Objectives: Staging data on patients with non-small cell lung cancer were prospectively collected to evaluate the accuracy and anatomic information provided by fluorodeoxyglucose F 18 positron-emission tomography and its impact on improving the accuracy of surgical staging.
Methods: A total of 142 patients with potentially resectable non-small cell lung cancer were imaged with positron-emission tomography (neck to pelvis). Positron-emission tomographic scans were read prospectively with thoracic computed tomographic comparison. Patients without distant metastases at positron-emission tomography underwent staging with bronchoscopy and mediastinoscopy, with or without mediastinotomy or thoracoscopy. Patients with metastases, pleural implants, or N2 or N3 disease did not undergo primary resection.
Results: Positron-emission tomography revealed unsuspected distant metastases in 24 of 142 patients (16.9%) and unsuspected pleural implants in 6 others. Nodal stage was surgically established in 118 cases. Positron-emission tomography showed that 5 patients had nodal disease not accessible by mediastinoscopy. In 35 (24.6%) of these 142 cases, positron-emission tomography directed the evaluation away from routine bronchoscopy and mediastinoscopy staging that would have resulted in inappropriate treatment selection. Positron-emission tomography correctly differentiated resectable stages IA through IIIA (N1) from stages IIIA (N2) through IV in 88.7% of cases. In identifying N2 or N3 disease, positron-emission tomography had an accuracy of 90.7%, a sensitivity of 80.9%, a specificity of 96%, and positive and negative predictive values of 91.9% and 90.1%, respectively. Of the 8 cases in which positron-emission tomography missed N2 disease, 7 had the disease discovered by mediastinoscopy and 1 had it discovered at thoracotomy.
Conclusions: The diagnostic accuracy of positron-emission tomography-enhanced clinical staging is high. Positron-emission tomography has previously been used primarily to screen for lymph node spread and distant metastases, but it also provides localizing information that allows directed and more sensitive surgical staging and refinement of patient selection for curative resection. Positron-emission tomography and surgical staging play complementary roles in the journey toward more accurate overall staging.