Risks & Benefits

Radiation effects from general radiography procedures are discussed. Studies evaluating the safety and impact on patients and current analysis on x-ray safety as it relates to general radiography are provided. Discussion of various methods in minimizing radiation exposure.

Articles discussing risk of radiography low dose radiation:
The Scoliosis Quandary: Are Radiation Exposures From Repeated X-Rays Harmful?

 

Loyola University Health System - 2015

In recent years, there has been widespread media coverage of studies purporting to show that radiation from X-rays, CT scans and other medical imaging causes cancer. But such studies have serious flaws, including their reliance on an unproven statistical model, according to a recent article in the journal Technology in Cancer Research & Treatment. Corresponding author is Loyola University Medical Center radiation oncologist James Welsh, MS, MD.

"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," Dr. Welsh and co-author Jeffry Siegel, PhD, write.

J. A. Siegel, J. S. Welsh. Does Imaging Technology Cause Cancer? Debunking the Linear No-Threshold Model of Radiation Carcinogenesis. Technology in Cancer Research & Treatment, 2015; DOI: 10.1177/1533034615578011

 

American Journal of Clinical Oncology

No Proof that Radiation from X-Rays and CT Scans Causes Cancer Radiation fears based on unproven theoretical model- Feb 3rd, 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, MD and colleagues write. Use of the LNT model drives unfounded fears and "excessive expenditures on putative but unneeded and wasteful safety measures."

 

LOW DOSE RADIATION

NO REASON TO FEAR LOW DOSE RADIATION

Jerry Cuttler, Ph.D. Nuclear Sciences and Engineering, past president of Canadian Nuclear Society. Is it safe to be exposed to low-level radiation? You can go to two different places for answers: 1) If you go to the radiation protection people, whose job it is to protect everyone from any exposure to radiation (human-made), you'll find there’s a higher risk of cancer. 2) But, if you go out into the real world, who do you know that’s ever been harmed by low-level radiation? There’s just no evidence of that. There are beneficial effects of low radiation from medical practitioners ~1900 to ~1960, to eliminate metastases or slow cancer growth, accelerate healing of wounds, stop infections: gas gangrene, carbuncles and boils, sinus, inner ear, pneumonia, and treat arthritis and other inflammatory conditions.

