FF‐J‐86: Intra‐ and Inter‐Breath‐Hold Position Variations for OBI Guided Amplitude Gating Treatment with Breath Hold

Conference Medical Physics · January 1, 2006 Purpose: We have applied OBI guidance together with a respiratory gating system to effectively control patient positioning for amplitude gating treatment with breath hold. The deep inspiration breath‐hold treatment has been proven effective in reducing the ... Full text Cite

MO‐A‐224C‐01: Daily Localization I: KV/CBCT

Conference Medical Physics · January 1, 2006 Daily target localization is a critical step to secure accurate delivery for 3‐D conformal radiation therapy and intensity‐modulated radiation therapy. One emerging technology using in‐room kilovoltage (kV) imaging has shown to be very promising for target ... Full text Cite

Effect of patient setup errors on simultaneously integrated boost head and neck IMRT treatment plans.

Journal Article Int J Radiat Oncol Biol Phys · October 1, 2005 Featured Publication PURPOSE: The purpose of this study is to determine dose delivery errors that could result from random and systematic setup errors for head-and-neck patients treated using the simultaneous integrated boost (SIB)-intensity-modulated radiation therapy (IMRT) ... Full text Link to item Cite

Dose sculpting with generalized equivalent uniform dose.

Journal Article Med Phys · May 2005 Featured Publication With intensity-modulated radiotherapy (IMRT), a variety of user-defined dose distribution can be produced using inverse planning. The generalized equivalent uniform dose (gEUD) has been used in IMRT optimization as an alternative objective function to the ... Full text Link to item Cite

SU‐EE‐A3‐02: Feasibility Study of Dose Compensation in Image‐Guided Radiotherapy (IGRT) of Prostate Cancer

Journal Article Medical Physics · January 1, 2005 Purpose: In image‐guided radiotherapy (IGRT), volumetric information of patient anatomy at treatment conditions is made available with in‐room imaging devices such as cone‐beam CT. Planning margin can therefore be reduced significantly through online guida ... Full text Cite

Development of methods for beam angle optimization for IMRT using an accelerated exhaustive search strategy.

Journal Article Int J Radiat Oncol Biol Phys · November 15, 2004 Featured Publication PURPOSE: The purpose of this article is to explore the use of the accelerated exhaustive search strategy for developing and validating methods for optimizing beam orientations for intensity-modulated radiation therapy (IMRT). Combining beam-angle optimizat ... Full text Link to item Cite

A dose calculation method including scatter for IMRT optimization.

Journal Article Phys Med Biol · October 7, 2004 Featured Publication IMRT optimization is an iterative process in which many dose calculations may be necessary. A fast and accurate dose calculation engine is essential for the optimization program to converge to a reliable solution in a reasonable time. Previously we develop ... Full text Link to item Cite

Simultaneous integrated boost intensity-modulated radiotherapy for locally advanced head-and-neck squamous cell carcinomas: II--clinical results.

Journal Article Int J Radiat Oncol Biol Phys · October 1, 2004 Featured Publication PURPOSE: To perform a Phase I radiation dose-escalation trial to determine the maximal tolerable dose (MTD) deliverable to the gross tumor volume (GTV) using an accelerated fractionation with simultaneous integrated boost intensity-modulated radiotherapy r ... Full text Link to item Cite

Speed and convergence properties of gradient algorithms for optimization of IMRT.

Journal Article Med Phys · May 2004 Featured Publication Gradient algorithms are the most commonly employed search methods in the routine optimization of IMRT plans. It is well known that local minima can exist for dose-volume-based and biology-based objective functions. The purpose of this paper is to compare t ... Full text Link to item Cite

Feasibility of sparing lung and other thoracic structures with intensity-modulated radiotherapy for non-small-cell lung cancer.

Journal Article Int J Radiat Oncol Biol Phys · March 15, 2004 Featured Publication PURPOSE: To investigate the possibility of using intensity-modulated radiotherapy (IMRT) to reduce the irradiated volumes of the normal lung and other critical structures in the treatment of non-small-cell lung cancer (NSCLC) and to investigate the effect ... Full text Link to item Cite

Potential of intensity-modulated radiotherapy to escalate doses to head-and-neck cancers: what is the maximal dose?

