A comprehensive study of the Gafchromic EBT2 radiochromic film. A comparison with EBT

Radiochromic film has become an important tool to assess complex dose distributions. In particular, EBT was accepted by the scientific community as a reference two-dimensional detector. Recently, Gafchromic EBT2 has replaced old film, providing new improvements in both accuracy and handling.

This work presents a dosimetric study of the new Gafchromic EBT2 using an Epson 10000XL flatbed scanner, also comparing the results with EBT film as reference when necessary. The most important film characteristics have been studied, such as ambient light sensitivity, different possibilities of the three RGB color channels, postirradiation development, high dose behavior, exposition at temperatures similar to the human body, and dependence on orientation during the scanning process.

The results obtained confirm a considerably lower sensitivity to ambient light of EBT2, as well as a fast stabilization of the film within 2 h. It has also been found that the green channel has a better behavior at high dose levels up to 35 Gy, in addition to good behavior of the red channel at doses below 10 Gy. Other features, such as temperature independence and scanning orientation dependence, have also been shown.

Gafchromic EBT2 can be used for clinical practice in the same way as the old EBT film. However, a much easier handling as the result of all new enhancements improves film behavior, expanding in this way the potential applications of radiochromic film dosimetry.