Positron emission tomographic imaging with fluorodeoxyglucose is efficacious in evaluating malignant pulmonary disease

Objective: Positron emission tomography (PET), when used with the intraveno usly administered radiopharmaceutical F-18 fluorodeoxyglucose (FDG), has th e potential to help in the evaluation of patients with lung cancer because the radiopharmaceutical is concentrated by metabolically active cells. We c onducted a retrospective study of PET-FDG in 96 patients evaluated at our i nstitution over the past 2 years for suspected primary pulmonary neoplasms. PET-FDG results were compared with the findings of computed tomographic sc ans on the same patients. All patients underwent surgical exploration with or without resection of the malignant tumors. Sites of potential malignancy were subjected to biopsy and/or excision, with subsequent pathologic evalu ation. Results: A total of 96 patients with suspected or proven primary pul monary malignant disease were evaluated. Sixty-six patients had histologica lly confirmed malignant tumors, and 30 had benign masses histologically, PE T-FDG had an accuracy of detecting malignancy in pulmonary lesions of 92% ( sensitivity 97%; specificity 89%). A total of iii surgically sampled sites were from lymph nodes. PET-FDG was accurate in predicting the malignancy of nodes in 91% of instances, whereas computed tomography was correct in 64%. The sensitivity, specificity, and predictive accuracy of PET in detecting metastatic lymphadenopathy in mediastinal lymph nodes were 98%, 94%, and 95 %, respectively, PET-FDG also changed the M stage in 8 (12%) patients (6 wi th and 2 without metastases). The 6 malignant (positive) lesions were corre ctly identified by PET-FDG, and the 2 without tumor were accurately predict ed as benign (negative), Conclusion: These initial results suggest that PET -FDG is highly accurate in identifying and staging lung cancer. PET-FDG als o appears to be more accurate in detecting metastatic mediastinal lymphaden opathy than computed tomographic scan.