1028 - Dosimetric Predictors of Sexual Toxicity in Cervical Cancer Patients Treated with Definitive Chemoradiation and MRI-Guided Brachytherapy
Presenter(s)
S. Gulstene1,2, E. Chuk1,2, J. Conway1,2, J. Hanuschak1,2, K. Han1,2, M. Milosevic1,2, J. Lukovic1,2, S. E. Ferguson3,4, A. Salman3,4, A. T. Santiago5, A. Rink1,6, and J. M. Croke1,2; 1Department of Radiation Oncology, University of Toronto, Toronto, ON, Canada, 2Radiation Medicine Program, Princess Margaret Cancer Centre, University Health Network, Toronto, ON, Canada, 3Department of Obstetrics and Gynecology, University of Toronto, Toronto, ON, Canada, 4Division of Gynecologic Oncology, University Health Network/Sinai Health System, Toronto, ON, Canada, 5Department of Biostatistics, University Health Network, Toronto, ON, Canada, 6Department of Medical Biophysics, University of Toronto, Toronto, ON, Canada
Purpose/Objective(s): Definitive radiotherapy for cervical cancer results in significant vaginal and sexual toxicity. Prior work has investigated dosimetric predictors of vaginal toxicity; however, sexual health outcomes are lacking. We assessed dosimetric predictors of sexual toxicity in cervical cancer patients treated with definitive radiation.
Materials/Methods: Stage IB-IVA cervical cancer patients treated with definitive chemoradiation and MR-guided brachytherapy were enrolled in a prospective, cross-sectional study. Sexual toxicity was assessed using 2 validated patient reported outcome measures (PROMs): Female Sexual Function Index (FSFI) (scores >11 indicating distress) and Female Sexual Distress Scale-Revised (FSDS-R) (scores <26 indicating dysfunction). Clinical and treatment data were collected by chart review. Vaginal dosimetry was abstracted from individual treatment plans, including: cumulative dose (EQD2) and maximum dose per fraction for vaginal D2cc, ICRU recto-vaginal point (RV point), vaginal lateral point (5 mm from applicator), posterior-inferior border of symphysis (PIBS), and PIBS±2cm. Vaginal Total Reference Air Kerma (TRAK) assessed dose loading within the vagina. Descriptive statistics summarized the data and correlations were evaluated using logistic regression analyses.
Results: Between August 2018 and April 2022, 73 patients were eligible for analysis. Median age at diagnosis was 50 (range: 23-80), median stage was IIB (49%), 61% had vaginal involvement at diagnosis, and 33% had involvement at brachytherapy. Mean EQD2 for vaginal D2cc, ICRU RV point, lateral point, PIBS+2cm, PIBS, and PIBS-2cm were 78.3Gy (SD±13.7), 63.5Gy (±10.1), 118.5Gy (±98.4), 55.7Gy (±22.5), 28.4Gy (±19.6), and 5.5Gy (±6.9), respectively. Patients completed PROMs a median of 19 months (range 3–63) after treatment. Criteria for sexual dysfunction and distress was met in 85% and 55% of participants, respectively. Cumulative ICRU RV point dose > 65 Gy (p=0.012) and vaginal TRAK (p=0.003) were associated with increased sexual distress on multivariable analysis.
Conclusion: Sexual health following radiotherapy for cervical cancer is an important and multifactorial issue. Here we highlight the importance of vaginal dosimetry in post-treatment sexual health. Attention to and evaluation of vaginal doses could improve our understanding of sexual health outcomes.