Investigation of the beam width and profile of kilovoltage CBCT using different measurement techniques and analysis of the dosimetric effects of beam parameters

The measured CTDI coefficients were higher than predicted by the manufacturer for all cases. The currently internationally recommended CTDI measurement protocols for CBCT contain no reference to the determination of the beam width as a basic element of the calculations. Based on our measurement results, the beam width parameters affect CTDI: therefore, it would be advisable to apply this type of correction.