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.