Characterisation of a commercial flatbed scanner for external beam dose verification using EBT gafchromic and EDR2 films

Objective: The goal of this study was to evaluate the performance of an inexpensive Epson Perfection V700 flatbed scanner for film dosimetry. The scanner was tested with EBT Gafchromic and Kodak EDR2 films and compared with a Vidar VXR-16 Dosimetry Pro scanner - the recognized standard for film dosimetry. Material and Methods: Measurements were made at the CHUV in Lausanne and Clinique de Genolier in Genolier. Planar dose distributions with doses in the range 0.1 to 3.5 Gy were delivered to the EBT Gafchromic and EDR2 films in a solid water phantom. Sensitometric curves were determined for each scanner-film combination and then IMRT and percentage depth dose measurements were made. Results: The uniformity of the scanner response is discussed for the two films and both scanners. Differences in percentage depth dose measurements and sensitometric curves for the two films and scanners are shown. The limitations of each scanner for EBT Gafchromic or EDR2 film dosimetry are described. Conclusion: An inexpensive Epson Perfection V700 flatbed scanner can be used for EBT Gafchromic film dosimetry, for example for verifying planar dose distributions for individual patient IMRT QA.