Clinical application of GAFCHROMIC® EBT film for in vivo dose measurements of total body irradiation radiotherapy

The GAFCHROMIC® EBT film model is a fairly new film product designed for absorbed dose measurements of high-energy photon beams. In vivo dosimetry for total body irradiation (TBI) remains a challenging task due to the extended source-to-surface distance (SSD), low dose rates, and the use of beam spoilers. EBT film samples were used for dose measurements on an anthropomorphic phantom using a TBI setup. Additionally, in vivo measurements were obtained for two TBI patients. Phantom results verified the suitability of the EBT film for TBI treatment in terms of accuracy, reproducibility, and dose linearity. Doses measured were compared to conventional dosimeter measurements using thermoluminescent dosimeters (TLDs), resulting in an agreement of 4.1% and 6.7% for the phantom and patient measurements, respectively. Results obtained from the phantom and patients confirm that GAFCHROMIC® EBT films are a suitable alternative to TLDs as an in vivo dosimeter in TBI radiotherapy.