Far infrared for decreasing surface radiation dose of phantom with EBT film dosimetry

Purpose: The skin-sparing advantage of high-energy X-rays is degraded by secondary low energy electrons, which increase the surface dose and shift the position of the maximum dose towards the surface. Studies of mounting purging magnet and helium gas replacing air on the linear accelerator to sweep secondary electrons have been conducted and published. This study describes the amount of low energy electron contamination generated by a clinical photon beam from medical linear accelerator can be reduced by projecting specific wavelength (17,000 nm) of Far Infrared (FIR) to the irradiating area simultaneously. Specific wavelength of FIR can decrease the absorption of low energy contamination electrons in the build-up region.