MOSFET detectors as a tool for dose verification in photon beam radiotherapy

Abstract

Purpose

Application of MOSFET detectors in photon beam dose measurements in vivo in radiotherapy.

Materials and methods

Before measuring doses in vivo the following parameters such as: the dosimeter response to dose absorption, temperature, gantry angles and field side changes were determined using 6MV and 15MV photon beams. All measurements were made in a phantom to investigate the MOSFET accuracy, in electron equilibrium with a 0.6 cm³ Farmer ionization chamber.

Results

MOSFET parameters are presented in graphs. The conformity between the planned dose and the dose measured in vivo within ±5% was observed in 86% of patients treated with 6MV photon beams and 91% patients treated with 15MV, respectively (SD=3.5%).

Conclusions

MOSFET detectors are a useful tool for verifying the planned dose in external photon radiotherapy.