Medical Imaging: Radiation Risks

“In the past two decades, improved imaging technologies, nuclear medicine examinations, and new pharmaceutical interventions have made possible significant strides in our ability to diagnose and treat human disease, including cancer.  It is becoming increasingly clear, however, that some of these same technologies and drugs that have contributed so greatly to health status and longevity also carry risks.

… Americans now are estimated to receive nearly half of their total radiation exposure from medical imaging and other medical sources, compared with only 15% in the early 1980s.  The increase in medical radiation has nearly doubled the total average effective radiation dose per individual in the United States.  Computed tomography [CT] and nuclear medicine tests alone now contribute 36% of the total radiation exposure and 75% of the medical radiation exposure to the U.S. population.  Medical imaging of children is of special concern; compared with adults, children have many more years of life during which a malignancy initiated by medical radiation can develop.  Many referring physicians, radiology professionals, and the public are unaware of the radiation dose associated with various tests or the total radiation dose and related increased cancer risk individuals may accumulate over a lifetime.  People who receive multiple scans or other tests that require radiation may accumulate doses equal to or exceeding that of Hiroshima atomic bomb survivors.  It is believed that a single large dose of ionizing radiation and numerous low doses equal to the single large dose have much the same effect on the body over time.

Moreover, radiation dose for the same test can vary dramatically depending on the equipment used, technologist skill, application of dose-reduction strategies, and patient size, age, and gender.  Licensure of imaging and radiation therapy technologists varies depending on the type of test performed by the technologist.  Some states have only partial regulation; six states and the District of Columbia have no licensure or regulatory provisions of any kind.

In addition, pharmaceuticals have become a considerable source of environmental contamination.  Drugs of all types enter the water supply when they are excreted or improperly disposed of; the health impact of long-term exposure to varying mixtures of these compounds is unknown.”

– Reducing Environmental Cancer Risk: What We Can Do Now (2008 – 2009) by the President’s Cancer Panel; page v

The estimated effective radiation dose of all imaging and nuclear medicine tests performed should be a required element in patient records and should be a core data element in all electronic health records systems.  In addition, patients should be assisted to reconstruct an estimate of the total medical radiation dose they have received.

– Reducing Environmental Cancer Risk: What We Can Do Now (2008 – 2009) by the President’s Cancer Panel; page xix

“To reduce exposure to radiation from medical sources, patients should discuss with their health care providers the need for medical tests or procedures that involve radiation exposure.  Key considerations include personal history of radiation exposure, the expected benefit of the test, and alternative ways of obtaining the same information.  In addition, to help limit cumulative medical radiation exposure, individuals can create a record of all imaging or nuclear medicine tests received and, if known, the estimated radiation dose for each test.”

– Reducing Environmental Cancer Risk: What We Can Do Now (2008 – 2009) by the President’s Cancer Panel; page xx