Fig 1.
Example FF-OCT image of a well-differentiated pancreatic ductal adenocarcinoma as shown to the pathologist for assessment.
The whole FF-OCT images were shown to the pathologists, but they were asked to only assess the selected regions of interest (two per FF-OCT image). Both the original (A,C,E) and the inverse (B,D,F) FF-OCT images are shown. Scale bars, 5 mm (A,B), 2 mm (C,D), and 1 mm (E,F).
Fig 2.
Examples of FF-OCT images of normal pancreatic tissue and corresponding histology.
Structures that are easily identified on FF-OCT images include normal pancreatic parenchyma (A-B), vessels (C-D), and a large pancreatic duct (E-F). Harder to recognize are nerve bundles (G-H). Scale bars, 250 μm (A-B, G-H), and 150 μm (C-F). Inset shows an islet of Langerhans (A-B) at 2.5 times higher magnification.
Table 1.
Comparison of features of pancreatic ductal adenocarcinoma detectable on H&E and on FF-OCT images.
Table 2.
Patient and tumor characteristics.
Table 3.
Test characteristics of FF-OCT on pancreatic tissue.
True positives are FF-OCT images which were correctly identified as malignant. True negatives are FF-OCT images which were correctly identified as benign. False positives are FF-OCT images which were incorrectly identified as malignant. False negatives are FF-OCT images which were incorrectly identified as benign. Pathologist 1 is the experienced pathologist, pathologist 2 is the pathologist in training.
Fig 3.
Example of benign pancreatic tissue FF-OCT images and corresponding histology.
Fibrotic pancreatic tissue after neoadjuvant therapy (A-B), pancreatitis (C-D), and a serous cystadenoma (E-F). Scale bars all 500 μm.
Fig 4.
Example FF-OCT image of a well differentiated pancreatic ductal adenocarcinoma.
A shows a n overview. B shows a magnified view of stromal disorganization, and C shows nests of tumor cells. Scale bars, 2 mm (A), 1 mm (B), and 500 μm (C).
Table 4.
Accuracy per histological diagnosis.
Fig 5.
Accuracy and interobserver variability.
Pathologist 1 is the experienced pathologist, pathologist 2 is the pathologist in training.
Fig 6.
Proposed decision tree to evaluate pancreatic FF-OCT images.
Scalebars are all 500 μm.
*The FF-OCT image and corresponding histology image only depict lymph node invasion.