Can Medical Scans Cause Cancer? Dr. Michael Lauer says yes
Dr. Michael Lauer hails from the National Heart, Lung, and Blood Institute in Bethesda, Maryland. He believes that as much as 2% of all cancers in the US are related to CT scans. He based this conclusion on an article that was published in the New England Journal of Medicine in 2009 by Dr. Reza Fazel entitled “Exposure to Low-Dose Ionizing Radiation from Medical Imaging Procedures”.
That article concludes:
In terms of rates of exposure to moderate and high doses of radiation, 193.8 per 1,000 enrollees per year were exposed to moderate levels of radiation (>3–20 mSv) and 18.6 and 1.9 were exposed to high (>20–50 mSv) and very high (>50 mSv) levels, respectively. The researchers point out that although most subjects received less than 3 mSv per year, “effective doses of moderate, high, and very high intensity were observed in a sizeable minority.”
He also believes that we just don’t know enough about how powerful scans affect our bodies. In my own experience, when I used to work at the Columbia University Cancer center, we would send our breast cancer patients to receive 3, and in some cases, up to 4 chest CT scans in one year. That is equivalent to 32 mSv which is getting somewhat close to the limit that radiation workers are legally able to receive (50 mSv in the US). We would also send them for bone scans and mammograms on top of this so I am sure some of our patients approached the limit that radiation workers should receive.
I just published a blog about the effects of radiation on human beings, and above certain doses, yes, high-dose exposure to ionizing radiation can lead to cancer. All of these scans (below) use Xrays. The radiation doses from a few different scans I have pasted below:
- Chest X-ray (0.10 mSv)
- CT scan of abdomen (10 mSv)
- CT scan of chest (8 mSv)
- CT scan of head (2 mSv)
- Dental X-ray (0.09 mSv)
- Mammogram (0.7 mSv)
- X-ray of skull (0.07 mSv)
- Whole-body CT scan (10 mSv)
Keep in mind that the average background radiation a human being is exposed to every year is around 3 mSv.
In that blog I also published this chart of acute radiation exposure effects :
Effect Dose (rems)
– No observable effect 0-25
– Slight blood changes 25-100
– Significant reduction in blood platelets
and white blood cells (temporary) 100-200
– Severe blood damage, nausea, hair loss,
hemorrhage, death in many cases 200-500
– Death in less than two months
for over 80% >600
So it seems that too many scans (even as much as 4 – 5 in one year) might indeed do some damage to tissues but, I agree with Dr. Lauer with this, exactly how much and in what way remains to be studied.