Dosimetric characterisation of commercial optically stimulated luminescence and tin-filtered radiophotoluminescence glass dosimeters for accurate radiation dose measurement in general radiography

Abstract

Background

Accurate radiation dose measurements rely on well-characterised dosimeter properties. This study investigated the characteristics of optically stimulated luminescence dosimeters (OSLD) and tin-filtered radiophotoluminescence glass dosimeters (RPLGD) in measuring incident air kerma (K_i), entrance surface air kerma (K_e), and absorbed dose (D) during general X-ray imaging.

Methods

We evaluated the radiation sensitivity and signal stability of OSLD and RPLGD. Their linear responses across doses from 0.5–7.0 mGy, energy dependence between 60 and 120 kVp, and variability in accumulated dose measurements were characterised using an ionisation chamber under K_i, K_e, and D measurement conditions.

Results

The sensitivity correction factors for OSLD and RPLGD ranged from 0.96 to 1.04 (CoV: 1.99 %) and 0.90–1.06 (CoV: 3.75 %), respectively. Signal depletion per reading was −0.40 ± 0.11 % for OSLD and −0.03 ± 0.04 % for RPLGD. Over 60 days, signal fading was −6.83 ± 0.40 % for OSLD and −2.70 ± 0.20 % for RPLGD. Both dosimeters showed excellent dose–response linearity (R² > 0.995), with correction factors of 0.98–1.01 (CoV: 1.20 %) for OSLD and 1.01–1.05 (CoV: 1.95 %) for RPLGD. Beam quality correction factors ranged from 0.93 to 1.14 (CoV: 5.76 %) for OSLD and 0.87–1.07 (CoV: 5.36 %) for RPLGD, relative to 80 kVp calibration in K_i condition. Reproducibility of accumulated dose readings across nine fractions was within 2.32 % and 7.96 % for OSLD and RPLGD.

Conclusions

OSLD demonstrated superior uniformity and greater reproducibility in accumulated measurements of K_i, K_e, and D, whereas RPLGD exhibited enhanced signal stability. Both dosimeters displayed distinct characteristics, underscoring the importance of applying correction factors for accurate radiation dose measurement.