Combined prostate brachytherapy and short-term androgen deprivation therapy as salvage therapy for locally recurrent prostate cancer after external beam irradiation

Purpose: We describe the treatment outcome in 17 patients who received combined salvage brachytherapy and short-term androgen deprivation therapy for local prostate cancer relapse after prior external beam irradiation. Materials and Methods: Median patient age was 68 years. Local relapse after external beam irradiation was confirmed by biopsy. Median prostate specific antigen at local relapse was 4.7 ng/ml. Five of the 17 patients were enrolled in a protocol combining androgen deprivation therapy with brachytherapy and the remaining men were treated off protocol. All patients received neoadjuvant androgen deprivation therapy for a median of 3 months, followed by ultrasound guided brachytherapy using I-125 in 9 and Pd-103 seeds in 8. Five patients also received adjuvant leuprolide for a median of 6 months. Biochemical failure was defined using the American Society for Therapeutic Radiology and Oncology definition. Toxicity was graded with a modified Radiation Therapy Oncology Group scale. Results: Median followup was 44 months. The actuarial 4-year biochemical control rate was 75%. Three patients died of intercurrent diseases. No prostate cancer mortality or local failure had occurred at last followup. One patient had bone metastasis. No clinical or treatment factor was associated with biochemical control. Grade 3 and 4 genitourinary toxicity developed in 7 (41%) and 1 patients (6%), respectively. Grade 2 and 3 gastrointestinal toxicity occurred in 5 (29%) and 1 patients (6%), respectively. Conclusions: Our series suggests that salvage brachytherapy and short-term androgen deprivation therapy can achieve biochemical control in select patients with local relapse after prior external beam irradiation. The major side effects are urinary complications, including grade 3 and 4 complications in 41% and 6% of cases, respectively.