Shared Decision-Making: Is It Time to Obtain Informed Consent Before Radiologic Examinations Utilizing Ionizing Radiation? Legal and Ethical Implications Leonard Berlin, MDa,b,c

Concerns about the possibility of developing cancer due to diagnostic imaging examinations utilizing ionizing radiation exposure are increasing. Research studies of survivors of atomic bomb explosions, nuclear reactor accidents, and other unanticipated exposures to similar radiation have led to varying conclusions regarding the stochastic effects of radiation exposure. That high doses of ionizing radiation cause cancer in humans is generally accepted, but the question of whether diagnostic levels of radiation cause cancer continues to be hotly debated. It cannot be denied that overexposure to ionizing radiation beyond a certain threshold, which has not been exactly determined, does generate cancer. This causes a dilemma: what should patients be informed about the possibility that a CT or similar examination might cause cancer later in life? At present, there is no consensus in the radiology community as to whether informed consent must be obtained from a patient before the patient undergoes a CT or similar examination. The author analyzes whether there is a legal duty mandating radiologists to obtain such informed consent but also, irrespective of the law, whether there an ethical duty that compels radiologists to inform patients of potential adverse effects of ionizing radiation. Over the past decade, there has been a noticeable shift from a benevolent, paternalistic approach to medical care to an autonomy-based, shared-decision-making approach, whereby patient and physician work as partners in determining what is medically best for the patient. Radiologists should discuss the benefits and hazards of imaging with their patients. Key Words: Radiation stochastic effects, CT, informed consent, ethics, shared decision making J Am Coll Radiol 2014;11:246-251. © 2014 Published by Elsevier Inc. on behalf of American College of Radiology

Medicine has moved to patient-centered instead of doctor-centered care, Where health decisions the physician and the patient mutually share. It is characterized by joint discussions and sharing of information and education, Mutual physician-patient decision-making, and open communication. The physician presents options not as a manager, but rather as a coach. The patient weighs the risks and benefits, so that both reach a common approach. [1]

Concerns about possible harmful effects of exposure to radiation arising from diagnostic radiologic procedures have been heightened over the past few years in large part because of news media reports and occasional sensationalized newspaper headlines in which confusion exceeds clarity and controversy exceeds certainty. Some examples are “CT Scans Linked to Cancer” [2], “Thousands of Cancer Cases From CT?” [3], “Two or Three CT Scans ¼ Hiroshima Radiation” [4], “Chest Radiation for Girls Is Linked to Breast Cancer Later” a

Department of Radiology, Skokie Hospital, Skokie, Illinois.

b

Department of Radiology, Rush University, Chicago, Illinois. Department of Radiology, University of Illinois, Chicago, Illinois.

c

Corresponding author and reprints: Leonard Berlin, MD, Skokie Hospital, 9600 Gross Point Road, Skokie, IL 60076; e-mail: [email protected].

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[5], “Cancer Risk to Children Is Found in CT Scans” [6], “Medical Radiation Soars, With Risk Often Neglected” [7], and “Patients who undergo five or more scans can approach the radiation dose absorbed by some survivors within two to three miles of the atom bomb blasts at Hiroshima and Nagasaki” [8]. Further engendering increased public concern about exposure to medical radiation are newspaper articles highlighting the cancer risk of nonmedical radiation from cell phones [9] and cosmic radiation to which astronauts traveling to Mars would be exposed (“the lifetime risk of dying from cancer is 21 percent.a round-trip mission to Mars would raise that risk by three percentage points, to 24 percent”) [10]. Other headlines and reports have also focused on the danger of “backscatter” x-ray scanners used for airport security (“X-Ray Scans at Airports Leave Lingering Worries” [11]), and one newspaper article reported that Senator Susan Collins of Maine has introduced a bill in Congress to order new tests on the safety of scanners that use backscatter technology because the daughter of a constituent had a miscarriage after going through an airport scanner: “‘We will never know for certain the cause of this family’s loss,’ Collins ª 2014 Published by Elsevier Inc. on behalf of American College of Radiology 1546-1440/14/$36.00  http://dx.doi.org/10.1016/j.jacr.2013.10.006

