Non-Small Cell Lung Cancer - Diagnostic Tests

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The use of helical CT for early screening is still controversial.

Click the icon to see an image of a CT scan of the chest.

Evidence to date has not proven a survival benefit of using CT scans to screen people without symptoms. Many experts are highly opposed to widespread screening for lung cancer. Some evidence, for example, suggests that lung cancer cells in non-small cell lung cancer are often very aggressive at microscopic levels (before a tumor is formed). If this were true, the cancer would be highly likely to have spread long before it was visible with CT scans. Moreover, some studies have found no association between tumor size at the time of diagnosis and survival times.

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It should also be noted that about 98% of suspicious areas seen on CT scans turn out to be benign. Even after rescreening, many scans will show suspicious areas that turn out to be harmless but will require invasive and expensive biopsies. In these cases, patients are more at risk from aggressive tests than from the disease itself. Additional experience with CT scans, however, may allow experts to better determine which abnormalities are likely to be benign.

High-risk individuals who are still interested in early screening with CT scans should ask their doctor about available clinical trials.

Other Imaging Tests for Staging and Tracking Cancer

Computed tomography is the standard imaging procedure for determining if and where the cancer has spread (metastasized). Other imaging tests, however, may also be useful for staging and tracking lung cancers (staging means finding out how advanced the cancer is).

A bone scan is done to check for spread of cancer to the bones for those with bone pain, or other findings suggesting spread of cancer to the bones.

Positron Emission Tomography. Positron emission tomography (PET), specifically a technique known as FDG-PET can diagnose lung tumors as small as 1 centimeter with very high accuracy. PET works best when used with CT scans.

With this imaging test, the patient is first injected with a specially formulated, radioactive liquid sugar (called FDG), and then viewed with a machine that records energy given off by cells that absorb high levels of FDG, such as lung tumor cells.