Percentage Change on FDG-PET/CT Predicts Complete Response to Neoadjuvant Radiochemotherapy in Esophageal Cancer

Objective: We evaluated whether the changes in FDG-PET/CT uptake between pre/and post-treatment might predict a complete response in esophageal cancer (EC). Patients and Methods: Fifty-six patients with 2 PET-CTs studies were evaluated retrospectively. Images were evaluated qualitatively and semiquantitatively (SUVs). Patients were classified as persistence of disease, complete metabolic response and unspecific FDG uptake. The SUVmax values and percentages of change in SUV were measured. Results: A significant difference was found between the persistence group and the non-persistence group regarding the median percentage change in SUVtumor (72.95% vs. 54.12%; p = 0.04) and regarding the percentage change in SUVnode (89.91% vs. 59.91%, p = 0.04). In patients treated with radiochemotherapy (RCTX), a significant difference was found between the persistence group and the no persistence group regarding the percentage change in SUVtumor (58.02% vs. 78.59%). Overall survival rate was related to the percentage of change in the SUVtumor. The group of ≥75% of change SUVtumor showed a median survival of 37.32 months (IC: 95% = 49.93 - 24.70) and the group of <75% of change SUVtumor showed a median survival of 18.39 months (IC: 95% = 25.14 - 11.65) (p = 0.04). In patients with metastatic relapse, a significant difference was found regarding the percentage change in SUVnode (94.63% vs. 74.09%). Conclusion: Our study provides evidence that the percentage change in the SUVmax is a predictor of the response to neoadjuvant treatment in patients with EC. When SUVmax decreases by 72.95% or more, the patient is likely a complete responder.