18F-FDG PET Response After Induction Chemotherapy Can Predict Who Will Benefit from Subsequent Esophagectomy After Chemoradiotherapy for Esophageal Adenocarcinoma

This study aimed to determine whether F-18-FDG PET response after induction chemotherapy before concurrent chemoradiotherapy can identify patients with esophageal adenocarcinoma who may benefit from subsequent esophagectomy. Methods: We identified and analyzed 220 patients with esophageal adenocarcinoma who had received induction chemotherapy before chemoradiotherapy, with or without surgery, with curative intent; all underwent F-18-FDG PET scanning before and after induction chemotherapy. F-18-FDG PET responders were defined as patients who achieved complete response (CR) after induction chemotherapy (maximum SUV <= 3.0). The predictive value of F-18-FDG PET response for patient outcomes was evaluated. Results: Overall, 86 patients had bimodality therapy (BMT; induction chemotherapy + chemoradiotherapy) and 134 had trimodality therapy (TMT; induction chemotherapy + chemoradiotherapy with surgery). Forty-eight patients (21.8%) achieved an F-18-FDG PET CR after induction chemotherapy. F-18-FDG PET CR was found to correlate with overall survival (OS) and progression-free survival (PFS) in BMT patients. For TMT patients, F-18-FDG PET CR predicted pathologic response (P = 0.003) but not survival. Among F-18-FDG PET nonresponders, TMT patients had significantly better survival than did BMT patients (P < 0.001). However, among F-18-FDG PET responders, BMT patients had OS (P = 0.201) and PFS (P 5 0.269) similar to that of TMT patients. After propensity scorematched analysis, F-18-FDG PET responders treated with BMT versus TMT still had comparable OS and PFS, but TMT was associated with better locoregional control. Conclusion: F-18-FDG PET response to induction chemotherapy could be a useful imaging biomarker to identify patients with esophageal adenocarcinoma who could benefit from subsequent esophagectomy after chemoradiotherapy. Compared with BMT, TMT can significantly improve survival in F-18-FDG PET nonresponders. However, outcomes for F-18-FDG PET responders were similar after either treatment (BMT or TMT). Prospective validation of these findings is warranted.