Researchers, led by Harm van Tinteren, M.D., of the Comprehensive Cancer Center in Amsterdam, presented the results of their study recently at the annual meeting of the American Society of Clinical Oncology in New Orleans.

Currently, patients with early stage cancer confined to the lung can be effectively treated by surgical removal of the tumor. However, doctors often find during surgery or follow-up that a patient’s cancer is more widespread than originally estimated – and cannot be removed completely by surgery. Also, some patients are found during surgery to have a benign (noncancerous) mass that could have been treated with medications alone or perhaps even left in place without any treatment at all.

As a way of avoiding these unnecessary operations, the researchers tested the power of PET scans to accurately learn the extent of disease. The team looked at 96 patients who had a conventional series of diagnostic tests and 92 patients who had the same tests followed by a PET scan. In the group given the standard tests, 78 patients had surgery and 39 – or 50 percent – of those surgeries turned out to be futile. In the group given PET scans, 60 patients had surgery, and 19, or 32 percent, of the surgeries were considered futile.

Four percent of patients in the PET group relapsed after surgery, compared to 14 patients in the group who had standard tests, according to the researchers. "PET more accurately shows the extent and stage of disease," Dr. van Tinteren says.

The test can save patients needless surgery and save health care dollars in the process, he adds. "The savings realized by reducing unnecessary surgery offsets the costs of using PET."

Herman Kattlove, M.D., an oncologist and medical editor for the American Cancer Society (ACS), says the Dutch study adds to the evidence that PET can improve diagnosis. "We’re always looking for a better way to stage lung cancer," he says.

Lung cancers are usually removed together with at least a half or a third of a lung. Sometimes an entire lung is removed. This operation involves a hospital stay of one to two weeks and most patients cannot return to their usual activities for one to two months. Patients whose survival will not be improved by surgery will have better quality of life if they can avoid spending too much of their remaining time recovering from surgery, Dr. Kattlove says.

PET scans work by using glucose (a form of sugar) that contains a radioactive atom. The substance emits tiny atomic particles called positrons. Unlike most other imaging tests, which give views of the shape and size of internal structures only, PET scanning provides information about their metabolic activity. A special camera records the precise location of the positrons as they leave the body.

PET scanning is becoming widely used to determine the spread of cancers of the breast, colon, rectum and ovaries in addition to lung cancers.