title: Verification of in-treatment tumor position using kilovoltage cone-beam computed tomography: a preliminary study.
abstract: Three-dimensional tumor position during rotational dose delivery was evaluated by acquiring in-treatment kilovoltage (kV) cone-beam CT (CBCT) to ensure treatment quality. The CBCT projection data of a phantom were acquired during rotational megavoltage (MV) dose delivery up to 6 Gy to evaluate image quality under MV beam irradiation. A lung tumor patient was treated with a total dose of 48 Gy in four fractions, each fraction including seven coplanar and noncoplanar beams, as well as a full-angle rotational beam. Tumor registration was performed between a planning CT image and a CBCT image immediately after patient setup. The patient couch was adjusted according to the registration results, and then the registration was repeated three times: immediately before treatment, during treatment, and immediately after treatment. The phantom image quality of the kV CBCT was not visually degraded up to the rotational MV dose of 6 Gy. Tumor position during rotational dose delivery was verified for the first time using kV CBCT.
authors.affiliation: Department of Radiology, University of Tokyo Hospital, Tokyo, Japan. k-nak@fg7.so-net.ne.jp
authors.forename: Keiichi
authors.initials: K
authors.lastname: Nakagawa
authors.forename: Hideomi
authors.initials: H
authors.lastname: Yamashita
authors.forename: Kenshiro
authors.initials: K
authors.lastname: Shiraishi
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Igaki
authors.forename: Atsuro
authors.initials: A
authors.lastname: Terahara
authors.forename: Naoki
authors.initials: N
authors.lastname: Nakamura
authors.forename: Kuni
authors.initials: K
authors.lastname: Ohtomo
authors.forename: Shigeki
authors.initials: S
authors.lastname: Saegusa
authors.forename: Takashi
authors.initials: T
authors.lastname: Shiraki
authors.forename: Takashi
authors.initials: T
authors.lastname: Oritate
authors.forename: Kiyoshi
authors.initials: K
authors.lastname: Yoda
mesh_terms: D054893:Cone-Beam Computed Tomography / Q000379:methods* / Q000592:standards; D005240:Feasibility Studies; D006801:Humans; D008175:Lung Neoplasms / Q000000981:diagnostic imaging* / Q000532:radiotherapy; D010315:Particle Accelerators; D019047:Phantoms, Imaging / Q000592:standards*; D011785:Quality Assurance, Health Care; D011879:Radiotherapy Dosage; D011880:Radiotherapy Planning, Computer-Assisted / Q000379:methods