Dosimetric impact of applicator displacement on three-dimensional image-guided high-dose-rate brachytherapy treatments for cervical cancer
Sandun Jayarathna, Matthew Hoang, Rajeev Badkul, A. Hoover
Abstract
Purpose: To determine the dosimetric impact of brachytherapy applicator displacement during intracavitary (IC) and combined intracavitary/interstitial (IC/IS) high-dose-rate brachytherapy in the treatment of cervical cancer. Material and methods: of bladder, rectum, and sigmoid) were calculated for each virtual applicator shift, and significance of displacements was assessed using general linear model and Kruskal-Wallis test. Results: doses of 94.4%, 85.8%, 80.4%, and 72.4% at virtual displacements of 2, 5, 7, and 10 mm, respectively. Conclusions: Applicator displacements of 5 mm or greater result in statistically significant and clinically meaningful decreases in radiation dose to HR-CTV during 3-dimensional high-dose-rate brachytherapy treatment planning, with corresponding increase in radiation dose to the rectum. IC/IS applicator displacements lead to relatively greater differences than those of IC applicators.