Is 18 F-FDG-PET useful for predicting R0 resection after induction therapy for initially unresectable locally advanced esophageal carcinoma?

Objective: Induction therapy followed by surgery is a promising strategy for esophageal cancer patients with invasion of the trachea/bronchus or aorta. However, no diagnostic criteria have been established to diagnose whether R0 resection can be performed. We investigated whether ¹⁸ F-2-deoxy-D-glucose positron emission tomography ( ¹⁸ F-FDG-PET) and other modalities are useful for predicting R0 resection.
Methods: Fifty-seven patients with esophageal cancer invading the trachea/bronchus or aorta who underwent induction therapy followed by surgery were enrolled. We divided the participants into two groups, an R0 resection group (n = 43) and a non-R0 resection group (n = 14), and then compared the between-group results of three modalities, including computed tomography (CT), endoscopy and ¹⁸ F-FDG-PET, before and after induction therapy.
Results: The post-maximal standardized uptake value (SUV _max ) after induction therapy in the R0 resection group was significantly lower than that in the non-R0 resection group (4.4 vs. 6.6, p = 0.005). The receiver operating characteristic curve analysis showed that the cut-off value for the post-SUV _max based on ¹⁸ F-FDG-PET prediction of R0 resection was 4.7. Furthermore, a tumor reduction rate of ≥44% on CT, no residual stenosis, and no deep ulcer on endoscopy were associated with R0 resection after induction therapy (p = 0.002, p = 0.091, and p = 0.059, respectively). Multivariate logistic analyses revealed that the tumor reduction rate on CT and post-SUV _max <4.7 in ¹⁸ F-FDG-PET were independent factors for R0 resection.
Conclusions: The post-SUV _max determined by ¹⁸ F-FDG-PET and the volume reduction rate based on CT scans were useful for predicting R0 resection after induction therapy for initially unresectable locally advanced esophageal carcinoma.