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Rectum dose reduction and individual treatment plan optimization for high-dose-rate prostate brachytherapy
Tobias Bölling1, Christos Moustakis, Hassan Elsayed
1Department of Radiotherapy, Radiation Oncology, University Hospital of Münster, Münster, Germany. Tobias.Boelling@ukmuenster.de
Brachytherapy
|November 10, 2007
Summary
This study developed objective quality parameters for high-dose-rate (HDR) prostate brachytherapy planning. These individual parameters enable faster, more accurate treatment plan evaluation and improvement for prostate radiation.
Area of Science:
- Radiation Oncology
- Medical Physics
Background:
- High-dose-rate (HDR) prostate brachytherapy involves varied techniques and doses, complicating universal quality parameter definition.
- Standardized evaluation of HDR prostate brachytherapy plans is challenging due to inter-patient anatomical variability.
Purpose of the Study:
- To develop individual, objective parameters for evaluating HDR brachytherapy plans in prostate cancer radiation.
- To establish a method for improving the quality of HDR prostate brachytherapy treatment plans.
Main Methods:
- Analysis of 53 patients undergoing HDR brachytherapy boost post-external radiation.
- Ultrasound-guided transperineal needle placement with (192)Ir source, followed by probe removal to minimize rectal dose.
- Estimation of rectal and prostate positions and anterior rectal wall dose under treatment conditions.
Main Results:
- Water balloon deflation increased space between anterior rectal wall and prostate (mean 6mm).
- A 'virtual rectum' dose, simulated by the ultrasound probe's ventral surface, correlated with actual rectal dose measurements.
- Pre-treatment evaluation using individual parameters led to plan modifications in two cases.
Conclusions:
- A novel method provides fast, objective, and individualized evaluation of HDR brachytherapy treatment plans.
- This approach facilitates timely improvements in prostate brachytherapy treatment planning.
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