[Research on the impact of metal implants with different materials on radiation dose distribution].

Objective: To investigate the impact of metal implants with different materials on radiation dose distribution based on film measurement method.

Methods: Titanium plate, titanium intramedullary pin and stainless steel plate were set into phantom and irradiated separately by 6 MV and 15 MV X ray from linear accelerator. Dose distributions derived from different materials metal implants were measured and analyzed by film dosimeter.

Results: For 6 MV X ray, the maximum interface dose increments of titanium plate, titanium intramedullary pin and stainless steel plate were 12.3%, 15.4% and 20.3%. As the radiation energy was increased from 6 MV to 15MV, the maximum interface dose increment of the titanium plate rose from 12.3% to 15.1%, the maximum interface dose increment of the steel plate rose from 20.3% to 30.8%.

Conclusions: Metal implants with different materials have obvious impact on radiation dose distribution. With the increase of the metal atomic number and energy of radiation, the degree of elevated dose also increases. These results suggest that correction of dose distribution is required for radiotherapy of patients with metal implants.