Recent studies throw into question the risk/benefit ratio of CT scans. Some are more risky than others in terms of cancer incidence.
We’ve discussed this on the blog a few times, here, here and here. The last link is to my book where I tell the story of a patient who had an unnecessary CT scan which then led to multiple problems. Not a cancer risk, but a cautionary tale about the importance of the risk/benefit ratio of CT scans.
First, Do No Harm. We can’t be reminded enough!
The first article discussed is here, by Maurie Markman
Smith-Bindman R, Chu PW, Azman Firdaus H, et al. Projected Lifetime Cancer Risks From Current Computed Tomography Imaging. JAMA Intern Med. 2025;185(6):710–719. doi:10.1001/jamainternmed.2025.0505
The second one is here.
Medical Imaging and Pediatric and Adolescent Hematologic Cancer Risk
Authors: Rebecca Smith-Bindman, M.D., Susan A. Alber, Ph.D., Marilyn L. Kwan, Ph.D., Priscila Pequeno, M.Sc., Wesley E. Bolch, Ph.D., Erin J.A. Bowles, M.P.H., Robert T. Greenlee, Ph.D., +10 , and Diana L. Miglioretti, Ph.D.Author Info & Affiliations
Published September 17, 2025
N Engl J Med 2025;393:1269-1278
The key points outlined in the article are
Hello. I’m Dr Maurie Markman, from City of Hope. In this particular segment, I’m going to wade into an incredibly controversial topic, but one I do believe needs much more discussion. There are two papers I’m going to note, one of which I’m going to talk about in a little detail. The other I’m just going to mention as it provides data that is supportive.
The first paper is entitled, “Projected Lifetime Cancer Risks From Current Computed Tomography Imaging,” published in JAMA Internal Medicine. The second paper is entitled, “Medical Imaging and Pediatric and Adolescent Hematologic Cancer Risk,” published in The New England Journal of Medicine. Again, and you can imagine just by the titles of the papers, this is controversial.
- CT radiation = known carcinogen; population-level risk remains debated.
- 2023: 62M patients underwent 93M CT exams; 2.5M were children.
- Modeling estimated ~103,000 radiation-induced cancers from 2023 CT exposure.
- Abdomen/pelvis CT had highest projected cancer impact.
- Sensitivity analysis ranged 80,000-127,000 induced cancers; authors estimated ~5% of new cancers/year.
“Now, surprisingly, the highest potential impact was for CT scans of the abdomen and pelvis. The investigators also did a sensitivity analysis that obviously changed certain assumptions, and this went from, I mentioned, 103,000 induced cancers from radiation exposure. The sensitivity analysis went from 80,000 at the low end to 127,000 at the high end. ”
Hello. I’m Dr Maurie Markman, from City of Hope. In this particular segment, I’m going to wade into an incredibly controversial topic, but one I do believe needs much more discussion. There are two papers I’m going to note, one of which I’m going to talk about in a little detail. The other I’m just going to mention as it provides data that is supportive.
The first paper is entitled, “Projected Lifetime Cancer Risks From Current Computed Tomography Imaging,” published in JAMA Internal Medicine. The second paper is entitled, “Medical Imaging and Pediatric and Adolescent Hematologic Cancer Risk,” published in The New England Journal of Medicine. Again, and you can imagine just by the titles of the papers, this is controversial.