title: The influence of the dose calculation resolution of VMAT plans on the calculated dose for eye lens and optic pathway.
abstract: To investigate the effect of dose calculation grid on calculated dose-volumetric parameters for eye lenses and optic pathways. A total of 30 patients treated using the volumetric modulated arc therapy (VMAT) technique, were retrospectively selected. For each patient, dose distributions were calculated with calculation grids ranging from 1 to 5 mm at 1 mm intervals. Identical structures were used for VMAT planning. The changes in dose-volumetric parameters according to the size of the calculation grid were investigated. Compared to dose calculation with 1 mm grid, the maximum doses to the eye lens with calculation grids of 2, 3, 4 and 5 mm increased by 0.2 ± 0.2 Gy, 0.5 ± 0.5 Gy, 0.9 ± 0.8 Gy and 1.7 ± 1.5 Gy on average, respectively. The Spearman's correlation coefficient between dose gradients near structures vs. the differences between the calculated doses with 1 mm grid and those with 5 mm grid, were 0.380 (p < 0.001). For the accurate calculation of dose distributions, as well as efficiency, using a grid size of 2 mm appears to be the most appropriate choice.
authors.affiliation: Department of Radiation Oncology, Seoul National University Hospital, Seoul, South Korea.|Institute of Radiation Medicine, Seoul National University Medical Research Center, Seoul, South Korea.|Biomedical Research Institute, Seoul National University College of Medicine, Seoul, South Korea.|Center for Convergence Research on Robotics, Advance Institutes of Convergence Technology, Suwon, South Korea.
authors.forename: Jong Min
authors.initials: JM
authors.lastname: Park
authors.affiliation: Department of Radiation Oncology, Seoul National University Hospital, Seoul, South Korea.|Institute of Radiation Medicine, Seoul National University Medical Research Center, Seoul, South Korea.|Biomedical Research Institute, Seoul National University College of Medicine, Seoul, South Korea.
authors.forename: So-Yeon
authors.initials: SY
authors.lastname: Park
authors.affiliation: Department of Radiation Oncology, Seoul National University Hospital, Seoul, South Korea.|Institute of Radiation Medicine, Seoul National University Medical Research Center, Seoul, South Korea.|Biomedical Research Institute, Seoul National University College of Medicine, Seoul, South Korea.
authors.forename: Jung-In
authors.initials: JI
authors.lastname: Kim
authors.affiliation: Program in Biomedical Radiation Sciences, Department of Transdisciplinary Studies, Graduate School of Convergence Science and Technology, Seoul, South Korea.
authors.forename: Joel
authors.initials: J
authors.lastname: Carlson
authors.affiliation: Department of Radiation Oncology, Seoul National University Hospital, Seoul, South Korea. jinho.kim.md@gmail.com.|Institute of Radiation Medicine, Seoul National University Medical Research Center, Seoul, South Korea. jinho.kim.md@gmail.com.|Biomedical Research Institute, Seoul National University College of Medicine, Seoul, South Korea. jinho.kim.md@gmail.com.
authors.forename: Jin Ho
authors.initials: JH
authors.lastname: Kim
mesh_terms: D004307:Dose-Response Relationship, Radiation; D006801:Humans; D007908:Lens, Crystalline / Q000528:radiation effects*; D011880:Radiotherapy Planning, Computer-Assisted; D050397:Radiotherapy, Intensity-Modulated; D014795:Visual Pathways / Q000528:radiation effects*
keywords: Dose calculation error; Dose calculation resolution; Eye lens dose; Optic pathway; Volumetric modulated arc therapy