Virtual microscopy for cytology proficiency testing: are we there yet?

Background: The objective of this study was to investigate the potential of virtual microscopy (VM) as an avenue for the delivery of mandatory cytology proficiency tests).
Methods: Three senior cytotechnologists and 2 board-certified cytopathologists participated in 3 virtual proficiency tests. Each set consisted of 10 ThinPrep slides that were digitized by an Aperio T3 ScanScope. The cytologic diagnoses covered the range of interpretive guidelines provided by the Centers for Medicare and Medicaid Services (CMS). Each cytotechnologist followed the requirement of a primary screener with the cytopathologists utilizing the secondary screener option.
Results: Analysis of the diagnostic interpretation of the first proficiency test showed correct classification of 100% of normal and abnormal cells for primary and secondary screeners. The second proficiency test analysis revealed a 93.3% correct classification (100% using CMS guidelines) among the primary screeners. The secondary screeners gave a 100% correct classification. The final proficiency test had primary screeners and secondary screeners with 100% correct classification.
Conclusions: The current results confirmed the feasibility of VM for proficiency tests with 2 main problems noted. First, primary screeners had difficulties meeting the mandatory time allocation; however, with increased familiarity with the software, the screening times decreased. Second, the 3-dimensional nature of certain lesions made them difficult to interpret even on monolayered, liquid-based preparations. Creation of a more user-friendly software interface and better methods to capture depth of focus should make this a valid measure of cervicovaginal cytopathologic interpretive competence.