Intensity-modulated radiotherapy/Volumetric modulated Arc therapy including four Brachytherapy fractions versus 3D conformal radiotherapy containing five Brachytherapy fractions in the treatment of cervical cancer

Definitive radiochemotherapy with external beam radiotherapy and brachytherapy is standard for locally advanced cervical cancer (LACC). Advanced techniques like intensity-modulated radiation therapy (IMRT) and volumetric modulated arc therapy (VMAT) have replaced 3D-conformal radiotherapy (3DCRT). This study compares two institutional definitive radiotherapy treatment pathways implemented in different time periods: 3DCRT with five BT fractions and IMRT/VMAT with four BT fractions. This retrospective single-center study included 145 patients with FIGO 2018 stage IB3–IVA LACC treated during 2008–2023. Patients received 3DCRT+5BT (2008–2016; n = 77) or IMRT/VMAT+4BT (2017–2023; n = 68) with concurrent chemotherapy. Histopathological biopsies at final BT evaluated tumor response. Dosimetric parameters (HRCTV-D90–EQD2₍₁₀₎ and OAR-D2cc for bladder, rectum, sigmoid) were analyzed. Endpoints included treatment duration, residual tumor, progression-free survival (PFS), overall survival (OS), and toxicity. After a median follow-up of 60 months, no significant differences were seen in PFS (HR 0.68, 95% CI 0.34–1.38, p = 0.285) or OS (HR 0.47, 95% CI 0.17–1.29, p = 0.133). Histologically confirmed residual tumor rates were 22.1% (IMRT/VMAT+4BT) vs. 31.2% (3DCRT+5BT; p = 0.262). IMRT/VMAT+4BT patients more often completed therapy within 49 days (63.2% vs. 20.8%; p < 0.001). Median HRCTV D90 EQD2₍₁₀₎ was 85.3 Gy vs. 76.5 Gy (p < 0.001) in favor of IMRT/VMAT, while OAR doses remained within limits. IMRT/VMAT showed significantly fewer gastrointestinal, genitourinary, skin, and mucosal toxicities (all p < 0.05) and less systemic deterioration. In this era-based single-institution comparison of two treatment pathways, IMRT/VMAT+4BT achieved numerically better oncologic outcomes without reaching statistical significance. IMRT/VMAT+4BT showed improved target coverage, lower toxicity, and shorter treatment duration, within the context of an integrated regimen change over time.