| Abstract: |
Objective The purpose was to compare local control (LC), overall survival (OS) and dose to the organs at risk (OAR) in women with locally advanced cervical cancer treated with MR-guided versus CT-guided interstitial brachytherapy (BT). Methods 56 patients (29 MR, 27 CT) were treated with high-dose-rate (HDR) interstitial BT between 2005–2015. The MR patients had been prospectively enrolled on a Phase II clinical trial. Data were analyzed using Kaplan-Meier (K-M) and Cox proportional hazards statistical modeling in JMP® & R®. Results Median follow-up time was 19.7 months (MR group) and 18.4 months (CT group). There were no statistically significant differences in patient age at diagnosis, histology, percent with tumor size > 4 cm, grade, FIGO stage or lymph node involvement between the groups. Patients in the MR group had more lymphovascular involvement compared to patients in the CT group (p < 0.01). When evaluating plans generated, there were no statistically significant differences in median cumulative dose to the high-risk clinical target volume or the OAR. 2-year K-M LC rates for MR-based and CT-based treatments were 96% and 87%, respectively (log-rank p = 0.65). At 2 years, OS was significantly better in the MR-guided cohort (84% vs. 56%, p = 0.036). On multivariate analysis, squamous histology was associated with longer OS (HR 0.23, 95% CI 0.07–0.72) in a model with MR BT (HR 0.35, 95% CI 0.08–1.18). There was no difference in toxicities between CT and MR BT. Conclusion In this population of locally advanced cervical-cancer patients, MR-guided HDR BT resulted in estimated 96% 2-year local control and excellent survival and toxicity rates. © 2017 Elsevier Inc. |
