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OPINION

742

Informing Patients About Risks and Benefitsof Radiology Examinations Utilizing IonizingRadiation: A Legal and Moral Dilemma

Leonard Berlin, MD

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The excellent article by Drs Car-dinal, Gunderman, and Tarver[1] tracing the ethical basis andlegal history of informed consentbrought us to the doorstep of thelatest dilemma regarding this top-ic: should radiologists discuss allpossible adverse effects arisingfrom exposure to ionizing radia-tion with, and then obtain in-formed consent from, patients be-fore their undergoing diagnosticradiologic examinations (espe-cially CT)? Let us ponder thisquestion.

Obtaining informed consent re-lated to radiation exposure is in-deed a dilemma, with no easy solu-tion. Dealing with complicationsfor which we have at our disposalmyriad published and accurate dataon their frequency (eg, death andother anaphylactic reactions fromcontrast media, arterial perfora-tions or abdominal hemorrhages,or pneumothoraces, resulting froma variety of interventional proce-dures) is a relatively simple matter.We are able to research the litera-ture and then quote accurate pre-dictions of the likelihood of suchadverse events, with documentednumerators and denominators. Butwhen it comes to the developmentof carcinomas related to diagnosticlevels of ionizing radiation, we haveno such data; we have only conjec-ture and unproven projectionsand extrapolations. Therein liesthe conundrum.

As Cardinal et al [1] pointed out,ur legal as well as moral duty toisclose known and proven compli-

ations of radiologic examinations

nd procedures to patients is clearut and not debatable. Whether weave the same duty to disclose thecomplications” of diagnostic radi-tion exposure that are not trulynown and proven, however, is noto clear cut and is indeed debatable.

The courts have given us someuidelines as to what does and doesot require informed consent. Inxonerating a radiologist for failingo obtain informed consent beforedministering an intravenous injec-ion of contrast media for intrave-ous pyelography (IVP) on a pa-ient who suffered a fatal acutenaphylactic reaction, the Iowa Su-reme Court [2] ruled that not allisks need to be disclosed, onlymaterial” risks that “would haveeen significant to a reasonable per-on in the circumstances, or wouldave affected the person’s willing-ess to undergo the IVP.” Theourt stated that “evidence was pre-ented that one in 100,000 patientsill die as a result of IVP contrastedia injection” and concluded

hat no prudent patient could rea-onably have considered this risk toe material requiring consent. Alsoealing with complications afterVP, the Washington Supremeourt [3] summarized how other

state appeals courts used publishedstatistical frequencies of complica-tions resulting from various medi-cal procedures to determine whatmust, or what need not, be di-vulged to patients as part of in-formed consent discussions: non-disclosure was held justified with a1 in 800,000 chance of aplastic ane-

mia, a 1.5% chance of loss of an

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eye, and a 1 in 250 to 1 in 500chance of perforation of the esoph-agus. On the other hand, a 1%chance of loss of hearing and a 3%chance of death or paralysis, re-quired disclosure.

Let us now turn to the statisticalfrequency of complications, specif-ically the development of cancer,arising from exposure to diagnosticlevel radiation. Where and what arethe data? Where are the numeratorsand the denominators? DeGonza-lez et al [4] “projected” that 29,000cancers every year, half of whichwill be fatal, will result from pastCT scan use. Archives of InternalMedicine editor Rita Redberg [5]claimed that “The radiation fromthe 19,500 CT scans performed ev-ery day in the US will translate, sta-tistically, into additional cancers.”In a 2010 JAMA article, researchersused numerators and denominatorswhen referring not to incidence butrather to risk: “Lifetime cancer riskdue to radiation exposure from a sin-gle CT scan to determine coronaryartery calcium score at age 40 is 9cancers per 100,000 in men and 28cancers per 100,000 in women” [6].Imagine that! In other words, a 40-year-old woman is 28 times morelikely to develop cancer from a CTscan than to die of an anaphylacticreaction due to an intravenous injec-tion of contrast media! If that weretrue, undoubtedly not only the IowaSupreme Court but also courts in allof the other 49 states would find aradiologist negligent for failing to dis-close that “fact” to a patient, not tomention that we would all be morally

derelict as well for nondisclosure.

