title: Contribution of Cerenkov radiation in high-energy x-ray and electron beam film dosimetry using water-substitute phantoms.
abstract: The contribution of Cerenkov radiation in high-energy film dosimetry was investigated using commercially available water-substitute phantoms. Doses were evaluated using six phantoms: RMI-451, Mix-DP, WE-211, WE-Black, PMMA and PMMA-Black. The contribution of Cerenkov radiation was determined from the shielded and unshielded evaluation doses when a bare film was inserted into the phantom in a dark room and irradiated. For both x-ray and electron beams, Cerenkov radiation produced a phantom-dependent increase in the unshielded dose when compared with the shielded dose. We also found that the darker the phantom, the smaller the contribution of Cerenkov radiation. These results suggest that for film dosimetry using bare film, the accuracy of dose evaluation may be improved by using phantoms with high opacity.
authors.affiliation: Department of Radiological Sciences, Ibaraki Prefectural University of Health Sciences, 4669-2 Ami, Ibaraki, Japan.
authors.forename: Tatsuya
authors.initials: T
authors.lastname: Fujisaki
authors.forename: Hidetoshi
authors.initials: H
authors.lastname: Saitoh
authors.forename: Takeshi
authors.initials: T
authors.lastname: Hiraoka
authors.forename: Akio
authors.initials: A
authors.lastname: Kuwabara
authors.forename: Shinji
authors.initials: S
authors.lastname: Abe
authors.forename: Tetsuo
authors.initials: T
authors.lastname: Inada
mesh_terms: D016477:Artifacts; D004583:Electrons; D005373:Film Dosimetry / Q000295:instrumentation* / Q000379:methods*; D019047:Phantoms, Imaging / Q000592:standards; D011786:Quality Control; D011879:Radiotherapy Dosage; D011880:Radiotherapy Planning, Computer-Assisted / Q000295:instrumentation* / Q000379:methods*; D014867:Water; D014965:X-Rays
chemical_list: D014867:Water