Comparison of the manual, semiautomatic, and automatic selection and leveling of hot spots in whole slide images for Ki-67 quantification in meningiomas.

Zaneta Swiderska,Anna Korzynska,Malgorzata Lorent,Bartlomiej Grala,Anna Wesolowska,Tomasz Markiewicz,Jakub Zak,Lukasz Roszkowiak,Janina Slodkowska

doi:10.1155/2015/498746

Abstract

Background. This paper presents the study concerning hot-spot selection in the assessment of whole slide images of tissue sections collected from meningioma patients. The samples were immunohistochemically stained to determine the Ki-67/MIB-1 proliferation index used for prognosis and treatment planning. Objective. The observer performance was examined by comparing results of the proposed method of automatic hot-spot selection in whole slide images, results of traditional scoring under a microscope, and results of a pathologist's manual hot-spot selection. Methods. The results of scoring the Ki-67 index using optical scoring under a microscope, software for Ki-67 index quantification based on hot spots selected by two pathologists (resp., once and three times), and the same software but on hot spots selected by proposed automatic methods were compared using Kendall's tau-b statistics. Results. Results show intra- and interobserver agreement. The agreement between Ki-67 scoring with manual and automatic hot-spot selection is high, while agreement between Ki-67 index scoring results in whole slide images and traditional microscopic examination is lower. Conclusions. The agreement observed for the three scoring methods shows that automation of area selection is an effective tool in supporting physicians and in increasing the reliability of Ki-67 scoring in meningioma.

Highlights

Immunohistochemistry (IHC) has become an important technique to both diagnostic pathology and clinical research, as it can help in the process of diagnosis, prognosis, and grading [1]
According to the World Health Organization (WHO) rules, the quantitative evaluation of the proliferation index is performed on a set of high power areas of hot spots selected in various places inside a whole specimen observed under a microscope
The hot-spot localization and areas of quantification selections performed by pathologists and the automated proposed method were compared using the localization concordance measure (LCM) measure

Summary

Introduction

Immunohistochemistry (IHC) has become an important technique to both diagnostic pathology and clinical research, as it can help in the process of diagnosis, prognosis, and grading [1]. The proliferation marker Ki-67 is used in meningiomas to differentiate cancer into meningothelial (WHO I), atypical (WHO II), and anaplastic (WHO III) and correlates with tumor recurrences [1,2,3,4,5] This is because the immunopositive signal expression is a surrogate measure of Ki-67 expression inside cells’ nuclei. The observer performance was examined by comparing results of the proposed method of automatic hot-spot selection in whole slide images, results of traditional scoring under a microscope, and results of a pathologist’s manual hot-spot selection. The agreement between Ki-67 scoring with manual and automatic hotspot selection is high, while agreement between Ki-67 index scoring results in whole slide images and traditional microscopic examination is lower. The agreement observed for the three scoring methods shows that automation of area selection is an effective tool in supporting physicians and in increasing the reliability of Ki-67 scoring in meningioma

Methods

Results

Conclusion