Fig. 4.

Output factors at a depth of 10 cm for IMRT– and SBRT–style fields from TrueBeam, as reported by IROC–H, and calculated with PRIMO using the DPM algorithm. The maximum differences of each field type between simulations and IROC–H data are 3.3% for IMRT 2×2 cm² field, and 3.2% for SBRT 2×2 cm² field. Uncertainty bars show (with k=2) the standard deviation of the IROC–H data, and the statistical uncertainty of the simulations. Data points are artificially separated along the horizontal axis for clarity