Radiation Protection and Dosimetry in PET and PET/CT

摘要

The use of Positron Emission Tomography (PET) and combination with ComputedTomography (PET/CT) has been growing rapidly over the past 5 years. An increasingdemand for use of ~(18)F-FDG PET in oncology has been the main reason for its growth. Newgeneration hybrid systems which combine PET with multi-slice CT (MSCT) is gettingincreased its use for radiation treatment planning, cardiac, breast and brain imaging. Thephysical characteristics of positron emissions result in higher radiation risk for staff andgrowing use of PET/CT for screening purposes increase public radiation exposure. Anunderstanding of the radiation protection and safety issues are very important to keepclinical and occupational exposure as low as reasonably achievable (ALARA).In this study we investigated radiation doses to the PET staff and strategies to loweroccupational exposure. Radiation doses measured by thermoluminescent dosimeters (TLD)for staff working in PET. Effects of implementing radiation protection methods and trainingwere evaluated.We found that the radiation exposure of PET technicians was higher than thattechnologist working conventional general nuclear medicine studies at the beginning. Afterimplementing radiation protection measures and procedures, PET technicians dosessignificantly reduced.Since high energy photons (511 keV) of positron emitters, facility planning for radiationprotection, including shielding, containments of sources, strict radiation protection measuresshould be implemented to working environment. Training of staff is also very important tokeep the dose levels within the accepted occupational guidelines.