Nonpalpable Supraclavicular Lymph Nodes in Lung Cancer Patients: Preoperative Characterization with 18F-FDG PET/CT

Abstract

Our purpose was to evaluate the usefulness of integrated 18F-FDG PET/CT in the detection and characterization of nonpalpable supraclavicular lymph node metastasis in patients with the initial diagnosis of lung cancer. This study was conducted from May 2005 to May 2006 and included 32 consecutively registered lung cancer patients in whom supraclavicular lymph nodes were not palpable but were identified on contrast-enhanced CT or exhibited increased FDG uptake on integrated PET/CT. Three patients had bilateral nodes, for a total of 35 nodes in the 32 patients. Results of cytologic analysis of a specimen obtained with sonographically guided fine-needle aspiration (n = 27), normal initial and follow-up sonographic findings (n = 3), and no change in the size of supraclavicular lymph nodes on follow-up sonography (n = 2) were the reference standards. The presence of supraclavicular lymph node metastasis was determined with integrated PET/CT (uptake greater than that of surrounding tissue) and contrast-enhanced CT (node short-axis diameter of 5 mm or more). The diagnostic efficacies of these methods in the detection of supraclavicular lymph node metastasis were compared. Supraclavicular lymph node metastasis was diagnosed cytologically in 12 (34%) of 35 lesions. The diagnostic accuracies of integrated PET/CT and contrast-enhanced CT in the detection of supraclavicular lymph node metastasis were 71% and 66%, respectively; the difference was not statistically significant. Although the difference was not statistically significant, the sensitivity (92%) and negative predictive value (93%) of integrated PET/CT were higher than those of contrast-enhanced CT. Because of its high sensitivity and negative predictive value, integrated PET/CT is useful in the detection and characterization of nonpalpable supraclavicular lymph nodes in lung cancer patients.