1 in 500? I don't like those odds.

October 27, 2009 7:44 AM

CT scans on children for hearing problems. Worried about radiation risks. Wait?

Asking for a friend:

Last year when my son was four years old it was discovered that he has what our ENT called maximum conductive hearing loss in his left ear. A little over two years ago, his older brother had stuck an opened large paperclip into the ear that now has hearing loss. The ENT is unsure if the paper clip incident is related to the hearing loss but has not ruled it out entirely. A CT scan has been ordered to look for "ossicular discontinuity due to h/o trauma, congenital ossicular abnormality, or congenital otosclerosis" (even though he passed his hearing test at birth).

The reason for the CT is so the doctor can determine if my son is a candidate for ear surgery to repair whatever is causing the hearing loss. When my son was tested for hearing the audiologist told me that he is a great candidate for a hearing aid as well, as he could hear well from the ear in question when she had the settings placed at what a hearing aid would acheive for him.

My question is if it's worth getting a CT scan for a five year old. I have read that one CT scan can be the equivalent of 4000 chest x-rays and that a child has a 1 in 500 chance of developing cancer later because of the CT itself. Does anyone know how true these claims are? The CT would be of the temporal bones for conductive hearing loss in the middle ear. I am afraid that unless he is completely sedated he may move and the image will not be clear enough and they will have to take another one, which would only expose him to that much more radiation. I am hoping that if I ask for them to make sure the CT scanner is set for pediatric dosage they will actually put it on that setting.

Thanks for any advice anyone may have. You are not [a / my son's] doctor.

posted by ostranenie to health & fitness (12 comments total)

My advice would be to listen to your son's doctor.
posted by squorch at 7:49 AM on October 27 [4 favorites has favorites]

There's a chance that surgery might repair the problem and a CT scan will determine that.

You'd really rather take the chance that his hearing might degenerate further and fit him with a bothersome and not permanent hearing aid, than listen to your doctor and give your kid one (1) CT scan? The pediatric dosage is there for a reason and since your son is a child that's the setting they WILL use.

Listen to your doctor.
posted by lydhre at 7:58 AM on October 27 [4 favorites has favorites]

Poster, I assume you will get many answers here urging you to do what your doctor suggests. If you want advice beyond that, you may want to look to other sources as well - are there online Parents of Kids with Hearing Loss forums or something along those lines? Other specialists you could meet with or talk to casually?

To share my perspective, if I were in a similar situation, I think the first thing I would do would be to ask myself whether I would want my child to have the procedure the doctor is considering. No point in assessing for the procedure if you know you don't want to have it. Then I'd ask my doctor how this scan would effect their decision. What are some different finding the scan might show, and what would the doc want to do given different possible findings. (When I was pregnant, my water broke early, and I was having these amniotic fluid indexes done every two days or so. Finally I asked my doc - what would you do different if I came in one day and had an Amniotic Fluid Index of 1 (the lowest amount) and the doctor acknowledged she'd do nothing different no matter the finding. So I stopped doing them.)

Also, I think your concern about CT scans is valid. If you do decide to get a CT, you may have a choice about where you get it. If possible, you can research what facilities may be more flexible or receptive to your request about settings.

Good luck!
posted by serazin at 7:59 AM on October 27

Does anyone know how true these claims are?

Yes, your doctor will. You should discuss all your options with the ENT specialist. For example, you might ask if there is any detriment to waiting on a decision on ear surgery until later. Make sure you know the risks of the surgery too, and how they compare to the chance of getting cancer from a CT scan.
posted by grouse at 8:01 AM on October 27

I'm just going to argue number heres. According to the American Cancer Society at cancer.org, the odds of a male getting cancer in their lifetime are 44.05%. The odds of him eventually dying from cancer are 23.24%. This 1/500 chance that you speak of, whether true or not and all other things being equal, would up that risk of getting cancer from 44.05% to 44.052%. In other words, this one CT scan is pretty insignificant, given all the other bad things going on or in our bodies.
posted by cgg at 8:10 AM on October 27 [7 favorites has favorites]

That 1-in-500 seemed curious to me. Here is one study cited by the National Cancer Institute:

Brenner DJ, Elliston CD, Hall EJ, Berdon WE. Estimated risks of radiation-induced fatal cancer from pediatric CT. American Journal of Roentgenology 2001; 176:289-296.

