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Perspective |
1 Department of Radiology, Rush North Shore Medical Center, 9600 Gross Point Rd., Skokie, IL 60076, and Rush Medical College, Chicago, IL.
Received July 16, 2002;
accepted after revision July 31, 2002.
Address correspondence to L. Berlin.
Introduction
 Top Introduction The Missed DiagnosisOverdiagnosis and ComplicationsRadiationAbandonmentInformed Consent and Duty...Conclusion: Whither Goest...References |
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TopIntroductionThe Missed DiagnosisOverdiagnosis and ComplicationsRadiationAbandonmentInformed Consent and Duty...Conclusion: Whither Goest...References |
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What about the error rate among radiologists interpreting CT studies? Let us first focus on CT colonography examinations. Forty-three years ago, Cooley et al. [15] reported that 32% of colon cancers were missed on barium enema examinations. One might speculate that the error rate for missed colon cancers in CT colonography is lower, but that may not be the case. Although some studies show that the overall sensitivity of CT colonography for the detection of polyps 10 mm or greater in diameter hovers in the range of 90% [16], no reports measuring actual error rates of the modality have yet been published. However, published reports address the frequency of errors committed in the interpretation of other kinds of CT examinations. White et al. [17], focusing on missed carcinomas on chest CT, found that an experienced thoracic radiologist, even knowing prospectively that each CT scan in a study group included a missed cancer, was able to identify the missed lesion in fewer than half the cases. In another report, researchers found that half the lung cancers detected on helical CT were present in retrospect on a prior CT screening examination [18]. Wechsler et al. [19] documented a miss rate of 13.5% in emergency body CT scans; and in another study of 213 CT body scans, Gollub et al. [20] reported a 37% disagreement rate among radiologists' interpretations. Kalbhen et al. [21] found a 32% discrepancy rate between initial interpretation and reinterpretations of abdominal CT scans, and Siegel et al. [22] documented a 25% disagreement rate in the interpretation of CT scans containing renal lesions smaller than 1.5 cm. On the basis of these studies, it does not appear unreasonable to predict that error rates in the interpretation of CT colonography and whole-body scans will fall into the same range.
Radiologists who are all too ready to advertise that whole-body CT scanning, with or without virtual colonoscopy, can find cancer "when it's as small as a grain of rice" [23] and will "save a person's life" because it will "find your cancer early" are in fact implying that every small carcinoma in a given screening CT scan will be observed and reported by the interpreting radiologist. A presently unknown number of these small carcinomas undoubtedly will be missed, and when they are, malpractice litigation is apt to follow.
Is CT colonography being sold prematurely to the public? A recent BusinessWeek magazine article [24] characterized the procedure as "virtually 100%" accurate in finding cancers. An advertisement appearing from time to time in a Chicago newspaper proclaims, "It's virtually unthinkable not to have a virtual colonography." The hype may be exceeding the reality. In a recently published report from the Radiological Society of North America [25], Boston University's radiology chair, Joseph Ferrucci, was quoted as stating, "While virtual colonoscopy is not yet ready for prime time as a widespread clinical tool, it's knocking at the door." In the same report, Peter Cotton of the Medical University of South Carolina echoed similar sentiments, adding, "Improved training and techniques are necessary before virtual colonoscopy can be considered for widespread use" [25].
Overdiagnosis and Complications
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TopIntroductionThe Missed DiagnosisOverdiagnosis and ComplicationsRadiationAbandonmentInformed Consent and Duty...Conclusion: Whither Goest...References |
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Among the adverse sequelae of overdiagnosis are complications that may result from diagnostic procedures designed to investigate an apparent abnormality on a CT scan that later turns out to be clinically unimportant. A recent New York Times article [31] described the experience of William Casarella, radiology chair at Emory University. Casarella related that after he underwent a virtual colonoscopy examination, nonspecific lesions were found in his liver and lung base. "I didn't want to sit around thinking I had a malignant lesion," explained Casarella, so he underwent surgery to discover the nature of the lesions. The lesions turned out to be granulomas from previous histoplasmosis, which was good news to Casarella, but the bad news was that the bill for his surgery and hospitalization totaled $47,000 and his postsurgical convalescence took 8 weeks. Casarella somberly reflected on radiologists who promote CT screening by advertising testimonials from grateful patients in whom screening has found a small carcinoma [31]:
They have poster children. Here's a patient we found who had a renal cancer. We took it out and he's cured. I'm sure that's a true story, but how many patients did they screen to find it, was it going to kill the patient, how big was it, was it invasive? [Promoting total body scans directly to the general public is] a prescription for panic.
