Abstract
Background: Mediastinal staging in non-small cell lung cancer with endosonography (EUS-FNA plus EBUS-TBNA) followed by mediastinoscopy is more sensitive to detect nodal metastasis as compared to mediastinoscopy alone (ASTER trial, JAMA 2010;304:2245). However 11 patients need to undergo a mediastinoscopy to detect one with N2/3 missed by endosonography. We analysed if FDG-PET identifies patients in whom the mediastinoscopy can be omitted.
Methods: In ASTER, 123 patients were randomized to endosonography followed by mediastinoscopy when the former did not show mediastinal metastasis. Sensitivity, negative predictive value (NPV) and number of mediastinoscopies needed to detect one false negative endosonography were calculated in the cases with complete data (n=120; 98%).
Results: With PET, 77 patients had FDG-avid mediastinal nodes; the prevalence of N2/3 was 73 (62-81)%. The sensitivity and NPV of endosonography was 88 (76-94) and 75 (57-88)%. Adding mediastinoscopy increased sensitivity and NPV to 96 (88-99) and 91 (73-98)%. 43 patients did not have FDG-avid mediastinal nodes, the prevalence of N2/3 was 23 (13-38)%. The sensitivity and NPV of endosonography was 70 (40-89)% and 92 (78-97)%. Adding mediastinoscopy increased sensitivity and NPV to 80 (49-94)% and 94 (81-98)%. In patients with FDG-avid vs. FDG-cold mediastinal nodes, the number of mediastinoscopies needed to detect one false negative endosonography is 6 vs 36 (p=0.078).
Conclusions: A negative endosonography should be followed by a mediastinoscopy if PET positive mediastinal nodes are present. In the absence of PET positive nodes, a mediastinoscopy following a negative endosonography can be omitted.
- © 2011 ERS
