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Think back to the last time you had an X-ray: The radiologic technologist probably placed a lead apron over part of your body to protect it from radiation. That’s now an outdated practice: The American Association of Physicists in Medicine no longer supports shielding patients’ reproductive organs and fetuses during imaging studies that use radiation, such as X-rays and CT scans.

Changing this practice has been a near impossible feat.

While the association’s statement rocks the boat of convention, it’s based on mounting evidence that shielding is not as helpful as once thought, and it might even have negative consequences.

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One of the downsides is that shielding can obscure the imaging field, leading to an unusable X-ray or CT scan, requiring the patient to have another. That increases his or her radiation exposure. One study found that shields were misplaced half of the time during pelvic X-rays and often obscured important bony landmarks.

Another concern is that most imaging machines that use radiation automatically determine the dose of radiation required to produce a successful image. If the machine senses a shield, it increases the dose in an effort to image through the shield, leading to an increase in radiation exposure.

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There are few positive effects to shielding. The chance of radiation exposure outside the beam’s scope is already minimal. If reproductive organs or a fetus are outside the beam’s path, there is no reason to shield. A Mayo Clinic study found that shielding the abdomen or pelvis during chest CT scans didn’t actually reduce the dose of radiation enough to justify the risk of artifacts in the imaging field.

There are two important exceptions to changing the practice of shielding. First, it still applies to providers. “Health care professionals who regularly use radiation, such as radiologic technologists or surgeons, have a higher rate of exposure day in and day out than a single patient undergoing an imaging study,” says Jennifer O’Riorden, director of health physics and radiation safety officer at Lahey Medical Center in Burlington, Mass. “These providers should continue to wear the appropriate protective apparel.”

Second, shielding should be used if or when it offers patients a psychological benefit. Some patients may be nervous if their provider doesn’t automatically shield them during an X-ray or CT or nuclear imaging scan. Rebecca Marsh, a medical physicist and author of the journal article that served as the framework for the American Association of Physicists in Medicine statement, suggests that providers should talk with their patients about the risks of shielding but still make the professional decision to shield if the comfort it provides outweighs the risks.

Given the evidence and the current guidelines, why is it so hard to change the status quo?

First, radiation is a very real fear for many people, partly because of past disasters. Chernobyl, Hiroshima, and Fukushima are very public demonstrations of the power of radiation gone wrong. In the clinical setting, the fear of radiation is also likely due to a lack of education and understanding of exposure and risk.

A survey of patients in an emergency department found that most do not accurately understand the radiation dose associated with various imaging studies: Standard X-rays use a negligible amount of radiation; CT scans and nuclear imaging use the most. Only 14% of those surveyed said that CT scans use more radiation than chest X-rays. Less than one-quarter accurately said that MRIs do not use radiation at all. A separate survey found that even medical providers do not always fully understand radiation exposure and risk.

Another reason it is hard to move away from shielding is that it is a deeply engrained practice for both patients and providers. “Provider education has always been based on the ALARA principle — as low as reasonably achievable — using time, distance, and shielding to minimize the radiation dose,” says O’Riorden. Patients have come to expect it, too.

Shielding reproductive organs and fetuses became the norm in the mid-1900s because experts worried that radiation-induced genetic mutations in sperm or eggs could be passed on to a patient’s future children. It’s worth noting that hereditary mutations due to radiation exposure have never been clinically documented. The federal government issued regulations in the 1970s recommending shielding, solidifying the practice. (The Food and Drug Administration is considering revising these regulations later this year.)

These recommendations and conversations leave out an important stakeholder: dentists. About half of the X-rays completed in the U.S. each year are done in dentists’ offices, not doctors’ offices. Shielding is less likely to interfere with a dental X-ray, or even be necessary for it. It seems logical that dentists would be willing to adopt new guidelines about shielding, but they were left out of the push to change the status quo. That was a huge oversight. (In the United Kingdom, dentists have been asked to cease “the widespread practice of applying patient contact shielding.”) If U.S. dentists continue to shield their patients while doctors don’t, there is potential for considerable confusion among patients.

Radiation exposure is an example of the risk/benefit trade-off we make with every decision. When imaging studies that use radiation are clinically appropriate, the benefits far outweigh the risks and shielding does little to mitigate those risks. “When it comes to patient safety and radiation risk, it is very important — yet difficult — to not let emotions and fear overrule an unbiased evaluation of available data,” says Marsh.

Fear and tradition are powerful forces that often work against change. Aligning current guidelines with the growing evidence that suggests shielding is not protective will take buy-in from both providers and patients. But to earn that, we must focus first on conversations that address the engrained fear of medical radiation and misunderstanding about it.

Elsa Pearson is a senior policy analyst at Boston University School of Public Health.

  • So, their main point is that the tech is misplacing the shields, thus creating the need for a repeat, and increasing PT dose. This is very misleading. Any tech worth their salt knows where to put the shields as to not cover anatomy. If they don’t, then they need to do some QC or remedial training. Also, shields absolutely reduce patient dose. Slapping a shield on someone is a very reasonable measure, thus falling under ALARA.

