PT - JOURNAL ARTICLE AU - Christof A. Bertram AU - Marc Aubreville AU - Taryn A. Donovan AU - Alexander Bartel AU - Frauke Wilm AU - Christian Marzahl AU - Charles-Antoine Assenmacher AU - Kathrin Becker AU - Mark Bennett AU - Sarah Corner AU - Brieuc Cossic AU - Daniela Denk AU - Martina Dettwiler AU - Beatriz Garcia Gonzalez AU - Corinne Gurtner AU - Ann-Kathrin Haverkamp AU - Annabelle Heier AU - Annika Lehmbecker AU - Sophie Merz AU - Erica L. Noland AU - Stephanie Plog AU - Anja Schmidt AU - Franziska Sebastian AU - Dodd G. Sledge AU - Rebecca C. Smedley AU - Marco Tecilla AU - Tuddow Thaiwong AU - Andrea Fuchs-Baumgartinger AU - Don J. Meuten AU - Katharina Breininger AU - Matti Kiupel AU - Andreas Maier AU - Robert Klopfleisch TI - Computer-Assisted Mitotic Count Using a Deep Learning-based Algorithm Improves Inter-Observer Reproducibility and Accuracy in canine cutaneous mast cell tumors AID - 10.1101/2021.06.04.446287 DP - 2021 Jan 01 TA - bioRxiv PG - 2021.06.04.446287 4099 - http://biorxiv.org/content/early/2021/06/05/2021.06.04.446287.short 4100 - http://biorxiv.org/content/early/2021/06/05/2021.06.04.446287.full AB - The mitotic count (MC) is an important histological parameter for prognostication of malignant neoplasms. However, it has inter- and intra-observer discrepancies due to difficulties in selecting the region of interest (MC-ROI) and in identifying/classifying mitotic figures (MFs). Recent progress in the field of artificial intelligence has allowed the development of high-performance algorithms that may improve standardization of the MC. As algorithmic predictions are not flawless, the computer-assisted review by pathologists may ensure reliability. In the present study we have compared partial (MC-ROI preselection) and full (additional visualization of MF candidate proposal and display of algorithmic confidence values) computer-assisted MC analysis to the routine (unaided) MC analysis by 23 pathologists for whole slide images of 50 canine cutaneous mast cell tumors (ccMCTs). Algorithmic predictions aimed to assist pathologists in detecting mitotic hotspot locations, reducing omission of MF and improving classification against imposters. The inter-observer consistency for the MC significantly increased with computer assistance (interobserver correlation coefficient, ICC = 0.92) compared to the unaided approach (ICC = 0.70). Classification into prognostic stratifications had a higher accuracy with computer assistance. The algorithmically preselected MC-ROIs had a consistently higher MCs than the manually selected MC-ROIs. Compared to a ground truth (developed with immunohistochemistry for phosphohistone H3), pathologist performance in detecting individual MF was augmented when using computer assistance (F1-score of 0.68 increased to 0.79) with a reduction in false negatives by 38%. The results of this study prove that computer assistance may lead to a more reproducible and accurate MCs in ccMCTs.Competing Interest StatementThe authors have declared no competing interest.