When does a positive finding on screening CT become a false-positive, or overdiagnosis? The answer is nebulous. Richard Penfil, a radiologist proponent of CT screening, has reported that 97% of all whole-body studies performed in his practice uncover "clinically significant pathology" [32]. Michael Brant-Zawadzki [33], also a radiologist proponent, places the positive-for-significant-abnormality figure in his practice at 22-23%. Addressing the issue of the high rate of detection of pathology that may or may not be "significant," the Web site of the United States Food and Drug Administration contains the following admonition [34]:
If your CT screening result is interpreted as abnormal and there is really nothing significant wrong with you, then you may be subjected to still further tests or treatments, all of which have their own risks.... The surprising fact about a CT interpretation of abnormality when there is nothing significant wrong is that it is far more likely to happen to you than the finding of any actual life-threatening disease, since the likelihood that you actually had any deadly disease is so small to begin with.
In its statement on whole-body CT, the American College of Radiology expresses similar sentiments [35]:
The ACR is concerned that [whole-body CT screening] will lead to the discovery of numerous findings that will not ultimately affect patients' health but will result in increased patient anxiety, unnecessary follow-up examinations and treatments and wasted expense.
Patients who sustain complications and injuries resulting from medical procedures that have been medically indicated may wonder whether their physicians have been negligent, and some will pursue malpractice litigation. Patients who sustain similar complications and injuries from medical procedures that may not have been indicated to begin with because they were performed due to an "abnormality" seen on CT screening that later turned out to be insignificant perhaps may be more apt to pursue such litigation.
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TopIntroductionThe Missed DiagnosisOverdiagnosis and ComplicationsRadiationAbandonmentInformed Consent and Duty...Conclusion: Whither Goest...References |
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Radiation effects are divided into two broad categories [36]. Deterministic effects are those that do not occur below a certain threshold; the degree of injury, such as skin erythema or necrosis, is related to the dose. The other broad category is termed "stochastic," in which there is no threshold and in which the severity of injury is not related to dose. Stochastic radiation effects include carcinogenesis, genetic mutations, and in-utero effects. Estimation of stochastic radiation effects are generally developed using effective dose.
The question of whether radiation exposure from CT screening will increase the incidence of cancer in the general population is controversial. On its Web site, the Food and Drug Administration explains the matter this way [38]:
A CT examination with an effective dose of 10 mSv may be associated with an increase in the possibility of fatal cancer of approximately one chance in 2000. This increase in the possibility of a fatal cancer from radiation can be compared to the natural incidence of fatal cancer in the United States population, about one chance in five. In other words, for any one person the risk of radiation-induced cancer is much smaller than the natural risk of cancer. Nevertheless, this small increase in radiation-associated cancer risk for an individual can become a public health concern if large numbers of the population undergo increased numbers of CT screening procedures of uncertain benefit.
Radiologist Everett Lautin [39, 40] has estimated that the risk of cancer death for those who undergo CT is 12.5 per 10,000 population, and he is therefore alarmed at the trend of encouraging the public to obtain what he calls "vanity" CT scans. Lautin also points out that if the abdomen is scanned twice, as in CT colonographic examinations, the risk would be increased to 25 per 10,000. The potential damage from CT radiation is greater in children because they are 10 times more sensitive to radiation [41]. The best risk estimates suggest that pediatric CT will result in more significantly increased lifetime radiation risk than adult CT [42]. Lee Rogers [43] has expressed concern about CT examinations that are ordered at the "slightest provocation, maybe not quite willy-nilly, but certainly at the drop of a hat," and he has, along with others [44,45,46,47], suggested ways of decreasing radiation exposure during CT examinations by lowering the milliampere-seconds and voltage and increasing the pitch.
