Relationship Between Surgical R0 Resectability and Findings of Peripancreatic Vascular Invasion on CT Imaging After Neoadjuvant S-1 and Concurrent Radiotherapy in Patients with Borderline Resectable Pancreatic Cancer
Abstract BackgroundBorderline resectable pancreatic cancer (BRPC) is frequently associated with positive surgical margins and a poor prognosis because the tumor is in contact with major vessels. This study evaluated the relationship between the margin-negative (R0) resection rate and findings indicating peripancreatic vascular invasion on multidetector computed tomography (MDCT) imaging after neoadjuvant chemoradiotherapy (NACRT) in patients with BRPC.MethodsTwenty-nine BRPC patients who underwent laparotomy after neoadjuvant S-1 with concurrent radiotherapy were studied retrospectively. Peripancreatic major vessel invasion was evaluated based on the length of tumor-vessel contact on MDCT. The R0 resection rates were compared between the progression of vascular invasion (PVI) group and the non-progression of vascular invasion (NVI) group. ResultsThere were 3 patients with partial responses (10%), 25 with stable disease (86%), and 1 with progressive disease (3%) according to the RECISTv1.1 criteria. Regarding vascular invasion, 9 patients (31%) were classified as having PVI, and 20 patients (69%) were classified as having NVI. Of the 29 patients, 27 (93%) received an R0 resection, and all the PVI patients received an R0 resection (9/9; R0 resection rate = 100%). The R0 resection rates did not differ significantly between the PVI and NVI groups (P = 1.000, 100% vs. 90%).ConclusionsPatients with BRPC after NACRT achieved high R0 resection rates regardless of the vascular invasion status. BRPC patients can undergo R0 resections unless progressive disease is observed after NACRT.Trial registrationUMIN-CTR, UMIN000009172. Registered 23 October 2012, https://upload.umin.ac.jp/cgi-open-bin/ctr_e/ctr_view.cgi?recptno=R000010762