Journal Article Int J Radiat Oncol Biol Phys · November 1, 2003 Featured Publication PURPOSE: To investigate the potential of intensity-modulated radiotherapy (IMRT) to escalate doses to head-and-neck cancer and find the maximal dose that could be prescribed to the target volume with IMRT while doses to critical organs were maintained at t ... Full text Link to item Cite

Algorithm and performance of a clinical IMRT beam-angle optimization system.

Journal Article Phys Med Biol · October 7, 2003 Featured Publication This paper describes the algorithm and examines the performance of an intensity-modulated radiation therapy (IMRT) beam-angle optimization (BAO) system. In this algorithm successive sets of beam angles are selected from a set of predefined directions using ... Full text Link to item Cite

A fast dose calculation method based on table lookup for IMRT optimization.

Journal Article Phys Med Biol · June 21, 2003 Featured Publication This note describes a fast dose calculation method that can be used to speed up the optimization process in intensity-modulated radiotherapy (IMRT). Most iterative optimization algorithms in IMRT require a large number of dose calculations to achieve conve ... Full text Link to item Cite

Simultaneous integrated boost intensity-modulated radiotherapy for locally advanced head-and-neck squamous cell carcinomas. I: dosimetric results.

Journal Article Int J Radiat Oncol Biol Phys · June 1, 2003 Featured Publication PURPOSE: This report describes the dosimetric analyses of a Phase I/II protocol, designed to examine the capabilities of an institutionally developed intensity-modulated radiotherapy (IMRT) system with respect to dose escalation. The protocol employed stri ... Full text Link to item Cite

Quantifying the effect of intrafraction motion during breast IMRT planning and dose delivery.

Journal Article Med Phys · April 2003 Featured Publication Respiratory motion during intensity modulated radiation therapy (IMRT) causes two types of problems. First, the clinical target volume (CTV) to planning target volume (PTV) margin needed to account for respiratory motion means that the lung and heart dose ... Full text Link to item Cite

How should we describe the radioblologic effect of extracranial stereotactic radlosurgery: equivalent uniform dose or tumor control probability?

Journal Article Med Phys · March 2003 Featured Publication Extracranial stereotactic radiosurgery (ESR) is now undergoing clinical investigation at numerous institutions as a treatment for solitary malignant lesions. Because there is no standard ESR technique, the same minimum dose might be applied through widely ... Full text Link to item Cite

Intensity-modulated radiotherapy optimization with gEUD-guided dose-volume objectives.

Journal Article Phys Med Biol · February 7, 2003 Featured Publication Currently, most intensity-modulated radiation therapy systems use dose-volume (DV)-based objectives. Although acceptable plans can be generated using these objectives, much trial and error is necessary to plan complex cases with many structures because num ... Full text Link to item Cite

Clinical application of intensity-modulated radiotherapy for locally advanced cervical cancer.

Journal Article Semin Radiat Oncol · July 2002 Featured Publication Intensity-modulated radiotherapy (IMRT) offers technical advantages over conventional external beam radiotherapy (CXRT) that might prove clinically advantageous in the management of gynecologic malignancies. Especially in the case of locally advanced cervi ... Full text Link to item Cite

Multiple local minima in IMRT optimization based on dose-volume criteria.

Journal Article Med Phys · July 2002 Featured Publication Multiple local minima traps are known to exist in dose-volume and dose-response objective functions. Nevertheless, their presence and consequences are not considered impediments in finding satisfactory solutions in routine optimization of IMRT plans using ... Full text Link to item Cite

Reducing dose calculation time for accurate iterative IMRT planning.

Journal Article Med Phys · February 2002 Featured Publication A time-consuming component of IMRT optimization is the dose computation required in each iteration for the evaluation of the objective function. Accurate superposition/convolution (SC) and Monte Carlo (MC) dose calculations are currently considered too tim ... Full text Link to item Cite

Technical considerations in the application of intensity-modulated radiotherapy as a concomitant integrated boost for locally-advanced cervix cancer.

