Three-dimensional image-based planning for cervix brachytherapy with bilateral hip prostheses: A solution using MVCT with helical tomotherapy

Abstract

Purpose We present a method of three-dimensional image-based planning for cervix high-dose-rate (HDR) brachytherapy for patients with bilateral metal hip prostheses using megavoltage computed tomography (MVCT) imaging. Methods and Materials Two patients with bilateral metal hip prostheses were treated with our standard HDR brachytherapy fractionation and critical structure tolerance limits for cervical cancer. MVCT imaging was used for treatment planning because of artifacts present in kilovoltage computed tomography (kVCT), which did not allow visualization of the organs of interest. Results The MVCT images provided adequate contrast to allow the contouring of organs at risk and the digitization of HDR applicators. HDR brachytherapy treatment planning was successfully accomplished based on MVCT images for 2 patients with bilateral metal hip prostheses. Conclusions Using MVCT imaging eliminated streak artifacts, which improved the image quality for treatment planning. MVCT offers an option for three-dimensional planning for cervix brachytherapy in patients with bilateral hip prostheses.