What's a woman to do? Should she believe one of the most trusted cardiologists in North America or expert radiologists specializing in breast imaging? You may have been left with such questions if you watched the "Dr. Oz Show" episode on thyroid shielding that aired April 14.
The program was dedicated to clarifying whether individuals should wear thyroid shields when having radiation-based procedures such as mammograms and dental x-rays. While radiology advocates believe the shields are unnecessary for mammography, women across the U.S. have been asking for the protection after an email went viral in March based on advice Dr. Mehmet Oz gave in a show that originally aired last year.
This week's episode was ostensibly intended to set the record straight, with Oz, the cardiothoracic surgeon who hosts the show, inviting experts from dentistry and radiology to comment on the email controversy and the pros and cons of thyroid shielding. But a combative Oz defended his original advice, and ultimately turned the show into a lecture for health professionals on the necessity of listening to their patients.
Rising thyroid cancer rate
The backstory for the controversy is the rising incidence of thyroid cancer, which has increased fourfold since the 1970s. The original episode in 2010 said that some of the increase could be due to radiation exposure from dental x-rays and mammograms, and advised the use of thyroid shields to reduce risk -- advice that prompted statements of opposition from imaging organizations.
Appearing on this week's show to represent healthcare professionals were luminaries from radiology and dentistry, including the following:
- Dr. Daniel Kopans, director of breast imaging at Massachusetts General Hospital
- Dr. Phil Evans, director of the University of Texas Southwestern Center for Breast Care
- Dr. Jocelyn Rapelyea, associate director of breast imaging at the Breast Imaging and Intervention Center of George Washington University
The show exuded the atmosphere of a pep rally, with Oz pointing out that many doctors did not agree with his recommendation for women to wear a thyroid shield when having a mammogram. "I'm taking on my critics," he stated emphatically, and from that point on he barely let the invited radiologists get an informative word in edgewise.
"My warnings sparked a firestorm," Oz said. "You turned the medical community upside down by demanding thyroid guards while getting x-rays. I want you to have the power. It's about your right to control your care."
The invited guests pointed out the impracticality of Oz's advice, indicating that the radiation dose exposure to the thyroid gland after 40 years of annual mammograms would be less than the background radiation received by sitting in a television studio for 60 minutes.
In addition, using thyroid shielding could affect the diagnostic quality of a mammogram, and images might be compromised altogether, requiring a retake and doubling the amount of radiation exposure to the breast.
Images from a patient who underwent mammography with a thyroid shield. The image on the left is a mediolateral oblique view demonstrating the thyroid shield obscuring the upper posterior breast along with a degraded image. The image on the right was repeated without the shield and shows normal breast tissue. All images courtesy of Dr. Phil Evans.When Kopans commented to Oz that "if you are going to promote thyroid shields for mammograms, your audience should be wearing them now" to protect the thyroid gland from normal background radiation levels that cumulatively are much greater, Oz interrupted him. Oz stated that the protection was for a dose that a thyroid gland was receiving in one second rather than spread over 30 minutes, and why not protect oneself during that one second?
Kopans' comment that radiation dose was cumulative, and if Oz wanted his audience to protect their thyroids they should wear a thyroid shield 24 hours a day, was ignored by the television host and appeared to fly over the heads of his studio audience.
A technologist positioned for a mammogram with the thyroid shield in place. Part of the thyroid shield is underneath the compression paddle and would cause a portion of the breast to be obscured on the mammogram.Rapelyea explained that a patient's body shape and mobility might prevent her from wearing a thyroid shield due to positioning requirements. She explained that in the past week, as patients at her center were demanding thyroid shields, approximately 20% of screening mammograms had to be repeated.
Oz acknowledged that this could be a problem, along with the concern raised by Evans that fear of radiation could scare many women away from having mammograms. He told his audience members to get their mammograms because they save lives, and to listen to breast imaging specialists if they say that for specific reasons an individual cannot wear a thyroid shield and have a successful mammogram.
But his concluding remarks to the television audience fit the tenor of the show:
"Mammography makes a ton of sense, but you have the right to ask for a thyroid guard," he said. "This is only going to happen if you make it happen. If you don't ask those tough questions, there isn't going to be any change. But if you do ask them, you have the power to make us doctors adjust to you and customize your care."
