High-dose-rate brachytherapy for localized prostate adenocarcinoma post abdominoperineal resection of the rectum and pelvic irradiation: Technique and experience.

Purpose: Treatment options are limited for patients with localized prostate cancer and a prior history of abdominoperineal resection (APR) and pelvic irradiation. We have previously reported on the successful utility of high-dose-rate (HDR) brachytherapy salvage for prostate cancer failing definitive external beam radiation therapy (EBRT). In this report, we describe our technique and early experience with definitive HDR brachytherapy in patients post APR and pelvic EBRT.

Patients And Methods: Six men with newly diagnosed localized prostate cancer had a prior history of APR and pelvic EBRT. Sixteen to 18 HDR catheters were placed transperineally under transperineal ultrasound-guidance. The critical first two catheters were placed freehand posterior to the inferior rami on both sides of the bulbar urethra under cystoscopic visualization. A template was used for subsequent catheter placement. Using CT-based planning, 5 men received 36Gy in six fractions as monotherapy. One patient initially treated with EBRT to 30Gy, received 24Gy in four fractions.

Results: Median age was 67.5 (56-74) years. At a median followup of 26 (14-60) months, all patients are alive and with no evidence of disease per the Phoenix definition of biochemical failure, with a median prostate-specific antigen nadir of 0.19ng/mL. Three men have reported grade 2 late genitourinary toxicity. There has been no report of grade 3-5 toxicity.

Conclusion: Transperineal ultrasound-guided HDR brachytherapy using the above technique should be considered as definitive therapy for patients with localized prostate cancer and a prior history of APR and pelvic EBRT.