Limitations of 18F-2-deoxy-D-glucose positron emission tomography in N1 detection in patients with pathologic stage II-N1 and implications for management.

BACKGROUND: The definitive use of 18F-2-deoxy-d-glucose positron emission tomography (FDG-PET) to detect nodal metastasis in patients with early-stage non-small cell lung cancer (NSCLC) being evaluated for local nonsurgical management, such as stereotactic body radiation therapy and minimally invasive percutaneous ablative therapies, underscores the importance of diagnosing N1 disease by FDG-PET. The purpose of this study was to evaluate FDG-PET in the detection of N1 disease and to determine if FDG-PET-positive N1 disease predicts poor survival in patients with pathologic stage II-N1 NSCLC.

METHODS: We reviewed all patients who underwent surgical resection for lung cancer at MD Anderson Cancer Center from 2000 to 2011 who had pathologic stage T1 to T2 and N1 disease and a preoperative FDG-PET. We compared the clinicopathologic characteristics and survival of patients who had PET-positive N1 and PET-negative N1 disease.

RESULTS: A total of 104 patients met the inclusion criteria. The pathologic stage in 87 patients was IIA (T1a N1, T1b N1 or T2a N1) and in 17 patients was IIB (T2b N1). Only 25 of 104 patients (24%) had PET-positive N1 disease. There was no clinical or pathologic difference between the patients who had PET-positive N1 and PET-negative N1 disease. No significant difference was found in the survival rates between patients from the PET-positive N1 and the PET-negative N1 groups (p = 0.9).

CONCLUSIONS: FDG-PET has poor sensitivity in detecting N1 disease, and N1-positive disease on FDG-PET does not have an effect on survival. FDG-PET should not be used alone to determine management in patients with early-stage non-small cell lung cancer being evaluated for local nonsurgical management.