To evaluate intra-observer diagnostic reproducibility using traditional slides (TS) versus whole slide images (WSI).
TS and WSI of 1427 prostatic biopsies (107 consecutive patients) were evaluated by a single pathologist. Agreement between readings was evaluated with Gwet's Agreement coefficient (AC) and Landis and Koch benchmark scale.
The positive/negative agreement between the readings was almost perfect (AC1= 0.962; 95% CI[0.949,0.974]), with method independent distribution of discrepancies. Among positive biopsies, 212 had identical Gleason score (GS) on TS and WSI and discordant GS in 69 cases (AC2 = 0.932; 95% CI[0.907, 0.956]). Concordant negative and positive patient classification was observed in 39 and 64 cases, respectively; two cases were assigned to the positive group on TS and 2 on WSI configuring an almost perfect agreement (AC1=0.929; 95% C1[0.860, 0.998]). ISUP Grade group (ISUP GG) agreement was evaluated in the 60 concordantly positive cases: in 45 cases it was identical on TS and WSI; in 10 biopsies the discrepancy implied a modification of the assigned ISUP GG of ≤ 1 class and in 5 the discrepancy implied a modification of 2 classes. Gwet's agreement coefficient was (95% CI [0.834, 0.962]), i.e.: almost perfect agreement.
Our data show almost perfect agreement between digital and traditional diagnostic activity in a routine setting, confirming that digital pathology can be safely introduced into routine workflows.
Pathologica. 2023 Aug [Epub]
Evelin Torresani, Maria Adalgisa Gentilini, Stefano Grassi, Luca Cima, Irene Pedrolli, Tommaso Cai, Marco Puglisi, Valentino Vattovani, Bianca Guadin, Matteo Brunelli, Claudio Doglioni, Mattia Barbareschi
Unit of Surgical Pathology, Santa Chiara Hospital, APSS, Trento, Italy., Epidemiology and Clinical Evaluation Unit, APSS, Trento, Italy., Department Pathology, Vita e salute University, San Raffaele Hospital, Milano, Italy., Unit of Urology, Santa Chiara Hospital, APSS, Trento, Italy., Experimental and Applied Biology, University of Pavia, Italy., Pathology Unit, Department of Diagnostics and Public Health, University and Hospital Trust of Verona, Verona, Italy.