External Exposure to Veterinary Staff and Pet Owners from ¹⁸F-fluorodeoxyglucose (¹⁸F-FDG) Positron Emission Tomography

Abstract

External exposure to veterinary staff and pet owners from 18 F-fluorodeoxyglucose positron emission tomography ( 18 F-FDG, dose 170±33 MBq/head) in veterinary nuclear medicine was measured by monitoring the surface (SDR) and ambient dose rates (ADR) from animal patients (dogs and cats). The patientsʼ weights ranged from 4.2 to 32.3 kg (11±9.4 kg). The highest SDR was at the ventral abdomen, and its SDR time course was within the degradation curve with a physical half-life (109.8 min). ADR demonstrated a significant decrease up to approximately 30-to 80-fold by keeping a 100-cm distance from the patient. The estimated occupational radiation dose from the FDG injection before sedation was higher than the dose received from the FDG injection after general anesthesia. All patients showed acceptable SDRs, which was less than 3.8 µSv/h at 24 h post-injection, where cumulative SDR until infinity was less than 1/100 of the limit of the yearly external public exposure (1 mSv/year) which recommended in ICRP publication 103. According to the current legislation in Japan, these results represent an overregulation of detention 24 h after FDG injection in the case of an adequate lower maximum SDR.

ICRP Publication 153: Radiological Protection in Veterinary Practice

“…Although additional study is warranted, interest in modelling and/or measuring doses to owners/handlers from veterinary nuclear medicine procedures has seemingly increased over the past few years (e.g. Davila, 2019; Wendt et al., 2020; Arno and Smith, 2021; Smith and Krimins, 2022; Suwannasaeng et al., 2022). (144) If exposure of an owner/handler is deemed justified based on the prevailing circumstances, dose constraints should be used, potentially set above the public dose limit, to guide the associated optimisation of protection in a proportionate, practical way, noting that children and individuals not engaged in direct comforting or care should be treated as members of the public (subject to the public dose limit of 1 mSv year −1 ), consistent with human medicine (ICRP, 2007a).…”

“…Although additional study is warranted, interest in modelling and/or measuring doses to owners/handlers from veterinary nuclear medicine procedures has seemingly increased over the past few years (e.g. Davila, 2019;Wendt et al, 2020;Arno and Smith, 2021;Smith and Krimins, 2022;Suwannasaeng et al, 2022).…”