Calculation of Dose Perturbation in Radiotherapy of Head and Neck Tumors Due to the Presence of Dental Implants: A Monte Carlo Study

Morteza  Hashemizadeh; Nasim  Shams; Mansour  Zabihzadeh; Masoud  Jamali; Zeinab  Sedaghat; Omid  Azadbakht

doi:10.18502/fbt.v11i4.16514

Morteza Hashemizadeh Department of Medical Physics, School of Medicine, Ahvaz Jundishapur University of Medical Sciences, Ahvaz, Iran
Nasim Shams Department of Oral and Maxillofacial Radiology, School of Dentistry, Ahvaz Jundishapur University of Medical Sciences, Ahvaz, Iran
Mansour Zabihzadeh Department of Medical Physics, School of Medicine, Ahvaz Jundishapur University of Medical Sciences, Ahvaz, Iran
Masoud Jamali Radiation Oncologist, Technical Manager in Sarerm Hospital, Tehran, Iran
Zeinab Sedaghat Department of Medical Physics, School of Medicine, Ahvaz Jundishapur University of Medical Sciences, Ahvaz, Iran
Omid Azadbakht Department of Radiology Technology, Behbahan Faculty of Medical Sciences, Behbahan, Iran

DOI: https://doi.org/10.18502/fbt.v11i4.16514

Keywords: Dental Implant; Dose Distribution; Electron Therapy; Monte Carlo Calculation; Radiotherapy; Head and Neck Tumors.

Abstract

Purpose: The presence of a dental implant across the irradiation beam has the potential to perturb the dose distribution. In this study, the effect of different commercial dental implants on dose distribution was investigated in electron beam therapy.

Materials and Methods: The Varian 2100 C/D linear accelerator (Linac) head was modeled precisely with proper components for electron mode (6 and 9 MeV) by MCNPX 2.6.1 and was benchmarked according to the International Atomic Energy Agency (IAEA) protocol, TRS -398. Dose distribution was calculated for Six different implant materials, including Titanium, Titanium alloy, Zirconia (Y-TZP), Zirconium oxide, Alumina, and PolyetherEtherKetone (PEEK), and for Four different scenarios.

Results: The highest and lowest increasing doses occurred for Y-TZP (114.44% and 108.69% for 6 and 9 MeV, respectively) and PEEK (104.85% and 98.84% for 6 and 9 MeV, respectively) directly in front of the implant, respectively. By removing an implant from the jaw, an increasing dose was not seen, but an increasing dose occurred behind its depths in the bone region (31.81 %).

Conclusion: The amount of dose perturbation due to the dental implant's presence depends on the beam energy, mass density, and atomic numbers of implants. Maximum and minimum increased doses were estimated for Y-TZP and PEEK implants, respectively. Considering the correction factors due to the presence of high density and atomic number dental implants are essential to estimate the accurate dose delivery in radiotherapy with electron beams.