The post "Mammogram of the Thyroid" prompted concern among some readers. Note: Today's post refers only to diagnostic x-rays (not therapeutic radiation therapy to treat cancer).
Some readers are wondering if they should request a thyroid guard whenever undergoing diagnostic x-ray studies. Others worry that their asking for a thyroid guard might annoy the radiology tech or the radiologist (and they sure don't want to annoy the person caring for them). The key issue here is risk versus benefit.
The risk to your thyroid of not using a thyroid guard depends on what kind of diagnostic x-ray test is being done. High-dose studies (such as real-time continuous pictures taken during coronary angiography or esophageal swallow studies) expose the thyroid to far more radiation than a simple two-view chest x-ray or mammogram. Direct hits of radiation to the thyroid carry greater risk than indirect, so-called "scatter" hits.
But using a guard carries important risks, too. Depending on the study being done as well as your particular anatomy, a thyroid guard might interfere with the the value of the diagnostic study. For example, if the thyroid guard blocks the upper edges of your lung tissue on the x-ray picture, your doctors won't be able to see a small abnormality (such as a tumor) hiding up there. Similarly, if the thyroid guard blocks the tail end of breast tissue near the axilla (arm pit) or deep breast tissue abutting the chest wall, your mammogram could not show a small cancer (or make it easy to miss).
Whenever my physician advises a diagnostic x-ray, we talk briefly about why he recommends this test over tests that don't expose me to more radiation. He knows I am concerned about all the radiation I've had over the past 18 years. He also knows -- and I make sure he knows every time -- I trust his judgment and will do what he recommends.
As a Healthy Survivor, I want to get the best care possible. When it comes to diagnostic x-rays this means:
- making sure my physicians are thinking about the risks of the tests they order on me.
- using a thyroid guard, but only if doing so will not diminish the value of the test.
- reminding myself that when a doctor advises an x-ray, (s)he has determined the risks of not doing the test outweigh the risks of doing it.
- reassuring myself that most people who are exposed to diagnostic radiation do not develop radiation-induced problems later on.
As for worries that requesting a thyroid guard would hamper your care by making you a "difficult patient," as I advised commenter "B": One approach is to be upfront: "I don't want to cause you any trouble, but I've been told to ask if I may have a thyroid guard for this x-ray. Will it interfere with the test, or is it okay?" And then, of course, thank the tech.
I often say, "Sorry for the extra trouble. I've had a lot of radiation to my neck. I'm trying to minimize additional x-ray exposure when possible." Requests that are both respectful and explanatory go a long way in working together with the techs.
This post breaks my "250 words or less" rule because the messages are vital: As a Healthy Survivor,
- accept that even simple measures (like having a screening x-ray) can create problems.
- take comfort in knowing the distress of making wise decisions is short-term and offers long-term peace-of-mind.
- know there is no one right answer that fits everyone; but there is a best answer for you.
- work together with your physicians to determine the risk-benefit ratio for you of each test, procedure or treatment paves the path to good care.