Monte-Carlo simulations of Al2O3 dosimetry in uniform MV photon beams: Influence of field and detector size

Abstract

This work was to evaluate the absorbed dose to different sizes Al 2 O 3 dosimeter in uniform MV photon beams using Monte Carlo simulation. The absorbed dose ratio factor f md of Al 2 O 3 dosimeters was calculated. The incident beams included 4 MV–24 MV X-rays using Mohan's spectra with different field sizes. Results show that the maximum variation of f md due to different dosimeter sizes is 5%. As the field diameter increases from 1 cm to 3 cm, the difference of f md can be up to 8%. The results of this work show that the effect of dosimeter size and the field size can't be neglected when using Al 2 O 3 dosimeter. ► Evaluate the absorbed dose to Al 2 O 3 dosimeter for radiotherapy beams. ► The effect of dosimeter size and field size can't be neglected. ► More attention should be paid when using an Al 2 O 3 dosimeter in small field.