Answer to Question #10235 Submitted to "Ask the Experts"

Category: Medical and Dental Equipment/Shielding — Shielding

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

I am an interventional cardiologist who has worn a lead apron and thyroid shield for the last six years since beginning my training and now as an attending. I recently incidentally discovered that my thyroid gland is "lingual"—i.e., did not descend during embryolgic development and is located at the base of my tongue adjacent to the epiglottis. It is roughly at the level of the angle of my jaw, in the midline, and above the "Adams apple." There is no thyroid tissue in the usual location. Are you aware of strategies for the rest of my career to shield my thyroid in its unusual location?
Depending on how your thyroid collar fits around your neck, you may have adequate protection with it. If you are using a separate thyroid collar, it seems that your thyroid would be right behind the top of the thyroid collar. Remember that most of the scatter radiation is coming up toward your neck at an angle from the patient, so the thyroid collar may protect the area that you are describing.

In addition, if you used a lead-glass pull-down shield for your cardiac procedures, it would protect your head and neck from scatter radiation if positioned properly. This would provide protection to those areas as if they were covered by a lead apron. If used properly, this type of shield is effective even if you do not have a thyroid collar on. We typically recommend these shields for any interventional work when dosimeter readings are at or near ALARA (as low as reasonably achievable) trigger levels set by institutions, and it is common for these to be installed in many new rooms.

Kennith “Duke” Lovins, CHP
Health Physicist
Answer posted on 19 April 2012. 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.