Treatment outcomes of high-dose-rate intracavitary brachytherapy for cervical cancer: a comparison of Ir-192 versus Co-60 sources

Abstract

ObjectiveTo determine and compare treatment outcomes between cobalt-60 (Co-60) and iridium-192 (Ir-192) high dose rate (HDR) brachytherapy in stage IB2–IIIB cervical cancer patients at Department of Radiology, Faculty of Medicine Vajira Hospital, Navamindrahiraj University.MethodsA retrospective cohort study of patients diagnosed with cervical cancer and treated with radiotherapy at the Department of Radiation Oncology, Faculty of Medicine Vajira Hospital between 2004 and 2014. Survival rate was analyzed by Kaplan-Meier method and were compared between groups with log-rank test. Multivariate analysis was performed using Cox proportional hazards model.ResultsA total of 480 patients with cervical cancer and treated with radiotherapy were included, 274 patients for Ir-192 group and 206 patients for Co-60 group. The 2- and 5-year disease-free survival rate in Ir-192 group were 80.4% and 73.1% and in Co-60 group were 82.5% and 74.7%, respectively (p=0.365). Overall survival rates at 2 and 5 years were 89.4% and 77% of the Ir-192 group, and 91.6% and 81.9% in the Co-60 group, respectively (p=0.238). The complications were primarily grade 1 or 2. Grade 3 and 4 complications were found in 13 of 274 and 7 of 206 in Ir-192 and Co-60 groups, respectively (p=0.232). Grade and clinical stage of cancer significantly affected the survival outcome.ConclusionCervical cancer patients who were treated with HDR Co-60 brachytherapy were comparable in survival and toxicity outcomes of those with HDR Ir-192 brachytherapy. Co-60 source has lots of economic advantages over Ir-192 and hence suitable for low resource radiotherapy setting.

Interstitial high-dose-rate brachytherapy using cobalt-60 source for cervical cancer: dosimetric and clinical outcomes from a single institute

“…In the present study, we have observed that the dose to 2 cm 3 of bladder, rectum, and sigmoid were within the recommended limits, as reported in the studies where 192 Ir source was used for interstitial brachytherapy. A five years follow-up study by Tantivatana et al in patients undergoing ICBT using 192 Ir or 60 Co sources did not find any significant difference in overall survival (77% vs. 81.9%), disease-free survival (73.1% vs. 74.7%), and grade 3 and grade 4 complications (4.7% vs. 3.4%) [21]. The available literature using 192 Ir for ISBT have reported local control in the range of 61-88% at 2 to 3 years.…”

“…A five years follow-up study by Tantivatana et al . in patients undergoing ICBT using 192 Ir or 60 Co sources did not find any significant difference in overall survival (77% vs. 81.9%), disease-free survival (73.1% vs. 74.7%), and grade 3 and grade 4 complications (4.7% vs. 3.4%) [ 21 ]. The available literature using 192 Ir for ISBT have reported local control in the range of 61-88% at 2 to 3 years.…”

Influence of dwell time homogeneity error weight parameter on treatment plan quality in inverse optimized HDR cervix brachytherapy using SagiPlan

“…Only small, often clinically insignificant differences have been reported between cervix plans using 60 Co or iridium-192 HDR sources [15]. This is especially true when dwell time optimization is utilized [15,29]. Moreover, cervical cancer patients who were treated with 60 Co or 192 Ir HDR afterloaders have been reported to have statistically nonsignificant differences in two- and five-year disease-free and overall survival and toxicity outcome [29].…”

Radiotherapy treatment in cancer control and its important role in Africa

“…The choice of source should be well considered in terms of frequency of change to avoid periods of lack of brachytherapy facilities. Most African countries are now opting for the use of high-dose-rate brachytherapy using cobalt sources that have a long half-life, short treatment times and, therefore, are economically viable without compromising outcome [19]. This has considerably improved the availability and efficiency of delivering brachytherapy services.…”