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Reduction of prostate intrafraction motion using gas-release rectal balloons
Zhong Su1, Tianyu Zhao, Zuofeng Li
1Department of Radiation Oncology, University of Florida Proton Therapy Institute, Jacksonville, FL, USA. zsu@floridaproton.org
Medical Physics
|October 9, 2012
Summary
Gas-release rectal balloons significantly reduce prostate intrafraction motion in the superior-inferior and anterior-posterior directions during proton therapy. This finding helps optimize planning target volume margins for improved treatment accuracy.
Area of Science:
- Radiation Oncology
- Medical Physics
Background:
- Prostate intrafraction motion is a critical uncertainty in image-guided radiotherapy.
- Rectal balloons are used to stabilize the prostate during treatment.
- Understanding motion reduction strategies is key to improving treatment precision.
Purpose of the Study:
- To analyze prostate intrafraction motion with non-gas-release (NGR) and gas-release (GR) rectal balloons.
- To evaluate the efficacy of GR rectal balloons in minimizing prostate intrafraction motion.
Main Methods:
- A comparative study involving 58 prostate cancer patients undergoing proton therapy.
- Random selection of patients treated with either NGR or GR rectal balloons.
- Analysis of orthogonal radiographs to quantify setup errors and intrafraction motion.
Main Results:
- GR rectal balloons demonstrated a reduction in prostate intrafraction motion in the superior-inferior (SI) and anterior-posterior (AP) directions.
- Patient setup residual errors were comparable between NGR and GR balloon groups.
- Planning target volume (PTV) margins were reduced in the SI and AP directions with GR balloons.
Conclusions:
- Gas-release rectal balloons effectively mitigate prostate intrafraction motion attributed to gas buildup.
- GR balloons offer improved accuracy in radiotherapy by reducing motion-related uncertainties.
- This technology enhances the precision of image-guided prostate cancer treatment.