    Also, what the article said about AEC (Automatic Exposure Control) is absolutely wrong. AEC isn’t used on most exams, and when it is, the detector isn’t deciding using the whole field. It averages radiation exposure via a combination of 3 special sensors called photocells. If the shield is covering a photocell, then you’re putting the shield in the middle of your light field and right over what you’re trying to x-ray.

    The ignorance of these simple facts really makes me doubt this article. I do not trust it.

  • Every study depends on who is behind/sponsoring that study and what interest they have. These arguments are ridiculous, I wouldn’t have even bothered myself doing this study. But there are of course a lot of people outside there, who will probably believe this crap. Maybe soon we will change also our perception, through different “studies”, that our planet is flat. Really?!

    • This wasn’t based on a single recent study. It is the recommendation from the American Association of Physicists in Medicine based on their accumulated experience with and knowledge of lead shields. Your questioning their motives. What type of conflicting interests do you think they have to make this recommendation. It’s not crap. It is based on sound reasoning.

    • I’m a radiologist. I’ve researched radiation risk extensively and frequently speak to provider groups on this topic. I can tell you that the data does not support the theory nor the experience we have of the purported risk from low doses of radiation. Unfortunately, the BEIR VII report greatly overstated the risks of low dose radiation which is where most of the common perception of risk comes from. It relies on the linear no-threshold model for cancer induction which has been shown to be baseless.

  • I’ve seen this article before. There are no studies which show that radiation exposure to reproductive organs or a fetus cause no damage. The central point of this article is that the rad tech does a poor job at placing the shielding, and thus results in the need to take additional images. The solution is not to get lazy about shielding, but to go back to enforcing quality standards. Many facilities had people designated to train others and ensure QC. These positions have been cut due to budget issues. Maybe, just maybe, QC should be everyone’s job!

    • The central point of this article is that shielding is not necessary due to the very low risk of radiation exposure and the greater risk of obscuring a significant finding AND the possibility of actually inadvertently increasing the dose because of the shield. The amount of radiation from an x-ray is miniscule. Radiation risks are greatly overestimated by the false theory of linear-no threshold model, greatly perpetuated by the BEIR VII report.

  • Quick question though… If these lead aprons offer nothing to patients, does it also offer nothing to radiographers and radiologists who may be in the diagnostic room during fluoroscopy examinations or when using a mobile x-ray machine in the ward? We can also do away with lead glasses and thyroid shields.

    Apart from shielding potentially leading to a repeat exposure (which I think is a lousy ethic on the part of a Radiographer to make such a mistake), I really don’t think I can agree soon enough that shielding offers little.

  • During a CT scan of the cheat, if a lead apron obscures the chest, the tech doing the exam.is NOT doing a very good job of placing the shield.
    Pelvic shielding is always recommended – for patients of child rearing age and below- to stave off genetic effects.
    The problem as the article points out is when the shielding is poorly placed and obscures anatomy of interest.
    I believe the answer is more stringent training surrounding use of shielding, not to abandon the.practice wholesale.
    As well, many operators of x-ray and CT machines are not optimallly trained; there are still states lacking any formal license requirements to operate such medical equipment.
    I would not be surprised if the studies done were in states where the training more or less amounts to which button does what with NO orientation to anatomy, biology, or physics, all of which Technologists who become nationally and state certified have training in.
    ALARA is a principle and practice which takes some thinking sometimes, but as radiation exposure can certainly be hazardous, it’s worthwhile trying harder to get it right, not dilute the criteria for good practice.

    • Typically, a shield for a chest CT is made of bismuth, not lead. Those shields create artifact but they also remove diagnostic information from the scan. The concept of “wasted photons.”

  • This is written by a person ignorant of facts. You don’t shield in instances where the body part being imaged will be obstructed. Protecting other body parts not being imaged is the right thing to do because, you know, physics.

    • This article is actually spot on. The “physics” you refer to do not support your view. In fact, these recommendations come from the American Association of “Physicists” in Medicine. You know, PHYSICISTS! It’s about time we move away from the radiation hysteria. In fact, many believe in the idea of hormesis, where low doses of radiation actually stimulate your bodies natural anti-cancer defense mechanisms. There are several well-known observed instances supporting this. Look at a map of radon exposure and lung cancer incidence. You’ll see that those geographic areas with higher background radon exposure have lower incidences of lung cancer. There was an apartment building in Taiwan that was built with steel with small amounts of a radioactive material. The residents had LOWER long-term rates of cancer. radiation oncologists recognize that part of their radiation treatments are the result of a radiation-induced immunologic response.

  • This article is inaccurate and false. Plus it is not approved my ARRT guideline. This is why there is a degree with detailed training for imaging personeel. Facts cannot be gathered by any other medical persons. This article should be classified as opinion not factual and harmful to public view whom are not educated in physics. The author has created a difficulty with patient compliance and understanding during exams.

    • This article is 100% accurate. And all of these institutions have endorsed exactly what this article is reporting:

      American College of Radiology (ACR)
      Australasian College of Physical Scientists & Engineers in Medicine (ACPSEM)
      Canadian Association of Radiologists (CAR)
      Canadian Organization of Medical Physicists (COMP)
      Health Physics Society (HPS)
      Image Gently
      Radiological Society of North America (RSNA)

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