Neoadjuvant androgen deprivation prior to transperineal prostate brachytherapy: smaller volumes, less morbidity.

Purpose: Prostate brachytherapy is becoming increasingly utilized in the definitive treatment of men with early-stage prostate cancer. Others have reported a close relation between total dose to the gland and genitourinary and gastrointestinal toxicity. We tested the hypothesis that 3 months of hormone deprivation would decrease gland size and decrease radioactivity implanted, which would result in less morbidity. Here, we report the toxicity associated with this novel treatment strategy.

Methods: One hundred fifty-five prostate cancer patients underwent ultrasound-guided transperineal implantation of palladium-103 at the Hospital of the University of Pennsylvania between January 1994 and July 1998. All men received at least 3 months of neoadjuvant luteinizing hormone-releasing hormone (LHRH) agonist therapy and were registered in the study. This group of men were compared with 55 men treated at the Hospital of the University of Pennsylvania with brachytherapy alone between December 1991 and December 1993.

Results: Compared with men treated with implant alone, men who received LHRH agonist therapy had significantly smaller glands at the time of implant (27.7 cm3 vs 36.3 cm3), required fewer seeds (47.9 vs 83.2), and had significantly less radioactivity implanted (76.3 mCi vs 117 mCi). The genitourinary and gastrointestinal morbidity in the men receiving hormone deprivation was minimal, with long-term side effects occurring in only three patients. In addition, potency was preserved in 83% of men.

Discussion: Three months or more of neoadjuvant LHRH agonist therapy before transperineal brachytherapy is safe, significantly reduces the amount of radioactivity implanted, and is associated with very low rates of genitourinary and gastrointestinal toxicity. In addition, potency preservation after combined-modality therapy is excellent and is similar to that of implantation alone. Further studies of this treatment approach are warranted.