Again sparking controversy among patients and medical professionals, we would like to address the recent topic of thyroid cancer as brought to light by the Dr. Oz show.
If you missed it, Dr. Oz recently blamed dental x-rays and mammograms for the rise in thyroid cancer in women, and is advocating the use of a thyroid guard during these procedures. Incidentally, and going unrecognized on the show, thyroid cancer for men is also on the rise, both since about 1980, per Dr. Daniel Kopans, Professor of Radiology at Harvard Medical School who was featured on the show as a critic of the thyroid guard.
Allow me to be casual here for a moment as it seems Dr. Oz points to one tiny cause for a very large effect. Dental radiation and mammography are two very, VERY small sources of radiation. He did not address the use of cell phones (coincidentally, also in use since the 1980’s), older televisions and microwaves, background radiation (we are all subject to), or even exposure to outdoor sunlight. The things I just mentioned largely contribute the amount of radiation that a person is exposed to in a lifetime. This is similar to the fluoride critics who blame fluoride in water (at the rate of one part per million), which occurs naturally in water anyway, for fluoride toxicity, cancers, and whatever else people are coming up with these days. But I digress; that is a topic for another day.
Back to the issue at hand, I am not a mammographer and will leave that topic alone, just leaving you with the one quote on the show that really stuck out in my mind. Dr. Kopans, an expert in mammography and professor at Harvard, stated that the amount of radiation that a woman gets from one mammogram a year, times 40 years, is still LESS than what the audience members were getting in background radiation during the hour they sat there; therefore, he said, if Dr. Oz were going to recommend thyroid guards during mammograms, then he should also be providing them for his audience.
Dental x-rays are aimed at the teeth and jaw, and the thyroid gland recieves little to no radiation from that exposure. Your thyroid is located low, near your clavicle, as pictured in the diagram below.
Now, if dental x-ray radiation was really causing thyroid cancer, why the rise since 1980? X-rays have been around for over 100 years and dental x-rays have certainly been the standard of care for the majority of the 20th century. Since the turn of the century, most dental practices have been making the move to digital x-rays, which use about a quarter of the radiation exposure than traditional film x-rays. So, shouldn’t we be seeing a decrease in thyroid cancer, if in fact dental x-rays are to blame?
You’re still concerned? That’s ok. There’s already a thyroid guard attached to our lead apron.