AbstractID: 7997 Title: Dosimetric Characterization of Kodak Extended Dose Range Film in Megavoltage
Photon Beams
Film dosimetry is an attractive tool for the verification of dose distribution. A characterization of the newly released Kodak Extended
Dose Range film (EDR2) is presented in this study. The influence of the photon energy spectrum on the film sensitometric response,
caused by changing beam energies, field size and depth within a solid water phantom has been investigated for both 6 MV and 15 MV
photon beams from a linac. Additionally, we have compared the accuracy of EDR film versus XV film and ion chamber for relative
depth dose and profile measurements across a range of field sizes (3x3 cm2 - 25x25 cm2) and depths (dmax – 15 cm). The variation in
sensitometric response for EDR film as a function of field size and depth is observed to be similar to that of XV film; the optical
density varied on the order of 2% - 3% for the smaller field sizes. Measurements for a 25x25 cm2 showed consistently higher optical
densities at depth, with 4% - 5% differences noted at a depth of 15 cm. Depth doses and profiles conducted with EDR film showed
good agreement (2%/2 mm) with ion chamber measurements except for the 25x25 cm2 at depths greater than 15 cm. The results
indicate that EDR film may be a useful tool for quality assurance at higher dose ranges, such as encountered in stereotactic
radiosurgery and dose escalation in the context of intensity modulated radiotherapy (IMRT), a significant advantage over XV film.
Supported in part by NIH grant P01-CA59827.