According to a recent study published in the Journal of the American College of Cardiology: Cardiovascular Imaging, scientists have noticed detectable cellular damage in patients who have had CT-Scans. Won Hee Lee, PhD, and Yong Fuga Li, PhD, both postdoctoral scholars and the study’s other lead authors from Stanford University School of Medicine used new laboratory technology to demonstrate the findings.
Consequences Of Using Medical Imaging Techniques
According to Joseph Wu, MD, senior author, Professor of Medicine and Radiology, and the Director of the Stanford Cardiovascular Institute, the use of medical imaging techniques has become fairly common in the past decade, especially in the context of heart diseases. He explained that these techniques exposed patients to nontrivial amounts of low-dose radiation. Nevertheless, the actual effects of the latter are not well-documented.
This boom in the use of advanced medical imaging tests has also led to an increase in public health concerns regarding the association between low-dose radiation and cancer. A CT-Scan (imaging and diagnostic test) exposes the body to about 150 times more radiation than a simple chest X-ray. In 2007, the National Cancer Institute predicted that about 29,000 cases of cancer could be expected as a result of the 72 million CT-Scans performed that year.
Considering these statistics and findings, it is feared that frequent exposure to radiation during these diagnostic tests might damage DNA, creating mutations that lead to tumors.
Study Reveals Increase In Cell Death And Damage
The research team examined the effects of low-dose radiation – from various cardiac and vascular CT-Scans – on human cells. These imaging techniques are generally used for monitoring patients with obstructive coronary artery disease and aortic stenosis (during preparation of transcatheter aortic valve replacement).
The researchers took blood samples from 67 patients that were undergoing cardiac CT angiograms. Using techniques such as whole-genome sequencing and flow cytometery, they measured the presence of DNA damage biomarkers. The blood samples were examined both, before and after the patients had their procedure.
How CT-Scan Can Damage Your DNA?
Results showed an increase in DNA damage and consequent cell death in blood samples of patients after they had been exposed to these radiations. Moreover, an increase in the expression of genes associated with cell repair and death was also observed. Even though most of the cells damaged by the low-dose radiation were repaired, a minute percentage did not recover.
What’s important to note is that no DNA damage was detected in patients – average weight and regular heart rates – receiving the lowest dose of radiation.
Understanding The Findings
The findings reveal that there is a significant possibility of DNA damage and cell death after exposure to advanced medical imaging/diagnostic procedures. If not promptly repaired or eliminated, this damage can lead to various mutations. Moreover, cumulative cell death after repeated exposures to such procedures is also a problem for the human body.
Patricia Nguyen, MD, one of the lead authors and an Assistant Professor of Cardiovascular Medicine at Stanford highlighted the importance of the non-benign effects of this low-dose exposure reported by the study. She explained that physicians shouldn’t eliminate CT-Scans completely, but they should focus on making them safer – reducing the radiation dose, using better technology, or by protecting patients before the test.
Further Research Required To Overcome Public Concerns
Despite these findings, there is still limited evidence to demonstrate the effect of low-dose radiation on the human body. There is currently a bill making its way through Congress, demanding funds for further research on how low-doses of radiation affect health.
Dr Nguyen assumes that the legitimate concerns of the public exist because a causal relationship between exposure to low-dose radiation and cancer is difficult to prove. Despite the study showing DNA damage and cell death, a large percentage of the damage is eventually repaired. The cells that escape repair and go on to mutate are the ones that cause cancer, and with current technology, those cells cannot be tracked.
“Whether or not exposure to low-doses of radiation through these imaging techniques causes cancer or any negative effect to the patient is still not clear, but these results should encourage physicians toward adhering to dose reduction strategies”, Dr Nguyen added.
In order to develop more conclusive predictions, scientists must unravel the underlying relationship between radiation and cancer. The effects of high doses of radiation are well-known – it is now important to understand what really happens at the cellular level.