Radiologists Discuss Ways To Reduce Patient Exposure, Cancer Risk

USA Today: “Doctors are exploring ways to reduce the amount of radiation exposure from medical imaging tests in light of renewed concerns about the cancer risk, according to research presented at a radiology conference this week.

Medical radiation from exams such as CTs, or computed tomography, causes 29,000 new cancers a year, a report in the Archives of Internal Medicine showed in December. … The Food and Drug Administration is considering safeguards for CT scanners and other imaging machines.”

One radiologist suggested that “patients would be even better off if the USA had more comprehensive, uniform standards aimed at reducing radiation” (Szabo, 5/5).

This information was reprinted from kaiserhealthnews.org with kind permission from the Henry J. Kaiser Family Foundation. You can view the entire Kaiser Daily Health Policy Report, search the archives and sign up for email delivery at kaiserhealthnews.org.

© Henry J. Kaiser Family Foundation. All rights reserved.

Need For Strategies To Address Overdiagnosis In Cancer

Many cancers detected by screening tests are not destined to cause symptoms or death and therefore represent a phenomenon known as overdiagnosis. And because overdiagnosis leads to unnecessary treatment and other harms, it is important to develop clinical and research strategies to quantify, recognize, and manage it, according to a review published online in the Journal of the National Cancer Institute.

H. Gilbert Welch, M.D. and William Black, M.D., of the Dept. of Veterans Affairs Medical Center, White River Junction, Vt. and the Dartmouth-Hitchcock Medical Center used data from large randomized screening trials to estimate the extent of overdiagnosis. They found that about 25% of breast cancers detected on mammograms and about 60% of prostate cancers detected with prostate-specific antigen (PSA) tests could represent overdiagnosis. In a lung cancer screening trial of chest x-rays and sputum tests, they estimate that 50% of the cancers detected represented overdiagnosis. They argue that this estimate will only increase with spiral CT scanning, which, in one observational study, found almost as many lung cancers in non-smokers as smokers.

The authors also point to cancer incidence and mortality statistics as evidence of overdiagnosis in some cancers. For five cancers – thyroid, prostate, kidney and breast cancer, and melanoma – data from the past 30 years show an increasing number of new cases but not an increase in deaths. In each of these cancers, an increase in screening or imaging tests has been associated with an increasing rate of new diagnoses.

In addition to screening, other procedures, such as diagnostic imaging, may contribute to overdiagnosis. CT colonography (virtual colonoscopy) for instance, often detects abnormalities outside the colon that can lead to more tests and possibly overdiagnosis.

The authors suggest several strategies to address the problem. One is to educate patients about the risks and benefits involved with early detection.

“Whereas early detection may well help some, it undoubtedly hurts others,” they write. “Often the decision about whether or not to pursue early cancer detection involves a delicate balance between benefits and harms…different individuals, even in the same situation, might reasonably make different choices.” Read more

Next Page »