A practical individualized radiation precaution based on the dose rate at release time after inpatient 131I ablation therapy

For DTC patients with intermediate or high risk of recurrence following total thyroidectomy, RAI ablation therapy is recommended [2–4]. [...]when 131I used is more than 1.22 GBq (33 mCi) for RAI therapy, which is equivalent to a dose limit of >5mSv, several days of hospitalization in a licensed facility is mandatory [5, 6]. According to the US Nuclear Regulatory Commission (NRC) regulations, Title 10 of the Code of Federal Regulations part 35.75 [6], licensed facilities can only release patients treated with RAI therapy from their control if the radiation exposure to any other individual near the released patients is not likely to exceed 5 mSv, and if any individual is likely to receive >1 mSv of radiation, they should provide radiation safety instructions to patients to help maintain radiation exposure as low as reasonably achievable (ALARA). [...]the current practice regarding radiation precaution is largely differed across physicians partly due to the presence of either too simple (based on administered radioactivity) or too sophisticated (fitting biokinetic model) methods [13]. [...]a total of 215 patients were included in the analysis to determine effective dose equivalent to other individuals near the patients.