ARTIFICIAL RECOGNITION OF POLYPS

In October 2018, ZiuZ, in collaboration with the Amsterdam University Medical Centre (Amsterdam AMC) and the Medical Centre Leeuwarden (MCL), started the POLAR project. The aim of the collaboration was the development of a computer-aided diagnosis (CADx) tool with which small intestinal polyps (1–5 mm) can be classified. Because polyps could be assessed during a colonoscopy, the doctor can decide to remove malignant polyps and leave benign polyps behind during the procedure.

Ten hospitals have registered to work on this innovative project. These hospitals have helped collect photos of intestinal polyps using the POLAR box. This box has been specially developed for collecting and storing prospective data. In May 2019, the Technical Service granted permission to deploy the POLAR boxes and the first POLAR box was delivered and deployed at Bergman Clinics in Amsterdam. After the first tests, the POLAR boxes were also produced for the other affiliated hospitals and used to collect data.

In addition, ZiuZ has also received a set of retrospective data. This data was used to develop an initial version of the algorithm. This is also the start of the development of the prototype for the CADx tool. The POLAR project was completed at the end of 2021. In the period from May 2019 to December 2020, a total of 2,637 photos of polyps were collected from 555 patients. These photos were used to train the CADx system that can locate polyps in endoscopic images and then classify them. Eventually, eight Dutch hospitals cooperated in collecting the data. After the development of the CADx system, the results of the model were compared with the optical diagnoses of endoscopists during a validation study (March – September 2021). In this phase, a total of 429 polyps were collected that met the criteria for small polyps. The validation study showed that the CADx system scores similarly to the optical diagnosis of the average endoscopist. See the table below for the results.

Table of CADx system results compared to endoscopist

For the training of the CADx system, photos based on narrow band imaging have been used without zooming in. As a result, the system has the same amount of detail as the endoscopists to make a classification. The final results did not yet meet the guidelines to enable an optical diagnosis strategy. Further research into other types of photos or the guidelines for ‘good’ photos of polyps probably offers more possibilities in this regard.

POLAR is co-financed by grants from the European Union: European Regional Development Fund (via SNN) and the province of Friesland.