Long-term potency preservation following brachytherapy for prostate cancer

OBJECTIVES: • To assess potency preservation in men following brachytherapy for prostate cancer with or without external beam radiation therapy (EBRT) and/or androgen deprivation therapy (ADT). • To evaluate the factors that significantly impact this rate. PATIENTS AND METHODS: • In all, 1063 potent men with T1-T3 prostate cancer were treated from 1990 to 2007 with seed implantation alone (¹⁰³Pd or ¹²⁵I) (69.6%) or combined modality treatment consisting of a partial dose ¹⁰³Pd implant followed 6-8 weeks later by EBRT (45 Gy, prostate/seminal vesicles only) (30.4%). ADT was used in 49.1% of cases (range 1-27 months). • Patients were required to have a minimum of 2 years follow-up and to be off ADT for a minimum of 1 year. • Erectile function was assessed prior to seed implantation and at each follow-up visit using the physician-assigned Mount Sinai Erectile Function Score (MSEFS): 0, unable to have erections; 1, erections insufficient for intercourse; 2, suboptimal erections but sufficient for intercourse; 3, normal erectile function. Potent was defined as a score of greater than or equal to 2 with or without use of a phosphodiesterase type 5 inhibitor. • The potency rate was calculated using actuarial methods with comparisons tested by log-rank and Cox regression analysis. RESULTS: • The 5-year and 10-year actuarial rate of potency preservation was 68.0% and 57.9%, respectively, at last follow-up. • On multivariate analysis, 5- and 10-year potency was 87.6% (79.5%) for men younger than 60, 68.0% (57.5%) for age 60-70, and 42.2% (31.0%) for men older than 70 (P < 0.001). • Pretreatment MSEFS of 2 had a potency rate of 51.7% (37.2%) vs 74.2% (65.2%) for an MSEFS of 3 (P < 0.001). • There was a 75.8% (62.6%) potency rate without ADT vs 60.0% (53.0%) with ADT (P < 0.001). • Five-year potency was 76.4% for implant alone, 71.0% for implant with EBRT, 62.2% for implant with ADT, and 57.9% for implant with EBRT and ADT (P < 0.001). CONCLUSION: • Increasing initial age at implant, diminished pretreatment erectile function and the use of combination therapy with EBRT and/or ADT significantly increases erectile dysfunction following brachytherapy.