Concern over radiation from medical imaging procedures has reached a fever pitch in the U.S. Women getting mammograms are asking for thyroid shields, while a pediatric department at a California hospital was temporarily relocated due to its proximity to imaging equipment. Much of the panic appears to be due to an email that's gone viral.
The hysteria has gotten bad enough that the American College of Radiology (ACR) and the Society of Breast Imaging (SBI) on April 4 issued a joint statement trying to assuage women's fears over the risk to the thyroid of radiation from mammography. Meanwhile, the television show that may have played a role in the rise of the email chain is airing an episode on April 14 with mammography expert Dr. Daniel Kopans in an effort to put the rumors to rest.
The hullaballoo demonstrates the power of the Internet to shape opinion in a world that's increasingly paranoid about the effects of radiation, be it from stricken nuclear reactors in Japan or from the mammography facility down the street.
Uneasy origins
Surprisingly, the origins of this month's panic were laid in a TV show that originally aired last year. The "Dr. Oz Show" is a nationally broadcast daytime TV show about health and medicine, hosted by Dr. Mehmet Oz, a cardiothoracic surgeon and vice chair and professor of surgery at Columbia University.
On September 27, 2010, the program focused on the subject of thyroid cancer. Oz pointed out that the number of thyroid cancers has doubled since the 1970s, stating that improved and more precise diagnostic technology -- specifically, imaging and biopsy procedures -- may be responsible for the increase in diagnoses. Because thyroid cancer is four times more likely to occur in women than in men, Oz stated that estrogen may fuel the growth of cancer cells, as it does with breast cancer.
He also explained that the thyroid gland is sensitive to radiation, which is a leading risk factor for the condition. Childhood cancer survivors are particularly vulnerable, especially if their thyroid glands had been exposed to high radiation levels from radiation therapy.
Where the misstep occurred, from the perspective of the ACR and SBI, was a statement that women may wish to wear a thyroid shield when having a mammogram. An article that accompanied the program on the show website stated:
And although routine dental x-rays, chest x-rays, and mammograms of today use much lower and safer amounts of radiation, some worry about this as a thyroid-damaging source. Some professionals say to protect the thyroid people should wear a lead thyroid shield when undergoing these procedures to block radiation reaching the thyroid gland. ...
Oz demonstrated how a thyroid shield was positioned, and went on to explain how thyroid cancer was identified.
At this point, the TV segment generated little attention beyond a few Twitter tweets and blog postings. But when the show was rerun on December 30, all hell was about to break loose.
An anonymous viewer drafted the following email, which soon began appearing in email chains, on blog sites, and throughout the Internet:
On Wednesday, Dr. Oz had a show on the fastest growing cancer in women, thyroid cancer. It was a very interesting program and he mentioned that the increase could possibly be related to the use of dental x-rays and mammograms. He demonstrated that on the apron the dentist puts on you for your dental x-rays there is a little flap that can be lifted up and wrapped around your neck. Many dentists don't bother to use it.
Also, there is something called a 'thyroid guard' for use during mammograms. By coincidence, I had my yearly mammogram yesterday. I felt a little silly, but I asked about the guard, and sure enough, the technician had one in a drawer. I asked why it wasn't routinely used. Answer: 'I don't know. You have to ask for it.' Well, if I hadn't seen the show, how would I have known to ask?
By March, the posting had gone viral. It can be found on numerous blog sites, whose authors either claimed that they wrote it or that it was the experience of a close friend. It was posted on the discussion board of BreastCancer.org on March 22, and several days later on the American Cancer Society's cancer survivorship network discussion board. The email even won the attention of Snopes, the Internet hoax-busting site, which devoted a page to the thyroid scare.
Imaging centers and radiologists soon began to feel the impact, as witnessed by a message thread started March 29 in the AuntMinnie.com Forums. The ACR and SBI began receiving telephone calls and emails from their members, leading to the April 4 statement, which advised that the amount of radiation women receive from annual mammograms does not increase their likelihood of developing thyroid cancer.
The posting soon made its way back to the "Dr. Oz Show," where staff began receiving copies of daisy-chain emails in late March, according to Tim Sullivan, director of publicity. Sullivan clarified that the misinformation did not originate with the show, and he also expressed surprise that the email would surface so many months after the show segment originally aired. "Usually, viewer comments are made within a week," he said.
To clarify the situation, the producers of the TV show have been working with the ACR and SBI to air a follow-up segment with Kopans, a professor of radiology at Harvard Medical School, director of breast imaging at Massachusetts General Hospital, and a frequent speaker on mammography issues. The segment will be produced on April 12 and broadcast on April 14.
Radiation concerns in California
At about the same time that the thyroid email was gaining steam, a conversation took place among hospital staff in the pediatric department at Sutter Amador Hospital, a 52-bed hospital in Jackson, CA, about what they considered to be an unusual number of thyroid abnormalities the workers had experienced.
The pediatric department is located directly above the radiology department, and the pediatric staff reported their concerns to the hospital administration, which began to investigate. Some staff expressed concern about the proximity of the radiology department and the possibility of "radiation leaks."
The hospital's safety team decided it would be prudent to temporarily relocate the pediatric center until radiation safety tests had been performed. Tests completed on March 30 by both hospital staff and the hospital's parent organization, Sutter Health, indicated that radiation levels were normal. The hospital also hired an independent medical physicist, who found normal radiation levels in tests that were reported on April 6.
The pediatric center staff underwent ultrasound exams, and thyroid nodules were detected in several individuals, according to hospital spokesperson Jody Boetzer. While thyroid nodules are relatively common, the hospital declined to comment further, citing HIPAA concerns. Both the county health department and the California Department of Public Health are in the process of conducting investigations.
The hospital's pediatric center is expected to move back to its original location next week, Boetzer said. She told AuntMinnie.com that the timing of the radiation scare and the national email blitz appeared to be a coincidence.
ASRT's advice
Meanwhile, many mammography facilities in the U.S. are faced with a rising number of requests for thyroid shielding. How should they respond?
Thyroid shielding is not recommended by the American Society of Radiologic Technologists (ASRT) because it can obscure anatomy and interfere with exam positioning, interpretation, and diagnosis, according to James Temme, president of the ASRT. Like the ACR and the SBI, the ASRT noted that the thyroid is not in the direct path of the x-ray beam, and thus receives only a very small dose of radiation during a mammography exam, Temme said.
The ASRT is directing radiology professionals to the X-rayRisk.com website, which has a calculator for patients to learn about risks and track their own exposure. The association also directs technologists to educate patients about the Image Gently and Image Wisely campaigns to promote safety during medical imaging exams.
