Speaker
Description
Cyclotron facilities are essential for the production of medical radionuclides, including ¹⁸F, ¹¹C, ¹³N, and ¹⁵O, which are widely used in positron emission tomography (PET) imaging. However, cyclotron operation involves high-energy particle acceleration and target irradiation, generating complex radiation fields and potential occupational hazards. Therefore, continuous monitoring of occupational radiation exposure in cyclotron facilities is necessary to ensure compliance with national and international radiation protection standards and to minimize the risk of radiogenic effects. Although cyclotron personnel including engineers, chemists, radiochemists, and radiopharmacists may receive comparatively higher radiation doses, limited studies have comprehensively reported their exposure levels. The objective of this study was to evaluate annual occupational exposure among cyclotron workers over the past five years. Annual effective doses for 52 workers were monitored using whole-body dosimeters at King Faisal Specialist Hospital and Research Centre, Riyadh, Saudi Arabia. The department operates three cyclotrons: CS-30 (26.7 MeV), RDS Eclipse (11 MeV), and IBA Cyclone 30 (30 MeV).The mean annual effective dose was 3.92 ± 2.73 mSv (range: 0.1–11.0 mSv), with a median of 3.22 mSv. Approximately 75% of workers received less than 4.8 mSv annually, indicating well-controlled occupational exposure. A small subgroup recorded higher doses (7.0–11.0 mSv), likely associated with direct cyclotron operation, target handling, and radiopharmaceutical processing. The five-year cumulative dose averaged 5.00 ± 4.22 mSv (0.13–16.73 mSv), while the total lifetime cumulative dose was 21.35 ± 36.86 mSv (0.13–201.76 mSv). The distribution showed moderate positive skewness, reflecting variability in job responsibilities. Importantly, no worker exceeded the annual occupational limit of 20 mSv.