2001 Plenary Session: Friday Imaging Symposium. CT Screening for Cancer.

Abstract

Screening, defined as the testing of asymptomatic individuals for subclinical disease, has become a major strategy in improving patient outcome through the early detection of cancer. The purpose of screening is to differentiate among those individuals who likely have cancer from those who do not. The premise of screening is that early diagnosis will yield positive health benefits by permitting early initiation of treatment and thus a reduction in morbidity and mortality (1‐3). Screening tests differ from diagnostic tests. Diagnostic tests are generally used in patients who come to medical evaluation for symptoms. Results of diagnostic tests are often accurate enough to establish a definite diagnosis, and they can be used as a basis for initiating treatment. By comparison, screening tests are generally offered to asymptomatic populations as a means of determining whether it is probable that they have a target disease. During the past few years, many institutions have established targeted screening programs for pulmonary cancer and colorectal adenomatous polyps and also whole-body screening programs that use both single-detector and multidetector computed tomography (CT). The Radiological Society of North America recognized the importance of screening tests for cancer and dedicated an afternoon session to this topic at the 2001 annual meeting. The following two articles by Yee and Brant-Zawadzki discuss the role for virtual colonography and whole-body CT in the detection of cancer. Because screening programs for cancer detection are increasing in the United States, we believe that publication of these presentations is appropriate. Radiologists will be asked to make decisions about offering screening tests in their own practices, and thus, they must be aware of the risk/benefit and cost/benefit ratios of screening imaging procedures. These introductory comments, which emphasize the general criteria for a good screening program and the clinical and financial implications of offering CT screening directly to the consumer, provide a foundation for the articles that follow.