Abstract: Patients with differentiated thyroid cancer (DTC) often need ¹³¹I treatment after total or subtotal thyroidectomy. When a single dose of ¹³¹I exceeds 400 MBq, they need to be hospitalized for isolation. With the continuous increase of DTC patients, ¹³¹I treatment is becoming more and more widely used, and the amount of application is getting larger and larger. Associated radiation protection issue has thus attracted widespread attention. Some protective measures and matters, which need to be taken during and after ¹³¹I treatment, is presented from the aspects of ward environmental protection, patient self-protection, medical staff protection, and surrounding crowd protection. It’s intended to better protect of patients, medical staff and the public.

Key words: ¹³¹I therapy, Radiation protection, Differentiated thyroid cancer(DTC)