Treatment Outcome of Cervical Cancer Patients Treated with Low-Versus High Dose Rate Brachytherapy after Concurrent Chemo-Radiation

Abstract

Cervical cancer (CC) is the commonest gynecological cancer seen in the Ghanaian woman. Majority of patients here present with locally advanced diseases due poor screening practices aimed at detecting and treating precancerous conditions. The current standard curative treatment for locally advanced CC is concurrent cisplatin-based chemo-radiation plus intracavitary brachytherapy. The brachytherapy (BT) component has been Low-Dose Rate (LDR) BT for almost a century now until a few decades ago when High-Dose Rate (HDR) BT was developed to overcome disadvantages of LDR BT such as long treatment duration. In October 2014, HDR BT was introduced as the BT technique for the management of CC patients at this Centre, after several years of using LDR BT. The hypothesis for this study was that there was no difference in the treatment outcomes of CC patients treated with HDR BT compared with those who received LDR BT at this center. The aim of this study was to compare the treatment outcomes and toxicity of CC patients treated with LDR BT versus HDR BT treated at this Centre. Patients with histologically confirmed CC treated from January 2008 to December 2017 were enrolled after applying the inclusion and exclusion criteria. Information regarding patient demographics, stage of disease, type of BT received, total radiation dose received, response to treatment and treatment related toxicities experienced were extracted from the medical records of the patients. The primary end points of the study included local control (LC), disease free survival (DFS) and overall survival (OS) all at 2 years. Toxicities were also assessed. Primary endpoints were estimated using the Kaplan-Meier method. Comparisons between treatment groups were performed using the log-rank test and Cox proportional hazards models. Over the 10-year period, 284 LDR (2008 –mid-2014) and 136 HDR (mid-2014-2017) patients fit the inclusion criteria. The median follow-up was 22 months (1-132months) vs. 11 months (1-41months) in LDR vs. HDR group respectively. For stages IB, IIA, IIB, IIIA and IIIB disease, the 2-year LC rates for LDR vs. HDR were 63 % vs. 61% p = 0.348, 86% vs. 90% p = 0.680, 86% vs. 88% p = 0.829, 66% vs. 60% p = 0.556 and 77% vs. 40% p = 0.005 respectively. The 2-year DFS for LDR vs. HDR BT were 64% vs. 61% p = 0.495, 81% vs. 69% p = 0.179, 81% vs. 80% p = 0.540, 62% vs. 33%, p = 0.818, and 71% vs.30%, p = 0.001 for stages IB, IIA, IIB, IIIA and IIIB respectively. The OS were comparable in both treatment groups stage for stage. Frequencies of acute and chronic toxicities for LDR vs. HDR were 22.6 % vs. 23.5%, and 3.9% vs. 6.9%, respectively. Comparable LC, DFS and OS were observed for IB, IIA, IIB and IIIA patients treated with LDR vs. HDR BT. HDR BT for the treatment of CC is therefore an acceptable alternative to LDR BT. However, the poorer LC and DFS rates observed for IIIB patients, and the higher frequencies of toxicities in the HDR BT cohort highlights the need for refining the HDR BT techniques at the Centre.