Improving Ki67 assessment concordance by the use of an artificial intelligence-empowered microscope: a multi-institutional ring study

Histopathology. 2021 Oct;79(4):544-555. doi: 10.1111/his.14383. Epub 2021 Jun 24.

Abstract

Aims: The nuclear proliferation biomarker Ki67 plays potential prognostic and predictive roles in breast cancer treatment. However, the lack of interpathologist consistency in Ki67 assessment limits the clinical use of Ki67. The aim of this article was to report a solution utilising an artificial intelligence (AI)-empowered microscope to improve Ki67 scoring concordance.

Methods and results: We developed an AI-empowered microscope in which the conventional microscope was equipped with AI algorithms, and AI results were provided to pathologists in real time through augmented reality. We recruited 30 pathologists with various experience levels from five institutes to assess the Ki67 labelling index on 100 Ki67-stained slides from invasive breast cancer patients. In the first round, pathologists conducted visual assessment on a conventional microscope; in the second round, they were assisted with reference cards; and in the third round, they were assisted with an AI-empowered microscope. Experienced pathologists had better reproducibility and accuracy [intraclass correlation coefficient (ICC) = 0.864, mean error = 8.25%] than inexperienced pathologists (ICC = 0.807, mean error = 11.0%) in visual assessment. Moreover, with reference cards, inexperienced pathologists (ICC = 0.836, mean error = 10.7%) and experienced pathologists (ICC = 0.875, mean error = 7.56%) improved their reproducibility and accuracy. Finally, both experienced pathologists (ICC = 0.937, mean error = 4.36%) and inexperienced pathologists (ICC = 0.923, mean error = 4.71%) improved the reproducibility and accuracy significantly with the AI-empowered microscope.

Conclusion: The AI-empowered microscope allows seamless integration of the AI solution into the clinical workflow, and helps pathologists to obtain higher consistency and accuracy for Ki67 assessment.

Keywords: AI-empowered microscope; Ki67; breast cancer; reference card; ring study.

Publication types

  • Multicenter Study

MeSH terms

  • Artificial Intelligence*
  • Biomarkers, Tumor / analysis*
  • Breast Neoplasms / diagnosis*
  • Female
  • Humans
  • Image Interpretation, Computer-Assisted / instrumentation
  • Image Interpretation, Computer-Assisted / methods*
  • Ki-67 Antigen / analysis*
  • Microscopy / instrumentation
  • Microscopy / methods*
  • Observer Variation
  • Pathology, Clinical / instrumentation
  • Pathology, Clinical / methods
  • Reproducibility of Results
  • Retrospective Studies

Substances

  • Biomarkers, Tumor
  • Ki-67 Antigen
  • MKI67 protein, human