Impact of uterine deformation induced by applicator on brachytherapy dosimetric value: an uterine-mimicking-phantom study

Author:

Seiri Mahnaz,Jaberi Ramin,Solgi Razieh,Shakeri Mahsa,Ghadiri Hossein

Abstract

Abstract Brachytherapy (BT) is subjected to uncertainties from imaging, treatment planning, and anatomical variations. It is necessary to identify the uncertainties, their magnitude, and their impact on the overall uncertainty of dose delivery. The aim of the present phantom-based study is to investigate the deformation of the uterus anatomy induced by BT applicator insertion and the relationship between dose and location of the inserted applicator. A novel flexible phantom was designed based on female pelvic anatomy by the 3D printing process to simulate the deformation and movement of the uterine during the BT process. The applicator was inserted into the uterus and in order to simulate the uterus motion, the phantom was moved in four directions, right, left, down, and up. The CT and ultrasound images were obtained. A two-stage registration algorithm was designed to register the ultrasound and CT images in order to calculate the applicator displacements map. This map was used to calculate delivered dose error to uterus and rectum and to correct the planned dose values in treatment planning procedure. The results showed that in a planned D90 (dose) of 9.4 Gy for the uterus and maximum dose of 1.8 Gy to the rectum, movement of applicator leads to a big deviation in final delivered doses. After the applicator moved to the right and left directions, the D90 delivered to the uterus was 6.2 Gy and 5.6 Gy, respectively. Moreover, by moving downwards and upwards, the uterus received 0.4 and 1.2 Gy lower than 9.4 Gy. Similarly, the maximum dose to the rectum in right, left, down, and up directions after applicator movement were 3.4 Gy, 3.3 Gy, 3.7 Gy and 3.2 Gy, respectively which highlighted the higher delivered dose to the rectum. The results of the study demonstrate that applicator displacement can lead to uterine underdosing and also increase the risk of rectum irradiation. Ultimately, image-guided brachytherapy and using image registration can increase the accuracy of treatment and reduce the errors of delivered dose to target volume and organs at risk, especially in uterus cancer.

Publisher

IOP Publishing

Subject

Mathematical Physics,Instrumentation

同舟云学术

1.学者识别学者识别

2.学术分析学术分析

3.人才评估人才评估

"同舟云学术"是以全球学者为主线,采集、加工和组织学术论文而形成的新型学术文献查询和分析系统,可以对全球学者进行文献检索和人才价值评估。用户可以通过关注某些学科领域的顶尖人物而持续追踪该领域的学科进展和研究前沿。经过近期的数据扩容,当前同舟云学术共收录了国内外主流学术期刊6万余种,收集的期刊论文及会议论文总量共计约1.5亿篇,并以每天添加12000余篇中外论文的速度递增。我们也可以为用户提供个性化、定制化的学者数据。欢迎来电咨询!咨询电话:010-8811{复制后删除}0370

www.globalauthorid.com

TOP

Copyright © 2019-2024 北京同舟云网络信息技术有限公司
京公网安备11010802033243号  京ICP备18003416号-3