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Proton Therapy Delivery and Its Clinical Application in Select Solid Tumor Malignancies
Published on: February 6, 2019
Simulated real time image guided intrafraction tracking-delivery for hypofractionated prostate IMRT.
Sabbir Hossain1, Ping Xia, Cynthia Chuang
1Department of Radiation Oncology, University of California San Francisco, San Francisco, California 94143-1708, USA. hossains@radonc.ucsf.edu
Medical Physics
|October 10, 2008
Summary
Intrafraction prostate motion significantly impacts hypofractionated stereotactic body radiotherapy (SBRT) for prostate cancer. On-line monitoring and correction are crucial for effective intensity-modulated radiotherapy delivery.
Area of Science:
- Radiation Oncology
- Medical Physics
Background:
- Hypofractionated stereotactic body radiotherapy (SBRT) is an evolving treatment for prostate cancer.
- Intrafraction motion during treatment delivery can affect dose distribution.
Purpose of the Study:
- To investigate the dosimetric impact of intrafraction prostate motion on target coverage and normal tissue sparing during SBRT.
- To evaluate the influence of treatment delivery time on intrafraction motion effects.
Main Methods:
- Recorded intrafraction prostate movements in patients treated with CyberKnife.
- Simulated hypofractionated intensity-modulated radiotherapy (IMRT) plans based on recorded motion.
- Analyzed dose-volume histograms (DVHs) for changes in target coverage (V100) and normal structure doses.
Main Results:
- Dosimetric effects of intrafraction motion are case-dependent, with minimal impact for movements within +/-5 mm.
- Sporadic movements exceeding 5 mm significantly reduced prostate V100 (coverage).
- On-line motion correction strategies could restore target coverage to near-ideal levels.
Conclusions:
- Intrafraction prostate motion necessitates on-line monitoring and correction for hypofractionated SBRT with intensity-modulated beams.
- Active motion management is essential to ensure accurate dose delivery in prostate cancer SBRT.
- The study highlights the importance of addressing intrafraction motion for optimal SBRT outcomes.
