| Abstract: |
Purpose: We report the toxicity and biochemical tumor control outcome of a prospective Phase II study using high-dose-rate brachytherapy (HDR) alone as a salvage therapy for recurrent disease after external beam radiotherapy (EBRT). Methods: Forty-two patients with biopsy-proven recurrence were enrolled on a Phase II study of salvage HDR monotherapy using iridium-192. Median pretreatment EBRT dose was 8100cGy (6840-8640cGy) and the median time from completion of EBRT to salvage HDR was 73 months. The protocol prescription dose of 3200cGy was delivered in four fractions over 30 hours in a single insertion. Median followup after salvage HDR was 36 months (6-67 months). Results: The actuarial prostate-specific antigen biochemical relapse-free survival and distant metastases-free survival rates at 5 years were 68.5% and 81.5%, respectively. Cause-specific survival was 90.3%. Late genitourinary Grade 1and 2 toxicities were found in 38% and 48%, respectively, and one patient developed Grade 3 urinary incontinence. Late Grade 1 and 2 gastrointestinal toxicity was noted in 17% and 8% of patients, respectively. Three patients (7%) developed Grade 2 late urinary toxicity (urethral stricture), which were corrected with urethral dilatation, and one patient developed Grade 3 urinary incontinence. No Grade 4 toxicities were observed. Conclusions: Genitourinary toxicity was the most commonly encountered toxicity observed after salvage HDR but severe toxicities were uncommon. Salvage HDR is an effective and well-tolerated modality for locally recurrent prostate cancer and should be considered even for patients who have previously been treated with ultra-high dose levels of EBRT. © 2014 American Brachytherapy Society. |
