Evaluation of the Blue Physics plastic scintillation detector performances compared to other detectors in radiation dosimetry.

PURPOSE: This study aims to characterize a Plastic Scintillation Detector (PSD), developed by Blue Physics (BP-PSD), and to compare its performance with that of other available detectors in radiation dosimetry. MATERIAL AND METHODS: Data have been collected in 6MV flattening-filter (WFF) and flattening-filter-free (FFF) photon beams from an Elekta Versa HD linear accelerator and using the IBA water tank. BP-PSD calibration procedure, linac output stability and dose-rate dependence have been studied. Percent Depth Dose (PDD) and Off Axis Ratio (OAR) distributions have been measured with BP-PSD for both small (0.6 × 0.6 cm2, 1 × 1 cm2, 2 × 2 cm2 and 3 × 3 cm2) and standard fields (5 × 5 cm2, 10 × 10 cm2 and 30 × 30 cm2) as well as Field Output Factors (FOFs). PDDs, OARs and FOFs in small fields have been compared with those measured with suitable detectors: PTW microDiamond, IBA Razor and EFD3G diodes. RESULTS: Linac output stability measured with the BP-PSD is maintained within 5% for doses above 3 MU, while non-linearities are observed at lower MU. Dose-rate dependence results in variations below 1.5% in the analyzed dose rate interval (from 100 MU/min to 1400 MU/min). Differences in the PDDs and OARs curves between investigated detectors are compatible with measurement errors for WFF and FFF beams. For small fields, BP-PSD provides suitable FOFs values without any correction factor. CONCLUSIONS: This study demonstrates that the BP-PSD is promising for its characteristics and it is suitable for standard and small field dosimetry in WFF and FFF beams, with no significant differences in terms of dose responses.