CHARACTERIZATION OF PULMONARY NODULES AND MEDIASTINAL STAGING OF BRONCHOGENIC-CARCINOMA WITH F-18 FLUORODEOXYGLUCOSE POSITRON EMISSION TOMOGRAPHY

Objective: To evaluate F-18 fluorodeoxyglucose positron emission tomog raphy (PET) in terms of its sensitivity and specificity in diagnosing malignant pulmonary nodules and staging bronchogenic carcinoma. Method s: A retrospective review of any patient that presented to the VA Pale Alto Health Care System with a pulmonary nodule between 9/94 and 3/96 revealed 49 patients (four female, 45 male) age 37-85 (mean 63) with 54 pulmonary nodules who had: chest CT scan: PET scan: and tissue char acterization of the nodule. Characterization of each nodule was achiev ed by histopathologic (N = 44) or cytopathologic (N = 10) analysis. Oi the 49 patients. 18 had bronchogenic carcinoma which was adequately s taged. Mediastinal PET and CT findings in these 18 patients were compa red with the surgical pathology results. N2 disease was defined as med iastinal lymph node involvement by the American Thoracic Society's cla ssification system, Mediastinal lymph nodes were interpreted as positi ve by CT if they were larger that 1.0 cm in the short-axis diameter. R esults: Sensitivity and specificity for the diagnosis of malignant pul monary; nodules using PET was 93 and 70%, respectively. All nodules (N = 3) that were falsely positive by PET scan were infectious in origin . All nodules (N = 4) that were falsely negative by PET were technical ly limited studies (outdated scanner, no attenuation correction, hyper glycemia) except for one case of metastatic adenocarcinoma. The sensit ivity and specificity of PET in diagnosing N2 disease was 67 and 100%, compared with 56% and 100% for CT scan (not statistically significant ). However, one more patient with NZ disease was correctly diagnosed b y PET than by CT scan. Conclusion: PET is a valuable tool in the diagn osis and management of pulmonary nodules and may more accurately stage patients with bronchogenic carcinoma than CT scanning alone. (C) 1997 Elsevier Science B.V.