Pages: 371-375

Authors: Arpad A. Toth, Milana S. Marjanović, Ivan V. Gencel, and Borislava S. Petrović

Abstract

The objective of this study was to analyze the dependence of the neutron dose from the geometry of the second band of the maze using dosimetric measurements of neutrons and Monte Carlo simulations, and based on those results to design a novel radiotherapy room layout. Measurements of the neutron dose at a two-band maze therapy room were performed for a 15 MeV photon beam only. Monte Carlo simulations were performed using the GEANT4 toolkit. In order to obtain the geometry dependence, we were changing the second band angle while we kept the length, height, and width the same as in reality. Results show that the highest calculated dose was obtained for the 60° angle of the second maze. It is 17 % higher than for standard 0° angle. For 30° it was 30 % smaller and for 90° was 10 % smaller. Although the lowest dose was obtained for 30° band angle with calculations, it is not very practical for clinical use. Clinically the most interesting would be the 90° angle which is practically a short three-band maze, which could be promising from the perspective of neutron radiation protection since it could offer a compact constructional solution, and better optimization of the available space.

Key words:radiotherapy, radiation protection, Monte Carlo method

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