A Monte Carlo study of organ and effective doses of cone beam computed tomography (CBCT) scans in radiotherapy
Cone-beam CT (CBCT) scans utilised for image guided radiation therapy (IGRT) procedures have become
an essential part of radiotherapy. The aim of this study was to assess organ and effective doses
resulting from new CBCT scan protocols (head, thorax, and pelvis) released with a software upgrade
of the kV on-board-imager (OBI) system. Organ and effective doses for protocols of the new software
(V2.5) and a previous version (V1.6) were assessed using Monte Carlo (MC) simulations for the
International Commission on Radiological Protection (ICRP) adult male and female reference
computational phantoms. The number of projections and the mAs values were increased and the size of
the scan field was extended in the new protocols. Influence of these changes on organ and effective
doses of the scans was investigated. The OBI system was modelled in EGSnrc/BEAMnrc, and organ doses
were estimated using EGSnrc/DOSXYZnrc. The MC model was benchmarked against experimental
measurements. Organ dos...
Source: Journal of Radiological Protection - Category: Physics Authors: Abdullah Abuhaimed, Colin J Martin and Marimuthu Sankaralingam Source Type: research