External beam radiotherapy followed by image-guided adaptive brachytherapy in locally advanced cervical cancer: a multicenter retrospective analysis.

Purpose: To evaluate oncological outcomes and toxicities in patients with locally advanced cervical cancer (LACC) treated with concurrent chemoradiotherapy followed by image-guided adaptive brachytherapy at two Italian centres.

Material and methods: A retrospective analysis was conducted on 122 patients with LACC treated between 2010 and 2022. Primary endpoints were local control (LC), pelvic control (PC), and nodal control (NC). Secondary endpoints included disease-free survival (DFS), metastasis-free survival (MFS), overall survival (OS), and late toxicity. Correlations between patient characteristics and oncological outcomes were conducted.

Results: Brachytherapy planning was CT and MRI-based in 88 (72.1%) and 34 patients (27.9%), respectively. The mean total dose (EQD2) delivered to high-risk clinical target volume was 82 Gy. Overall treatment time was ≤ 50 days and > 50 days in 48 (39.3%) and 74 patients (60.7%), respectively. At a mean follow up of 101 months, 3 and 5-year LC rates were 87% and 85%, respectively. Five-year PC and NC rates were 77% and 85.1%. Five-year DFS and OS were 61% and 65.4%, respectively, with significant correlations between these outcomes and FIGO stage and nodal status at diagnosis. Gastrointestinal, genitourinary and vaginal adverse effects were the most reported late toxicities and 8 (6.5%) grade 3-5 events were observed. 32 patients (26.2%) had vaginal stenosis and it was significantly related to 3D imaging used for brachytherapy planning.

Conclusions: The study confirmed the efficacy and safety of chemoradiotherapy and IGABT for LACC. Full implementation of MRI treatment planning and interstitial techniques could further enhance personalized treatment and outcomes.