title: A study on a dental device for the prevention of mucosal dose enhancement caused by backscatter radiation from dental alloy during external beam radiotherapy.
abstract: The changes in dose distribution caused by backscatter radiation from a common commercial dental alloy (Au-Ag-Pd dental alloy; DA) were investigated to identify the optimal material and thicknesses of a dental device (DD) for effective prevention of mucositis. To this end, 1 cm3of DA was irradiated with a 6-MV X-ray beam (100 MU) in a field size of 10 × 10 cm2using a Novalis TX linear accelerator. Ethylene vinyl acetate copolymer, polyolefin elastomer, and polyethylene terephthalate (PET) were selected as DD materials. The depth dose along the central axis was determined with respect to the presence/absence of DA and DDs at thicknesses of 1-10 mm using a parallel-plate ionization chamber. The dose in the absence of DDs showed the lowest value at a distance of 5 mm from the DA surface and gradually increased with distance between the measurement point and the DA surface for distances of ≥5 mm. Except for PET, no significant difference between the DA dose curves for the presence and absence of DDs was observed. In the dose curve, PET showed a slightly higher dose for DA with DD than for DA without DD for thicknesses of ≥4 mm. The findings herein suggest that the optimal DD material for preventing local dose enhancement of the mucosa caused by DA backscatter radiation should have a relatively low atomic number and physical density and that optimal DD thickness should be chosen considering backscatter radiation and percentage depth dose.
authors.affiliation: Division of Oral and Maxillofacial Radiology, Niigata University Graduate School of Medical and Dental Sciences, 2-5274 Gakkocho-dori, Chuo-ku, Niigata City, Niigata 951-8514, Japan katsu@dent.niigata-u.ac.jp.|Department of Oral Radiology, Niigata University Medical and Dental Hospital, 1-754 Asahimachi-dori, Chuo-ku, Niigata City, Niigata 951-8520, Japan.
authors.forename: Kouji
authors.initials: K
authors.lastname: Katsura
authors.affiliation: Department of Radiological Technology, Niigata University Graduate School of Health Sciences, 2-746 Asahimachi-dori, Chuo-ku, Niigata City, Niigata 951-8518, Japan.
authors.forename: Satoru
authors.initials: S
authors.lastname: Utsunomiya
authors.affiliation: Department of Radiology and Radiation Oncology, Niigata University Graduate School of Medical and Dental Sciences, 1-757 Asahimachi-dori, Chuo-ku, Niigata City, Niigata 951-8510, Japan.|Department of Radiation Oncology, Niigata University Medical and Dental Hospital, 1-754 Asahimachi-dori, Chuo-ku, Niigata City, Niigata 951-8520, Japan.
authors.forename: Eisuke
authors.initials: E
authors.lastname: Abe
authors.affiliation: Department of Radiation Oncology, Niigata University Medical and Dental Hospital, 1-754 Asahimachi-dori, Chuo-ku, Niigata City, Niigata 951-8520, Japan.
authors.forename: Hironori
authors.initials: H
authors.lastname: Sakai
authors.affiliation: Department of Radiation Oncology, Niigata University Medical and Dental Hospital, 1-754 Asahimachi-dori, Chuo-ku, Niigata City, Niigata 951-8520, Japan.
authors.forename: Naotaka
authors.initials: N
authors.lastname: Kushima
authors.affiliation: Department of Radiation Oncology, Niigata University Medical and Dental Hospital, 1-754 Asahimachi-dori, Chuo-ku, Niigata City, Niigata 951-8520, Japan.
authors.forename: Satoshi
authors.initials: S
authors.lastname: Tanabe
authors.affiliation: Department of Radiation Oncology, Niigata University Medical and Dental Hospital, 1-754 Asahimachi-dori, Chuo-ku, Niigata City, Niigata 951-8520, Japan.
authors.forename: Takumi
authors.initials: T
authors.lastname: Yamada
authors.affiliation: Department of Radiological Technology, Niigata University Graduate School of Health Sciences, 2-746 Asahimachi-dori, Chuo-ku, Niigata City, Niigata 951-8518, Japan.
authors.forename: Takahide
authors.initials: T
authors.lastname: Hayakawa
authors.affiliation: Department of Oral Radiology, Niigata University Medical and Dental Hospital, 1-754 Asahimachi-dori, Chuo-ku, Niigata City, Niigata 951-8520, Japan.
authors.forename: Yoshihiko
authors.initials: Y
authors.lastname: Yamanoi
authors.affiliation: Department of Oral Radiology, Niigata University Medical and Dental Hospital, 1-754 Asahimachi-dori, Chuo-ku, Niigata City, Niigata 951-8520, Japan.
authors.forename: Syuhei
authors.initials: S
authors.lastname: Kimura
authors.affiliation: Department of Radiological Technology, Niigata University Graduate School of Health Sciences, 2-746 Asahimachi-dori, Chuo-ku, Niigata City, Niigata 951-8518, Japan.
authors.forename: Shinichi
authors.initials: S
authors.lastname: Wada
authors.affiliation: Department of Radiology and Radiation Oncology, Niigata University Graduate School of Medical and Dental Sciences, 1-757 Asahimachi-dori, Chuo-ku, Niigata City, Niigata 951-8510, Japan.|Department of Radiation Oncology, Niigata University Medical and Dental Hospital, 1-754 Asahimachi-dori, Chuo-ku, Niigata City, Niigata 951-8520, Japan.
authors.forename: Hidefumi
authors.initials: H
authors.lastname: Aoyama
authors.affiliation: Division of Oral and Maxillofacial Radiology, Niigata University Graduate School of Medical and Dental Sciences, 2-5274 Gakkocho-dori, Chuo-ku, Niigata City, Niigata 951-8514, Japan.|Department of Oral Radiology, Niigata University Medical and Dental Hospital, 1-754 Asahimachi-dori, Chuo-ku, Niigata City, Niigata 951-8520, Japan.
authors.forename: Takafumi
authors.initials: T
authors.lastname: Hayashi
mesh_terms: D003722:Dental Alloys; D006046:Gold / Q000737:chemistry; D006801:Humans; D052016:Mucositis / Q000517:prevention & control; D010165:Palladium / Q000737:chemistry; D010315:Particle Accelerators; D019047:Phantoms, Imaging; D011093:Polyethylene Terephthalates / Q000737:chemistry; D011829:Radiation Dosage; D011835:Radiation Protection / Q000295:instrumentation*; D011878:Radiotherapy / Q000379:methods*; D011879:Radiotherapy Dosage; D011880:Radiotherapy Planning, Computer-Assisted; D012542:Scattering, Radiation; D012834:Silver / Q000737:chemistry
chemical_list: D003722:Dental Alloys; D011093:Polyethylene Terephthalates; D012834:Silver; D010165:Palladium; D006046:Gold
keywords: backscatter radiation; dental alloy; dental device; head and neck radiotherapy; oral mucositis