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said in a statement. ‘But they believe in their hearts the backscatter is to blame’” [12]. Concern about the likelihood of developing cancer after radiographic examinations has extended even to dental x-rays. A recent report found that people in whom brain meningioma was diagnosed were more than twice as likely as people without the tumor to have undergone bitewing x-ray examinations sometime in their lives [13]. The study also found that people who reported having undergone Panorex radiographic examinations as children were nearly 5 times as likely to have developed meningioma than those who underwent them later in life. The American Dental Association called the study “flawed” and encouraged further research. Other newspaper articles have focused on comments of radiation physicists. Columbia University physicist David Brenner was quoted as stating that there is no threshold: “Radiation damages DNA, he says, and just one damaged cell can become the seed of a cancer” [14]. The same article generated more confusion than concern by quoting Vanderbilt University epidemiologist John Boice: “Don’t multiply a tiny dose by millions and say that there will be thousands of deaths. It’s inappropriate, misleading and alarmist. You’ve gone orders of magnitude below where we have proof of any effects at all.” Further confusing if not alarming the public are newspaper accounts focusing on the findings of radiologists and epidemiologists published in scientific journals. Examples include epidemiologist Berrington deGonzalez and her colleagues’ estimate that eventually 29,000 cancers every year, half of which would be fatal, could be the result of past CT scan use [15], and University of California radiologist-epidemiologist Rebecca SmithBindman estimates that the risk for cancer from a single CT scan could be as high as 1 in 80 [16]. Putting aside the hyperbole characterizing the dangers of exposure to diagnostic levels of radiation when undergoing CT scans and other radiologic examinations utilizing ionizing radiation, the scientific community does recognize that there are legitimate concerns regarding adverse effects that can result from radiation exposure. These adverse effects are divided into two types: stochastic and deterministic. The probability that a stochastic effect, such as a radiation-induced cancer or genetic mutation, will occur increases with radiation dose and has a latency period measured in years. It is believed by many researchers that there is no dose threshold below which a stochastic effect can be caused. Deterministic effects, such as erythema, epilation, cataracts, and even death, can occur in hours, days, or months. There is a dose threshold below which deterministic effects will not occur, but once it is surpassed, the higher the dose, the more severe the effect. This brings us to the dilemma of whether, and if so how and in what manner, radiologists should discuss potentially adverse effects of radiation with patients who are about to undergo CT scans and similar studies. Should

radiologists apprise patients of all of the possible potential risks of radiation, both those that are hypothetical and those that have been proved? Should radiologists obtain informed consent from these patients, as they would if the patients were to undergo interventional radiologic procedures? Let us analyze this dilemma in greater detail.

INFORMED CONSENT

Obtaining informed consent from patients is an integral part of the practice of medicine. That patients should determine for themselves what kind of medical procedures, if any, they will undergo, was ingrained into American common law 100 years ago with the oftquoted words of Justice Benjamin Cardozo: “Any human being of adult years and sound mind has a right to determine what should be done with his own body” [17]. This now universally accepted right of selfdetermination is evidenced legally in the form of consent, or permission, which must be sought from, and granted by, a patient before any medical diagnostic or therapeutic measure is instituted. The type of consent required depends on the medical procedure that is being contemplated. Implied consent, which is given by a patient’s actions rather than spoken words, satisfies legal requirements for simple procedures in radiology practice. Examples of legally acceptable acts of implied consent include a patient’s voluntarily climbing onto a radiographic table or extending an arm to receive an intravenous injection [18]. The other kind of consent is expressed consent, or informed consent, that which is explicitly stated. It is required for all patients who are about to undergo radiologic examinations or procedures that are not considered simple. The Hawaii Supreme Court explained the nature of and basis for informed consent in this manner [19]: The decision as to what procedure to undergo is ultimately the patient’s..Courts emphasize what the patient needs to know to make an informed decision..Since the patient must suffer the consequences of medical treatment, fundamental fairness requires that the patient be allowed to know what risks a proposed treatment or exam entails, and what the alternatives thereto are..The focus [of the physician’s duty to disclose] should be on what a reasonable person objectively needs to hear from his or her physician to allow the patient to make an informed and intelligent decision regarding medical treatment.

The Wisconsin Supreme Court used similar language [20]: The Doctrine of Informed Consent focuses on the reasonableness of a physician’s disclosure to a patient..Information regarding risk is material when a reasonable person would be likely to attach significance to it in deciding whether or not to forego the proposed [examination or treatment]..The crux of the issue is the effect of the non-disclosure on the patient’s ability to make an intelligent choice..The standard to which a physician is held is determined.by what a reasonable person in the patient’s position would want to know.[that is] whether a reasonable person in the

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patient’s position would have arrived at a different decision about the treatment or surgery had he or she been fully informed.

