Tumor Interface Stability On Ct Imaging Is An Early Marker Of Response To Cytotoxic Therapy In Pancreatic Ductal Adenocarcinoma.

284Background: There is currently no reliable biomarker for assessing the response to therapy of pancreatic ductal adenocarcinoma (PDAC). Here, we investigated how changes in the tumor/parenchyma interface associate with response. Methods: We reviewed pre- and post-therapy scans of patients who received chemotherapy and/or chemoradiation for both localized and metastatic PDAC. We classified the interface between the PDAC tumor and surrounding pancreas parenchyma as stable (remains or becomes well-defined) or unstable (becomes poorly defined) using a novel visual scoring system and quantified changes in enhancement at this interface (Philips Intellispace Portal, quantitative European Association for the Study of Liver [qEASL]). Results: Three retrospective datasets were used to develop this method with consensus visual scoring performed by 3 radiologists. The first dataset included 99 patients with localized PDAC who received neoadjuvant chemoradiation. Patients who were classified as having a stable inter...