Journal Article Med Dosim · 2002 Featured Publication The technical aspects of IMRT applied to cervix cancer are discussed in this paper, as well as issues related to tumor delineation, target volume definitions, inverse planning, and IMRT delivery. A theoretical example illustrating how IMRT can accurately m ... Full text Link to item Cite

Optimization of intensity-modulated radiotherapy plans based on the equivalent uniform dose.

Journal Article Int J Radiat Oncol Biol Phys · January 1, 2002 Featured Publication PURPOSE: The equivalent uniform dose (EUD) for tumors is defined as the biologically equivalent dose that, if given uniformly, will lead to the same cell kill in the tumor volume as the actual nonuniform dose distribution. Recently, a new formulation of EU ... Full text Link to item Cite

The effect of setup uncertainty on normal tissue sparing with IMRT for head-and-neck cancer.

Journal Article Int J Radiat Oncol Biol Phys · December 1, 2001 Featured Publication PURPOSE: Intensity-modulated radiotherapy (IMRT) is being evaluated in the management of head-and-neck cancers at several institutions, and a Radiation Therapy Oncology Group study of its utility in parotid sparing is under development. There is an inheren ... Full text Link to item Cite

Intensity-modulated stereotactic radiosurgery using dynamic micro-multileaf collimation.

Journal Article Int J Radiat Oncol Biol Phys · July 1, 2001 Featured Publication PURPOSE: The implementation of dynamic leaf motion on a micro-multileaf collimator system provides the capability for intensity-modulated stereotactic radiosurgery (IMSRS), and the consequent potential for improved dose distributions for irregularly shaped ... Full text Link to item Cite

Acceleration of dose calculations for intensity-modulated radiotherapy.

Journal Article Med Phys · June 2001 Featured Publication The requirements and trade-offs between accuracy and speed for radiotherapy dose computations have been discussed for decades. Inverse planning used for intensity-modulated radiotherapy (IMRT) optimization imposes additional demands on dose calculation sin ... Full text Link to item Cite

Dosimetric validation for multileaf collimator-based intensity-modulated radiotherapy: a review.

Journal Article Med Dosim · 2001 Featured Publication The creation of intricate dose distributions produced by intensity-modulated radiotherapy (IMRT) depends on complex planning systems and specialized mechanical devices. The many possible sources of inaccuracy and the complexity of the dose maps themselves ... Full text Link to item Cite

A method for determining multileaf collimator transmission and scatter for dynamic intensity modulated radiotherapy.

Journal Article Med Phys · October 2000 Featured Publication The main purpose of this work is to demonstrate a practical means of determining the leaf transmission and scatter characteristics of a multileaf collimator (MLC) pertinent to the commissioning of dynamic intensity modulated radiotherapy, especially for th ... Full text Link to item Cite

Dynamic splitting of large intensity-modulated fields.

Journal Article Phys Med Biol · July 2000 Featured Publication The aims of this paper are to describe a method of splitting large intensity-modulated fields that cannot be delivered as a single field and to verify the accuracy of our method. Some multi-leaf collimators may be operated in the dynamic mode to deliver in ... Full text Link to item Cite

The impact of fluctuations in intensity patterns on the number of monitor units and the quality and accuracy of intensity modulated radiotherapy.

Journal Article Med Phys · June 2000 Featured Publication The purpose of this work is to examine the potential impact of the frequency and amplitude of fluctuations ("complexity") in intensity distributions on intensity-modulated radiotherapy (IMRT) dose distributions. The intensity-modulated beams are efficientl ... Full text Link to item Cite

Algorithms and functionality of an intensity modulated radiotherapy optimization system.

Journal Article Med Phys · April 2000 Featured Publication The main purpose of this paper is to describe formalisms, algorithms, and certain unique features of a system for optimization of intensity modulated radiotherapy (IMRT). The system is coupled to a commercial treatment planning system with an accurate dose ... Full text Link to item Cite

Radiobiological considerations in the design of fractionation strategies for intensity-modulated radiation therapy of head and neck cancers.