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X-Ray Basics Safety
Molecular biology, epidemiology, and the demise of the linear no-threshold (LNT) hypothesis.Pollycove M1, Feinendegen LE.; Comptes Rendus de I'Academie des sciences,C R Acad Sci III. 1999 Feb-Mar;322(2-3):197-204.The biologic effect of radiation is not determined by the number of mutations it creates, but by its effect on the biosystem that controls the relentless enormous burden of oxidative DNA damage. At low doses, radiation stimulates this biosystem with consequent significant decrease of metabolic mutations. Low-dose stimulation of the immune system may not only prevent cancer by increasing removal of premalignant or malignant cells with persistent DNA damage, but used in human radioimmunotherapy may also completely remove malignant tumors with metastases. The reduction of gene mutations in response to low-dose radiation provides a biological explanation of the statistically significant observations of mortality and cancer mortality risk decrements, and contradicts the biophysical concept of the basic mechanisms upon which, ultimately, the NCRPs confidence in the LNT hypothesis is based.2Q
“The argument that Low dose radiation can induce a genomic instability, which can in turn induce a cancer is not based on convincing data” No significant correlation between sensitivity to radiation-induced genomic instability and cancer induction. Doses of less than 100 mSv, cancer excess is not seen. However it doesn’t rule out the possibility of a smaller effect inducing cancer.
Atomic bomb data does not provide solid arguments for the LNT model. Among humans there is no carcinogenic effects for acute irradiation at doses less than 100mSv and for protracted Irradiation at doses less than 500mSv. Fears associated with LNT at any dose lack scientific justification. If the carcogenic risk exists, it is so small that it is without clinical importance
Does Imaging Technology Cause Cancer? Debunking the Linear No-Threshold Model of Radiation Carcinogenesis.Siegel JA, Welsh JS; Technology in cancer research and treatment,Technol Cancer Res Treat. 2016 Apr;15(2):249-56. doi: 10.1177/1533034615578011. Epub 2015 Mar 30.The risk:benefit ratio models used to calculate the hazards of radiological imaging studies may be grossly inaccurate if the linear no-threshold hypothesis is wrong. Here, we review the myriad inadequacies of the linear no-threshold model and cast doubt on the various studies based on this overly simplistic model.The current model of radiation carcinogenesis is based on linear transgression of high-dose radiation exposure. Low-dose radiation exposure (<100-200 mSv) is what the medical and chiropractic fields operate in, and are not comparable to the conclusions from high-dose studies. The authors further state that low-dose radiation exposure is likely beneficial when the healing function of the boy is considered.
It Is Time to Move Beyond the Linear No-Threshold Theory for Low-Dose Radiation Protection.Cardarelli JJ 2nd, Ulsh BA.; ,Dose Response. 2018 Jul-Sep; 16(3): 1559325818779651.
Published online 2018 Jul 1. doi: 10.1177/1559325818779651
Currently, the USEPA uses the linear no-threshold (LNT) model to estimate cancer risks and determine cleanup levels in radiologically contaminated environments. The LNT model implies that there is no safe dose of ionizing radiation; however, adverse effects from low dose, low-dose rate (LDDR) exposures are not detectable. This article (1) provides the scientific basis for discontinuing use of the LNT model in LDDR radiation environments, (2) shows that there is no scientific consensus for using the LNT model, (3) identifies USEPA reliance on outdated scientific information, and (4) identifies regulatory reliance on incomplete evaluations of recent data contradicting the LNT.This study shows low dose radiation in X-rays are not as dangerous as previously thought
Diagnostic pediatric computed tomographic scans of the head: actual dosage versus estimated risk.Jaffurs D, Denny A; Plast Reconstr Surg. 2009 Oct;124(4):1254-60. doi: 10.1097/PRS.0b013e3181b59d2d.The authors suggest that published experimental evidence does not support the linear no-threshold model at low linear energy transfer levels similar to the exposure of their patients undergoing computed tomographic scans of the head. In addition, no convincing epidemiologic data exist demonstrating an increase in cancer incidence for doses below 100 mSv.This study shows low dose radiation in X-rays are not as dangerous as previously thought
Regarding the Credibility of Data Showing an Alleged Association of Cancer with Radiation from CT Scans.Socol Y1, Welsh JS;Technol Cancer Res Treat. 2016 Feb;15(1):159-62. doi: 10.1177/1533034614566923. Epub 2015 Jan 23.Computed tomography (CT) scans are of high clinical value as a diagnostic technique, and new applications continue to be identified. However, their application is challenged by emerging concerns regarding carcinogenesis from their radiation. Recent articles made a significant contribution to the above-mentioned concerns by reporting evidence for direct association of the radiation from CT scans with cancer. Such interpretation of the data has already been criticized; there is the possibility of reverse causation due to confounding factors. Nevertheless, such work has had a high impact, with one article being cited more than 300 times from the Web of Science Core Collection within 2 years. However, the data points on cancer relative risk versus CT dose in that article fit straight lines corresponding to the linear no-threshold hypothesis suspiciously well. Here, by applying rigorous statistical analysis, it is shown that the probability of the fit truly being that good or better is only 2%. The results of such studies therefore appear "too good to be true" and the credibility of their conclusions must be questioned.This study discusses CT scans and cancer risk. It states previous studies cite the same study that was statistically suspicious. This study re-analysis this study and shows that probability of the CT-Cancer study being accurate is 2%.
Risk of radiation-induced malignancies from CT scanning in children who underwent shunt treatment before 6 years of age: a retrospective cohort study with a minimum 10-year follow-up.White IK1, Shaikh KA, Moore RJ, Bullis CL, Sami MT, Gianaris TJ, Fulkerson DH; J Neurosurg Pediatr. 2014 May;13(5):514-9. doi: 10.3171/2014.2.PEDS12508. Epub 2014 Mar 14.Previously published models predict a significant number of future cancers directly caused by CT scanning. However, there are very few published clinical data. In the authors' study, zero future radiation-induced malignancies were detected after routine CT scanning in a high-risk group. While the authors do not consider their single-institution study adequate to define the actual risk, their data suggest that the overall risk is low. The authors hope this study encourages future collaborative efforts to define the actual risk to patients.This study shows that after routine CT scans in a high-risk group of children, no cases of radiation-induced malignancies were observed after 10 year follow up.