Abstract

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Title:: Dosimetric comparison of RapidArc and IMRT in hippocampus sparing during postoperative radiotherapy for glioma

Author(s):: DAI Hongya1; HUANG Jianghua2; CHEN Lu1; ZHONG Liangzhi1; ZHOU Yibing1; 1. Department of Oncology, the Second Affiliated Hospital of Army Medical University, Chongqing 400037, China; 2. Guangdong Provincial Key Laboratory of Malignant Tumor Epigenetics and Gene Regulation/Department of Radiotherapy, Sun Yat-sen Memorial Hospital, Sun Yat-sen University, Guangzhou 510120, China

Keywords:: ; Keywords: RapidArc; intensity-modulated radiotherapy; glioma; hippocampus; postoperative radiotherapy

Abstract:: Abstract: Objective To compare the dosimetric differences between volumetric modulated arc therapy with RapidArc (RapidArc) and intensity-modulated radiotherapy (IMRT) in hippocampus sparing during postoperative radiotherapy in patients with glioma. Methods Twenty-two postoperative patients with glioma were selected. Based on the fusion of CT images and MRI images, the target areas and organs-at-risk were delineated. Both IMRT and RapidArc plans were designed for each patient. The dosimetric parameters of target areas and organs-at-risk were compared between two plans. Results Both IMRT and RapidArc plans met the requirements of prescribed dose. Compared with that of IMRT, the conformity index of RapidArc was closer to 1 (P<0.05), but there was no significant difference in homogeneity index. In the protection of brainstem and hippocampus, RapidArc was superior to IMRT, especially in the Dmax and Dmean of hippocampus which were lower in RapidArc (P<0.05). Conclusion Compared with IMRT, RapidArc shows a similar or better target dose distribution and reduces the irradiation doses to organs-at-risk, with the advantages of less monitor units and shorter treatment time. RapidArc with hippocampus sparing can be considered as the preferred treatment option in postoperative radiotherapy for glioma.