ESTRO 2025 - Abstract Book

S207

Brachytherapy - Gynaecology

ESTRO 2025

78

Digital Poster Optimizing quality of life in cervical cancer survivors: A comparative study of the vaginal doses delivered with three HDR brachytherapy applicators Salwa Fathy 1,2 , Duaa ALhawi 1 , Mazen Al-Gaoud 1 , Nasser Al-Dhaibani 1 , Maha Alidrisi 1 , Umme Salma Mohamed 1 1 Radiation Oncology, King Abdullah Medical City, Makkah, Saudi Arabia. 2 Radiotherapy& Nuclear Medicine, South Egypt Cancer Institute, Assiut University, Egypt Purpose/Objective: The standard treatment for locally advanced cervical cancer is concurrent chemoradiation (CCRT) followed by image-guided adaptive brachytherapy (IGABT). While this approach has improved cancer outcomes, vaginal morbidity often leads to sexual dysfunction in cancer survivors. This study compares the doses delivered to vaginal points using three intracavitary brachytherapy applicators in cervical cancer treatment. Material/Methods: A retrospective study of 45 locally advanced cervical cancer patients treated at the oncology center with a combination of CCRT and IGABT. Patients received External beam radiotherapy dose of 45 Gy/25 fractions in 5 weeks with concurrent chemotherapy, followed by CT-based brachytherapy of 8 Gy to high-risk clinical target volume (HR-CTV) for 3 doses. The vaginal dose points( PIBS, PIBS+2 and PIBS-2 ), defined according to GEC ESTRO on planning CT using the Posterior- Inferior Border of Symphysis as an anatomical landmark, along with vaginal reference length (VRL) and recto vaginal reference point (RV-RP) were retrieved for comparison. These points’ doses were normalized to 2 Gy/fraction (EQD2) using α/β of 3 Gy considering the vagina as an organ at risk. Results: A total of 45 cervical cancer patients were randomly allocated to receive HDR brachytherapy with Miami, Fletcher Suit Delclos(FSD) or Ring applicator. The mean VRL was 4.15, 4.04, 4.88 cm for Miami, FSD, and Ring applicators respectively. The Median D 90% of HR-CTV was, 89.96 Gy for Miami applicator,90.66 Gy for FSD applicator and 92.67 Gy for Ring applicator. On analyzing the doses to vaginal points, FSD applicator delivered significantly higher doses to all PIBS points (except PIBS+2 cm) than other applicators ( P-Value: 0.0013 &0.0103 ). A significant low doses at RV-RP level was observed with Ring applicator ( P-Value: 0.00096 ). Although the mean D 2cc for bladder, and sigmoid were comparable among all the applicators, the mean D 2cc for rectum was significantly low with Miami ( P-Value: 0.0062 ). Conclusion: The choice of brachytherapy applicator significantly impacts the vaginal dose in carcinoma cervix. Specifically, FSD was associated with higher doses to vaginal points, Ring delivered less upper posterior vaginal doses, and single simple step Miami provided good reproducibility that effectively treated a variety of anatomies. Meanwhile, a comparable HR-CTV dosimetry was observed among all applicators. These findings underscore the importance of tailoring applicator selection to the individual patient’s anatomy and disease status to optimize treatment efficacy and minimize vaginal morbidity, ultimately contributing to a more personalized and better quality of life for cervical cancer survivors.

Keywords: Cancer cervix, vaginal points, life quality

References: 1] Haie-Meder C, Potter R, Van Limbergen E, et al. Recommendations from gynecological (GYN) GEC-ESTRO Working Group (I): concepts and terms in 3D image based 3D treatment planning in cervix cancer brachytherapy with emphasis on MRI assessment of GTV and CTV. Radiother Oncol 2005;74:235–245. [2] Potter R, Haie-Meder C, Van Limbergen E, et al. Recommendations from gynecological (GYN) GEC ESTRO working group (II): concepts and terms in 3D image-based treatment planning in cervix cancer brachytherapy-3D dose