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Updated: May 12, 2026
Irradiator Commissioning and Dosimetry for Assessment of LQ α and β Parameters, Radiation Dosing Schema, and in vivo Dose Deposition
Published on: March 11, 2021
Benchmarking a new radiochromic film type for photon and proton beam dosimetry
Peter Kuess1,2, Barbara Knäusl1,2,3, Sarah Helletzgruber1
1Department of Radiation Oncology, Medical University of Vienna, Währinger Gürtel 18-20, Vienna, A-1090, Austria.
Background And Purpose:
EBT4 Radiochromic films (RCFs) are replacing the well-described EBT3 type. This study aimed to benchmark the EBT4 type against its predecessor for photon (kV and MV) and proton beam dosimetry.
Materials And Methods:
Differences between the film types regarding the signal-to-noise ratio (SNR) were investigated in 6 MV photon and 148.2 MeV proton beams in the dose range of 0.2 Gy to 10 Gy for all RGB channels. The effect of the dose-averaged linear energy transfer (LET ) on the response of both film types was compared within a proton spread-out Bragg peak (SOBP). Furthermore, the relative response in low-kV X-rays was studied and the effect of long-term storage on both film types.
Results:
The SNR of EBT4 films was statistically superior for MV-photon irradiations above 1.5 Gy in the red channel by up to 29 %. For low-dose proton irradiations, the SNR of EBT3 was higher. The underresponse of both film types in a proton SOBP reached 5 to 7 %. In low kV X-ray beams, EBT4 deviated from EBT3 on average by 2.5 %. For irradiations of films with a dose of 2 Gy or less after 216 days of storage, smaller differences in terms of pixel values were observed for films placed at 10°C.
Conclusions:
The presented results are in accordance with recent studies on EBT4 films and extend the knowledge on this film type, especially regarding proton beams and film storage.
