Dosimetric Evaluation of Radiation Treatment Planning for Simultaneous Integrated Boost Technique Using Monte Carlo Simulation

Ravindra Shende; S J Dhoble; Gourav Gupta

doi:10.4103/jmp.jmp_4_23

Dosimetric Evaluation of Radiation Treatment Planning for Simultaneous Integrated Boost Technique Using Monte Carlo Simulation

J Med Phys. 2023 Jul-Sep;48(3):298-306. doi: 10.4103/jmp.jmp_4_23. Epub 2023 Sep 18.

Authors

Ravindra Shende^{1

2}, S J Dhoble², Gourav Gupta¹

Affiliations

¹ Department of Radiation Oncology, Balco Medical Centre, Raipur, Chhattisgarh, India.
² Department of Physics, RTM Nagpur University, Nagpur, Maharashtra, India.

Abstract

Monte Carlo (MC) techniques have been recognized as the gold standard for the simulation of radiation transport in radiotherapy. The aim of the study is to perform dosimetric evaluation of Simultaneous Integrated Boost (SIB) radiation treatment planning using MC simulation approach. The geometrical source modeling and simulation of 6 MV Flattening Filter Free (FFF)beam from TrueBeam linear accelerator have been carried out to simulate Volumetric Modulated Arc Therapy (VMAT) plans using MC simulation software PRIMO. All the SIB plans have been generated using VMAT techniques for patients with locally advanced postoperative head-and-neck squamous cell carcinoma in Eclipse Treatment Planning System (TPS) retrospectively. TPS plans have been compared against their respective MC-simulated plans in PRIMO. The quality assessments of plans have been performed using several dose volume parameters, plan quality indices, and methods of gamma analysis. D_mean, D_50%, and D_2% received by planning target volume (PTV), PTV₆₀, and PTV₅₂ have been found significantly lower in TPS-generated plans compared to MC-simulated plans. D_100%, D_98%, and D_95% received by PTV₆₀ exhibit good agreement. However, PTV₅₂ shows a significant deviation between TPS and MC plans. The mean organ-at-risk doses have been found significantly lower in TPS plans compared to MC plans. TPS and MC plans have been found in close agreement within gamma acceptance criteria of 3% Dose Difference (DD) and 3 mm Distance to Agreement (DTA). Dose distributions computed using MC simulation techniques are reliable, accurate, and consistent with analytical anisotropic algorithm. Plan quality indices have been found slightly compromised in MC-simulated plans compared with TPS-generated plans appeared to be a true representation of real dose distribution obtained from MC simulation technique. Validation using MC simulation approach provides an independent secondary check for ensuring accuracy of TPS-generated plan.

Keywords: Dosimetric evaluation; Monte Carlo; PRIMO simulation; radiation planning.