On episode 15 of The Kinked Wire, Warren Krackov, MD, FSIR, speaks with radiation safety officer Joseph Ring, DO, about radiation safety in interventional radiology, measures IRs should be taking to protect themselves, and what medical students considering a career in interventional radiology should keep in mind.
This episode was published Nov. 10, 2021. It has been edited for flow.
Warren Krackov, MD, FSIR: Thanks so much for being here to give us an overview of radiation safety. My understanding of radiation in my specialty is similar to my view of chocolate cake—I need a little bit of it to survive, but if I have too much of it I’m in trouble.
Radiation safety at a glance:
Respect exposure risks, but don’t worry too much.
Patients receive much higher radiation doses with no adverse effects.
Wear proper shielding, including around the eyes.
Exposure risk is well within guidelines for those who are pregnant or planning to become pregnant.
Be safe: minimize exposure to yourself and patients as much as possible.
Joseph Ring, DO: I like the way you put that. Radiation protection in medicine is an interesting subject because you have to have it. I see two extremes: people who don’t worry about it at all, and those who worry too much. We want to exist in the middle ground.
There are studies out there that get people worked up—both patients and clinicians—about radiation exposures. But I like to look at it from what we deliver to our patients: During interventional procedures, our patients receive large radiation exposures and have no health impact from the radiation and no long-term health effects that we can quantify. That said, when you have very sick patients who have multiple procedures or imaging, that’s a different story. As the professionals completing the procedure, we get a much lower dose than our patients—which is a good comparison to show that we’re probably not looking at large radiation risks from the exposure we receive in the clinic. Not to say we shouldn’t minimize risks—but they’re relatively small.
However, I’m of the philosophy that if you can eliminate some exposure without complicating the procedure, why not? Many of my colleagues would call me overly conservative, but if I can stand around a corner and push an X-ray button and not get any exposure, or stand next to the patient and get all the exposure, which one am I going to pick?
It’s also important to note that in fluoroscopy, the dose delivered to the patient is about 1000x higher than what the clinician receives. So, it’s important to remember that the main goal of this is to reduce the exposure to the patient. Anything we do to reduce the exposure to the patient is going to reduce the exposure to the staff in the procedure room. That means using the lowest frame rate possible, focusing only on the area of interest, keeping your foot off the pedal if you’re not watching the image and wearing your radiation gown. I highly recommend wearing a vest, collar and skirt, because they will distribute the weight much better and reduce the fatigue level. Bear in mind that aprons are going to attenuate 95% plus of the radiation that’s incident on you.
WK: Is that why there’s the 1000x less number? Because we’re wearing lead?
JR: No, it’s because the patient absorbs the radiation and scatters it.
WK: So we only get the scatter, and less than we normally would, if we distance properly and wear our apron.
JR: Yes, you’re going to get 1000x less, but if you wear the lead apron, you’re going to cut it even more. We still call them lead aprons, but I recommend that you don’t buy a lead apron, you buy one of the newer composites because they’re 5–10 pounds lighter.
WK: Even with wearing gear, are there still risks?
JR: There are. We always thought cataracts were something that would happen when you got a large radiation exposure, let’s say two gray and above. But we’ve recently learned that the threshold for cataracts is probably a lot lower, possibly around half a gray. That means it’s closer to the values that clinicians may see over a lifetime. So consider wearing leaded eyewear. You’ll want to have the wrap around eyewear or side shields, because a lot of the scatter will come in from the corners and up around the nose. They find that people who have radiation-induced cataracts get them in the corners of the eyes where they were vulnerable to scatter.
But be sensible and don’t panic. A lot of people are worried about the radiation exposure to their heads and want to wear skull caps. The head is very radio-resistant, and has the least likelihood of coming up with adverse health effects.
WK: Do skullcaps make exposure worse or are you just wasting your money?
JR: You’re just wasting your money. And when people wear them, they get hot and sweaty and it distracts from the procedure. Anything that’s going to cause you to push the pedal longer or make you feel uncomfortable is going to increase exposure to you and the patient.
WK: What about gloves?
JR: Gloves are even more insignificant. By wearing gloves, we have the potential to put the gloves in the way of the radiation field. Imaging devices are smart and adjust to what they see in the field. When a glove shows up inadvertently, the system says “Oh, something changed, increase the parameters to maintain image quality,” and everyone gets a much higher dose.
WK: Has it been your experience that women and men have different concerns about radiation?
JR: I tend to find that men are less concerned about radiation exposures than women, and that could be because pregnancy and breast cancer aren’t in the equation for them. But women tend to be more practical in managing their radiations exposures. With many female radiologists, as soon as they find out they are pregnant or are interested in becoming pregnant, their radiation dosimeters practices change dramatically. They’ll become more interested and knowledgeable about risks. However, while their practices change, they don’t necessarily decrease their radiation exposure.
WK: Are you aware of any statistical validation or studies that show one gender may be of more risk, or that fetuses are at more risk if certain precautions aren’t taken?
JR: We know for certain that fetuses are at more risk because they’re developing faster. However, is it something to really worry about? I wouldn’t say so. When we look at exposures to fetuses, for the most part they are well under the radiation limits for pregnant workers. Even my male clinicians who work in the very highest doses receive exposure to their bellies well under the limits.
WK: That should hopefully be reassuring to a clinician who is or wants to get pregnant, that the data suggests there won’t be long term risk to the fetus. Is that accurate?
JR: That’s accurate. The units of exposure are too small for traditional radiation units in medicine so we use the millirem. Most under-apron belly badges are going to be in the 10 millirem or less per month range, even on highly exposed IRs. The regulations say we should be under 50 millirem per month. When looking at a pregnancy’s potential impact from exposure, we don’t do anything until the exposure is 10,000 millirem. And the guidance from the American College of Radiology and the American College of Obstetrics and Gynecology has no problems allowing CT exposures of a pregnant woman—and that’s when you’re going to get a dose that will be deep enough to bypass shielding. But we see no impacts. That said, you obviously want to manage the exposure and minimize the dose as much as possible.
WK: That’s great to know, especially because we want to make IR more inclusive, and a lot of younger colleagues in medical school have concerns about the risk, both male and female. In your opinion, is that something we can discount when counseling them?
JR: I appreciate the concern for radiation exposure and will never minimize someone’s concern for it. But except for the cataract issue, we don’t really consider exposure risks until your body gets up into the tens of rem, or the tens of milli-gray. Even over a lifetime, that’s a lot of exposure, and most of my interventionalists never reach that dose. And in any medical field today, especially surgery, you really can’t get away from exposure. If someone has a passion for IR, they should follow it and not worry about risks as long as they follow good safety practices: minimize the patient dose, wear protective clothing, use the fold on shields as close to the patient as you can and utilize the table skirt to minimize the radiation under the table.
Read more about radiation safety in IRQ:
- Primer on radiation exposure and protective equipment
- Allaying radiation safety concerns for pregnancy in IR
