Toxicity and outcomes associated with high-dose rate brachytherapy for medically inoperable endometrial cancer

Abstract

Purpose: To evaluate toxicity in inoperable endometrial cancer (EC) treated with definitive radiation therapy (RT).

Materials and methods: Patients treated with definitive RT for EC were retrospectively reviewed. EQD2 values were calculated for bladder, rectum, and sigmoid. Acute and late toxicities were retrospectively graded. Descriptive statistical analysis was performed.

Results: Fifty-one patients were included. The majority of patients had endometrioid histology (N = 46, 90.2%) and Grade 1 disease (N = 32, 62.75%). Thirty-seven patients (72.5%) were treated with image-guided BT (IGBT) and 14 (27.5%) with two-dimensional BT. Forty patients (78.4%) received EBRT + BT and 11 (21.57%) received BT alone. No grade 2 (G2) or higher toxicities were reported with BT alone. G2 or higher acute toxicities with EBRT + BT were G2 proctitis (N = 2, 5.0%) and G3 proctitis (N = 1, 2.5%). Late toxicities included G3 vaginal stenosis (N = 1, 2.5%), proctitis (N = 1, 2.5%), enteritis (N = 1, 2.5%), and one G4 gastrointestinal bleed. One- and 2-year local control were 100% with BT alone and 93% and 89%, respectively, with EBRT + BT. One- and 2-year locoregional control were 100% with BT and 97% and 93%, respectively, with EBRT + BT. Recurrence-free survival was 89% at 1 and 2 years with BT alone compared to 87% and 80% with EBRT + BT. One- and 2-year overall survival were 88% and 72% with BT alone compared to 94% and 84% with EBRT + BT. There were no statistically significant differences in cancer control between the two groups.

Conclusions: Women with inoperable EC treated with definitive RT have low toxicity rates and durable local control.

Keywords: Brachytherapy; Endometrial cancer; Image-guided; Inoperable; Toxicity.