© 2011 American College of Radiology-2182/11/$36.00 ● DOI 10.1016/j.jacr.2011.06.024

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Opinion 743

The word fact is defined as“something that has been objec-tively verified” [7]. The claim thatcancer will develop as a result ofradiation exposure to diagnostic ra-diologic examinations is not, norbased on, fact. Indeed, a Kansasfederal court [8] stated,

In matters of determining the cancer riskfrom low doses of radiation, scientists donot deal with what exists in fact; rather,they deal with theory, hypothesis and as-sumption which cannot be used to establishlegal cause . . . . Law needs to be foundedon more than a theory or hypothesis.

Mayo Clinic medical physicistCynthia McCollough [9] and oth-rs [10,11] doubt that there may be

any risk whatsoever from the radia-tion received from a CT scan. Em-phasized McCollough [9],

The US judicial system is based on thepremise “innocent until proven guilty.”Low-levels of ionizing radiation have notbeen proven beyond a shadow of a doubt tobe harmful to human health. Rather, con-siderable evidence to the contrary exists.

Thus, contended McCullough,obtaining “informed consent”may do far more harm than good,for it may encourage unneces-

sary and unsubstantiated worries

about radiation that will dissuadepatients from obtaining neededCT examinations. Elsewhere,McCullough and Fletcher [12]concluded that they do “not con-sider CT examinations performedas part of noninterventional proce-dures to meet the threshold of riskat which information consent is ap-propriate.”

In summary, here is the dilemmathat confronts radiologists: yes, ofcourse we have a legal and moralduty to disclose potential complica-tions based on facts to patients andto obtain informed consent on thebasis of those facts. But when itcomes to conjectures and unproventheories regarding the question ofwhether diagnostic-level radiationcauses cancer, what, if anything,does our legal and moral duty re-quire us to disclose to patients? It isa dilemma that has no solution to-day and indeed may not have a so-lution in the foreseeable future.

REFERENCES

1. Cardinal JS, Gunderman RB, Tarver RD.Informing patients about risks and benefitsof radiology examinations: a review article.

J Am Coll Radiol 2011;8:402-8.

2. Pauscher v Iowa Methodist Medical Centeret al, 408 NW 2d 355 (Iowa Supreme Court1987).

3. Smith v Shannon, 666 P 2d 351 (Washing-ton Supreme Court 1983).

4. deGonzalez AB, Mahadevappa M, Kim KP,et al. Projected cancer risks from computedtomographic scans performed in the UnitedStates in 2007. Arch Intern Med 2009;169:2071-7.

5. Redberg RF. Cancer risks and radiation ex-posure from computed tomographic scans:how can we be sure the benefits outweighthe risks? Arch Int Med 2009;169:2049-50.

6. Ioannidis JPA, Tzoulaki I. What makes agood predictor? The evidence applied tocoronary artery calcium score. JAMA 2010;303:1646-7.

7. The American Heritage Dictionary 2nd colled. Boston: Houghton Mifflin; 1985:484.

8. Johnston v United States, 597 F Supp 374(D Kansas 1984).

9. McCollough CH. Defending the use ofmedical imaging. Health Phys 2011;100:318-21.

10. Tubiana M, Feinendegen LE, Yang C, Ka-minski JM. The linear no-threshold rela-tionship is inconsistent with radiation bi-ologic and experimental data. Radiology2009;251:13-22.

11. Mezrich RS. Radiation exposure from med-ical imaging procedures. N Engl J Med2009;361:2290.

12. McCollough CH, Fletcher JG. Is this ap-propriate: will CT take my life? AJR Am J

Roentgenol 2011;196:218.

Leonard Berlin, MD, NorthShore University HealthSystem – Skokie Hospital, Department of Radiology, 9600 Gross Point Road,Skokie, IL 60076; e-mail: lberlin@live.com.