This post is by Gabriel's dear old Dad, Eric. One of the recommendations of our speech therapist was to get an upper-GI barium swallow study done, which is a series of X-rays performed while the baby is swallowing. I was concerned about the radiation dose of such a procedure, and wasn't able to get an answer I could understand. This letter I wrote to the head of the imaging department at Tacoma General Hospital explains the process if you're interested in learning more...
Jim Sapienza
Imaging Administrator
Mail Stop 315C3IAD
315 Martin Luther King Way
Tacoma, WA 98405
Dear Mr. Sapienza:
I am writing you to give some comments and suggestions about the experience of a parent trying to get information about radiation doses that a child might receive while getting x-ray procedures performed. A month ago, we scheduled an upper GI barium swallow study at Tacoma General for our 8 ½ month-old son, but I wanted to get information about how much radiation he would receive in such a procedure, or to put it bluntly, how much the child would be zapped? I was not able to find the information.
To give you a little background, our son was born 17 weeks premature at Swedish Hospital in Seattle, and got a number of x-rays performed there (and I’m not interested in increasing his dose if it can be avoided). He has grown out of almost all of his preemie issues except for eating. He does not drink enough from his bottle and must be supplemented through a gastric tube. Our son’s speech therapist recommended a barium swallow study. We scheduled this.
A call to the GI clinic at Mary Bridge eventually got me transferred to Michael Smith, who was quite helpful in explaining how the procedure was done. He explained that he would shield his eyes and genitals, try to dodge his spine, but his thyroid would get a direct hit. I wanted to know how many millisieverts or millirems he would receive from the procedure.
To tell you a little bit about my own experience on the topic, I am a bookkeeper, and one of the employers I serve is a lawyer who represents workers at the Hanford Nuclear Reservation. This means that I don’t know a great deal about radiation, but I do know that we receive about 2.5 mSv of background radiation per year, and that the annual federal limit for additional radiation on a job is 10 millirem, or 0.1 mSv. I also know that the typical chest x-ray gives us about 0.1 mSv of radiation. I was hoping for an estimate that would compare to these sorts of levels.
Michael provided me with radiation doses from the last five patients to receive upper GI barium swallow studies. The numbers were:
81.7 cGy cm2 over 1 minute 51 seconds
177 cGy cm2, 3:43
168.8 cGy cm2, 1:52
206.1 cGy cm2, 0:49
73.9 cGy cm2, 3:22
Michael wasn’t able to tell me the age or size range of the patients receiving these doses, and he also wasn’t able to explain how the per-centimeter-squared thing worked. I know what a centigray is, but converting these numbers to something that compares to other experiences that a person might have with radiation was difficult. A friend of my boss’ explained that you needed to divide the number of centigrays by the number of square centimeters in the target area to get the correct dose. If you assumed that the target area would be 25 square centimeters, you’d end up with a dose between 32 and 83 mSv, which seemed awfully high. I doubted that I had the numbers correct, but that was about as far as I could get in finding an explanation that made sense.
I brought it up with the speech therapist who originally wanted the test performed, who assured me that the procedure involved no more radiation than a dental x-ray, but I knew that wasn’t close to true -- dental x-rays are a few snapshots that don’t hit the thyroid, while a swallow study is an animation, or a whole lot of snapshots that do hit the thyroid.
Unable to find an answer to my original question -- how much will the child be zapped -- I canceled the appointment. I don’t mean to be “that parent” who overreacts when a pre-school doesn’t use organic food in the meals, or who refuses the polio vaccine because he believes it will cause autism, but in this case, objecting does make sense. Radiation will increase cancer risk, and I didn’t want to increase my son’s dose, especially when I do not have any idea how much he would receive. A stock answer that medical professionals provide when asked about radiation is that it’s a “minimal dose,” which to me sounds like someone trying to assure me my house has “minimal flooding.”
So let me conclude by again speaking well of Michael Smith’s helpfulness, but advising you that parents need access to better information about radiation doses than is currently available. I am still open to the idea of performing this procedure which may provide information that improves my son’s eating ability, but I need accurate and comparable information about the expected radiation dose before I allow it.
I would appreciate hearing your thoughts on the topic.
Sincerely,
Eric Ruthford
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