Abstract Introduction Sexual dysfunction after treatment greatly impacts the quality of life of many female patients with gynecologic cancers, yet research on radiation-induced sexual dysfunction is limited. Prior prostate cancer studies have established dose-response relationships for erectile tissues and pelvic neurovasculature, but comparable data for female pelvic anatomy are lacking. Female sexual organs of interest (OOIs) such as the bulboclitoris and pelvic neurovasculature, including the inferior hypogastric plexus (IHP) and internal pudendal artery (IPA), exist in the radiation-exposed region. Yet, dose exposure to OOIs during treatment has not been quantified nor has the relationship between dose exposure and organ function been evaluated. Objective Our aim was to examine organ-specific dose exposure to the bulboclitoris and related neurovasculature (IHPs and IPAs) as it varies by treatment type (external beam radiotherapy (EBRT), EBRT + brachytherapy (BT), BT alone) and evaluate the relationship between dose to each OOI and sexual function outcomes. Methods We conducted a cohort study of adult female uterine and cervix cancer patients who had completed radiotherapy ≥1 year before enrollment. Sexual function outcomes were using the Patient-Reported Outcome Measurement Information System (PROMIS) Sexual Function and Satisfaction Full Profile (Female) questionnaire for general and erectile tissue function-related domains: sexual activity, interest, clitoral discomfort, lubrication, orgasm-pleasure, and satisfaction. Calibrated T-scores were obtained via the HealthMeasures Scoring Service and compared to sexually active adult female population means for clinically significant dysfunction (≥ or ≤3). Cumulative dose-volume indices were extracted for each OOI (bulboclitoris: D95%, D50%, D5%; IHP: D0.03cc, D0.1cc, D50%) representing the minimum dose to the most irradiated reference volume, in equivalent dose in 2Gy fractions (α/β=3). Dose-volume indices were compared by treatment type and correlated with T-scores using Spearman’s correlation coefficient (Rs) as follows: strong 0.6, moderate 0.4–0.59, weak 0.2–0.39. Results 28 adult female uterine and cervix cancer survivors (mean age 63, IQR 53-72; months post-treatment, median 21 (IQR 15-38)) completed the PROMIS Sex SF questionnaire. 15 (54%) received chemotherapy, 3 (11%) underwent a radical hysterectomy, and 22 (79%) a total hysterectomy. 17 (61%) participants received brachytherapy (BT), 7 (25%) external beam radiotherapy (EBRT), and 4 (14%) were treated with both. 18 (64%) participants reported sexual activity in the past 30 days. Among them, 2 (12%) reported clitoral discomfort and 4 (27%) experienced orgasm ability dysfunction. OOI dose exposure varied by treatment type for all dose-volume indices (Table 1). Dose-volume indices (Table 2) demonstrate a weak positive correlation with clitoral discomfort in both the bulboclitoris and IHPs. IHP D0.03cc and D0.1cc indicated a moderate positive correlation with orgasm ability dysfunction. Conclusions This study demonstrates that the bulboclitoris and neurovasculature receive substantial radiation doses during treatment for cervix and uterine cancers, varying by treatment type, and that there is a correlation between dose-volume indices of neurovascular structures and impaired orgasm ability. Neurovascular pathways are critical for arousal and orgasm function, likely playing a key role in radiation-induced sexual dysfunction. Further research is warranted to establish dose guidance for the IHPs and other sexual OOIs, to refine radiation planning and mitigate sexual dysfunction in female cancer survivors. Disclosure No
Munoz et al. (Mon,) studied this question.