The sensitivity of 18F-fluorodeoxyglucose positron emission tomography in the evaluation of metastatic pulmonary nodules.

OBJECTIVE Pulmonary metastasectomy is beneficial in select patients. The sensitivity of (18)F-fluorodeoxyglucose positron emission tomography (FDG-PET) for pulmonary metastasis is unknown. The aims of the study were to determine the accuracy of FDG-PET in detecting pulmonary metastasis and identify factors affecting sensitivity. METHODS All patients undergoing metastasectomy from September 2002 through December 2006 who had both chest computed tomography (CT) and FDG-PET scans or a fused CT/FDG-PET within 6 weeks prior to surgery were reviewed. Univariate and multivariate analysis were performed to determine predictors of positivity. RESULTS There were 83 patients (41 men, 42 women) who had 104 resections. Median age was 61 years (range, 32-87). In total 154 nodules were resected; 1 nodule in 47 patients and multiple in 36. Histopathology was adenocarcinoma in 94 nodules, sarcoma in 18, squamous cell carcinoma in 15, renal cell carcinoma in 7 and other in 20. At least one nodule was FDG-PET positive in 68 patients (81.9%). True positive FDG-PET was found in 104 nodules (67.5%) while 50 were false negative (32.5%). Multivariate analysis revealed tumor diameter and grade correlated with increased sensitivity of FDG-PET. CONCLUSION FDG-PET is positive in only 67.5% of metastatic pulmonary nodules. Nodule size and grade affect the sensitivity of FDG-PET for metastatic pulmonary nodules. FDG-PET is not a sensitive test in the evaluation of patients considered for pulmonary metastasectomy. Moreover, a negative FDG-PET should not be used to rule out metastatic disease.