A recent article by Dr. James Welsh and Dr. Jeffry Siegel claims that the studies, which show that radiation from X-rays, CT scans, and other medical imaging cause cancer, have serious flaws.
Although radiation is known to cause cancer at high doses and high-dose rates, no data have ever unequivocally demonstrated the induction of cancer following exposure to low doses and dose rates.
Studies that have found a cancer link to medical imaging typically employ a model called 'linear no-threshold' (LNT). In LNT, the well-established cancer-causing effects of high doses of radiation are simply extrapolated downward in a straight line to low doses.
The LNT model assumes there is no safe dose of radiation, no matter how small. But although LNT is used by regulators around the world, the model "is of questionable validity, utility and applicability for estimation of cancer risks," write the authors.
Contrary to the LNT model, there is compelling evidence that the human body has evolved the ability to repair damage from low-dose radiation. Studies purporting to find a cancer link to medical imaging radiation have other flaws as well.
For example, two recent studies suggested possible increased cancer risks from low-radiation doses associated with pediatric CT scans. But these cancers likely are due to the medical conditions that prompted the CT scans, and have nothing to do with the radiation exposure.
While many people focus on the purported risks of radiation in medical imaging, the more significant and actual risks associated with not undergoing an imaging procedure or undergoing a more invasive exploratory surgery are generally being ignored in both the scientific literature and the popular media.