Comparison of Endobronchial Ultrasound, Positron Emission Tomography, and CT for Lymph Node Staging of Lung Cancer: Patients
From December 2003 to March 2005, patients with suspected or pathologically established lung cancer referred to the Department of Thoracic Surgery, Chiba University Hospital were enrolled in this study. All patients were evaluated by history; physical examination; CBC count; renal, liver, and pulmonary function tests; chest radiography; CT scan of the chest and upper abdomen; brain MRI; bone scan; and FDG-PET. All tests were presented in a multidisciplinary session, and the staging of the disease, tumor resectability, and medical operability was verified by specialists. The primary tumor and lymph node status was classified according to the international TNM staging system reported by Mountain and Dressler. Source
Patients were included in this prospective study if they were believed to be candidates for curative thoracic surgery from the multidisciplinary session. Following CT and PET, EBUS-TBNA was performed to evaluate mediastinal lymph nodes. The study was approved by the ethical committee of our institute, and written informed consent was obtained in all the patients included in the study.
Chest and upper abdominal CT were performed with contrast single injection and multidetector-row CT (Light Speed; GE Medical System; Milwaukee, WI). The slice thickness was 5 mm with a pitch of 1.6, and images were reconstructed at 5-mm intervals. It was used for the assessment of the resectability of the primary tumor, the evaluation of mediastinal lymph nodes, and the exclusion of distant metastases. Radiologists blinded to the results of other tests performed the scan reading and staged the patients accordingly by the criteria of Webb et al. Lymph nodes with the short axis > 1 cm were considered positive for malignancy.
Whole-body FDG-PET (GE PET Advance Nxi; GE Medical Systems) was performed followed by overnight fasting. The glucose levels of patients were within normal limits prior to examination. Sixty to 90 min after injection of 300 MBq of FDG, whole-body acquisition was performed. Images were reconstructed using the attenuation-weighted ordered-subset expectation maximization technique. Images were visually interpreted using a display of three orthogonal sections and maximum intensity projections. One experienced nuclear medicine physician (K.M., 12 years of experience) who was masked to the results of other tests read the PET images. Standardized uptake values were calculated as the ratio of the regional radioactivity concentration divided by the injected amount of radioactivity normalized to body weight. FDG-PET was considered positive for an N1, N2, or N3 lymph node if the PET report stated that there was hypermetabolic activity consistent with malignant disease (defined as standardized uptake value > 2.5).