ディジタルカメラを用いた呼吸波形の変化による動体追尾照射精度の検証

• Published in: Nippon Hōshasen Gijutsu Gakkai zasshi Vol. 74; no. 3; pp. 262 - 269
• Main Authors: 榎﨑, 翼, 津田, 信太朗, 三浦, 英治, 早田, 将博, 山田, 聖, 小澤, 修一, 川久保, 淳, 永田, 靖
• Format: Journal Article
• Language: Japanese
• Published: Kyoto 公益社団法人 日本放射線技術学会 2018; Japan Science and Technology Agency
• Subjects: 4D-model; Accuracy; Cameras; Digital cameras; Dithiothreitol; Modelling; quality assurance; Radiation therapy; Respiration; tracking accuracy; Tracking errors; Tumors; Visual task performance
• ISSN: 0369-4305; 1881-4883
• DOI: 10.6009/jjrt.2018_JSRT_74.3.262

It is important for high-precision radiation therapy that tracking accuracy in dynamic tumor tracking (DTT) using the gimbal X-ray head. We evaluated the tracking accuracy under various respiratory patterns differ from a correlation model [four-dimensional model (4D-model)] in real-time using a digital camera. A sheet of paper with luminous line was placed on the programmable respiratory motion table (CIRS Inc.) and operated with the laser projector. The luminous line was defined as a target and the laser was defined as a gimbal. Motion table was operated at a period of 4 s and amplitude of ±10 mm to create 4D-modeling. This movement was defined as the basic operation. To investigate the tracking accuracy, target and gimbal positions were recorded using a digital camera under amplitudes (±5–20 mm) and periods (2–8 s) and analyzed by ImageJ software (NIH). The maximum tracking errors under various period and amplitude were 1.7–0.9 mm and 0.4–1.9 mm, respectively. From the creation of 4D-modeling, it was confirmed that when the period has shortened and the amplitude has increased, tracking accuracy was reduced.