Virtual Slides in Surgical Pathology Practice – Keep Them or Toss Them?
Charles M van Slambrouck, David S McClintock. University of Chicago, Chicago, IL
Background: As whole slide imaging (WSI) gains acceptance in the surgical pathology clinical workflow, the issue of virtual slide storage will become the primary hurdle to adoption. Virtual slides range up to 9GB in size, depending on the scanner and compression used on acquisition. Given that surgical pathology labs generate tens to hundreds of thousands of slides annually, storage requirements could approach up to a petabyte of data storage per year. Unlike radiology, which operates clinically on a “write once, read often” data storage model, pathology has been postulated to operate on a “write once, read once” model, an assertion that has not been formally evaluated. This study assesses the clinical usage of surgical pathology archives during the signout process.
Design: Seven pathology trainees (five residents and two fellows) recorded the number of prior cases and their respective slides pulled from the pathology archives during the clinical signout process with attending pathologists. Information for each case pulled included: 1) age of prior material; 2) number of slides pulled; 3) number of slides viewed; and 4) number of times each slide was viewed (trainee and attending). Data analysis of the surveys was performed in Microsoft Excel.
Results: Over thirteen work days, the participants signed out 791 cases, from which in 17 cases prior material was requested (2.2% of all cases). Prior archival material was pulled in 13 of 17 cases (1.6% of all cases). Archival material was viewed in all 13 instances it was pulled. Of a total of 172 slides pulled, only 24 slides were used for review (14.0% of slides pulled, 1.8 slides per case pulled). Given that each slide was reviewed by multiple individuals (slide-views), there were 50 slide-views of prior case materials (3.9 slide-views per case, 0.55 slide-views per work day). Prior cases had a mean age of 672 days (median age 62 days; range 13 to 5874 days). Trainees pulled 92.3% (12/13) of prior cases before sign-out with attendings.
Conclusions: From the data above, surgical pathology does indeed seem to fall in a “write-once, read-once” model of data persistence – pathologists rarely need to go back to prior case material during clinical signout. With the considerable data storage requirements for WSI, the argument for permanent persistence of virtual pathology slides (similar to radiology) seems unwarranted at this time. However, given the median age of prior case material, a temporary persistence model may be reasonable solution.
Wednesday, March 6, 2013 1:00 PM
Poster Session VI # 263, Wednesday Afternoon