Brant-Zawadzki and Silverman [48] downplay the potential association of carcinogenesis with radiation. They write:
Although some of us may "know" that low doses of radiation cause cancer, objective authentication of that "knowledge" simply is not available at this time, and may never be.
With regard to a woman who is pregnant or who may think she is pregnant, it should be pointed out that radiation-induced teratogenesis is primarily a concern from the 10th to the 17th week of gestation [49]. Radiation-induced abnormalities such as microcephaly, mental retardation, other central nervous system defects, and growth retardation most commonly occur in fetuses between 2 and 15 weeks' gestation. The radiation dose below which no deleterious effects on the fetus occur, even in the most sensitive developmental phase, is not known with certainty, but it has been estimated to range from 50 to 150 mGy [50]. So as to provide some perspective to this figure, Macari et al. [16] have estimated the radiation dose for combined supine and prone CT colonography to be 11.4 mGy.
The medical malpractice risks arising from allegations of radiation injury caused by CT screening are unknown. Could potential plaintiffs be successful in alleging in a malpractice lawsuit that they developed carcinoma from screening CT? Could a woman potential plaintiff successfully claim that she gave birth to a baby with congenital anomalies caused by the radiation exposure received when she had undergone CT screening at a time when, unknown to her or the radiologist, she was pregnant? These questions cannot be answered at this time. As a precaution in the meantime, Nickoloff and Alderson [37] recommend that CT screening patients receive written and verbal information about potential cancer and other radiation risks associated with the procedure. Those researchers point out that, given the latency time of up to 30 years for cancer induction, "Policies need to be adopted now to avoid problems in the future" [37].
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TopIntroductionThe Missed DiagnosisOverdiagnosis and ComplicationsRadiationAbandonmentInformed Consent and Duty...Conclusion: Whither Goest...References |
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Radiologists should recognize potential obligations in assuming the care and treatment of patients who present themselves for imaging studies on a self-referred basis. Such obligations may include communicating the results of the imaging studies to the patient and the necessity of appropriate follow-up.
Traditionally, most radiologists have not thought of themselves as primary care physicians to patients. The CT screening movement has markedly altered this dynamic. Radiologists who directly or indirectly solicit patients to undergo screening radiologic examinations without being referred by a primary care physician will find themselves placed in the position of primary care physician. Once a patient undergoes the screening radiologic examination, a physician—patient relationship between the radiologist and patient has been established. The radiologist cannot unilaterally terminate this relationship until or unless the patient is formally notified and arrangements for alternative medical care are made. A radiologist's failure to carry out this duty (and to document it appropriately) could well expose the radiologist to a charge of patient abandonment [53].
Informed Consent and Duty to Disclose
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TopIntroductionThe Missed DiagnosisOverdiagnosis and ComplicationsRadiationAbandonmentInformed Consent and Duty...Conclusion: Whither Goest...References |
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Any human being of adult years and sound mind has a right to determine what shall be done with his own body, and a surgeon who performs an operation without his patient's consent commits an assault.
Traditionally, physicians have disclosed to patients the benefits and risks of invasive procedures, alternative measures that might give similar results, and the risks of not performing the procedure [55]. However, in recent years the informed consent process has been slowly but inexorably expanded not only to encompass a growing number of diagnostic radiologic and nonradiologic procedures, but also to broaden the content of the disclosures. The nation's courts have imposed duties on physicians to disclose to patients much more information than had been traditionally required, such as physicians' experience, credentials, and personal habits that could affect professional performance [56].
