Innovative Imaging Techniques Used to Evaluate Borderline-Resectable Pancreatic Adenocarcinoma

Theranostic nanoparticles for detection and treatment of pancreatic cancer

Pancreatic ductal adenocarcinoma (PDAC) is one of the most recalcitrant cancers due to its late diagnosis, poor therapeutic response, and highly heterogeneous microenvironment. Nanotechnology has the potential to overcome some of the challenges to improve diagnostics and tumor-specific drug delivery but they have not been plausibly viable in clinical settings. The review focuses on active targeting strategies to enhance pancreatic tumor-specific uptake for nanoparticles. Additionally, this review highlights using actively targeted liposomes, micelles, gold nanoparticles, silica nanoparticles, and iron oxide nanoparticles to improve pancreatic tumor targeting. Active targeting of nanoparticles toward either differentially expressed receptors or PDAC tumor microenvironment (TME) using peptides, antibodies, small molecules, polysaccharides, and hormones has been presented. We focus on microenvironment-based hallmarks of PDAC and the potential for actively targeted nanoparticles to overcome the challenges presented in PDAC. It describes the use of nanoparticles as contrast agents for improved diagnosis and the delivery of chemotherapeutic agents that target various aspects within the TME of PDAC. Additionally, we review emerging nano-contrast agents detected using imaging-based technologies and the role of nanoparticles in energy-based treatments of PDAC. This article is categorized under: Implantable Materials and Surgical Technologies > Nanoscale Tools and Techniques in Surgery Therapeutic Approaches and Drug Discovery > Nanomedicine for Oncologic Disease Diagnostic Tools > In Vivo Nanodiagnostics and Imaging.

Currently Debated Topics on Surgical Treatment of Pancreatic Ductal Adenocarcinoma: A Narrative Review on Surgical Treatment of Borderline Resectable, Locally Advanced, and Synchronous or Metachronous Oligometastatic Tumor

BACKGROUND

Previously considered inoperable patients (borderline resectable, locally advanced, synchronous oligometastatic or metachronous pancreatic adenocarcinoma (PDAC)) are starting to become resectable thanks to advances in chemo/radiotherapy and the reduction in operative mortality.

METHODS

This narrative review presents a chosen literature selection, giving a picture of the current state of treatment of these patients.

RESULTS

Neoadjuvant therapy (NAT) is generally recognized as the treatment of choice before surgery. However, despite the increased efficacy, the best pathological response is still limited to 10.9-27.9% of patients. There are still limited data on the selection of possible NAT responders and how to diagnose non-responders early. Multidetector computed tomography has high sensitivity and low specificity in evaluating resectability after NAT, limiting the resection rate of resectable patients. Ca 19-9 and Positron emission tomography are giving promising results. The prediction of early recurrence after a radical resection of synchronous or metachronous metastatic PDAC, thus identifying patients with poor prognosis and saving them from a resection of little benefit, is still ongoing, although some promising data are available.

CONCLUSION

In conclusion, high-level evidence demonstrating the benefit of the surgical treatment of such patients is still lacking and should not be performed outside of high-volume centers with interdisciplinary teams of surgeons and oncologists.

Intraoperative Imaging in Hepatopancreatobiliary Surgery

Hepatopancreatobiliary surgery belongs to one of the most complex fields of general surgery. An intricate and vital anatomy is accompanied by difficult distinctions of tumors from fibrosis and inflammation; the identification of precise tumor margins; or small, even disappearing, lesions on currently available imaging. The routine implementation of ultrasound use shifted the possibilities in the operating room, yet more precision is necessary to achieve negative resection margins. Modalities utilizing fluorescent-compatible dyes have proven their role in hepatopancreatobiliary surgery, although this is not yet a routine practice, as there are many limitations. Modalities, such as photoacoustic imaging or 3D holograms, are emerging but are mostly limited to preclinical settings. There is a need to identify and develop an ideal contrast agent capable of differentiating between malignant and benign tissue and to report on the prognostic benefits of implemented intraoperative imaging in order to navigate clinical translation. This review focuses on existing and developing imaging modalities for intraoperative use, tailored to the needs of hepatopancreatobiliary cancers. We will also cover the application of these imaging techniques to theranostics to achieve combined diagnostic and therapeutic potential.