18F-FMT Uptake Seen Within Primary Cancer on PET Helps Predict Outcome of Non-Small Cell Lung Cancer

L-[3-F-18]-a-methyl tyrosine (F-18-FMT) is an amino-acid tracer for PET imaging. We evaluated the prognostic significance of F-18-FMT PET in patients with non-small cell lung cancer. Methods: Ninety-eight patients (80 men and 18 women; age range, 42-82 y; median age, 69 y) with stage I-IV non-small cell lung cancer were enrolled in this study. They included 57 with adenocarcinoma, 31 with squamous cell carcinoma, 5 with large cell carcinoma, and 5 with other conditions. The median follow-up duration was 17.0 mo. A pair of PET studies with F-18-FMT and F-18-FDG was performed, and tracer uptake by the primary tumor was evaluated using the maximal standardized uptake value (SUVmax). Overall survival and disease-free survival were calculated by the Kaplan-Meier method. The prognostic significance was assessed by univariate and multivariate analyses. Results: The best discriminative SUVmax cutoffs for F-18-FMT and F-18-FDG in the primary tumors were 1.6 and 11, respectively. In the univariate analysis, a high SUVmax was significant in predicting poor overall survival for F-18-FMT (P = 0.0129) and F-18-FDG PET (P = 0.0481). According to histologic types, F-18-FMT and F-18-FDG uptake were a stronger prognostic predictor in adenocarcinoma than in nonadenocarcinomatous disease. Patients with a high SUVmax for F-18-FMT showed significantly worse disease-free survival rates than those with a low SUVmax, and multivariate analysis confirmed that a high SUVmax for F-18-FMT was an independent and significant factor in predicting a poor prognosis in patients with adenocarcinoma (P = 0.0191). Conclusion: Uptake of F-18-FMT in primary tumors was an independent prognostic factor in patients with pulmonary adenocarcinoma.