Reduction of toxicity in brachytherapy using a new technique

Area of Science:

• Oncology
• Radiotherapy
• Medical Physics

Background:

• High-dose-rate brachytherapy (HDR-BT) is a key treatment for prostate cancer.
• Late genitourinary (GU) toxicity remains a significant concern for patients undergoing HDR-BT.
• Accurate dose evaluation is crucial for minimizing treatment-related side effects.

Purpose of the Study:

• To assess the effectiveness of a specific dose evaluation method for reducing late GU toxicity in prostate cancer patients.
• To investigate the relationship between urethral dose distribution and the occurrence of GU toxicity following HDR-BT.
• To identify high-risk urethral segments that may benefit from dose modification.

Main Methods:

• Retrospective analysis of 174 localized prostate cancer patients treated with HDR-BT and external beam radiotherapy.
• Urethral segmentation into base, midgland, and apex, further subclassified into seven subgroups.
• Dose evaluation using a D10% color map of the urethra and statistical analysis of urethral D0.1% and D10% across subgroups.
• Scoring GU toxicity using Common Terminology Criteria for Adverse Events version 4.0.

Main Results:

• A significant difference in Grade < 2 and Grade ≥ 2 GU toxicity was observed in the midgland (M) urethral subgroup compared to others (p < 0.05).
• Findings suggest increased radioresistance in the midgland urethra.
• The D10% color map highlighted specific urethral areas associated with varying toxicity levels.

Conclusions:

• A high-dose-area evaluation method utilizing a urethral D10% color map shows promise in mitigating late GU toxicity in prostate cancer HDR-BT.
• This method can aid in personalized dose planning to spare critical urethral structures.
• Further research is warranted to validate and refine this dose evaluation technique for improved patient outcomes.