On the basis of the standard models applied here, the lifetime cancer mortality risks attributable to radiation from a pediatric CT examination are estimated to be considerably higher than for adults. For example, a best estimate of the lifetime cancer mortality risk attributable to the radiation exposure from a single abdominal CT examination in a 1-year-old child is approximately one in 550, and approximately one in 1500 for a head CT examination. These estimated risks are an order of magnitude higher than risks for adults. In the United States, at least 600,000 abdominal and head CT examinations per year are currently performed on children less than 15 years old and, of these individuals, a rough estimate is that approximately 500 will ultimately die from a cancer attributable to the radiation from the CT.

Although the absolute estimated risks that we have projected are quite high, the percentage increase in the cancer mortality rate over the natural background rate is very low. For example, of the approximately 600,000 children less than 15 years old who are estimated to undergo CT each year in the United States, approximately 140,000 will ultimately die of cancer. Thus, the estimated projected 500 CT-related deaths represents a small (»0.35%) percentage increase over this background.

I think this shows how hard it is to interpret the summaries that news orgs put out. 1 in 500 sure sounds bad, eh? But everyone dies of something, and 1 in 4 kids will die from cancer anyway, eventually.

One other thing to consider is that these are lifetime cancer rates. The CT scan was invented in the early 70's. So there isn't "real" lifetime data for child CT scans, since most of them haven't died yet. It's all theoretical modeling.
posted by smackfu at 8:10 AM on October 27 [2 favorites has favorites]

You are aware that by the time your child reaches the age of 65 there is a 40-50% chance that he will have had skin cancer (the most common variant), and overall 20% of Americans will develop some for of skin cancer in their lifetimes. So assuming you let your child go outside regularly it is 100x more likely that he will develop some form of cancer over the course of his life than he will from getting a CT according to claims you found on the internet.

Talk to you doctor about this and listen to him/her.
posted by BobbyDigital at 8:11 AM on October 27

please ignore the typos. So looking forward to eventually getting that opportunity to edit our posts.
posted by cgg at 8:12 AM on October 27

Bad numbers. I fail at math this morning. That should be 44.05 goes to 44.25. Still insignificant though. Sorry about that.
posted by cgg at 8:17 AM on October 27 [1 favorite has favorites]

I think you need to take a step back - in many instances where there is hearing loss in one ear, it is not usual to fit a hearing aid to the other. I am one of them. I was deaf in my right ear from birth and had reconstructive surgery, but no surgery to improve hearing in that ear. In children, it is more usual to monitor the hearing of the 'good' ear, and if something happens to that one then consider hearing aids. Because being a kid, one adapts quite readily to these situations and grow up fine.

On the matter of the CT scan, I can't even remember cancer risks being raised when I was going through my ear surgery (initial consult, age 2, surgery age 8-12). But I do remember that depending on the procedure, there is significant risk associated with ear surgery due to the nerves that run close by to the face. CT scan I didn't care so much about. Potentially being facially paralysed, yeah I cared about that.

Maybe get a second opinion on whether this surgery is needed at all. I know I know, if I was a parent, I would surely feel differently.
posted by wingless_angel at 9:02 AM on October 27

I agree with those above who point out that the risks from a single CT scan are pretty small. You/your friend are right to be concerned about unneccessary radiation, but the real problem there is when people get CT scans at the drop of a hat for weak indications "just to make sure we don't miss anything." In this child's case it sounds as if they are looking for a specific problem that can be treated. In some instances an MRI can be an acceptable alternative to a CT scan and so is worth asking about, but it may well be that the bones of the middle ear will not show up well enough to make a diagnosis from MRI. Also, a CT scan on modern equipment only takes a couple of minutes, while an MRI would take a minimum of 30 minutes; to keep a 5 year old still for that long would almost certainly require sedation or anesthesia. Some sort of sedation might be neccessary for the CT scan, but there are 5 year olds who can be still long enough. It helps if you are going to a hospital that cares for children; they will be used to addressing all those concerns.
posted by TedW at 10:01 AM on October 27

Thanks so much for all your advice.
posted by ostranenie at 11:44 AM on October 27