Year: 2025
Type: article
Abstract: BACKGROUND: Dose calculation around inhomogeneities is challenging for many algorithms. A validation of dose distributions in these conditions is not straightforward, as detector response close to material interfaces is affected by the non-equilibrium situation, the changing energy spectrum and the volume effect in a steep dose gradient. PURPOSE: Detector response lateral to an inhomogeneity of high density was studied, mimicking the situation of bone surrounded by soft tissue. METHODS: Profiles obtained with different detectors (diodes, ion chamber, synthetic diamond) in water in the vicinity of an aluminum cylinder were compared. Dose deposition was also calculated with different commercial treatment planning systems and algorithms as well as using Monte Carlo simulations within and lateral to the cylinder and compared to measurements. RESULTS: at 3 mm distance from the cylinder surface (2.5%), followed by the synthetic diamond (1.7%), then the unshielded (1.4%) and finally the shielded diode (1.0%). Dose calculated by different commercial dose engines differed up to 3% at that point from the detector values (Collapsed Cone). CONCLUSIONS: Dose calculation near inhomogeneities depends on the used algorithm, dose measurements in the same region differ depending on the detector type used. We recommend verification of dose calculation with second type of algorithm and measurements with at least two detector types.
DOI: 10.1002/acm2.70302
Institution: Universitätsklinikum Würzburg
Language: English
Subfield: Radiation
Field: Physics and Astronomy
Domain: Physical Sciences
Open Access status: gold
Estimated APC paid: $900
OpenAlex ID: W4415396985