Toxicities and Recurrences after Co-60 High-Dose-Rate Brachytherapy for Cervical Cancer in a Tertiary Government Hospital in the Philippines

Abstract

Introduction Despite the rising popularity of high-dose-rate (HDR) brachytherapy and use of Co-60 in the country, local data on brachytherapy outcomes are lacking. The study reviewed the incidence of toxicities and recurrences in patients with cervical cancer treated with Co-60 intracavitary HDR brachytherapy in a tertiary government hospital in the Philippines. Methods Records of patients with cervical cancer who completed external beam radiotherapy (EBRT) and brachytherapy from 2016 to 2018 were reviewed. Patient-related (age, smoking history, body mass index, histology, stage, mass size) and treatment-related (overall treatment time [OTT], EBRT machine used, brachytherapy fractionation, dose prior to midline shielding/central tumor dose [CTD]) parameters were analyzed for possible associations with the incidence of toxicities and recurrences. Results One hundred and sixty-three patients were identified and reviewed for baseline characteristics. Patients who had inadequate follow-up (<90 days) were excluded in the analysis of outcomes. Among the remaining 132 patients, median follow-up duration was 389 days. Gastrointestinal (GI) and genitourinary (GU) toxicities were present in 19.7% (n = 26) and 1.5% (n = 2), respectively. Recurrence was noted in 31.8% (n = 42). The most commonly involved sites of locoregional and distant recurrence was the uterocervix (n = 16, 59.3%) and para-aortics (n = 42, 31.8%), respectively. CTD was significantly associated with toxicities (p = 0.03), while OTT was borderline significantly associated with recurrence (p = 0.06). Conclusion We present outcomes of GI and GU toxicities, and locoregional and distant recurrences after chemoradiation and Co-60 HDR brachytherapy in a tertiary government hospital in the Philippines. Our study suggests that CTD was significantly associated with incidence of toxicities, while OTT was weakly associated with recurrence. Interventions should be made to control these factors, especially in high-volume, low-resource cancer centers.