The advent of CT screening will likely further expand the ground rules for informed consent. By encouraging persons to undergo testing designed to detect early disease, radiologists may be required to assume the responsibility of explaining to these persons the myriad uncertainties that pertain to early detection. A recent editorial in the New York Times described the nature of these uncertainties [57]:
The ability of screening tests to detect very tiny tumors in the breast, prostate and other organs has far outstripped scientists' understanding of how to interpret and respond to the findings.... For some decades now it has been an article of faith in the cancer community that early detection is a sure-fire way to save lives. It seems intuitively obvious that if one detects a tumor very early, when it is tiny and least likely to have spread malignant cells to distant parts of the body, doctors will have the best chance of removing the cancer entirely. But in recent years that rationale has been challenged in screening for several types of cancer.... A key issue is whether the tests are finding a lot of tumors that would never become dangerous but cannot be distinguished from tumors that could become deadly, thereby causing many patients to undergo the risk of surgery, radiation or chemotherapy for no good reason.... Patients and their doctors will have to chart a course that feels comfortable to them.... No expert has the answer to what is essentially a matter of individual choice.
To reach a decision about whether to undergo screening CT, patients will have to be educated by their physicians. As has already been pointed out, in the case of screening CT the self-referred patient's physician will be the radiologist. Therefore radiologists, whether they be proponents or opponents of CT screening, will have to divorce themselves from their personal feelings about screening and provide unbiased information to patients about the procedure. Various ethical, governmental, and legal sources affirm this responsibility. The American Medical Association's Principals of Medical Ethics state in part [58]:
The patient has the right to receive information from physicians and to discuss the benefits, risks, and costs of appropriate treatment alternatives. Patients should receive guidance from their physicians as to the optimal course of action.... The patient has the right to make decisions regarding the health care that is recommended by his or her physician. Accordingly, patients may accept or refuse any recommended medical treatment.... A physician shall deal honestly with patients and colleagues.
The Principles of Ethics of the American College of Radiology [59] hold that rendering of a service by a radiologist should be "governed by what is in the best interest of the patient."
In their book on medical ethics, Murphy et al. [60] observed:
The physician's allegiance is toward the individual patient and must be directed to fostering and championing what is best for that patient. The issue in deciding whether or not a treatment or diagnostic test is, then, a matter of balancing the good that will result to the patient against the bad that will result to that patient.
A coalition of American and European physicians formed to develop a new Charter on Medical Professionalism, chaired by physician Troyen Brennan, issued the following statement [61]:
Patients' decisions about their care must be paramount, as long as those decisions are in keeping with ethical practice and do not lead to demands for inappropriate care.
Schwartz et al. [62] specifically addressed screening tests and emphasized the need to "acknowledge uncertainty":
Be explicit about uncertainty by presenting some measure of estimate precision.... In the special case of screening, remember that the benefits can only be shown in randomized trials; improved 5-year survival for cancers detected by screening is not proof of benefit.
Many campaigns use scare tactics to promote a particular behavior... "Get screened today!" or "You can't see it or feel it, but you may have cancer".... These messages make it clear that no one is really healthy.... These aggressive tactics may convey a false sense of the magnitude and certainty of the benefits of interventions, engendering unrealistic expectations.... The increasing prevalence of persuasive messages coincides with a shift in contemporary medical ethics to a shared decision-making model in which the clinician's role is not to persuade patients to adopt a particular behavior...but, where possible, to help patients understand the risks and benefits of the options they face so they can make informed choices.
In February 2002, the United States Preventive Services Task Force, an independent panel of experts that reviews research in a wide range of preventive services, issued a statement confirming recommendations that women older than 40 years undergo annual mammography. Included in that statement, however, was the following directive [63]:
Clinicians should inform women about the potential benefits (reduced chance from dying from breast cancer), potential harms (e.g., false-positive results, unnecessary biopsies), and limitations of the test that apply to women their age.
Although not directly addressing CT screening, the New Jersey Supreme Court nevertheless echoed similar sentiments [64]:
Physicians do not adequately discharge their responsibility by disclosing only treatment alternatives that they recommend.... Physicians may [not] impose their values on their patients.
