Pichet Mali. Radiation dose to healthcare workers and members of the public from nuclear medicine imaging procedures. Master's Degree(Radiological Science ). Mahidol University. : Mahidol University, 2008.
Radiation dose to healthcare workers and members of the public from nuclear medicine imaging procedures
Abstract:
Many studies have demonstrated that radiation exposure to nuclear medicine technologists
arises primarily from radioactive patients. This study was based on the activities in the Nuclear
Medicine department at Siriraj Hospital over three months. Services provided by the department
include diagnostic imaging (560 cases/month), administrating therapeutic doses of I-131 for the
treatment of thyroid cancer (360 cases/y), and more recently, use of a PET/CT scan with F-18-
FDG (110 cases/y).
The purposes of this study were to directly measure the dose received by technologists
working with routine nuclear medicine diagnostic and therapeutic procedures, to estimate doses to
other staff and accompanying persons who were in close contact with the patients in the waiting
areas, and then compare the results with the legal limits recommended by the International
Commission on Radiological Protection (ICRP).
In the study, the whole-body radiation dose of nuclear medicine workers, other staff and
accompanying family members or relatives was measured directly, by electronic semiconductor
detectors (ALOKA Model PDM-112), and indirectly, from dose rate measured by ionization
chamber (ALOKA Model ICS-311) and the expected accumulated dose at 1 meter from the
patients.
The results showed that technologist received an average dose of 0.77 μSv/procedure with a
range from 0.18 to 4.16 μSv/procedure. The highest dose to technologists was from the PET scan
(4.16 ± 2.71 μSv/examination). They received a dose of 3.84 μSv/d which corresponds to 1.165
mSv/y. This amount was lower than the ICRP dose limits of 20 mSv/y for radiation workers.
Stretcher-bearers received 4.75 ± 1.35 μSv/trip through transporting patient back to the wards.
Nurses in the radioiodine treatment ward received 5.53 ± 2.30 μSv/patient visit. Room cleaners
received a negligible amount of the dose, 1.80 ± 2.99 μSv/d. Accompanying persons who were in
close contact with the patient in waiting areas received as high as 26.6 μSv. However, this amount
was only 0.5% of the legal limit of 5 mSv/y.
In conclusion, the radiation dose received by nuclear medicine workers, the stretcher-bearers
and nurses at the hospital ward, and accompanying persons coming into close contact with the
patients was far below the legal limits recommended by the International Commission on
Radiological Protection (ICRP) both for occupational workers and members of the general public.