Anatomy-based inverse planning dose optimization in HDR prostate implant: a toxicity study

Area of Science:

• Radiation Oncology
• Medical Physics
• Urologic Oncology

Background:

• Locally advanced prostate cancer requires effective treatment strategies.
• High-dose-rate (HDR) brachytherapy boost offers a method for dose escalation.
• Inverse planning optimizes radiation dose distribution.

Purpose of the Study:

• To evaluate acute and late complications of inverse-planned HDR brachytherapy boost.
• To identify dose-volume correlations with toxicity.
• To assess quality of life outcomes in prostate cancer patients.

Main Methods:

• 44 patients with locally advanced prostate cancer received external beam radiation therapy followed by inverse-planned HDR brachytherapy boost.
• Median follow-up was 1.7 years.
• Toxicity was graded using RTOG criteria; quality of life was assessed via questionnaires and IPSS.

Main Results:

• Low rates of Grade 3-4 acute and late GU/GI toxicity were observed.
• Acute (late) Grade 2 urinary symptoms occurred in 31.8% (11.4%) and rectal symptoms in 4.6% (4.6%).
• A trend suggested higher acute GU toxicity with HDR doses >18 Gy; erectile dysfunction was ~27%.

Conclusions:

• Inverse-planned HDR brachytherapy is a safe and effective boost strategy for prostate cancer.
• This approach enables dose escalation without increasing GU or rectal complications.
• Further dose escalation with HDR brachytherapy is feasible.