Prospective evaluation of a specific technique of sexual function preservation in external beam radiotherapy for prostate cancer.

Abstract

Sexual preservation is an important issue in the treatment of localized prostate cancer. A technique of irradiation was developed to better preserve this function and has been evaluated. Eleven patients, with no erectile dysfunction (ED), were treated with daily IMRT-IGRT (total dose: 76-78 Gy). The pudendal arteries, penile bulb and cavernous body were delineated on the planning CT scan. The doses to these structures (with a 5 mm margin) were optimized to be as low as possible. The erectile function was documented using IIEF-5 scores at baseline, 6 months, 1 and 2 years. No ED was defined by an IIEF5 ≥ 20/25, a mild ED by an IIEF5 score of 17-19 and an important ED by a score <17. The mean age was 68.4 years. At the median follow-up of 36 months, there was no biochemical relapse. Before RT, the mean IIEF5 score in all 11 patients was 23.4 (range, 20-25). At 6, 12, 18 and 24 months after RT, the mean IIEF scores were 21.2 (14-25), 21.3 (14-25), 21.8 (16-25) and 21.8 (16-25), respectively. At 2 years, 8 patients (72.7%) had no ED and 2 patients (18.2%) experienced a mild ED. The only patient with an important ED had a medical treatment and recovered a satisfactory IIEF score from 16 to 24. The results of this technique of optimisation for sexual preservation are encouraging. Despite a mean age close to 70 years at the time of treatment, 90.9% of the patients had no to mild ED at 2 years. This rate increases at 100% with medical treatment. Advances in knowledge: Dose optimization on sexual organs is possible and could decrease the ED rates.