Prospective Evaluation of a Specific Technique of Sexual Function Preservation in External Beam Radiation Therapy for Prostate Cancer

Abstract

Sexual preservation is an important issue in the treatment of localized prostate cancer. A specific technique of irradiation was developed to better preserve this function and has been evaluated. Between 2010 and 2014, 13 patients, with no erectile dysfunction (ED), were treated with intensity-modulated radiation therapy (total dose: 74-78Gy, 2Gy/fraction) and daily set-up on 3 intra-prostatic gold markers (for a low- or intermediate-risk prostate cancer). 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 (EF) was documented using IIEF-5 (International Index of Erectile Function) scores at baseline (before RT), 6 months, 1 year and 2 years. No erectile dysfunction was defined by an IIEF-5 >20/25, a mild ED by an IIEF-5 score of 17-19 and an important ED by a score<17. The mean age was 69.2 years [58-76]. At the time of follow-up, there was no biochemical relapse. Before RT, the mean IIEF5 score in all 13 patients was 23.4 [20-25]. At 6, 12 and 24 months after RT, the IIEF scores were 19.5 [5-25], 18.8 [5-25] and 20.3 [6-25], respectively. At two years, 8 patients (61.5%) had no ED and 2 patients (13.3%) experienced a mild ED. The mean reduction of the IIEF5 score was 3.15. Among the 3 patients with important ED, 2 had a medical treatment (Sildenafil Citrate) and recovered a satisfactory IIEF score at 22 and 24. The primary results of this technique of optimization for sexual preservation are encouraging. Despite a mean age close to 70 years at the time of treatment, almost 75% of the patients had no to mild sexual dysfunction at two years. This rate increases at 92% with the use of Sildenafil Citrate.