Utility of PET-CT CMR after neoadjuvant chemotherapy with DCF for esophageal cancer as a predictive factor of recurrence.

434 Background: PET-CT is considered as standard modality for evaluating metastasis of esophageal cancer before treatment. On the other hand, it is unclear whether PET-CT CMR (complete metabolic response) could be useful for assessment after neoadjuvant chemotherapy. To clarify the utility of PET-CT CMR as an adequate modality of prediction for recurrence after neoadjuvant chemotherapy with DCF for esophageal cancer. Methods: Fifty-eight cases of esophageal cancer (cStageII-IVa) who received the esophagectomy with neoadjuvant chemotherapy of DCF since June 2013 in Oita University. We evaluated the clinicopathological factors, RFS and OS between CMR group (n=22, 38%) and non-CMR group (n=36, 62%). Results: In the clinical stage before chemotherapy, T-factor was higher in the non-CMR group (p = 0.044), but there were no significant differences of lymph node metastasis (p = 0.27) and stage (p = 0.94) between the two groups. There was no significant difference of the SUV max (16.4 ± 6.5 vs 15.7 ± 6.5, p = 0.98) of the main lesion before chemotherapy and the FDG accumulation rate of lymph nodes (14 cases (63.6%) vs 21 cases) (58.3%), p = 0.69) between the two groups. There were no significant differences of the surgical procedure, lymph node dissection area, number of harvested lymph nodes, amount of bleeding, operation time, curability, and intra/post-operative complications between the two groups. There were 5 cases (15%) with postoperative recurrence in the CMR group (lung 1 case, extra-regional lymph nodes 3 cases, bone 1 case), 17 cases (47%) in the non-CMR group (local 4 cases, lung 3 cases, livers 5 cases, extra regional lymph nodes 6 cases, bone 4 cases, pleura 2 cases), but there was no significant difference between the two groups (p = 0.062). There were significant differences between the two groups for 3-year RFS (81.3 vs 65.3 months, p=0.021) and 3-year OS (93.8 vs 61.6 months, p=0.011). Conclusions: PET-CR CMR could not predict recurrence at present. PET-CR CMR cases had better prognosis compared to non-CMR cases in terms of 3-year RFS and 3-years OS.