True informed consent for a radiologic examination includes detailed information regarding the purpose and nature of the proposed examination; the risks, complications, and expected benefits of the examination; the risk of not performing the examination; and the disclosure of any reasonable alternatives to the examination [21]. Under what exact circumstances must informed consent be obtained? There is no definitive answer to this question, but several professional societies and legal commentators have addressed it. According to the “ACR-SIR Practice Guideline on Informed Consent for Image-Guided Procedures” [21], informed consent “must be obtained prior to the initiation of any procedure that is likely to expose the patient to any significant risks and potential complications.” Medicolegal experts at the Mayo Clinic believe that informed consent is required for all severe risks, for example, death, paralysis, and loss of cognition, even if probability is negligible, and for less severe risks if their occurrence is frequent. Nominal risks with low probability need not be disclosed [22]. It is obvious that the terms severe risks, nominal risks, and negligible probability, have no clear-cut definitions. The Iowa Supreme Court addressed this point in a medical malpractice lawsuit brought on behalf of a young woman who died of an anaphylactic reaction after being given an injection of contrast media before undergoing excretory urography. The court acknowledged that not all risks need be disclosed to a patient, only the “material risks.” Evidence was presented that the incidence of death after intravenous injection of contrast media was 1 per 100,000 patients. The court concluded that no prudent juror could reasonably have considered the 1 per 100,000 risk for death material to a decision about whether to consent to the procedure. Thus, the court ruled in favor of the defendant radiologist [23]. Another court defined a “material risk” as one whereby “in the circumstances of the particular case, a reasonable man in the patient’s position if warned of the risk, would be likely to attach significance to it” [24,25]. In yet another somewhat similar case, the Washington Supreme Court summarized statistical frequencies of complications resulting from various medical procedures to determine what must, or what need not, be divulged to patients as part of an informed consent. Nondisclosure was held justified with a 1 in 800,000 chance of aplastic anemia, a 1.5% chance of loss of an eye, and a 1 in 250 to 1 in 500 chance of perforation of the esophagus. On the other hand, a 1% chance of loss of hearing and a 3% chance of death or paralysis required disclosure [26]. What constitutes “significant incidence” is further muddled by a Mayo Clinic study whose investigators undertook a survey to determine what percentage of patients would want to be informed of a very rare complication of

surgery. Postoperative visual loss, although not well known in the general medical or radiology community, is a devastating and life-altering complication, occurring in 0.2% of patients during spinal fusion surgery. Surgeons are therefore reluctant to discuss this complication because of its rarity and severity. The survey disclosed that 80% of patients would want full disclosure from their surgeons about this rare complication before they would agree to undergo the surgery [27]. With this in mind, one may now ask, What is the incidence of developing a carcinoma as a result of exposure to diagnostic level radiation? Obviously, there are no reliable data to answer this question. There are, however, myriad estimates. One report stated that the lifetime cancer risk of radiation from a single coronary calcium score CT scan at age 40 years is 9 cancers per 100,000 in men and 28 cancers per 100,000 in women [28], 14 to 20 times the incidence of postoperative vision loss! Of course, these two “statistics” cannot be compared; the incidence of postoperative vision loss is based on accurate data, whereas the cancer risk incidence is based on projections and estimates. Nevertheless, if 80% of people want to be informed about a complication that has an occurrence rate of 0.2%, it is likely that the percentage of people wanting to be informed about a potential adverse effect that is up to 20 times more likely to occur would be substantially higher. Therein lies the conundrum of whether obtaining informed consent from a patient is not only indicated, but rather if it is even possible, before the patient undergoes a CT scan or another ionizing radiation imaging examination. The word fact is defined as “something that has been objectively verified” [29]. If one wants to determine whether informed consent is required before performing an interventional radiologic procedure and wishes to find data that disclose the incidence of various complications that might occur during such a procedure, one need only consult the scientific literature to find factual data regarding the incidence, for example, of pneumothorax after a thoracentesis, hemorrhage after arteriography, anaphylactic reaction after the injection of contrast media, perforation of the colon after colonography, thrombosis after angioplasty, stroke after cerebral angiography, or specific complications after radiologic procedures such as percutaneous biopsies, abscess drainages, and other miscellaneous procedures. However, the published literature is devoid of facts regarding the relationship between diagnostic-level radiation and the development of cancer. On the other hand, the scientific literature is replete with hypotheses, theories, conjectures, estimates, projections, extrapolations, statistical probabilities, and opinions. Noting the difference between factual data and estimates, a Kansas federal court stated [30], In matters of determining the cancer risk from low doses of radiation, scientists do not deal with what exists in fact; rather they deal with theory, hypotheses, and assumption which cannot be used to

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establish legal cause..Law needs to be founded on more than a theory or hypothesis.

