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TH-CD-BRA-02: 3D Remote Dosimetry for MRI-Guided Radiation Therapy: A Hybrid Approach.

Publication ,  Journal Article
Rankine, L; Mein, S; Adamovics, J; Cai, B; Curcuru, A; Juang, T; Miles, D; Mutic, S; Wang, Y; Oldham, M; Li, H
Published in: Med Phys
June 2016

PURPOSE: To validate the dosimetric accuracy of a commercially available MR-IGRT system using a combination of 3D dosimetry measurements (with PRESAGE(R) radiochromic plastic and optical-CT readout) and an in-house developed GPU-accelerated PENELOPE Monte-Carlo dose calculation system. METHODS: (60) Co IMRT subject to a 0.35T lateral magnetic field has recently been commissioned in our institution following AAPM's TG-119 recommendations. We performed PRESAGE(R) sensitivity studies in 4ml cuvettes to verify linearity, MR-compatibility, and energy-independence. Using 10cm diameter PRESAGE(R), we delivered an open calibration field to examine the percent depth dose and a symmetrical 3-field plan with three adjacent regions of varying dose to determine uniformity within the dosimeter under a magnetic field. After initial testing, TG-119 plans were created in the TPS and then delivered to 14.5cm 2kg PRESAGE(R) dosimeters. Dose readout was performed via optical-CT at a second institution specializing in remote 3D dosimetry. Absolute dose was measured using an IBA CC01 ion chamber and the institution standard patient-specific QA methods were used to validate plan delivery. Calculated TG-119 plans were then compared with an independent Monte Carlo dose calculation (gPENELOPE). RESULTS: PRESAGE(R) responds linearly (R(2) =0.9996) to (60) Co irradiation, in the presence of a 0.35T magnetic field, with a sensitivity of 0.0305(±0.003)cm(-1) Gy(-1) , within 1% of a 6MV non-MR linac irradiation (R(2) =0.9991) with a sensitivity of 0.0302(±0.003)cm(-1) Gy(-1) . Analysis of TG-119 clinical plans using 3D-gamma (3%/3mm, 10% threshold) give passing rates of: HN 99.1%, prostate 98.0%, C-shape 90.8%, and multi-target 98.5%. The TPS agreed with gPENELOPE with a mean gamma passing rate of 98.4±1.5% (2%/2mm) with the z-score distributions following a standard normal distribution. CONCLUSION: We demonstrate for the first time that 3D remote dosimetry using both experimental and computational methods is a feasible and reliable approach to commissioning MR-IMRT, which is particularly useful for less specialized clinics in adopting this new treatment modality.

Duke Scholars

Published In

Med Phys

DOI

EISSN

2473-4209

Publication Date

June 2016

Volume

43

Issue

6

Start / End Page

3873

Location

United States

Related Subject Headings

  • Nuclear Medicine & Medical Imaging
  • 5105 Medical and biological physics
  • 4003 Biomedical engineering
  • 1112 Oncology and Carcinogenesis
  • 0903 Biomedical Engineering
  • 0299 Other Physical Sciences
 

Citation

APA
Chicago
ICMJE
MLA
NLM
Rankine, L., Mein, S., Adamovics, J., Cai, B., Curcuru, A., Juang, T., … Li, H. (2016). TH-CD-BRA-02: 3D Remote Dosimetry for MRI-Guided Radiation Therapy: A Hybrid Approach. Med Phys, 43(6), 3873. https://doi.org/10.1118/1.4958145
Rankine, L., S. Mein, J. Adamovics, B. Cai, A. Curcuru, T. Juang, D. Miles, et al. “TH-CD-BRA-02: 3D Remote Dosimetry for MRI-Guided Radiation Therapy: A Hybrid Approach.Med Phys 43, no. 6 (June 2016): 3873. https://doi.org/10.1118/1.4958145.
Rankine L, Mein S, Adamovics J, Cai B, Curcuru A, Juang T, et al. TH-CD-BRA-02: 3D Remote Dosimetry for MRI-Guided Radiation Therapy: A Hybrid Approach. Med Phys. 2016 Jun;43(6):3873.
Rankine, L., et al. “TH-CD-BRA-02: 3D Remote Dosimetry for MRI-Guided Radiation Therapy: A Hybrid Approach.Med Phys, vol. 43, no. 6, June 2016, p. 3873. Pubmed, doi:10.1118/1.4958145.
Rankine L, Mein S, Adamovics J, Cai B, Curcuru A, Juang T, Miles D, Mutic S, Wang Y, Oldham M, Li H. TH-CD-BRA-02: 3D Remote Dosimetry for MRI-Guided Radiation Therapy: A Hybrid Approach. Med Phys. 2016 Jun;43(6):3873.

Published In

Med Phys

DOI

EISSN

2473-4209

Publication Date

June 2016

Volume

43

Issue

6

Start / End Page

3873

Location

United States

Related Subject Headings

  • Nuclear Medicine & Medical Imaging
  • 5105 Medical and biological physics
  • 4003 Biomedical engineering
  • 1112 Oncology and Carcinogenesis
  • 0903 Biomedical Engineering
  • 0299 Other Physical Sciences