ACR responds to recent concerns over CT use, possible cancer risk
ACR responds to bad press on CT scans. Source:  
The American College of Radiology (ACR) is concerned that certain conclusions and comparisons made in a CT study published in the Nov. 29, 2007 issue of the New England Journal of Medicine, and reexamined in a June 27 Time article, may be inappropriate and cause patients to mistakenly avoid getting life-saving medical imaging care.

According to the NEJM study, up to 2 percent of all cancers in the United States may be caused by radiation received from CT scans. Yet, the study authors admit that there are currently no published studies directly linking CT scans (even multiple CT scans) to cancer.

While the study equates radiation exposure and effects experienced by many atomic bomb survivors in Japan to present day patients who receive CT scans, most CT exams are performed in a controlled setting, resulting in limited radiation exposure to a small portion of the body, according to the ACR.

The college said it has long held that no medical test, particularly those utilizing ionizing radiation, should be performed unless the medical benefits clearly outweigh any risk associated with the exam. For example, the ACR opposes full body CT scans for asymptomatic patients, one of the exams that the NEJM article authors put forth as a driver of future CT growth. The college said it also supports the ‘as low as reasonably achievable’ concept which urges providers to use the minimum level of radiation needed in such exams to achieve the necessary results.

Additionally, the ACR has developed (and has updated) its appropriateness criteria to help physicians prescribe the most appropriate imaging exam for more than 200 clinical conditions (particularly when an imaging exam that does not use radiation may be more appropriate for a given condition). Appropriateness criteria as well as ACR practice guidelines and technical standards that lay out the acceptable protocols for performing imaging exams are available to all physicians.

Aside from mammography, the ACR said there are currently no federally mandated quality and safety standards for medical imaging facilities, including those that provide CT scans. The college has asked Congress to implement mandatory accreditation for medical imaging facilities.

Mandatory accreditation and a pilot study regarding the use of appropriateness criteria in imaging are included in the current Medicare legislation under consideration in both the U.S. House of Representatives and the U.S. Senate. 

The ACR said it also has urged Congress to address financial incentives for physicians to install imaging equipment in their offices for self-referrals. “Such in-office imaging is where dramatic growth in CT scans has occurred and is a primary driver of the increased radiation dosage that Americans receive annually. Studies show that the ability to directly profit from the ordering of more scans greatly increases the use of such tests. Any serious effort to reduce the number of unnecessary scans performed nationwide must address financially driven self-referral,” according to the ACR.

In response to the concern over pediatric CT scans specifically outlined in the Time article, the ACR is a founding member of the Alliance for Radiation Safety in Pediatric Imaging, comprising more than 500,000 imaging professionals, which on Jan. 22, launched the Image Gently campaign to reinforce that children are more sensitive to radiation than adults, and cumulative radiation exposure to their growing bodies could, over time, have adverse effects.

To date, nearly 1,200 imaging providers, representing more than 900 facilities nationwide, have taken the Image Gently pledge to reduce the radiation dose for pediatric CT scans. More than 5,300 providers have downloaded the helpful protocols which aid physicians and facilities in performing appropriate CT scans on children, according to the ACR.