The Clinical Course of the Late Toxicity of Definitive Radiotherapy in Cervical Cancer

<i>Background and Objectives</i>: This study aimed to investigate the clinical course and characteristics of late toxicity over time following the completion of definitive radiotherapy (RT) in patients with cervical cancer. <i>Materials and Methods</i>: We retrospectively reviewed the medical records of 60 patients with cervical cancer who underwent pelvic external beam radiotherapy followed by intracavitary brachytherapy. Late toxicity was assessed for the lower gastrointestinal (GI) tract and bladder organ at 6, 12, 24, 36, and >36 months post-RT. We examined the onset and prevalence of late toxicity at each time point. Clinical remission and interventions for managing late toxicity were also investigated. <i>Results</i>: The peak onset of lower GI toxicity occurred 12 months after RT completion, with a median symptom duration of 9.9 months (range, 0.1-26.3 months), and exhibited its highest prevalence rate of 15.5% at 24 months post-RT. Most GI toxicities developed and resolved within three years post-RT, with a prevalence rate of 8.1% at three years, followed by a decreasing trend. Bladder toxicity first peaked at 24 months post-RT and continued to occur beyond 36 months, showing the re-increasing pattern in the prevalence rate after 36 months (23.5%). In terms of clinical remission, 66.7% of lower GI toxicities (12 of 18 patients) and 60% of bladder toxicities (9 of 15 patients) achieved complete remission by the last follow-up date. <i>Conclusions</i>: Late toxicities of the GI and bladder following definitive RT in cervical cancer are partially reversible and exhibit distinct patterns of onset and prevalence over time. A systematic follow-up strategy should be established for the early detection and timely intervention of late toxicity by understanding these clinical courses.