CT-based cervix HDR brachytherapy treatment planning: Is CT simulation necessary for each HDR insertion?

Abstract

Purpose: HDR brachytherapy for cervical carcinoma involves multiple insertions of intracavitary applicators. Often, the treatment plan from the initial insertion is used throughout the course of treatment. Applicator geometry is, however, known to change between consecutive insertions. Using CT-based treatment planning we evaluated the impact on dose to organs-at-risk (OAR) (bladder and rectum) using a single plan versus custom plans for each insertion. OAR doses were characterized using both the dose to the hottest 2cm3 and ICRU points.