Informed Consent for Radiation Risk from CT Is Unjustified Based on the Current Scientific Evidence.

O ver the past several years, many sources of information have emerged regarding the potential risks of low-dose ionizing radiation from medical imaging. Many published educational materials and scientific studies have heightened awareness among patients, the public, and medical professionals. The press has extensively reported on this topic, sometimes omitting nuances regarding the strength of evidence supporting various statements or conclusions. With this background, some concerned practitioners have questioned whether patients, or the parents of pediatric patients, should participate in informed consent for medical imaging with ionizing radiation. While patients and providers should jointly practice informed decision making when contemplating an imaging examination , the evidence supporting diagnostic radiation carcinogenesis is too uncertain to warrant a formal informed consent process. To date, published studies that suggest significant cancer risks from diagnostic radiation are much weaker than we—as a purported evidence-based field—would normally accept. We, the authors, contend that informed consent is unjustified based on an objective look at the currently available scientific evidence. Moreover , cloaking uncertain radiation risks with the credibility suggested by an informed consent process does not further patient autonomy or protect patient interests. Until the effects of diagnostic radiation are further clarified , it is not possible to perform a risk-benefit calculation with sufficient certainty to warrant informed consent. Rather, patients and providers should make an informed decision about the use of diagnostic radiation on the basis of what is known and be cognizant of what is not. For many, the current interest in the risks of diagnostic radiation in the field of medicine started in 2006, when the Biological Effects of Ionizing Radiation (BEIR) VII report endorsed a linear no-threshold (LNT) risk model for low-dose radiation (LDR) based on available data (1). The LNT model states that the risk for cancer from radiation exposure proceeds in a linear fashion irrespective of the dose, without a threshold. As such, the LNT model would hold that even the smallest radiation dose could translate into an increased risk for cancer. In reaching their decision to endorse the LNT model, the BEIR VII committee heavily relied on two key pieces of evidence: the atomic bomb survivor data and radiation worker studies. However, since the release of the BEIR VII report, these two sources of evidence have undergone important changes and no longer support the LNT assumption (2,3). In the following sections, we review some of the major literature to …