Editorial: Innovations in Imaging for Early Diagnosis and Monitoring for Patients With Gastrointestinal Cancer

Medical imaging is an essential tool for risk assessment, early detection, therapeutic decision making and monitoring of abdominal cancers such as liver, pancreas and luminal gastrointestinal cancers. Various CT, PET, MRI and endoscopic techniques have been developed in recent years having an impact on these critical medical disorders. We proposed this research topic to act as a platform for presenting new methods in imaging that can be developed into applicable clinical tools for a variety of tasks in management of gastrointestinal cancers. We posited that new methods development will play an increasingly important role in several aspects of cancer management with the goal of improving outcomes for patients who are at risk or who have one of the gastrointestinal cancers. Furthermore, we anticipate that although the methods described in the papers in this research topic are usually applied to one cancer, lessons learned about a method for an individual cancer will likely be applicable to other cancers. For a summary of the papers in this series, we have grouped methods presented around specific diseases for readers to consider further development for the disease; and/or considering development of the method(s) used in management of another cancer whether in the gastrointestinal tract or elsewhere.


OVERVIEW
Medical imaging is an essential tool for risk assessment, early detection, therapeutic decision making and monitoring of abdominal cancers such as liver, pancreas and luminal gastrointestinal cancers. Various CT, PET, MRI and endoscopic techniques have been developed in recent years having an impact on these critical medical disorders.
We proposed this research topic to act as a platform for presenting new methods in imaging that can be developed into applicable clinical tools for a variety of tasks in management of gastrointestinal cancers. We posited that new methods development will play an increasingly important role in several aspects of cancer management with the goal of improving outcomes for patients who are at risk or who have one of the gastrointestinal cancers. Furthermore, we anticipate that although the methods described in the papers in this research topic are usually applied to one cancer, lessons learned about a method for an individual cancer will likely be applicable to other cancers. For a summary of the papers in this series, we have grouped methods presented around specific diseases for readers to consider further development for the disease; and/or considering development of the method(s) used in management of another cancer whether in the gastrointestinal tract or elsewhere.

PANCREATIC DISEASES
Several papers in this Research Topic addressed methods for pancreatic diseases. Distinguishing different forms of pancreatic cancer-pancreatic ductal adenocarcinoma (PDAC) and pancreatic neuroendocrine tumors from each other and inflammatory pancreatitis is often challenging. Two papers in this Research Topic address the differential diagnosis of these diseases using; 1. In one of these papers, (Xu et al.) the authors demonstrated that greater contrast enhancement is associated with better patient outcomes while another paper (Zaid et al.) showed that differences in CT characteristics between the tumor and the surrounding "normal" tissue is also a predictor of outcome. As an example of theranostics, one of the papers in the series demonstrated the feasibility of combining endoscopic optic coherence tomography with brachytherapy for the treatment of early PDAC lesions (Lu et al.). Finally, as an example of developments for future MRI applications for identifying specific molecular signatures in a cancer, a paper in the series shows preclinical studies using a probe for fibronectin (Qiao et al.).
A clinically valuable study (Wang et al.) used clinical and imaging findings for creating a robust algorithm to distinguish between a benign from malignant bulging duodenal papilla (papilla of Vater). The paper is important as early identification of a malignant papilla (a subset of pancreatic cancers) leads to improved outcomes.
In contrast to PDAC tumors of pancreas which have almost universal deadly outcome unless treated, neuroendocrine tumors of the pancreas have much more variable biologic behavior. Thus, developing methods to enhance to ability to distinguish malignant neuroendocrine tumors from those with a more benign clinical course are highly valuable. Two papers in the This last study is a reminder that in the future, multiple measurements including clinical and imaging data but also tissue biomarkers will provide the most advance approaches for early diagnosis and precision application of treatment.

FUTURE DIRECTIONS
The papers in this Research Topic show by examples the enormous potential of several imaging techniques for diagnosis, outcome prediction and responses to therapeutic interventions. In addition, some papers show that future directions can involve measurements that reflect histology and biologic behavior of cancers and potentially even biochemistry of its constituents by MRI methods such as APT (amide proton transfer) (1) and CEST (chemical exchange saturation transfer) (2). Additional overarching observation is that radiomics and artificial intelligence will be necessary analytic tools accompanying advances in imaging. The application of artificial intelligence analytics will furthermore involve addition of patient clinical data and other potential revealing information including germline and tumor genetics. Finally, as suggested by a Meta-Analysis of studies measuring Volatile Organic Compounds (VOCs) (Xiang et al.) other measures whether volatile or liquid biomarkers will provide further enhancement of diagnostic and predictive algorithms. The stage is set for rapid advancements that will certainly lead to better outcomes for patients.