Centralization of MR image-guided adaptive brachytherapy for cervical cancer in Austria: feasibility and outcomes.

Abstract

Purpose: Magnetic resonance image-guided adaptive brachytherapy (MR-IGABT) is the standard of care for definitive radiochemotherapy in locally advanced cervical cancer, but radiotherapy departments with sufficient case volume and unrestricted access to MRI capacity remain limited. This study evaluated the feasibility and outcomes of a nationwide Austrian model combining decentralized external-beam radiotherapy (EBRT) with centralized MR-IGABT.

Materials and methods: This retrospective cohort study included patients with FIGO IB-IVA cervical cancer treated between 2018 and 2022 who received EBRT ± concomitant chemotherapy at external Austrian institutions and were subsequently referred to the Medical University of Vienna for brachytherapy. All patients received four fractions of MR-IGABT with MRI-based target delineation according to GEC-ESTRO recommendations. Primary endpoints were local control (LC) and overall survival (OS). Secondary endpoints included pelvic lymph node control (PLNC), recurrence-free survival (RFS), and grade ≥ 3 morbidity requiring medical intervention.

Results: Eighty-nine patients from nine institutions were analyzed. Median age was 52 years; 54% had T2b disease and 60% nodal involvement, including 17% paraaortic nodes. Median overall treatment time was 50 days, with a median 6.5-day interval between EBRT and brachytherapy. Combined intracavitary/interstitial brachytherapy was used in 87%, with a median of six needles. The median CTV_HR D90 was 91 Gy EQD2. After a median follow-up of 36 months, the estimated 3‑year OS was 74%, LC 95%, PLNC 95%, and RFS 65%. Recurrences were predominantly distant. Grade ≥ 3 morbidity occurred in 26.1%.

Conclusion: Centralized MR-IGABT within a nationwide referral network is feasible and enables guideline-conform, high-quality cervical cancer treatment in a real-world setting.