Radiotherapy dose distribution in patients with metal implants - application of the Monte Carlo method

The Monte Carlo method was applied to the calculation of the absorbed dose of a high-energy photon beam during radiotherapy of a tissue with a metallic material. Two materials, viz. iron and titanium, were used, and two radiation energies, 6 MV and 16 MV, were applied. The dose increase at the water-metal proximal junction did not exceed 30% and dropped rapidly with increasing distance from the junction. Except for the high-energy beam - iron combination, a shadow was apparent behind the metal. The higher energy level was associated with a lower dose inhomogeneity. This dose inhomogeneity, which is relatively low and limited in volume, can be additionally reduced in several ways, owing to which the indicated radiotherapy can be applied in such cases with a minimal risk