Exposure dose estimation of nursing personnel and visitors following ¹²⁵I brachytherapy

Abstract

An automated access management system to the controlled sickrooms for ¹²⁵I brachytherapy was developed. The system consists of access control and video surveillance units. The patients implanted ¹²⁵I seeds were isolated for about 20 h after surgery in the controlled sickrooms. The maximum doses and dose rates of the nurses and visitors were estimated by using the legal upper limit activity of 1, 300 MB q, the measured longest staying time, and the shortest distance between the patients and individuals. Video analysis revealed activities of the nurses, patients, and visitors in the controlled sickroom, and relationships between the access frequency and staying time. The nurses' measured doses ranged from 1 to 3, μ S v, and averaged 1.6 μ Sv. The nurses' maximum dose and dose rate were 16, μ Sv and 5.6 nSv·h^-1·EMBq^-1. The visitors' maximum dose and dose rate were 6 μ Sv and 2.6 n Sv·Eh^-1·EMBq^-1. The nurses and visitors' exposure doses per patient were estimated to be negligible compared with the annual limit of the public.