Prospective study of vaginal dilator use adherence and efficacy following pelvic and intravaginal radiotherapy.

Abstract

9524 Background: Vaginal stenosis (VS) as a late effect of pelvic radiotherapy (RT) and intravaginal brachytherapy (IVB) can impair long-term quality of life. The best care guideline for post-treatment 3x/week vaginal dilator (VD) use is based on limited research. This prospective study aimed to determine adherence and efficacy of VD use as measured by ability to return to pre-RT VD size at 12 months (mos). Methods: From 2009-2011, women with rectal (n=28), anal (n=35), endometrial (n= 45) and cervical (n=1) cancers were followed for one-year post-radiation therapy (RT). Clinicians provided structured teaching to use dilators 3x/week, regardless of frequency of sexual intercourse. For 12 mos, patients self-reported dilator size and vaginal symptoms in monthly diaries. At pre-RT, 1, 6 and 12 mos post-RT, clinicians graded VS using CTCAE v3. Adherence was measured as the percentage of times patients used the dilator out of the number of times they were instructed (3x/week X 52 weeks=156). Fisher’s exact and Kruskal-Wallis tests were used to assess differences among groups. Results: Among 109 participants, aged 28-81 years (median = 58), mean adherence with VD use over a 12 mos period was 42% (sd 34%, 95% Cl:36%- 49%). Adherence was highest in the first quarter (58%), but fell to 25% by the fourth quarter. Disease type, treatment sequence and chemotherapy were predictors of adherence (all p<0.05). Rectal cancer patients were less likely to adhere to dilator use than anal and endometrial patients. 82% of all patients returned to pre-RT size at 12 mos; of the 49% who reported a decrease in dilator size from pre-RT to 1 month post-RT, 71% were able to return to pre-RT size at 12 mos. Anal cancer patients were most likely to report a decrease in VD size at 1 mo post-RT (77%), but 68% of these patients were able to return to baseline at 12 mos. Disease type and greater adherence to VD use at 6 months were associated with returning to pre-RT size at 12mos (both p <0.05). Conclusions: Based on this prospective study, VD use is an effective strategy in minimizing VS, but adherence at 12 mos was poor. Future studies are needed to evaluate methods of improving adherence with VD use and to determine the optimal frequency and duration of VD use.