Re-irradiation with image-guided radiotherapy for recurrent cervical cancer: an analysis of outcomes and toxicity

Recurrent cervical cancer within previously irradiated fields remains a major therapeutic challenge. This study aimed to evaluate clinical outcomes and safety of image-guided re-irradiation and to identify prognostic factors associated with tumor control and treatment-related toxicity. All consecutive patients who underwent image-guided re-irradiation between March 2020 and December 2024 were retrospectively analyzed. Re-irradiation was delivered using image-guided external beam radiotherapy and/or image-guided brachytherapy. Concurrent chemotherapy or immunotherapy was administered when clinically indicated. Organ at risk doses were recorded from re-irradiation plans. Logistic models were applied to evaluate tumor control probability and normal tissue complication probability. A total of 102 patients were included. At recurrence, 45.1% had central relapse, 14.7% pelvic relapse, 17.6% combined central and pelvic relapse, and 22.5% had distant metastasis. The median re-irradiation dose was 56.8 Gy (a/β = 10). With a median follow-up of 13.7 months, the 1- and 2-year LC were 67.6% and 59.2%, and the 1- and 2-year PFS were 52.7% and 42.6%. Higher re-irradiation prescription EQD2 was associated with improved tumor control. A progression-free interval > 2 years after initial radiotherapy predicted better progression-free survival and local control, whereas distant metastasis was associated with inferior progression-free survival. Higher rectal and bladder D2cc values were significantly associated with increased late toxicity. The risk of grade ≥ 2 late complications rose substantially when the rectal or bladder D2cc exceeded approximately 50 Gy (a/β = 3). No grade 4 or 5 toxicities were observed in this study. Re-irradiation is a feasible and effective salvage option for patients with recurrent cervical cancer and provides moderate local control with acceptable toxicity.