Answer to Question #9143 Submitted to "Ask the Experts"

Category: Nuclear Medicine Patient Issues — Diagnostic Nuclear Medicine

The following question was answered by an expert in the appropriate field:

Can a patient be advised to undergo an ultrasound or echocardiography study on the same day immediately after completion of his/her nuclear medicine scan? Are there any guidelines for regulating exposure of the staff working in the ultrasound department and what about other nonnuclear diagnostic procedures like getting a holter monitor?

Radiation exposure from nuclear medicine patients to hospital staff varies depending on the type of radiopharmaceutical, how much was administered and when it was administered. The half-life of nuclear medicine radiopharmaceuticals, that is the time it takes for the radioactivity to drop by half, is typically in the two-to-six-hour range although the half-life can be longer.

Sonographers work in close proximity to patients which is why it is reasonable to ask what kind of radiation exposure they might be getting from nuclear medicine patients. Because nuclear medicine patients might undergo additional examinations other hospital staff might also be exposed. The question of "how much radiation exposure" has been researched by direct measurement and reported in publications including the National Council on Radiation Protection & Measurements (Reports No. 124/105).

The Journal of Nuclear Medicine Technology (Volume 23, issue 3, pg. 186-187) published results from a study on radiation exposure to sonographers from patients who were injected with the PET (positron emission tomography) imaging radiopharmaceutical 18F-fluorodeoxyglucose (FDG). The conclusion was that the radiation exposure to the sonographer was usually minimal; if there is daily contact with nuclear medicine patients, radiation risks should be assessed. Monitoring for several months may be appropriate. Scheduling patients several hours after their nuclear medicine procedure is a good practice as well as asking the patient to void before the secondary examination. Please contact your hospital radiation safety officer if you have additional work environment concerns.

Dawn Banghart, CHP

Answer posted on 4 August 2010. The information posted on this web page is intended as general reference information only. Specific facts and circumstances may affect the applicability of concepts, materials, and information described herein. The information provided is not a substitute for professional advice and should not be relied upon in the absence of such professional advice. To the best of our knowledge, answers are correct at the time they are posted. Be advised that over time, requirements could change, new data could be made available, and Internet links could change, affecting the correctness of the answers. Answers are the professional opinions of the expert responding to each question; they do not necessarily represent the position of the Health Physics Society.