Comparison of whole-body equivalent doses from volumetric modulated arc therapy and static intensity-modulated radiotherapy for cervical cancer

Abstract

Objective To compare the whole-body equivalent doses from volumetric modulated arc therapy (VMAT) and static intensity-modulated radiotherapy (IMRT) for patients with cervical cancer. Methods Nine patients with cervical cancer admitted to our hospital in 2014 were included in this study. Both VMAT and IMRT were planned for each patient. Each patient’s personal dose equivalent (Hp (10)) was measured using thermoluminescent dosimeters placed at the xiphoid process and glabella during IMRT and VMAT. The whole-body equivalent doses were estimated based on the results measured at the xiphoid process and compared between the VMAT and IMRT techniques. The paired t test was used for difference analysis. Results The Hp (10) values measured at the xiphoid process and glabella of every patient were lower for VMAT than for IMRT. At a prescribed dose of 50 Gy, if the mean Hp (10) values measured at the xiphoid process were considered to represent the whole-body equivalent doses, the whole-body equivalent doses for VMAT and IMRT were 364 mSv and 538 mSv, respectively. Conclusions VMAT results in a lower whole-body equivalent dose to patients compared with IMRT. The decreased whole-body equivalent dose delivered by VMAT may reduce the likelihood of a radiation-induced secondary malignancy. Key words: Cervical neoplasms/volumetric modulated arc therapy; Cervical neoplasms/intensity modulated radiation therapy; Whole-body equivalent dose