Computational and Experimental Approaches for Evaluating Dose under a Block in TBI Geometry ()
ABSTRACT
Total Body Irradiation (TBI) patients are often
treated at extended distances of several meters, with blocking made from high-Z
materials placed close to the patients’ skin. Evaluating the dose under a block (e.g., for implanted medical device
shielding purposes) in such a geometry is challenging. We compare the performance of two commonly used dose
calculation algorithms, Anisotropic Analytical
Algorithm (AAA) and Acuros XB, with Optically Stimulated Lumine- scence (OSLD) and ion chamber measurements in
phantoms. The calculations and phantom measurements are also compared with in-vivo OSLD measure- ments. We find that OSLD and ion chamber
measurements in phantom are good predictors of in-vivo measurements, while both AAA and
Acuros XB sys- tematically overestimate the block transmission. We found Acuros XB to be
accurate enough for a rough upper estimate (dose under block overestimated by 7% - 22%), while for AAA the overestimate was more severe (90% - 110%); the reason is that AAA does not account for the increase in
pair production cro- ss-section in high-Z materials.
Share and Cite:
Russell, L. and Sillanpaa, J. (2022) Computational and Experimental Approaches for Evaluating Dose under a Block in TBI Geometry.
International Journal of Medical Physics, Clinical Engineering and Radiation Oncology,
11, 77-83. doi:
10.4236/ijmpcero.2022.111007.
Cited by
No relevant information.