ESTRO 2024 - Abstract Book

S3277

Physics - Detectors, dose measurement and phantoms

ESTRO 2024

Results:

Maximum differences in PTV mean dose of 0.4 cGy (for a 2Gy fraction) were observed when comparing dose distributions in selected structures with and without IVFD. The comparison between the measured and calculated doses for 3 simple plans (zero gantry angle) and 6 VMAT plans, each repeated 3 times, is shown in Table 1. The rigorously defined uncertainty of dose measurement is less than 1.7% (1 standard deviation). The average difference obtained for all simulated geometries and real VMAT plans was 1.9%. The maximum single measurement difference was 3.8% (the absolute value).

Conclusion:

Dose can be measured with high accuracy for dynamic techniques using the film detector designed for in vivo measurements. The presence of the detector has a negligible effect on the dose distribution. The information stored on the detector is permanent proof of the correctness of the therapy.