Fluorodeoxyglucose uptake measured by positron emission tomography and standardized uptake value predicts long-term survival of CT screening detected lung cancer in heavy smokers

BACKGROUND: Fluorodeoxyglucose-positron emission tomography (FDG-PET) has proven its value in the diagnosis of undetermined pulmonary lesions, lung cancer staging, and assessment of prognosis. Purpose of this study is to clarify whether standardized uptake value (SUV) can predict clinical outcome of computed tomography (CT) screening detected lung cancer. METHODS: We tested the predictive value of FDG-PET using SUV on long-term survival of 34 lung cancer patients, detected from 1035 heavy smokers > or = 50 years monitored by annual low-dose CT for 5 years, with a median follow-up of 75 months from diagnosis. FINDINGS: PET scan was performed in 34 (89%) of 38 lung cancer patients diagnosed during the 5 years of screening and was positive in 32 (94%). Complete resection was achieved in 30 cases (88%), 20 (59%) were pathologic stage I and 23 (68%) were adenocarcinoma. Median SUV was 5.0 overall, being significantly lower in stage I (2.5 vs. 10.1, p = 0.001) and in adenocarcinoma (2.5 vs. 13.0, p = 0.001). The 5-year survival of lung cancer patients was 100% for SUV levels < or = 2.5, 60% for SUV more than 2.5 and less than 8, and only 20% for SUV > or = 8 (p = 0.001). CONCLUSIONS: FDG-PET using SUV can predict long-term survival of screening detected lung cancer, in a noninvasive manner. Metabolic assessment of biologic behavior might improve the clinical management of CT-detected lung cancer and reduce the risk of unnecessary treatments for indolent disease.