Purpose: To compare prospectively the diagnostic efficacies of integrated positron emission tomography (PET)/computed tomography (CT) and 3.0-T whole-body magnetic resonance (MR) imaging for determining TNM stages in non-small cell lung cancer (NSCLC).
Materials and methods: Institutional review board approval and informed consent were obtained. The study included 165 patients (125 men, 40 women; mean age, 61 years) with NSCLC proved at pathologic examination who underwent both unenhanced PET/CT and whole-body MR imaging. Pathologic findings for T (n = 123) and N (n = 150) staging and pathologic or follow-up imaging findings (n = 154) for M staging were reference standards. The efficacies of PET/CT and whole-body MR imaging for lung cancer staging were compared by using the McNemar test.
Results: Primary tumors (n = 123 patients) were correctly staged in 101 (82%) patients at PET/CT and in 106 (86%) patients at whole-body MR imaging (P = .263). N stages (n = 150 patients) were correctly determined in 105 (70%) patients at PET/CT and in 102 (68%) patients at whole-body MR imaging (P = .880). Thirty-one (20%) of 154 patients had metastatic lesions. Accuracy for detecting metastases was 86% (133 of 154 patients) at PET/CT, and that at whole-body MR imaging was 86% (132 of 154 patients) (P > .99). Although the differences were not statistically significant, whole-body MR imaging was more useful for detecting brain and hepatic metastases, whereas PET/CT was more useful for detecting lymph node and soft-tissue metastases.
Conclusion: Both PET/CT and 3.0-T whole-body MR imaging appear to provide acceptable accuracy and comparable efficacy for NSCLC staging, but for M-stage determination, each modality has its own advantages.