Effect of dental restorations and prostheses on radiotherapy dose distribution: a Monte Carlo study.
Dental restorations, fixed prosthodontics, and implants affect dose distribution in head and neck radiation therapy due to the high atomic number of the materials utilized. The backscatter of electrons from metallic materials due to the impinging treatment x-ray results in localized dose enhancements. These dose enhancements cause localized mucositis in patients who have dental work, a significant clinical complication. We investigated the backscatter effect of 23 configurations of dental work using the EGS4nrc Monte Carlo (MC) simulation system. We found that all-metal fixed partial dentures caused the highest amount of dose enhancement--up to 33%--while amalgam restorations did not cause a significant amount. Restorations with a ceramic veneer caused up to 8% enhancement. Between 3 mm and 5 mm of water-equivalent material almost completely absorbed the backscatter. MC simulations provide an accurate estimate of backscatter dose, and may provide patient-specific estimates in future.
Chin
David W H
DWH
Department of Radiation Oncology, Dana-Farber/Brigham and Women's Cancer Center and Harvard Medical School, Boston, MA, U.S.A.
Treister
Nathaniel
N
Dana-Farber/Brigham and Women's Cancer Center and Harvard School of Dental Medicine, Boston, MA, U.S.A.
Friedland
Bernard
B
Harvard School of Dental Medicine, Boston, MA, U.S.A.
Cormack
Robert A
RA
Department of Radiation Oncology, Dana-Farber/Brigham and Women's Cancer Center and Harvard Medical School, Boston, MA, U.S.A.
Tishler
Roy B
RB
Department of Radiation Oncology, Dana-Farber/Brigham and Women's Cancer Center and Harvard Medical School, Boston, MA, U.S.A.
Makrigiorgos
G Mike
GM
Department of Radiation Oncology, Dana-Farber/Brigham and Women's Cancer Center and Harvard Medical School, Boston, MA, U.S.A.
Court
Laurence E
LE
Department of Radiation Oncology, Dana-Farber/Brigham and Women's Cancer Center and Harvard Medical School, Boston, MA, U.S.A.
D003723:Dental Amalgam / Q000528:radiation effects; D003764:Dental Materials / Q000528:radiation effects; D003793:Dental Restoration, Permanent; D006258:Head and Neck Neoplasms / Q000532:radiotherapy*; D006801:Humans; D009010:Monte Carlo Method; D019736:Prostheses and Implants; D011879:Radiotherapy Dosage
D003764:Dental Materials; D003723:Dental Amalgam