Abstract

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Title:: Dosimetric comparison between single spot scanning of proton therapy and tomotherapy for prostate cancer

Author(s):: XU Wei1; YANG Tao1; XIE Chuanbin1; QU Baolin1; CAO Lin2; WANG Zishen2; SONG Yuanyuan2; FANG Chunfeng2; XU Shouping1; 1. Department of Radiotherapy, the First Medical Center of Chinese PLA General Hospital, Beijing 100853, China; 2. Department of Radiotherapy, Yizhou Cancer Hospital, Zhuozhou 072550, China

Keywords:: prostate cancer; proton therapy; single spot scanning; helical tomotherapy; dosimetry

Abstract:: Abstract: Objective To compare the dosimetric characteristics between single spot scanning of proton therapy (SSS-PT) and helical tomotherapy (HT) for prostate cancer, so as to provide some reference for clinical practice. Methods Twelve patients with the previous history of prostate cancer were enrolled as subjects. After positioning, CT images were transferred into Raystation and HT planning systems for radiotherapy planning. The prescription dose was 69 Gy/25 F. The conformity index and homogeneity index of target areas and the dosimetric parameters of target areas and organs-at-risk in two radiotherapy schemes were compared. Results SSS-PT was superior to HT in the homogeneity index of target areas (P=0.001). Compared with HT, SSS-PT had lower mean doses to rectum ［(21.92±4.00) Gy vs (31.97±2.60) Gy, P=0.000］ and bladder ［(17.62±3.15) Gy vs (30.52±3.94) Gy, P=0.000］. For the sparing of rectum and bladder, SSS-PT was always better than HT in the low- and medium-dose regions. Conclusion Both SSS-PT and HT can satisfy the clinical requirement of target coverage. For the same target coverage, SSS-PT is superior to HT in the sparing of rectum and bladder, especially in the low- and medium-dose regions.