ESTRO course Dose Modelling and Verification 2017

Detector composition: d) extracameral effects

Extra-cameral components refer to walls, electrodes, stems. These also affect detector response

Monte Carlo simulations of cavity dose response to 1.25MeV photon pencil beams with the cavity surrounded by a wall

Edge of cavity

Edge of cavity

Air cavity: 5mm radius, 2mm thick + graphite wall

Silicon cavity: 2mm radius, 2mm thick + aluminium wall

Extracameral perturbation effects can be significant in comparison to density perturbation effects

Bouchard et al, Med. Phys. 42 (10), 6048-61, Oct 2015