Salvage permanent perineal radioactive-seed implantation for treating recurrence of localized prostate adenocarcinoma after external beam radiotherapy

Abstract

Objective: To assess our experience with salvage permanent perineal radioactive-seed implantation (SPPI) as a possible therapeutic option for recurrent prostate adenocarcinoma, as salvage therapies for recurrences after definitive external beam radiotherapy (EBRT) for localized adenocarcinoma of the prostate are associated with significant morbidity and biochemical failure.

Patients and methods: We retrospectively analysed on patients who had SPPI for localized recurrent prostate adenocarcinoma from 1996 to 2007 after primary treatment with EBRT. Excluded were patients who had other primary treatment or had no follow-up. Primary outcomes were time to biochemical relapse-free survival, using the Phoenix definition of a prostate-specific antigen (PSA) nadir +2 ng/mL, and cancer-specific survival. Secondary outcomes were the International Prostate Symptom Score (IPSS), the International Index of Erectile Function-5 score (IIEF-5), and complications based on Common Terminology Criteria for Adverse Events (version 3).

Results: In all, 37 patients had SPPI during this period; after applying inclusion and exclusion criteria, 24 remained for analysis. At the time of salvage therapy, the median time to the diagnosis of local recurrence was 49 months, the median PSA level was 3.36 ng/mL, the median PSA doubling time was 20 months, and all patients were clinically re-staged at <or=T2 with negative transrectal ultrasonography and/or magnetic resonance spectroscopy. The original Gleason score was <or=6 in nine patients, 7 in eight and >or=8 in three (not recorded in two). The median follow-up after SPPI was 30 months; the cancer-free survival was 96% (one death) and biochemical relapse-free survival was 88% (three patients). The PSA level was higher than the levels before SPPI at 3 months in all three failures, but lower in all 21 patients considered relapse-free. Complications included one urethral stricture, one grade 3 rectal haemorrhage and five grade 2 gross haematuria that resolved with conservative management. Insufficient data were available to assess the IPSS or IIEF-5 scores.

Conclusion: With a short-term follow-up SPPI appears to provide excellent prostate cancer control with an acceptable rate of complications for patients with local recurrence of prostate cancer after EBRT. An extended follow-up is necessary to determine the long-term durability and safety of SPPI.