Mayo Clinic physicist Cynthia McCollough [31] echoed this viewpoint, in more metaphorical terms [31]: “The US judicial system is based on the premise ‘innocent until proven guilty.’ Low levels of ionizing radiation have not been proven beyond a shadow of a doubt to be harmful to human health.” OBTAIN OR DO NOT OBTAIN INFORMED CONSENT BEFORE RADIOLOGIC EXAMINATIONS UTILIZING IONIZING RADIATION?

There is no clear-cut consensus in the radiology community as to whether informed consent should be obtained before a patient undergoes an imaging examination utilizing ionizing radiation [25]. In one recent commentary, Canadian researchers contended that “because the estimated risk of radiation-induced cancer from a typical abdominal CT scan is approximately 1 in 300 to 1 in 2,000.it is clear that this information must be provided to patients” [32]. These researchers continued, “Twenty years from now it will not be a valid argument that patients were not informed of the risks from radiation because physicians were operating under a world of uncertainty.” Similar sentiments were expressed by Semelka et al [33]: referring to published estimates from the Committee on Biologic Effects of Ionizing Radiation that 10 mSv of radiation exposure carries with it a 1-in-1,000 chance of future malignancy in a 40-year-old adult, and a risk of 1 in 100 in a 1-year-old infant, these researchers asserted that either verbal or written informed consent before CT examinations should be obtained. Taking an opposite stance, however, Brink et al [34] pointed out that real informed consent is not truly achievable relative to the low levels of ionizing radiation used in medical imaging: Because of the uncertainty of the stochastic risk from ionizing radiation associated with medical imaging, it is impossible to describe precisely the risks of a medical imaging procedure. “What is needed,” they concluded, “is informed decision making rather than informed consent.”

LEGAL DUTY, MORAL DUTY, AND SHARED DECISION MAKING

Over the past decade there has been a gradual but noticeable shift from a benevolent, paternalistic approach to medical care (“I, the doctor, know what is best for you, the patient”) to an autonomy-based, shared-decision-making approach (“You, the patient, and I, the doctor, are equal partners in determining what is best for you”). The patient and physician work together to reach a mutual decision [35]. Indeed, this “meeting in the middle” concept of medical care has been endorsed by the AMA and other medical societies and organizations [36]. Although this shared-decision-making model most often focuses on treatment issues, it has as well prompted more frequent and detailed doctor-patient discussions regarding diagnostic

tests: their indications, their cost, and their possible downsides and adverse effects. This emerging shareddecision-making environment has set the stage for, and should encourage, more doctor-patient discussions regarding the potential hazards of exposure to ionizing radiation from CT and similar imaging examinations. Because the carcinogenic properties of diagnosticlevel radiation are presumptive, no law today requires the obtaining of informed consent before a patient undergoes a CT scan. Nevertheless, ethical considerations cannot be ignored. Although the distinction between what physicians must do because of legal dictates and what they should do because of moral dictates is often blurred, the extent of medical information that a physician conveys to a patient required to satisfy a moral imperative may at times exceed that what is required by the law [37]. The Code of Ethics of the AMA states that physicians should “sensitively and respectfully disclose all relevant medical information to patients..The quantity and specificity of this information should be tailored to meet the needs of the individual patient” [38]. A recently published survey disclosed that patients have little knowledge of radiation risks [39]. Another recently published survey of patients presenting for nonurgent outpatient CT and cardiac single-photon emission CT scans revealed that 90% said that it was important to be informed of imaging risks [40]. In yet another survey of parents who brought their children who had sustained head injuries to a hospital emergency department, 90% wanted to be informed of potential malignancy risks before proceeding with CT scans [41]. With regard to exposure to radiation from diagnostic imaging, is it not the radiologist who knows both the benefits and the potential harms of radiation? Is it not the radiologist who has the duty, moral if not legal, to educate referring physicians and, if necessary, patients? Notwithstanding the controversy and debate surrounding the quantification and nature of adverse effects from radiation exposure, can anyone honestly claim that exposure to radiation is absolutely free of such effects? Radiologists are physicians first, and one of the fundamental precepts of the physician is primum non nocere: first, do no harm. Physicians are healers but are also educators and teachers. Thus, in keeping with the shared-decision-making movement, what seems to be needed, as pointed out by Brink et al [34], is “informed decision making” rather than “informed consent.” An example of one possible approach radiologists can take as part of a discussion about the risks of radiation with patients is found in the ACR’s “Practice Guideline for Imaging Pregnant or Potentially Pregnant Women” [42]: Conveying information in a positive, rather than negative, format is useful in helping a patient understand an accurate perspective of risk. Rather than telling the patient what the likelihood is that her child could develop cancer later in life, the message with a positive, accurate perspective is that the cancer risk is small and that the

