Introduction I am charged with the difficult task of presenting the argument that ALARA and Image Gently should be terminated. My plea to you all is to use the infrastructure and energy provided by Image Gently to provide your patients with the best possible care. But, make changes because they are the correct thing to do, not because of a hypothetical fear of radiation. We will present evidence that ALARA and Image Gently have caused harm to our patients by getting them to believe that there is a risk of getting cancer from a CT scan. Understanding why ALARA was created The world of CT changed dramatically and the current Media obsession with cancer risk from CT radiation started on the 19 th June 2001 with the publication on the front page of the newspaper USA TODAY of an article by Steve Sternberg entitled “CT scans in children linked to cancer”. This received worldwide attention. This newspaper story was the direct result of a newly published scientific article in the AJR by Brenner. Its title was “Estimated Risks of Radiation Induced Fatal Cancer from Pediatric CT”. Pediatric Radiologists faced a terrible dilemma . How should they respond to the USA Today article? If they rejected the article they would be challenged to provide proof that there was no cancer risk from CT radiation; a daunting task . They could not endorse the article and start to deny children medically indicated imaging. The response was neither, but brilliant. Just two months after the USA today article the SPR organized a conference “the ALARA concept in pediatric CT”. Thus was ALARA introduced into pediatric radiology. This was not done to implement changes in pediatric radiology practice as a result of scientific proof that CT scans can cause cancer. No, ALARA entered pediatric radiology as the defense mechanism 1
to a newspaper article! ⦁ ALARA’s achievement has been to lower radiation dose to pediatric patients. What, we may ask is the benefit of lower pediatric radiation dose? ⦁ This is a very fair question as ALARA has been a dominant theme in Pediatric Radiology and beyond for almost 15 years. The evidence presented to prove that low dose radiation increases the cancer risk is completely hypothetical and it lacks scientific proof 1. Firstly we have the linear no threshold (LNT) unproven hypothesis. Mohan Doss will discuss this next. 2. Secondly we have epidemiological studies. In 2012 Pearce showed, and I quote “significant associations between the estimated radiation doses provided by CT scans and subsequent incidence of leukemia and brain tumors”, in children With over 1000 citations this article is probably the best known and most quoted epidemiological study. The methodology used by Pearce is severely flawed. ALARA justification Even without definite proof that CT radiation causes cancer, many may justify ALARA and Image Gently by saying “ it is better to be safe than sorry ". This is not a satisfactory justification. We accept small daily risks all the time, without campaigning to reduce them. We have cooking stoves in our homes, with risk of burns. We allow our children to swim, visit playgrounds, and ride bikes. Being safe would ban these 2
activities, but we don’t. Yes minimize radiation, but just take this as a normal sensible everyday approach to risk, not as something unique and special that needs endless articles and publicity. Unfortunately, there have been many negative effects of ALARA and Image Gently ⦁ They have caused many frightening media articles, which have generated unwarranted patient and referring physician anxiety and fear of CT scans . Media outlets use scientific publications as the source material for their articles. Soon after publication of the Pearce study many alarming reports of his article appeared. Examples include headlines such as “ CT scans on children could triple brain cancer risk'” (BBC News. ); “ CT scans can triple the risk of children getting leukemia ” (Times Newspaper) ⦁ Diagnostic errors are another negative outcome of Image Gently . In your own individual experience I suspect that you have seen overreactions by, referring physicians and parents, where relieving anxiety has taken precedent over diagnostic accuracy. We must place patient care first. Our obligation to our patients is an accurate diagnosis. We should not switch from CT to other less accurate imaging tests because of fear of radiation. ⦁ Journal peer review has often failed. Many scientific articles now have poor, invalid conclusions, driven by emotion and not based on experimental data. For example Brenner reported in 2015 that in 17 children, plasma antioxidant levels were lower one hour post CT compared pre-CT. His biased dogmatic conclusion, not based on his data , was “When possible and appropriate CT should be replaced with non-ionizing radiation techniques such as ultrasound or magnetic resonance imaging” (13). Media love to report these conclusions . It is fair to ask if ALARA and Image Gently are responsible for the many frightening global Media publications about CT scans and cancer? 3
Don Frush and Marylyn Goske, the Image gently campaign Chairpersons believe that ALARA and Image Gently have no responsibility for the extensive negative Media interest in CT and Cancer. In a 2015 publication they stated “Suffice is to say that the Alliance’s message has not been the impetus for alarm. Not one of the lay press articles implicates the presence of the Alliance as a cause for concern . The alarm generated is not a result of the Image Gently campaign but because of forces outside of this group. This fear would arguably be more substantial without the balanced and consistent voice of the Alliance. The intent of the Alliance is not to promote the debate of cancer risk with low-level radiation. The essence of the Alliance is education and advocacy” There is ample evidence contradicting the above statement that ALARA and Image Gently have not caused the alarming Media articles and patient fear of CT. They have! In the same 2015 article the Frush and Goske contradict themselves and state “ At the heart of the matter is the potential risk of medical imaging radiation-induced cancer in children resulting from a CT scan” . It is our scientific publications and Radiology Organizations that provide the Media with all the fuel that feeds their fires, that produces their articles that frighten our patients . Despite the claims of Drs Frush and Goske, there are endless prominent scientific publications, many under the ALARA and Image Gently banners claiming that CT imaging radiation causes cancer. ⦁ In an editorial in Radiology titled “The ALARA Concepts in Pediatric CT”, Tom Slovis stated “ There is an excess cancer incidence in individuals who were exposed to radiation doses comparable with the dose involved in helical CT” (3). ⦁ Reporting in Pediatric Radiology on an ALARA summit, Voss states” Numerous reports have emphasized that even low doses of radiation exposure, such as those occurring during radiological examinations, can lead to increases in risk of malignancy” ( 15). ⦁ In a white paper in Pediatric Radiology, on the ALARA concept Willis stated “Research indicates an increased risk of childhood leu kemia from plain film studies (16). 4
⦁ In an article on the Image Gently campaign Goske stated “However, one fact is indisputable: We must continue our efforts to do a better job of reducing radiation dose to children when they need a CT scan”. The media has not invented the concept that CT causes cancer . The media have merely responded to conclusions from peer reviewed publications and national scientific meetings. Many prominent Radiology websites also clearly claim that CT causes cancer. I will give just a few examples. Currently on the Image Gently web site are statements such as: ⦁ “However it must be understood that no procedure using ionizing radiation is without risk . ⦁ “There are increased cancers in people who have been exposed to radiation at levels that can be encountered by patients undergoing CT scans. ⦁ A recent American College of Radiology white paper states “ However, the evolution of imaging has also resulted in an increase in the population’s exposure to ionizing radiation and a potential increase in cancer risk.” Conclusion In summary, for the past 15 years ALARA and Image Gently , have maintained a very narrow focus on the topic of diagnostic imaging radiation causing cancer . All the alarming media articles on the subject are the direct result of ALARA inspired peer reviewed publications and scientific meetings that claim that medical imaging radiation may cause cancer. ALARA and Image Gently are the cause of the CT cancer problem, not the solution. They cannot now claim that they now exist only to educate patients about radiation and CT imaging. They created the false perception of cancer risk from CT. When the risk is negligible or nonexistent, why create educational 5
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