Imaging response evaluation after novel neoadjuvant treatments of pancreatic cancer

Emergent neoadjuvant concepts have improved the rate of margin-free (R0) resections in borderline resectable and locally advanced pancreatic ductal adenocarcinoma. However, due to specific properties of pancreatic cancer, imaging response assessment is difficult. The concepts of histologic response patterns and their imaging correlates are outlined, together with efforts in morphologic and functional imaging to overcome the challenges of response assessment. Imaging evaluation after neoadjuvant therapy remains a diagnostic dilemma. To date, better understanding of the specific transformations of PDAC under neoadjuvant agents could not be transformed into validated imaging criteria for defining response and selecting surgical candidates. Currently, patients with non-metastatic borderline resectable and locally advanced pancreatic ductal adenocarcinoma are brought to diagnostic laparotomy in the absence of overt radiologic progression after neoadjuvant therapy. Apart from morphologic patterns, ongoing research is focused on defining robust functional imaging parameters for response assessment.