Journal Article Int J Radiat Oncol Biol Phys · February 1, 2000 Featured Publication PURPOSE: The dose distributions of intensity-modulated radiotherapy (IMRT) treatment plans can be shown to be significantly superior in terms of higher conformality if designed to simultaneously deliver high dose to the primary disease and lower dose to th ... Full text Link to item Cite

The potential for sparing of parotids and escalation of biologically effective dose with intensity-modulated radiation treatments of head and neck cancers: a treatment design study.

Journal Article Int J Radiat Oncol Biol Phys · January 1, 2000 Featured Publication PURPOSE: Conventional radiotherapy for cancers of the head and neck (HN) can yield acceptable locoregional tumor control rates, but toxicity of many normal tissues limits our ability to escalate dose. Xerostomia represents one of the most common complicati ... Full text Link to item Cite

Intensity-modulated stereotactic radiosurgery

Journal Article Frontiers of Radiation Therapy and Oncology · January 1, 2000 Featured Publication Full text Cite

IMRT optimization based on the generalized equivalent uniform dose (EUD)

Journal Article Annual International Conference of the IEEE Engineering in Medicine and Biology - Proceedings · January 1, 2000 Featured Publication Equivalent Uniform Dose (EUD) for tumors is defined as the biologically equivalent dose which, if given uniformly, leads to the same cell kill in the tumor volume as the actual non-uniform dose distribution. Recently it has been generalized to include norm ... Full text Cite

Determining the optimal block margin on the planning target volume for extracranial stereotactic radiotherapy.

Journal Article Int J Radiat Oncol Biol Phys · September 1, 1999 Featured Publication PURPOSE: To determine the block margin that minimizes normal tissue irradiation outside of the planning target volume (PTV) for body stereotactic radiotherapy (Body-SRT) of lung and liver tumors. METHODS AND MATERIALS: Representative patient cases of lung ... Full text Link to item Cite

A comparison of three stereotactic radiotherapy techniques; ARCS vs. noncoplanar fixed fields vs. intensity modulation.

Journal Article Int J Radiat Oncol Biol Phys · September 1, 1998 Featured Publication PURPOSE: Linac arc based stereotactic radiotherapy is being used with increasing frequency to treat brain tumors. This approach can be used for single or fractionated treatments, and is typically carried out with circular collimators which are optimal for ... Full text Link to item Cite

Computer-controlled delivery of 3D conformal radiation treatments.

Journal Article Cancer Treat Res · 1998 Featured Publication Full text Link to item Cite

Planning, delivery, and quality assurance of intensity-modulated radiotherapy using dynamic multileaf collimator: a strategy for large-scale implementation for the treatment of carcinoma of the prostate.

Journal Article Int J Radiat Oncol Biol Phys · November 1, 1997 Featured Publication PURPOSE: To improve the local control of patients with adenocarcinoma of the prostate we have implemented intensity modulated radiation therapy (IMRT) to deliver a prescribed dose of 81 Gy. This method is based on inverse planning and the use of dynamic mu ... Full text Link to item Cite

Number and orientations of beams in intensity-modulated radiation treatments.

Journal Article Med Phys · February 1997 Featured Publication The fundamental question of how many equispaced coplanar intensity-modulated photon beams are required to obtain an optimum treatment plan is investigated in a dose escalation study for a typical prostate tumor. Furthermore, optimization of beam orientatio ... Full text Link to item Cite

Intensity modulation optimization, lateral transport of radiation, and margins.

Journal Article Med Phys · December 1996 Featured Publication Intensity modulation provides greatly increased control, leading to superior dose distributions with a potential for improved clinical outcome. It also allows us to compensate for deviations from the expected patterns in dose distributions caused by the la ... Full text Link to item Cite

Conformal radiation treatment of prostate cancer using inversely-planned intensity-modulated photon beams produced with dynamic multileaf collimation.

Journal Article Int J Radiat Oncol Biol Phys · July 1, 1996 Featured Publication PURPOSE: To implement radiotherapy with intensity-modulated beams, based on the inverse method of treatment design and using a multileaf collimation system operating in the dynamic mode. METHODS AND MATERIALS: An algorithm, based on the inverse technique, ... Full text Link to item Cite