Spectroscopic parametrization of dose-dependent changes in EBT3 film

This study aimed to establish an empirical relationship between the absorption spectrum of the EBT3 model GafChromic (R) film and absorbed radiation dose. Radiochromic films were irradiated with doses ranging from 1 Gy to 10 Gy using a Cobalt-60 Leksell Gamma Knife (R) Perfexion (TM) unit. Spectral analysis, conducted with the Agilent (R) Cary60 UV-Vis spectrometer 72 h post-irradiation, involved decomposing the net spectrum into nine Lorentzian components. Characteristic peaks remained stable within 5 nm, with the 583 nm and 635 nm absorption bands exhibiting a logistic response corresponding to the absorbed dose. Overall, the results present an empirical model showcasing dose-dependent spectrum evolution, emphasizing the potential of the ratio of two absorption band changes as a dose specifier. Furthermore, this spectroscopic approach provides key insights into radiation-induced optical changes in EBT3 films and facilitates the refinement of radiochromic film dosimetry.