Verification of in-treatment tumor position using kilovoltage cone-beam computed tomography: a preliminary study.
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.
Nakagawa
Keiichi
K
Department of Radiology, University of Tokyo Hospital, Tokyo, Japan. k-nak@fg7.so-net.ne.jp
Yamashita
Hideomi
H
Shiraishi
Kenshiro
K
Igaki
Hiroshi
H
Terahara
Atsuro
A
Nakamura
Naoki
N
Ohtomo
Kuni
K
Saegusa
Shigeki
S
Shiraki
Takashi
T
Oritate
Takashi
T
Yoda
Kiyoshi
K
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