One conclusion that can be drawn from these policy statements and commentaries is that the public is demanding now more than ever before complete and accurate information regarding medical diagnostic testing and they may seek assistance from the courts if they fail to receive that information. A British physician recently wrote [65]:
The public has rightly become more critical of those who make decisions on their behalf. The media and electronic communication networks bring difficulties to the attention of the public more rapidly than previously. The public is also more suspicious of science, and aware of its limitations. People want to be included in decision making, not just told what to do, and the level of trust has fallen.
People's failure to receive complete and accurate information from physicians often breeds anger. Anger often breeds contempt. Contempt often breeds malpractice litigation.
These statements from professional societies, governmental agencies, and the court do not in and of themselves indicate how courts will deal with informed consent and duty-to-divulge issues that may arise out of CT screening lawsuits that may be filed in the future. These statements also fail to indicate how the courts would respond to a potential plaintiff patient's lawsuit charging a radiologist with misrepresenting the value of a CT screening examination by overemphasizing its accuracy and efficacy while ignoring its potential risks. However, these and other similar statements are noteworthy because attorneys and judges have shown an increasing willingness to look to such statements as a basis for legal advocacy and decision making in matters of health care law and litigation [58].
One additional point on this topic should be noted. Patients may expect radiologists not only to disclose the pitfalls of CT screening but also to give specific recommendations for follow-up screening examinations. The extent to which a radiologist has a duty to recommend follow-up screening is as yet undetermined. However, if the radiologist had not urged the patient to undergo CT screening in the first place, there would not even be the semblance of a duty imposed on the radiologist to recommend follow-up screening.
Conclusion: Whither Goest Malpractice Litigation and Whole-Body CT
Screening?
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TopIntroductionThe Missed DiagnosisOverdiagnosis and ComplicationsRadiationAbandonmentInformed Consent and Duty...Conclusion: Whither Goest...References |
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Many medical—legal questions have been raised in this article, but no answers have been provided. It will be left to plaintiff's lawyers, radiologists, defense attorneys, professional liability insurance company representatives, and the judiciary itself to grapple with all the conflicting data and divergent opinions that permeate CT screening. It is they who will have to ponder the issues and eventually begin to formulate the answers.
A concluding comment regarding expert witnesses is in order. Ideally, expert witnesses seek the truth, are honest and unbiased, and do not become an advocate or a partisan in a legal proceeding [78]. Unfortunately, however, medical expert witnesses are sometimes accused of doing just the opposite. Opinions rendered by an expert radiology witness are sometimes slanted or influenced by what that radiologist believes to be right or wrong. Many honest, well-credentialed, and highly respected radiologists truly believe that CT screening is beneficial; many similarly honest, well-credentialed, and highly respected radiologists believe that CT screening is of no value. Some may even believe the motivation of those who promote screening is not one of patient benefit but rather one of personal financial gain [79]. In such an environment, a plaintiff's attorney who has filed a malpractice lawsuit against a radiologist claiming negligence involving a CT screening examination probably will have little difficulty in finding a respected and reputable radiologist to testify as an expert witness against the defendant radiologist.
Pandora's box is the mythic box that was given by the Greek god Zeus to Pandora, the first mortal woman [80]. Pandora's box contained the human ills of the world, all of which escaped when the box was opened. Perhaps the Pandora's box of 2003 carries the label "Whole-Body CT Screening" and contains within it all the potential malpractice ills that may arise from promoting and performing these examinations. Perhaps this proverbial box will never be opened and an onslaught of malpractice litigation will never materialize. Indeed, one radiologist who states he has screened more than 30,000 patients in his career reports that he has never had a malpractice lawsuit related to CT screening lodged against him (Eisenberg H, personal communication). On the other hand, perhaps the CT screening—labeled Pandora's box will be opened, and with that opening will be unleashed into the radiology community a host of medical malpractice ills that will haunt radiologists for years to come.
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TopIntroductionThe Missed DiagnosisOverdiagnosis and ComplicationsRadiationAbandonmentInformed Consent and Duty...Conclusion: Whither Goest...References |
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1. In: Digest of council actions 2001. Reston,
VA: American College of Radiology, 2001:23
-26
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