The management of inoperable Stage I endometrial cancer using intracavitary brachytherapy alone: a 20-year institutional review.

OBJECTIVE: To review our institution's results with primary low dose rate (LDR) intracavitary brachytherapy using Heyman's capsules for medically inoperable cancer of the endometrium. METHODS: The study was a retrospective review of inoperable early-stage endometrial cancer patients at the Cross Cancer Institute in Edmonton, Canada, treated with primary radiotherapy from January 10, 1986 to July 17, 2006. Forty-four patients with International Federation of Gynaecology and Obstetrics (FIGO) clinical Stage I disease were included in the study. Kaplan-Meier survival analysis was performed to obtain estimates of overall survival (OS), disease-free survival, and disease-specific survival (DSS). Tumor grade was assessed as a potential predictor of OS by comparing survival curves using a log-rank test. RESULTS: The median OS time was 75.5 months (95% confidence interval 55.6-95.3 months). For the entire group, the 5- and 10-year OS was 60.5% and 24.0%, respectively. The 5- and 10-year DSS was 87.7% and 79.7%, respectively. For a subset treated as planned, the 5- and 10-year OS was 54.5% and 34.5%, respectively. The 5- and 10-year DSS was 83.0% and 76.4%, respectively. When stratified by grade, trends in survival analysis are inversely related to grade. Both the trend analysis and the log-rank test were statistically significant at a p<0.05 level. CONCLUSIONS: Our experience with LDR brachytherapy for the treatment of Stage I endometrial cancer is comparable to surgical treatment and to results reported in the literature for high dose rate brachytherapy. Further study that would help define the indications for a primary radiotherapeutic approach in early-stage endometrial cancer may lower current thresholds for recommending primary radiotherapy versus surgery.

Inter-observer comparison of target delineation for MRI-assisted cervical cancer brachytherapy: application of the GYN GEC-ESTRO recommendations.

BACKGROUND AND PURPOSE: To investigate the inter-observer variation of target contouring when using the GYN GEC-ESTRO recommendations for MR image-guided brachytherapy (IGBT) for cervical cancer. MATERIALS AND METHODS: Nineteen cervical cancer patients, treated by radiotherapy at the Institut Gustave Roussy (IGR) in France (n=9) or at the Medical University of Vienna (AKH) in Austria (n=10) were included in this study. IGBT was used for all patients. Two radiation oncologists, one from IGR and the other from AKH, outlined the target volumes on MRI at the time of brachytherapy according to the GYN GEC-ESTRO recommendations. The absolute, common and encompassing volumes and their conformity indices (CIs) were assessed for the GTV, HR CTV and IR CTV. D90 and D100 for each volume were assessed. Visual evaluation was made to assess the reasons for the most frequent inter-observer differences. RESULTS: The mean volumes of GTV and HR CTV did not differ significantly between the observers, p>0.05. Significant differences were observed only for the mean volumes of the IR CTV of both centres, p<0.05. CIs ranged from 0.5 to 0.7. DVH-parameter analyses did not reveal any statistical differences, except for the D100 for the GTV at AKH, and the D90 for the IR CTV at IGR, p<0.05. Underlying reasons for inter-observer differences included image contrast adjustment and neglecting to consider anatomical borders. CONCLUSIONS: The results of this inter-observer study show that the application of the GYN GEC-ESTRO recommendations for IGBT contouring at two different institutions with two different traditions for applicators, CTV assessment, MR image acquisition and dose prescription is feasible, and it produces acceptable inter-observer variability.