Neoadjuvant therapy for pancreatic cancer: Limitations and advances of response assessment (Review).

Neoadjuvant therapy (NAT) has been widely recommended for managing patients with borderline resectable pancreatic cancer and resectable tumors with high risk factors. Accurate evaluation of the response after NAT is crucial to decide surgery, which then improves the rate of R0 resection and avoids meaningless surgery. The response to NAT is currently evaluated by conventional radiological examination and changes of serum CA19‑9 levels. However, these assessments cannot accurately reflect the response to NAT. This article describes the limitations and advances of NAT response evaluation in pancreatic cancer. The values of some traditional imaging techniques, including positron emission tomography, endoscopic ultrasound, and diffusion weighted magnetic resonance imaging, are discussed, as well as novel imaging modalities or biomarkers, such as radiomics, dual energy computed tomography and liquid biopsy.