Evaluation of Annual Staff Doses and Radiation Shielding Efficiencies of Thyroid Shield and Lead Apron during Preparation and Administration of 131I, 81Kr, and 99mTc-Labeled Radiopharmaceuticals

Nayereh Khalili; Seyed Salman Zakariaee; Elahe Jazayeri Gharebaghi; Yalda Salehi; Vahid Changizi

doi:10.4103/jmss.JMSS_45_20

Evaluation of Annual Staff Doses and Radiation Shielding Efficiencies of Thyroid Shield and Lead Apron during Preparation and Administration of ¹³¹I, ⁸¹Kr, and ^99mTc-Labeled Radiopharmaceuticals

J Med Signals Sens. 2021 Dec 28;12(1):90-94. doi: 10.4103/jmss.JMSS_45_20. eCollection 2022 Jan-Mar.

Authors

Nayereh Khalili¹, Seyed Salman Zakariaee², Elahe Jazayeri Gharebaghi¹, Yalda Salehi³, Vahid Changizi¹

Affiliations

¹ Department of Radiology and Radiotherapy, Allied Medical Sciences School, Tehran University of Medical Sciences, Tehran, Iran.
² Department of Medical Physics, Faculty of Paramedical Sciences, Ilam University of Medical Sciences, Ilam, Iran.
³ Department of Nuclear Medicine, Vali-Asr Hospital, Tehran University of Medical Sciences, Tehran, Iran.

Abstract

Nuclear medicine technicians would receive unavoidable exposures during the preparation and administration of radiopharmaceuticals. Based on the staff dose monitoring, the dose reduction efficiencies of the radiation protection shields and the need to implement additional strategies to reduce the staff doses could be evaluated. In this study, medical staff doses during the preparation and administration of Tc-99 m, I-131, and Kr-81 radiopharmaceuticals were evaluated. The dose reduction efficiencies of the lead apron and thyroid shield were also investigated. GR-207 thermoluminescent dosimeter (TLD) chips were used for quantifying the medical staff doses. The occupational dose magnitudes were determined in five organs at risk including eye lens, thyroid, fingers, chest, and gonads. TLDs were located under and over the protective shields for evaluating the dose reduction efficiencies of the lead apron and thyroid shield. The occupational doses were normalized to the activities used in the working shifts. During preparation and injection of Tc-99 m radiopharmaceutical, the average annual doses were higher in the chest (4.49 mGy) and eye lenses (4 mGy). For I-131 radiopharmaceutical, the average annual doses of the point-finger (15.8 mGy) and eye lenses (1.23 mGy) were significantly higher than other organs. During the preparation and administration of Kr-81, the average annual doses of the point-finger (0.65 mGy) and chest (0.44 mGy) were higher. The significant dose reductions were achieved using the lead apron and thyroid shield. The radiation protection shields and minimum contact with the radioactive sources, including patients, are recommended to reduce the staff doses.

Keywords: Annual staff doses; lead apron; nuclear medicine; occupational dose; thermoluminescent dosimeter; thyroid shield.