ESTRO 2024 - Abstract Book

S3367

Physics - Detectors, dose measurement and phantoms

ESTRO 2024

Figure 1. Film measurement v.s. Monte Carlo simulation. A. Film measurement at phantom surface. B. MC simulation result. C. Minibeam Aperture. The piece is cut one-sided to allow access to the EDM wire cutting. The thickness of the aperture is 6 cm. D. profile plot of the film measurement and MC simulation. The profile is centered at the central slit peak. The peak dose is close to 20 Gy to ensure a valley dose >1 Gy. The peaks are numbered as 1-5 for easy reference of result reporting. Figure 2 shows the depth-dose profile with film placed in the beam direction. The plot of the peak-to-valley dose ratio (PVDR) with respect to the measurement depth in water is shown in Figure 2B, and the PVDR extracted from MC simulation is also shown in Figure 2B. The PVDR differences between measurements and MC simulations are all within 10%. This variation is consistent with the intrinsic PVDR measurement variation.

Figure 2. Depth-dose profile. A. Film measurement of a uniform 150MeV beam passing through the aperture. The film is stacked in solid water, and gantry at 90 degrees. B. Plot of PVDR of the dose in various depth, showing film measurement versus MC simulation.