Document Type : Original Paper
PhD Student of Medical Physics, Medical Physics Research Center, Mashhad University of Medical Sciences, Mashhad, Iran
MSc Student in Nuclear Physics, Shahrood University of Technology, Semnan, Iran
Assistant Professor, Department of Nuclear Medicine, Shahrood University of Medical Sciences, Semnan, Iran
Most studies to date have focused on estimated doses from patients administered radiopharmaceutical in nuclear medicine by hospital staff but other people in connecting to patients need radiation protection. The purpose of this study was to measure the dose rate with increasing distance from patients to estimate the average effective dose in hospital staff and companion of patients.
Myocardial perfusion scanning was performed using Technetium99m-methoxyisobutyl isonitril (99mTc-MIBI) (in 2groups of stress and rest). We measured the external dose rate for 48 patients (23 men and 25 women) at 4 distances and 5 times. Doses are estimated for a range of scenarios, in hospital staff, the public transportation and family contacts. Finally the obtained data were compared to the trigger level introduced by the International Commission on Radiological Protection 53 and 62 (ICRP). Data analysis was performed using SPSS version 24.
The length of the times when patients need family or hospital staff to be with them were divided into 4 categories(injection to scanning, using public transport, emergency patients during injection to scanning and emergency patients after finishing medical procedures). In all categories maximum dose rate was obtained less than 100µSv but in stress, the values were higher than the rest.
In all scenarios effective dose were obtained less than 100 µsv according to ICRP guidelines. Due to the significant increase of the uptake in the heart and skeleton, after injection, the dose rate per MBq in the stress rate before 1hr decreases more slowly than the rest test and the effective dose of hospital staff in stress procedure more than rest procedure.