コイケ　ユウヘイ   KOIKE YUHEI   小池　優平    所属   関西医科大学  放射線科学講座    職種   助教
論文種別	原著(症例報告除く)
言語種別	英語
査読の有無	査読あり
表題	Dual-energy computed tomography image-based volumetric-modulated arc therapy planning for reducing the effect of contrast-enhanced agent on dose distributions
掲載誌名	正式名：Medical dosimetry 略　 称：Med Dosim ISSNコード：09583947/18734022
掲載区分	国外
巻・号・頁	46(4),pp.328-334
著者・共著者	Ohira S, Komiyama R, Koike Y, Washio H, Kanayama N, Inui S, Ueda Y, Miyazaki M, Koizumi M, Teshima T.
発行年月	2021
概要	To compare the effect of a contrast-enhanced (CE) agent on volumetric-modulated arc therapy plans based on four types of images-virtual monochromatic images (VMIs) captured at 70 and 140 keV (namely VMI70 and VMI140, respectively), water density image (WDI), and virtual non-contrast image (VNC) generated using a dual-energy computed tomography (DECT) system. A tissue characterization phantom and a multi-energy phantom were scanned, and VMI70, VMI140, WDI, and VNC were retrospectively reconstructed. For each image, a lookup table (LUT) was created. For 13 patients with nasopharyngeal cancer, non-CE and CE scans were performed, and volumetric-modulated arc therapy plans were generated on the basis of non-CE VMI70. Subsequently, the doses were re-calculated using the four types of DECT images and their corresponding LUTs. The maximum differences in the physical density estimation were 21.3, 5.2, -3.9, and 0.5% for VMI70, VMI140, WDI, and VNC, respectively. Compared with VMI70, the WDI approach significantly reduced (p < 0.05) the dosimetric difference due to the CE agent for the planning target volume (PTV) (D50%), whereas the difference was significantly increased for D1%. Except for PTV (D1%), the differences were significantly lower (p < 0.05) in the treatment plans based on VMI140 and VNC than that based on VMI70. For the VNC, the mean difference was less than 0.2% for all dosimetric parameters for the PTV. For patients with NPC, treatment plans based on the VNC derived from CE scan showed the best agreement with those based on the non-CE VMI70. Ideally, the effect of CE agent on dose distribution does not appear in treatment planning procedures.
DOI	10.1016/j.meddos.2021.03.006
PMID	33931321