Fogging effect correction of Gafchromic HD-V2 film response for its use in high-dose radiotherapy

GAFChromic® HD-V2 film is a reliable dose measurement device, thin, flexible, inexpensive, simple to use and easy to analyze. The response in terms of net absorbance with respect to absorbed dose was found to be linear in a large dose range, which supports the feasibility of using the film dosimeters in many applications, such as radiotherapy. For its use, a \"fogging\" effect must be take into account since film response changes with time. To determine a calibration curve valid for any time, fogging effect was investigated for more than 400 days. A correction procedure allows the use of HD-V2 film dosimeters in high-dose radiotheraphy, as brachytherapy, and quality assurance (QA) procedures.