title: Inter-reader variability in follicular lymphoma grading: Conventional and digital reading.
abstract: BACKGROUND
  Pathologists grade follicular lymphoma (FL) cases by selecting 10, random high power fields (HPFs), counting the number of centroblasts (CBs) in these HPFs under the microscope and then calculating the average CB count for the whole slide. Previous studies have demonstrated that there is high inter-reader variability among pathologists using this methodology in grading.
  
  
  OBJECTIVE
  The objective of this study was to explore if newly available digital reading technologies can reduce inter-reader variability.
  
  
  METHODS
  IN THIS STUDY, WE CONSIDERED THREE DIFFERENT READING CONDITIONS (RCS) IN GRADING FL: (1) Conventional (glass-slide based) to establish the baseline, (2) digital whole slide viewing, (3) digital whole slide viewing with selected HPFs. Six board-certified pathologists from five different institutions read 17 FL slides in these three different RCs.
  
  
  RESULTS
  Although there was relative poor consensus in conventional reading, with lack of consensus in 41.2% of cases, which was similar to previously reported studies; we found that digital reading with pre-selected fields improved the inter-reader agreement, with only 5.9% lacking consensus among pathologists.
  
  
  CONCLUSIONS
  Digital whole slide RC resulted in the worst concordance among pathologists while digital whole slide reading selected HPFs improved the concordance. Further studies are underway to determine if this performance can be sustained with a larger dataset and our automated HPF and CB detection algorithms can be employed to further improve the concordance.
authors.affiliation: Department of Pathology, The Ohio State University, Columbus, OH, USA.
authors.forename: Gerard
authors.initials: G
authors.lastname: Lozanski
authors.affiliation: Division of Biostatistics, College of Public Health, The Ohio State University, Columbus, OH, USA.
authors.forename: Michael
authors.initials: M
authors.lastname: Pennell
authors.affiliation: Department of Pathology, The Ohio State University, Columbus, OH, USA.
authors.forename: Arwa
authors.initials: A
authors.lastname: Shana'ah
authors.affiliation: Department of Pathology, The Ohio State University, Columbus, OH, USA.
authors.forename: Weiqiang
authors.initials: W
authors.lastname: Zhao
authors.affiliation: Department of Pathology, The Ohio State University, Columbus, OH, USA.
authors.forename: Amy
authors.initials: A
authors.lastname: Gewirtz
authors.affiliation: Department of Pathology, The Ohio State University, Columbus, OH, USA.
authors.forename: Frederick
authors.initials: F
authors.lastname: Racke
authors.affiliation: Cleveland Clinic, Cleveland, OH, USA.
authors.forename: Eric
authors.initials: E
authors.lastname: Hsi
authors.affiliation: Department of Pathology, Central Ohio Pathology Associates, Westerville, OH, USA.
authors.forename: Sabrina
authors.initials: S
authors.lastname: Simpson
authors.affiliation: Vanderbilt University, Nashville TN, USA.
authors.forename: Claudio
authors.initials: C
authors.lastname: Mosse
authors.affiliation: Department of Pathology, Battle Creek, MI, USA.
authors.forename: Shadia
authors.initials: S
authors.lastname: Alam
authors.affiliation: The Reading Hospital Medical Center, Reading PA, USA.
authors.forename: Sharon
authors.initials: S
authors.lastname: Swierczynski
authors.affiliation: Massachusetts General Hospital, Boston, MA, USA.
authors.forename: Robert P
authors.initials: RP
authors.lastname: Hasserjian
authors.affiliation: Department of Biomedical Informatics, Ohio State University, Columbus, OH, USA.
authors.forename: Metin N
authors.initials: MN
authors.lastname: Gurcan
keywords: Centroblast; follicular lymphoma; inter-reader variability; whole-slide images