title: Scattered radiation from dental metallic crowns in head and neck radiotherapy.
abstract: We aimed to estimate the scattered radiation from dental metallic crowns during head and neck radiotherapy by irradiating a jaw phantom with external photon beams. The phantom was composed of a dental metallic plate and hydroxyapatite embedded in polymethyl methacrylate. We used radiochromic film measurement and Monte Carlo simulation to calculate the radiation dose and dose distribution inside the phantom. To estimate dose variations in scattered radiation under different clinical situations, we altered the incident energy, field size, plate thickness, plate depth and plate material. The simulation results indicated that the dose at the incident side of the metallic dental plate was approximately 140% of that without the plate. The differences between dose distributions calculated with the radiation treatment-planning system (TPS) algorithms and the data simulation, except around the dental metallic plate, were 3% for a 4 MV photon beam. Therefore, we should carefully consider the dose distribution around dental metallic crowns determined by a TPS.
authors.affiliation: Department of Radiological Technology, Nagoya University School of Health Sciences, 1-1-20 Daikohminami, Higashi-ku, Nagoya, Aichi 461-8673, Japan. shimo-p@umin.ac.jp
authors.forename: T
authors.initials: T
authors.lastname: Shimozato
authors.forename: Y
authors.initials: Y
authors.lastname: Igarashi
authors.forename: Y
authors.initials: Y
authors.lastname: Itoh
authors.forename: N
authors.initials: N
authors.lastname: Yamamoto
authors.forename: K
authors.initials: K
authors.lastname: Okudaira
authors.forename: K
authors.initials: K
authors.lastname: Tabushi
authors.forename: Y
authors.initials: Y
authors.lastname: Obata
authors.forename: M
authors.initials: M
authors.lastname: Komori
authors.forename: S
authors.initials: S
authors.lastname: Naganawa
authors.forename: M
authors.initials: M
authors.lastname: Ueda
mesh_terms: D000465:Algorithms; D002294:Carcinoma, Squamous Cell / Q000000981:diagnostic imaging / Q000532:radiotherapy*; D003198:Computer Simulation; D003442:Crowns; D006258:Head and Neck Neoplasms / Q000000981:diagnostic imaging / Q000532:radiotherapy*; D006801:Humans; D008670:Metals / Q000737:chemistry*; D009010:Monte Carlo Method; D019047:Phantoms, Imaging; D017785:Photons / Q000627:therapeutic use; D011829:Radiation Dosage; D011859:Radiography; D011874:Radiometry / Q000379:methods; D011880:Radiotherapy Planning, Computer-Assisted / Q000379:methods*; D011882:Radiotherapy, High-Energy / Q000009:adverse effects; D012542:Scattering, Radiation; D012680:Sensitivity and Specificity; D000077195:Squamous Cell Carcinoma of Head and Neck
chemical_list: D008670:Metals