Five-Year Occupational Radiation Exposure of Nuclear Medicine Personnel: Whole-Body, Skin, Estimated Eye Lens, and Extremity Dosimetry in Southwestern Hospital of Saudi Arabia

Occupational radiation exposure in nuclear medicine (NM) is heterogeneous because personnel handle unsealed radionuclides and work near injected patients. This five-year retrospective study characterised whole-body Hp(10), whole-body Hp(0.07), ring Hp(0.07), and estimated eye-lens Hp(3) in six NM staff over 20 quarterly monitoring cycles (2020–2024). TLD-100 whole-body and ring dosimeters were analysed, and Hp(3) was estimated from collar-level Hp(0.07), with two alternative surrogates examined in sensitivity analyses. Temporal trends were assessed using mixed-effects models supported by worker-cluster bootstrap, log-transformed, Winsorised, and Benjamini–Hochberg-adjusted analyses. A total of 120 quarterly measurements per quantity were available. Mean annual doses were 1.3 ± 0.44 mSv for Hp(10), 1.4 ± 0.37 mSv for Hp(0.07), 1.4 ± 0.37 mSv for estimated Hp(3), and 4.3 ± 3.8 mSv for ring Hp(0.07). All doses remained well below ICRP limits. Ring dose showed a robust downward trend across sensitivity analyses, whereas the Hp(10) decline was directionally suggestive but statistically fragile under small-cluster inference; Hp(0.07) remained stationary. The low ring-to-Hp(10) ratio and low estimated Hp(3) values support continued ALARA optimisation, while the observed inter-individual variability identifies extremity handling as a priority for future monitoring.