title: Dynamic positioning accuracy of a novel multileaf collimator for volumetric modulated arc therapy.
abstract: We investigated the dynamic positioning accuracy of Agility (Elekta) for volumetric modulated arc therapy (VMAT). The accuracy of the multileaf collimator (MLC) leaf position during VMAT was evaluated using three different tests: (1) a dynamic multileaf collimator (DMLC) output test with various leaf speeds, and gantry angles; (2) a slit-fence test with and without gantry rotation; and (3) a complicated VMAT plans test with dose distributions compared with measurements using gamma analysis. The DMLC output was within 1.5 % under all test conditions. The agreement between the static and VMAT in the slit-fence test was within 0.5 mm. The pass rate of each complicated VMAT test plan was more than 93.9 % ± 0.36 for gamma analysis. We confirmed the dynamic positioning accuracy of Agility, which during VMAT delivery is within VMAT tolerances. The fastest MLC was found to have the potential to offer clinical advantages, such as high-quality rapid VMAT.
authors.affiliation: Department of Radiological Technology, Kumamoto University Hospital, 1-1-1 Honjyo, Kumamoto, Japan. nakaguchi@fc.kuh.kumamoto-u.ac.jp.
authors.forename: Yuji
authors.initials: Y
authors.lastname: Nakaguchi
authors.affiliation: Faculty of Life Sciences, Kumamoto University, 4-24-1 Kuhonji, Kumamoto, Japan.
authors.forename: Takeshi
authors.initials: T
authors.lastname: Ono
authors.affiliation: Graduate School of Health Sciences, Kumamoto University, 4-24-1 Kuhonji, Kumamoto, Japan.
authors.forename: Ryota
authors.initials: R
authors.lastname: Onizuka
authors.affiliation: Department of Radiological Technology, Kumamoto University Hospital, 1-1-1 Honjyo, Kumamoto, Japan.
authors.forename: Masato
authors.initials: M
authors.lastname: Maruyama
authors.affiliation: Department of Radiological Technology, Kumamoto University Hospital, 1-1-1 Honjyo, Kumamoto, Japan.
authors.forename: Yoshinobu
authors.initials: Y
authors.lastname: Shimohigashi
authors.affiliation: Department of Radiological Technology, Kumamoto University Hospital, 1-1-1 Honjyo, Kumamoto, Japan.
authors.forename: Yudai
authors.initials: Y
authors.lastname: Kai
mesh_terms: D019047:Phantoms, Imaging; D011880:Radiotherapy Planning, Computer-Assisted / Q000379:methods*; D050397:Radiotherapy, Intensity-Modulated / Q000295:instrumentation*
keywords: DMLC; Leaf position accuracy; Multileaf collimator; Quality assurance; Volumetric modulated arc therapy