Full-body CT Scans May Benefit Only Select Group
According to Study by UCSD Radiologist

A full-body computed tomography (CT) scan may be beneficial to fewer people than previously thought, according to a study presented December 3, 2002 at the 88thScientific Assembly and Annual Meeting of the Radiological Society of North America (RSNA) in Chicago. The results of a second study pointed out the need to establish guidelines and standardized reporting systems for this hotly debated diagnostic procedure.

The studies were presented by Giovanna Casola, M.D., professor of radiology and chief of body imaging at the University of California, San Diego (UCSD) School of Medicine, and her UCSD colleagues, who said that "radiologists must be careful to present their patients with imaging procedures that have value and do not have unintentional consequences."

Despite the concern in the medical community over full-body screening CT, public interest is high and cuts across age, gender and socioeconomic status. A full-body CT scan provides images from the shoulders to the pelvis, including the abdominal cavity, bones, heart and lungs. From this scan, radiologists can detect some cancers, as well as potentially life-threatening conditions, such as aortic aneurysms. They can identify osteoporosis, gallstones, kidney stones, enlarged lymph nodes and signs of early liver cirrhosis. They can also obtain information to assist them in classifying patient risk for coronary artery disease.

Some researchers theorize that an early cancer or heart disease diagnosis can lead to increased survival. Others are concerned because these widely available, costly diagnostic tests have yet to be proven beneficial or life saving on a large-scale basis, while exposing a patient to radiation. A lack of evidence proving full-body CT's impact on mortality has created a controversy within medicine.

In her first presentation, Casola described data collected from 1,192 full-body CT examinations performed at a private outpatient-imaging center. Early numbers indicate that approximately 54 percent (642) of those scanned were given a clean bill of health or exhibited benign disease of minimal clinical significance. However, 46 percent (550) exhibited abnormal radiographic findings—most commonly in the lungs, kidney or liver—that required additional imaging or clinical correlation. Of the abnormal findings, 15 percent exhibited significant benign disease, such as emphysema; 25 percent indicated indeterminate or suspected malignancy; and 1 percent were classified as highly suspicious for malignancy or life-threatening disease (aortic aneurysm). Of the 1,192 patients screened, 442 (37 percent) were given recommendations for further evaluation. No patients under age 45 had findings that were highly suspicious of malignancy.

One objective of the study was to determine which patient groups will benefit the most from full-body CT scans, taking into consideration the cost of the recommended follow-up versus the benefit, Casola said.

"Although our results are still preliminary, we can immediately identify two patient groups for whom full-body CT is not cost-effective," she added. "Patients younger than 40 had very few findings, with 9 percent requiring additional work up. Patients with a previous cancer diagnosis can also be excluded, because this scan does not detect metastatic disease."

Although patients may want to confirm they are healthy, Casola cautioned that many patients (and their families) with inconclusive results face intense anxiety while waiting for additional tests and final diagnosis.

Casola's UCSD co-authors on the study were radiology fellow Claudia D. Furtado, M.D., radiology resident Stephan Stamato, M.D., Patrick Lee, M.D., and medical students David Dang and Farhad Sani, M.B.B.S.

For the second study, the researchers reviewed the full-body screening CT data to determine assessment categories to help standardize patient reports and management.

"If radiologists are going to do full-body CT, then we need standardized reporting to communicate findings to clinicians with consistent recommendations that everyone understands," Casola said.

The only comparison radiologists have for mass screening is the mammography model, which has specific categories. Clinicians know what the categories signify and the necessary follow-up. Casola believes a similar system should be adopted for full-body CT screening. "This would place patients into one of six categories and help standardize reports and management," she said.

"Considering that almost 40 percent of patients we studied who underwent full-body CT screening fell into categories that required further tests, we think it is crucial that we establish a system of assessment and recommendations," Casola concluded.

Casola's co-investigators on the assessment and recommendations study were Furtado, Stamato, Dang, Wong and Sani.

Both studies were done with university funding.

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Abstracts of the presentations by Casola and her team can be seen at the following websites:

http://shows.rsna.org/rsna2002/V40/conference/session.cvn?eID=3103282

http://shows.rsna.org/rsna2002/V40/conference/session.cvn?eID=3108056

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