OBJECTIVE: Nuclear medicine technologists rely on a single dosimeter to measure 
their work-related dose. Estimates of whole-body effective dose are based on the 
assumptions that the radiation is incident from the front and in a uniform beam. 
We sought to investigate these assumptions and also to quantify doses associated 
with different activities.
METHODS: A single technologist wore 3 electronic dosimeters for 3 mo, at the 
front waist, the back waist, and the front collar. The technologist also 
recorded her activities throughout the day.
RESULTS: We found that the assumption of an anterior beam held about two thirds 
of the time, breaking down only when the technologist was receiving lower doses. 
Overall, the average whole-body dose was estimated correctly by assuming an 
anterior beam. We also found that irradiation was uniform (i.e., waist and 
collar badges gave equivalent readings) except when the technologist was 
performing injections. Then, the collar readings were 1.7 times the waist 
readings. Finally, average doses were measured for different types of 
activities. Performing injections registered a dose rate of approximately 2 
microSv/h. Doses received while scanning ranged from 0.2 to 2 microSv/h. The 
average dose for a scan depended not only on the administered activity and 
isotope but also on the amount of patient contact required. Even for high 
activities, such as patients who had already received therapy, the dose to the 
technologist was low for patients requiring little assistance.
CONCLUSION: The assumption of anterior irradiation correctly estimates 
whole-body effective dose. The assumption of a uniform beam is good except when 
injections are being performed, when the upper torso receives a much higher dose 
than the waist. Overall, doses to the technologist were found to be 5.4 
microSv/d for scanning and 12 microSv/d for injections. These correspond to 1.4 
mSv/y and 3.2 mSv/y, respectively, which are comparable to naturally occurring 
radiation levels and are much lower than regulatory limits. However, if the dose 
to a particular technologist needs to be minimized (e.g., for a pregnant 
worker), the most effective strategy is for the technologist to be assigned 
patients requiring little contact or assistance and, in particular, to avoid 
administering injections.