Combination external beam radiation and brachytherapy boost with androgen suppression for treatment of intermediate-risk prostate cancer: An initial report of CALGB 99809

Purpose:Transperineal prostate brachytherapy (TPPB) can be used with external beam radiation therapy (EBRT) to provide a high-dose conformal boost to the prostate. The results of a multicenter Phase 11 trial assessing safety of combination of EBRT and TPPB boost with androgen suppression (AST) in treatment of intermediate-risk prostate cancer are present here. Materials and Methods: Patients had intermediate-risk prostate cancer. Six months of AST was administered. ERRT to the prostate and seminal vesicles was administered to 45Gy followed by TPPB using either I-125 or Pd-103 to deliver an additional 100Gy or 90Gy. Toxicity was graded using the National Cancer Institute CTC version. 2 and the Radiation Therapy Oncology Group late radiation morbidity scoring systems. Results: Sixty-three patients were enrolled. Median follow-up was 38 months. Side effects of AST including sexual dysfunction and vasomotor symptoms were commonly observed. Apart from erectile dysfunction, short-term Grade 2 and 3 toxicity was noted in 21 % and 7%, primarily genitourinary related. Long-term Grade 2 and 3 toxicities were noted in 13% and 3 %. Two patients had Grade 3 dysuria that resolved with longer follow-up. The most common Grade 2 long-term toxicity was urinary frequency (5%). No biochemical or clinical evidence of progression was noted for the entire cohort. Conclusions: In a cooperative group setting, combination EBRT and TPPB with 6 months of AST was generally well tolerated with expected genitourinary and gastrointestinal toxicities. Further follow-up will be required to fully assess long-term toxicity and cancer control. (C) 2008 Elsevier Inc.