Patent ID: 8604415

Claim:
A radiation dosimetry method comprising: (a) providing a radiation dosimetry calibration film comprising a substrate and a layer of radiation-sensitive material disposed on said substrate wherein said radiation-sensitive material comprises a radiation-sensitive active component and a radiation-impervious material; (b) exposing discrete areas of said radiation dosimetry calibration film to known doses of radiation; (c) scanning said exposed radiation dosimetry calibration film in a plurality of color response channels to generate a digital image, I C ; with responses in a plurality of component color channels; (d) measuring said digital image I C to determine the scanner response values of the exposed areas in each component color channel; (e) determining dosimetry film calibration curves for each component color channel by plotting said scanner response values in each component color channel versus the corresponding dose values and fitting the data to a mathematical function expressing the dose values as a function of the scanner response values; (f) providing a radiation dosimetry measurement film comprising a substrate and a layer of radiation-sensitive material disposed on said substrate wherein said radiation-sensitive material comprises a radiation-sensitive active component and a radiation-impervious material; scanning the radiation dosimetry measurement film in a plurality of color response channels, said measurement film comprised of areas exposed to a pattern of radiation dose to generate a digital image, I M ; with responses in a plurality of component color channels; (g) applying said dosimetry film calibration curves to divide the responses at each location and each component color channel comprising the digital image of the measurement film into a dose dependent portion comprising a plurality of dose dependent values that are dependent on radiation dose and a dose independent portion comprising a plurality of dose independent values that are independent of radiation dose using a plurality of calibration curves so that the differences between the radiation dose values in the component color channels are minimized; (h) using said dose dependent values and said dose independent values to generate a dose map and relative thickness map of said radiation dosimetry measurement film; (i) using said dose dependent values and said dose independent values to generate a map of the signal noise contained in said dose map of said radiation dosimetry measurement film; (j) determining a correction function to remove said signal noise from said dose map of the radiation dosimetry measurement film; and (k) applying said correction function to provide a corrected dose map which accounts for variations in thickness of the layer of radiation sensitive material.