Prevalence and predicting factors for commonly neglected sexual side effects to brachytherapy for prostate cancer: a cross-sectional observational study.

Background: Low-dose-rate brachytherapy (LDR-B) is an established treatment for localized prostate cancer. However, while erectile function is relatively well documented, other changes in sexual function are sparsely investigated. Aim: The study sought to investigate orgasmic dysfunction, urinary incontinence during sexual activity (UIS), changes in penile morphology, and sensory disturbances in the penis following LDR-B. Methods: A cross-sectional questionnaire-based study in patients who underwent LDR-B at our center from 2010 to 2020. The questionnaire included the International Index of Erectile Function-Erectile Function Domain (IIEF-EF) and questions on orgasm, UIS, changes in penile morphology, and penile sensory disturbances. Outcomes: Outcomes were prevalence rates of altered perception of orgasm, orgasm associated pain, anejaculation, UIS, alterations in penile morphology, penile sensory disturbances, and predictors of these side effects. Results: Overall, 178 patients responded to the questionnaire. The median age was 70 years (range, 51-83 years), and the median time since LDR-B was 93 months (range, 21-141 months).Overall, 142 (80%) were sexually active and 126 (70.8%) had erectile dysfunction (ED). Of the sexually active patients, 8 (5.6%) reported anejaculation and 7 (4.9%) reported anorgasmia. Another 67 (46.9%) had decreased orgasmic intensity, while 69 (49.3%) reported an increased time to orgasm. Twenty-six (18.3%) patients had experienced orgasm-associated pain with a median visual analog pain score of 2. Considering overlap, 44 (31.0%) patients had an unchanged orgasmic function. Six (3.3%) patients had experienced UIS at least a few times. Penile length loss was reported by 45 (25.2%) patients. Seventeen (9.6%) patients reported an altered curvature of their penis and 9 (5%) had experience painful erection. Thirty-three (18.5%) patients had experienced decreased penile sensitivity. On multivariate analyses, ED was the only independent risk factor for altered perception of orgasm (odds ratio [OR], 6.6; Clinical implications: Patients undergoing LDR-B should be adequately informed about possible side effects, and clinicians should inquire about these during follow-up visits. Strength and Limitations: We are the first to comprehensively explore the previously neglected side effects of LDR-B for prostate cancer. Limitations are the cross-sectional design assessing the cohort at different time points following their treatment and the response rate. Conclusions: Orgasmic dysfunction, changes in penile morphology, and sensory disturbances in the penis are common side effects of LDR-B for prostate cancer. UIS is only experienced by a small minority.