The Blessing and the Burden of the CT Scan

CT SCANS

In the era of medical marvels, few technologies are as celebrated–or as ubiquitous–as the computed tomography (CT) scan. Offering rapid and detailed internal imaging, it has revolutionized diagnostics, saving countless lives. Yet beneath this technological triumph lies a growing unease.

A groundbreaking 2025 study published in JAMA Internal Medicine has drawn a sobering conclusion: CT scans performed in the United States in 2023 could result in more than 100,000 future cancer cases–a staggering projection that may position CT as the source of up to 5% of annual U.S. cancer diagnoses.

The Problem Behind the Picture: Context for Concern

CT scans work by using ionizing radiation–a form of energy that can damage DNA and, over time, potentially initiate cancer. While other medical imaging techniques like ultrasound or MRI are radiation-free, CT is often the first resort due to its speed and detail, especially in emergency settings.

In 2023, 93 million CT exams were performed on over 61 million patients, an increase of more than 30% since 2007. Many were likely necessary. But as the authors note, a significant portion were not. This has led to what some experts now label a public health paradox: a diagnostic tool that helps detect cancer may also be contributing to its rise.

What the New Study Reveals

Methodology in a Nutshell

The University of California, San Francisco (UCSF)-led team analyzed 121,000 real-world CT scans from 143 hospitals across 20 states. Using the National Cancer Institute’s RadRAT modeling software, the researchers estimated the organ-specific doses of radiation and projected lifetime cancer risks for different age, sex, and scan-type groups.

They excluded patients in the last year of life–where cancer risk from radiation is moot–and found that even with such adjustments, 103,000 radiation-induced cancers could be expected over the coming decades.

Key Findings

• Adults bear the brunt: 91% of the projected cancers occurred in adults.
• Children face higher per-scan risks, with infants under one year facing up to 20 cancers per 1,000 scans.
• Most common scan types causing cancer: Abdominal/pelvic (37% of cases), chest (21%), and head (12%).
• Most common cancers linked to CT:
  • Lung cancer (22,400 cases)
  • Colon cancer (8,700)
  • Leukemia (7,900)
  • Breast cancer (5,700)
  • Thyroid cancer (7,000; half in children)

Notably, this projection marks a tripling from a similar 2009 study, driven by both increased CT use and better data on scan-related radiation exposure.

Industry Pushback and Scientific Contention

Critics of the study, including respected radiologists from Mayo Clinic and Duke University, argue the projections may overstate risk due to reliance on atomic bomb survivor data and statistical models rather than observed patient outcomes. They emphasize the life-saving nature of CT in trauma, stroke, and cancer staging, cautioning against fear-mongering.

Yet these rebuttals, while valid, skirt a deeper ethical issue: Informed consent and medical necessity.

CT’s Dirty Secret: Radiation Is Cumulative

While a single CT scan may seem harmless–equivalent to several years’ worth of background radiation–repeated scans multiply exposure. Many patients, particularly those with chronic illnesses or undergoing cancer surveillance, may accumulate radiation doses well beyond safe thresholds, increasing their risk of cancer induction by orders of magnitude.

As Dr. Madan Rehani of Harvard notes, DNA breaks caused by CT radiation may go unrepaired or be misrepaired, creating the perfect storm for mutations and malignancies.

Overuse and Under-regulation: A Systemic Issue

One of the most troubling admissions from the medical community itself is that up to 30% of imaging exams may be unnecessary–ordered out of habit, fear of litigation, or diagnostic overkill. This “defensive medicine” not only inflates healthcare costs but may actively harm patients.

Moreover, older CT scanners still in use in many rural and underfunded clinics often emit higher doses, and few patients are ever informed of their radiation exposure.

The Image Gently and Image Wisely campaigns aim to reduce unnecessary scans, especially in pediatrics. Yet without mandatory dose tracking or patient disclosure laws, much of the burden still falls on uninformed patients.

What the Natural Health Movement Has Long Warned

Natural and integrative medicine advocates have long cautioned against overreliance on radiological interventions, especially when non-ionizing options like MRI* or ultrasound are suitable. They argue that true prevention lies in nutrition, detoxification, and lifestyle–not in exposing sensitive tissues to carcinogenic energy in the name of diagnostics.

The UCSF study doesn’t dispute CT’s utility–but it affirms what holistic health advocates have warned for decades: More imaging does not equal better care. And in many cases, less is more when it comes to radiation.

A Path Forward: Safer Scanning, Smarter Decisions

If CT must be used, radiation optimization protocols should be standard. The good news? The technology already exists. It is believed that ultra-low-dose scanners and AI-enhanced imaging may cut exposure by up to 90% without sacrificing clarity. But until patients demand it, and hospitals invest, progress will remain slow.

According to Dr. Rehani, market demand is key: “Manufacturers say they could produce ultra-safe machines today–but buyers aren’t asking for them.”

What You Can Do: Empowerment Through Awareness

Patients must become advocates. Before undergoing a CT scan, ask questions:

• Is this scan truly necessary?
• What will it change in my treatment plan?
• Could an MRI* or ultrasound provide similar information?
• Has the radiation dose been adjusted for my age and body size?

Even one empowered conversation can shift the trajectory of care–and health.

Conclusion: Rethinking Our Relationship with Radiation

While it is commonly believed and publicized that CT scans have saved millions of lives, the UCSF-led study makes clear they may also be silently costing lives – up to 5% of all US cancers. Renewed risk-benefit analyses need to be conducted, given these findings. A tool this powerful must be wielded with precision, humility, and transparency–not as a reflex, but as a last resort.

*MRIs are routinely performed with toxic contrast agents like gadolinium. Please educate yourself to learn about the real risks. 

References

1. Smith-Bindman R et al., Projected Lifetime Cancer Risks From Current Computed Tomography Imaging, JAMA Intern Med. 2025

2. Pearce MS et al., Radiation exposure from CT scans in childhood, Lancet. 2012

3. Mathews JD et al., Cancer risk in 680,000 people exposed to CT in childhood, BMJ. 2013

4. CT Scans May Account for 5 Percent of US Cancers–Doctors Say the Story Is More Comple

Sayer Ji is founder of Greenmedinfo.com, author of international best-seller REGENERATE: Unlocking Your Body’s Radical Resilience through the New Biology, co-founder of Stand for Health Freedom (501c4), and UNITE.live, a global, multi-media platform for conscious creators and their communities. 

Disclaimer: This article is not intended to provide medical advice, diagnosis or treatment. Views expressed here do not necessarily reflect those of GreenMedInfo or its staff.