L-[3-18F]-α-Methyltyrosine Uptake by Lymph Node Metastasis Is a Predictor of Complete Response to CRT in Esophageal Cancer

Background/Aim: The amino acid positron emission tomography (PET) tracer [F-18]-3-fluoro-alpha-methyltyrosine (F-18-FAMT) is known to be highly specific for malignancies. We evaluated the accumulation of F-18-FDG or F-18-FAMT in lymph nodes (LN) prior to definitive chemoradiotherapy (CRT) for esophageal cancer. Patients and Methods: We retrospectively reviewed 30 patients with esophageal squamous cell carcinoma. All patients received definitive CRT. The relationship between the accumulation of F-18-FDG PET or F-18-FAMT PET in LNs prior to CRT and clinical outcomes was assessed. Results: A correlation was observed between LNs in which most of F-18-FAMT was accumulated and complete response (CR) rate, but was not for F-18-FDG. Additionally, for F-18-FAMT, the CR rate was significantly higher in the LN accumulated lesion <= 1 group than in the LN accumulated lesion >2 group. Discussion: To predict the outcome of definitive CRT in patients with esophageal cancer, it is important to evaluate the LN status.