Abstract
Background and Aims:
This study at Atomic Energy Medical Center Karachi (AEMCK) marks the first-ever implementation of ring thermoluminescent dosimeters (TLDs) in 2020 for extremity dose monitoring of Nuclear Medicine employees. It aimed to assess finger doses during radiopharmaceutical preparation/administration and evaluate compliance with radiation protection standards.
Methods:
Five Nuclear Medicine technologists (two workers from the Hot Laboratory, two from the Gamma Camera, and one from the Stress Laboratory) wore ring TLDs on the dominant hand’s index/ring finger base for monthly cycles over the period (2020–2021). Doses measured skin equivalent at Hp(0.07). TLDs calibrated with Cs-137 in a Secondary Standard Dosimetry Laboratory at KANUPP-1. Statistical analysis used Microsoft Excel and the t-test distribution.
Result:
Hot Laboratory staff showed higher mean finger doses (58.79 ± 30.48 mrem) than Gamma/Stress Laboratory staff (18.19 ± 7.30 mrem), with a significant difference (p = 0.000238). The maximum monthly dose was 110 mrem. All doses remained well below the 50,000 mrem/year (500 mSv/year) extremity limit.
Conclusion:
The study highlights the importance of continuous extremity dose monitoring in nuclear medicine practice. All measured doses across different areas were within permissible limits; adopting protective measures such as syringe shields, short-tubing butterfly cannulas, staff rotation, and simulated training can further optimize safety. Regular extremity monitoring is strongly recommended across Atomic
Energy Cancer Hospitals (AECHs).

Key words: Occupational radiation exposure; Extremity dose monitoring; Ring thermoluminescent dosimeter (TLD); Nuclear medicine personnel' Finger dose' Radiation protection