ConferenceInternational journal of radiation oncology, biology, physics · November 2021
Purpose/objective(s)Post-operative radiotherapy (PORT) is utilized in select prostate cancer patients. IMRT has been associated with improved dosimetry and acute toxicity. Smaller treatment margins for PORT have been recommended when using image g ...
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ConferenceMedical 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 ...
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ConferenceJ Phys Conf Ser · 2013
Six base of skull IMRT treatment plans were delivered to Presage dosimeters within the RPC Head and Neck Phantom for quality assurance (QA) verification. Isotropic 2mm 3D data were acquired by optical-CT scanning with the DLOS system (Duke Large Optical-CT ...
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ConferenceMedical Physics · January 1, 2011
Purpose: Two‐dimensional (2D) detector arrays for QA of volumetric‐modulated‐arc‐therapy (VMAT) plans show angular dependence. An angular correction‐factor‐table (CFs) minimize this effect, but assumes: (1) the response of all ion chambers (IC) is identica ...
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ConferenceMedical Physics · January 1, 2011
Purpose: Respiratory signal for 4DCT is typically extracted using an external respiratory positioning management device (RPM) which is often inconvenient and time consuming. The efficiency of 4DCT imaging could be substantially improved if anatomical body ...
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ConferenceMedical 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 ...
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ConferenceMedical 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 ...
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ConferenceMedical Physics · January 1, 2009
Objectives: To investigate the feasibility of using an intensity modulated arc technique for multi‐focal intracranial stereotactic radiosurgery with a single isocenter setup to significantly decrease the treatment time. Methods: A Novalis Tx linear acceler ...
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ConferenceMedical 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 ...
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ConferenceMedical 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 ...
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ConferenceMedical 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 ...
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ConferenceMedical 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 ...
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ConferenceMedical Physics · January 1, 2009
Purpose: Recently, radiation treatment technology has out‐paced the advances in QA technology, and a critical gap has been created within the arc motion delivery systems such as Rapid Arc®, High Art®, and VMAT®. Gantry position, speed and MU rate create ex ...
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ConferenceMedical Physics · January 1, 2008
Purpose: Target coverage is of outmost importance for curative radiation treatment of anal cancers. When the tumor is close to the skin surface, inferior patient displacements could cause significant dosimetric losses. Moreover, the PTV may extend beyond t ...
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ConferenceMedical Physics · January 1, 2008
The annual AAPM student meeting welcomes current and prospective trainees in medical physics. Speakers will address issues of importance to trainees, including the impact of the 2012/2014 residency requirement for the ABR, and what the AAPM is doing to inc ...
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ConferenceMedical Physics · January 1, 2008
Purpose: To determine appropriate planning margins around the GTV for concomitant boost image‐guided lung cancer treatments where the GTV is prescribed a higher dose than the CTV. Method and Materials: The dosimetric impact of the GTV planning margin (pGTV ...
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ConferenceMedical Physics · January 1, 2006
Purpose: To evaluate the impact of internal organ variations on IMRT treatments of head‐and‐neck cancers using different daily alignment techniques. Method and Materials: Eleven head‐and‐neck cancer patients were imaged twice weekly during their course of ...
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ConferenceMedical Physics · January 1, 2006
Purpose: To compare the effectiveness of two off‐line “No‐Action‐Level” (NAL) correction protocols with daily image‐guided alignments using bony registration (simulating electronic portal image alignment), ultrasound, and CT for direct prostate target loca ...
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ConferenceMedical Physics · January 1, 2006
Purpose: To quantify the dosimetric impact of intrafractional motion on reduced‐margin IMRT treatments of prostate cancer. Methods and Materials: CT images were acquired immediately before and after a daily treatment for 46 prostate cancer patients. These ...
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