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likelihood the child will remain healthy with no adverse radiation effects is only slightly different from that of any other child.

INFORMED CONSENT BEFORE CT SCANS, STATUS 2014

Currently there are insufficient data from the scientific community to justify an unequivocal determination of whether cancer develops from diagnostic-level radiation. The standard of care does not today require that informed consent be obtained from patients before they undergo imaging examinations utilizing ionizing radiation. However, although the courts generally do not require full disclosure of all possible risks or complications, there are no clearly legislative or common lawedefined rules governing what needs and does not need to be divulged to patients. The moral, if not legal, responsibility of clinicians is to make every effort to ensure that each CT scan or other imaging examination utilizing ionizing radiation is indicated, to order the least invasive modality with the highest likelihood of yielding the desired diagnostic information, and, if uncertain, to freely discuss questionable issues with a radiologist—and the patient when appropriate. It is the moral, if not legal, responsibility of radiologists to be adequately educated [43] to understand radiation doses, review requests involving high-dose studies, use appropriate technical factors, and discuss the benefits and potential hazards of radiologic imaging with clinicians and patients when the radiologists believe it is appropriate to do so. Radiologists should support efforts such as Image Wisely [44], and they should endeavor to keep radiation doses “as low as reasonably achievable” [45]. TAKE-HOME POINTS

 There are currently insufficient data to justify an unequivocal determination of whether cancer will develop from diagnostic-level radiation.  The standard of care currently does not require that informed consent be obtained before patients undergo imaging examinations utilizing ionizing radiation.  Particularly in this age of shared decision making between patients and physicians, the moral duty of radiologists is to be adequately educated about all facets regarding the radiation emanating from radiologic examinations and to discuss the benefits and potential risks of proposed examinations with patients, when the radiologists believe it is appropriate.  Radiologists should support the Image Wisely campaign and the principle of “as low as reasonably achievable.” REFERENCES 1. Berlin L. To disclose or not to disclose radiologic errors: should “patientfirst” supersede radiologist self-interest? Radiology 2013;268:4-7. 2. Wang SS. CT scans linked to cancer. The Wall Street Journal. December 15, 2009. Available at: http://online.wsj.com/news/articles/SB1260823 98582691047. Accessed October 26, 2013.

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39. Caverly TJ, Prochazka AV, Cook-Shimanek M, Pawlak M, Stickrath C. Weighing the potential harms of computed tomography: patient survey. JAMA Intern Med 2013;173:588-9. 40. Busey JM, Soine LA, Yager JR, Choi E, Shuman WP. Patient knowledge and understanding of radiation from diagnostic imaging. JAMA Intern Med 2013;173:239-40. 41. Phend C. Parents want CT cancer risk info in ED. Available at: http://www.medpagetoday.com/EmergencyMedicine/EmergencyMedicine/ 40313. Accessed July 12, 2013. 42. American College of Radiology. ACR practice guideline for imaging pregnant or potentially pregnant adolescents and women with ionizing radiation. Available at: http://amclc.acr.org/LinkClick.aspx?fileticket¼o8 CkXsiGj-0%3D&tabid¼61. Accessed July 12, 2013. 43. Pandharipande PV, Eisenberg JD, Avery LL, et al. How radiation exposure histories influence physician imaging decisions: a multicenter radiologist survey study. AJR Am J Roentgenol 2013;200:1275-83. 44. Brink JA, Amis ES Jr. Image Wisely: a campaign to increase awareness about adult radiation protection. Radiology 2010;247:601-2. 45. Hendee WR, O’Connor MK. Radiation risks of medical imaging: separating fact from fantasy. Radiology 2012;264:312-21.