News | Radiation Dose Management | February 04, 2016

No Proof Medical Imaging Radiation Causes Cancer

Radiation fears based on unproven theoretical model, study finds

medical imaging, low-dose radiation, cancer, LNT model study

February 4, 2016 — The widespread belief that radiation from X rays, CT scans and other medical imaging can cause cancer is based on an unproven, decades-old theoretical model, according to a study published in the American Journal of Clinical Oncology.

The model, known as linear no-threshold (LNT), is used to estimate cancer risks from low-dose radiation such as medical imaging. But risk estimates based on this model “are only theoretical and, as yet, have never been conclusively demonstrated by empirical evidence,” corresponding author James Welsh, M.D., and colleagues write. Use of the LNT model drives unfounded fears and “excessive expenditures on putative but unneeded and wasteful safety measures.”

Welsh is a Loyola University Medical Center radiation oncologist and a professor in the Department of Radiation Oncology of Loyola University Chicago Stritch School of Medicine.

The LNT model dissuades many physicians from using appropriate imaging techniques and “discourages many in the public from getting proper and needed imaging, all in the name of avoiding any radiation exposure,” Welsh and colleagues write.

The authors reexamined the original studies, dating back more than 70 years, which led to adoption of the LNT model. This reappraisal found that the data reported in those studies do not actually support the LNT model.

In the LNT model, the well-established cancer-causing effects of high doses of radiation are extended downward in a straight line to very low doses. The LNT model assumes there is no safe dose of radiation, no matter how small. However, the human body has evolved the ability to repair damage from low-dose radiation that naturally occurs in the environment.

The LNT model dates to studies, conducted in the 1940s, of fruit flies exposed to various doses of radiation. The scientists who conducted those studies concluded there is no safe level of radiation, thus giving rise to the LNT model that is used to this day. But their conclusion was unwarranted because their experiments had not been done at truly low doses. A study exposing fruit flies to low-dose radiation wasn’t conducted until 2009, and this study did not support the LNT model.

Studies of atomic bomb survivors and other epidemiological studies of human populations have never conclusively demonstrated that low-dose radiation exposure can cause cancer.

Any claim that low-dose radiation from medical imaging procedures is known to cause cancer “should be vigorously challenged, because it serves to alarm and perhaps harm, rather than educate,” Welsh and colleagues write.

The authors conclude the LNT model “should finally and decisively be abandoned.”

The study is titled “The birth of the illegitimate linear no-threshold model – an invalid paradigm for estimating risk following low-dose radiation exposure.”

In addition to Welsh, co-authors are: Jeffry Siegel, Ph.D., president and CEO of Nuclear Physics Enterprises (first author); Charles Pennington of NAC International and Bill Sacks, M.D., Ph.D., emeritus medical officer in the U.S. Food and Drug Administration (FDA) Center for Devices and Radiological Health.

 

Read the article, “Public Perception of Long-term Health Effects of Atomic Bomb Radiation Worse than Reality.”

Read the article “CT Cancer Risk Poorly Understood by Many Healthcare Providers.”

 

For more information: www.journals.lww.com/amjclinicaloncology

Related Content

DISRUPT BTK Study Shows Positive Results With Lithoplasty in Calcified Lesions Below the Knee
News | Peripheral Artery Disease (PAD)| September 20, 2017
Shockwave Medical reported positive results from the DISRUPT BTK Study, which were presented at the annual...
CZT SPECT camera detectors offered by GE.

A display of CZT SPECT gamma camera detectors at RSNA 2016. These detectors are more sensitive than those used in older cameras, allowing for faster scans or lower radiation dose. 

Feature | Nuclear Imaging| September 19, 2017 | Dave Fornell
Cardiac nuclear myocardial perfusion imaging (MPI) has been a mature area of imaging for years, but has recently star
Corindus Announces First Patient Enrolled in PRECISION GRX Registry
News | Robotic Systems| September 18, 2017
September 18, 2017 — Corindus Vascular Robotics Inc.
Two-Year ILLUMENATE Trial Data Demonstrate Efficacy of Stellarex Drug-Coated Balloon
News | Drug-Eluting Balloons| September 18, 2017
Philips announced the two-year results from the ILLUMENATE European randomized clinical trial (EU RCT) demonstrating...
Sentinel Cerebral Protection System Significantly Reduces Stroke and Mortality in TAVR
News | Embolic Protection Devices| September 18, 2017
September 18, 2017 – Claret Medical announced publication of a new study in the...
Philips Launches CardioMD IV Cardiac SPECT Solution at ASNC 2017
Technology | SPECT Imaging| September 15, 2017
September 15, 2017 — Philips highlighted its newest solution for...
Marijuana Associated With Three-Fold Risk of Death From Hypertension
News | Hypertension| September 14, 2017
Marijuana use is associated with a three-fold risk of death from hypertension, according to research published recently...
Peter Schneider, M.D. presents late breaking clinical trial results at VIVA 17 in Las Vegas. Panelists (l to r) Krishna Rocha-Singh, M.D., Sean Lyden, M.D., John Kaufman, M.D., Donna Buckley, M.D.

Peter Schneider, M.D. presents late breaking clinical trial results at VIVA 17 in Las Vegas. Panelists (l to r) Krishna Rocha-Singh, M.D., Sean Lyden, M.D., John Kaufman, M.D., Donna Buckley, M.D.

Feature | Cath Lab| September 14, 2017
September 14, 2017 — Here are quick summaries for all the key late-breaking vascular and endovascular clinical trials
Mississippi Surgical and Vascular Center Uses Toshiba Ultimax-i FPD to Save Patients' Limbs
News | Angiography| September 14, 2017
The southern U.S. sees some of the highest numbers of chronic medical conditions, such as peripheral artery disease...
Overlay Init