Positron emission tomography-computed tomography compared with invasive mediastinal staging in non-small cell lung cancer: results of mediastinal staging in the early lung positron emission tomography trial.

INTRODUCTION: Patients with non-small cell lung cancer (NSCLC) require careful preoperative staging to define resectability for potential cure. Fluorodeoxyglucose positron emission tomography combined with computed tomography (FDG PET-CT) is widely used to stage NSCLC. If the mediastinum is positive on PET-CT examination, some practitioners conclude that the patient is inoperable and refer the patient for nonsurgical treatment. METHODS: In this analysis of a previously reported trial comparing PET-CT with conventional imaging in the diagnostic work-up of patients with clinical stage I, II, or IIIA NSCLC, we determined the accuracy of PET-CT in mediastinal staging compared with invasive mediastinal staging either by mediastinoscopy alone or by mediastinoscopy combined with thoracotomy. RESULTS: All 149 patients had mediastinal nodal staging at mediastinoscopy alone (14), thoracotomy alone (64), or both (71). The sensitivity of PET-CT was 70% (95% confidence interval [CI], 48-85%), and specificity was 94% (95% CI, 88-97%). Of 22 patients with a PET-CT interpreted as positive for mediastinal nodes, 8 did not have tumor. The positive predictive value and negative predictive value were 64% (95% CI, 43-80%) and 95% (95% CI, 90-98%), respectively. Based on PET-CT alone, eight patients would have been denied potentially curative surgery if the mediastinal abnormalities detected by PET-CT had not been evaluated with an invasive mediastinal procedure. CONCLUSIONS: PET-CT assessment of the mediastinum is associated with a clinically relevant false-positive rate. Our study confirms the need for pathologic confirmation of mediastinal lymph node abnormalities detected by PET-CT.

Positron emission tomography in staging early lung cancer: a randomized trial.

BACKGROUND: Among patients with early-stage non-small cell lung cancer (NSCLC), preoperative imaging tests are important in defining surgical candidates. OBJECTIVE: To assess whether whole-body positron emission tomography and computed tomography (PET-CT) plus cranial imaging correctly upstages cancer in more patients with NSCLC than does conventional staging plus cranial imaging. DESIGN: Randomized clinical trial with recruitment from June 2004 to August 2007. The centralized, computer-generated, variable block size randomization scheme was stratified by treatment center and cancer stage. Participants, health care providers, and outcome assessors were not blinded to imaging modality assignment. SETTING: 8 hospitals and 5 PET-CT centers in academic institutions. PATIENTS: Eligible patients were older than 18 years; had histologic or cytologic proof of stage I, II, or IIIA NSCLC on the basis of chest radiography and thoracic CT; and had a tumor considered to be resectable. INTERVENTION: PET-CT or conventional staging (abdominal CT and bone scan). All patients also had cranial imaging using CT or magnetic resonance imaging. MEASUREMENTS: The primary outcome was correct upstaging, thereby avoiding stage-inappropriate surgery. Secondary outcomes were incorrect upstaging and incorrect understaging. RESULTS: 170 patients were assigned to PET-CT and 167 to conventional staging. Eight patients (3 who had PET-CT and 5 who had conventional staging) did not have planned surgery. Disease was correctly upstaged in 23 of 167 PET-CT recipients and 11 of 162 conventional staging recipients (13.8% vs. 6.8%; difference, 7.0 percentage points [95% CI, 0.3 to 13.7 percentage points]), thereby sparing these patients from surgery. Disease was incorrectly upstaged in 8 PET-CT recipients and 1 conventional staging recipient (4.8% vs. 0.6%; difference, 4.2 percentage points [CI, 0.5 to 8.6 percentage points]), and it was incorrectly understaged in 25 and 48 patients, respectively (14.9% vs. 29.6%; difference, 14.7 percentage points [CI, 5.7 to 23.4 percentage points]). At 3 years, 52 patients who had PET-CT and 57 patients who had conventional staging had died. LIMITATION: The relatively small sample and the fact that some patients did not have planned surgery limited the ability to determine precise differences in clinical outcomes that were attributable to testing strategies. CONCLUSION: Preoperative staging with PET-CT and cranial imaging identifies more patients with mediastinal and extrathoracic disease than conventional staging, thereby sparing more patients from stage-inappropriate surgery, but the strategy also incorrectly upstaged disease in more patients.