Thinprep Imager Feasibility Study Anne Park Project Manager 17.0609
Who am I? • 30 years experience in cytology • Started in Perth Royal Infirmary • Based in Ninewells now for <6 years • Senior Biomedical Scientist <6 years • Project Manager 21st July 08
Cervical Cytology Laboratory Review • Commissioned by Scottish Govt. • Steering Group 1st Meeting May 2007 • Chair John Burns Remit • To oversee the review of provision of laboratory services for the Cervical Cancer Screening Programme and to provide a report with recommendations for the future to NHS Scotland and the Scottish Government.
Cervical Cytology Laboratory Review Drivers • Effect of technology including Imager • Manpower planning • Declining coverage • Effect of HPV Vaccination • Effect of HPV testing
Cervical Cytology Laboratory Review • Decision to look in depth at the national options for delivery • Tribal Consultants Appointed June 2008 • Options – Status Quo through single/multicentre, networking etc… • Due to report 2009
Imager Feasibility Study • Commissioned by the Review Group • Scottish Governmentresourced • 80,000 samples (50:50 split between manual and imager arms) • Commitment to roll out across Scotland if successful (exit strategy) • Contract signed with Hologic after a European tender exercise • Project went live in September 2008 and due to last 9 months to 1 year • Final report by late 2009
Terms of reference • To conduct the feasibility study and report the findings to the Cervical Cytology Laboratory Review Group. • Specifically: • to ensure the quality and standards for the Cervical Screening Programme are met during the study • to advise if the technology meets the needs of the Cervical Screening Programme
What could the feasibility study deliver To assess the likelihood that the Imager will realise the claimed benefits within a Scottish Cohort Increased High and Low grade abnormality detection Reduction in the false negatives without increasing false positives Reduction in workflow time Staff support
Quality • ThinPrep Plus Imaging increases the sensitivity of cytology
Feasibility Study – hub and spoke arrangements Cohorts: • 3: Aberdeen. • 5: Dundee • 11: Inverness • 4. Glasgow Royal Infirmary • 7: Glasgow Southern General • 10: Greenock 11 3 5 10 10 4 7 7
Protocol Manual arm • Standard full manual primary screen • Rapid review/preview • Abnormals referred to checkers • Abnormals reported by Advanced Practitioner/Cytopathologist V Imager arm • Imaged and 22FOV’s reviewed • Rapid review/preview IQC • Abnormals full screen/(autoscan) • Abnormals reported by Advanced Practitioner/Cytopathologist
Slide selection for imaging • A minimum of 80,000 (40,000 manual and 40,000 imager) cases over 6 sites, in 2 hub and spoke groupings • Half of lab workload for time period • In batches by accession number • 1 – 50 imaged; 51 – 100 manual
What should be measured? • Specificity • Sensitivity • Positive Predictive Value • Productivity • Colposcopy referral rate • BMS/Cytology screener/Consultant perceptions • Costs • Risks
What are we recording • Imaging time • Screening time and review scope time • Transport times • Rejection rate • Full review/Autoscan rates • IQC detected abnormals/Imager negative
Questions we want to answer • Are the qualitative and quantitative improvements published reflected in a Scottish Cohort • What are the strengths, weaknesses and risks. (SWOT) • What information will it add to future service design • Interface with National Call Recall computer system for Scotland (SCCRS) • Is it the right technology for the Scottish screening programme? • Financial Impact
The imager • Analyses objects in each of 2000+ images • Ignores objects that are considered not to be nuclei and clusters considered not to be epithelial cells • Sorts nuclei and clusters by integrated optical density dependent on amount of DNA present • Screener is presented with 22 fields of view (FOV) on each slide to review using an automated Review Scope. Two of these FOV are sheets or clusters of cells. • Location guided system. No Sorting or Ranking
Staining • ThinPrep Imager requires standardised stain provided by Hologic as part of test • Requires “acclimatisation” for screeners • Only approved staining machines can be used • Possible adoption as national stain for Scotland
Stain validation • Uses archive vials and slides • Screener review of original slides and duplicate slides stained by imager stain. • Carried out blinded • 100 slides (25 abnormal, 75 negatives) • Compare results • Must meet Positive Percent Agreement target
Review scope operation • Must look at entire FOV (but not necessarily beyond the FOV) • Not just centre of field • Can set and save Autoscan settings for each screener • Can mark a maximum of 30 objects • Confidence levels in authorising negatives on 22 FOV’s.
Screening process • Review scope guides screener to 22 FOVs • If any thought abnormal, electronically marked, scope guides screener through whole slide (autoscan) • Anything abnormal is physically marked using scope • Adequacy and infections assessed during 22 FOV screening • IQC continues as usual • Review/preview, checking, Advanced Practitioner/Cytopathologists use own microscope
Training Schedule • Comprehensive programme delivered by Hologic • 1.5 day programme • Overcalling was common • Well received by staff • Additional support available • Certificate • Second phase of training highlighted gaps
Validation protocol • CPA compliance • Use Hologic test slides • 100 slides (75 neg, 25 BNA+) • Assesses agreement between manual screen and review of 22 FOV • Carried out after training • Must meet Positive Percent Agreement target
Issues/challenges encountered • Transport • Slide labels • IQC & EQA • Slow building of confidence levels • Ergonomics • Full review/Autoscan facility • Data security/back-up and integration
Transport • Inverclyde and Aberdeen hubs for study • 2 transport models tested • Existing transport links in one health board • New links over health board boundaries • Boxes, trays, packing • Coordinates sent on CD (roll out review) • Paper (or IT) trail for slides in transit
Labelling • TPI reads the number printed by T3 • Format 7 over 7, no letters • May be accession or SCCRS number • Paper label on front of slide only • Labelling on back of slide – if validated during pilot this will be roll out protocol • T2 slides require printed label for TPI
EQA • Technical • Local solutions not appropriate • Join the Hologic scheme • Interpretive • Scottish system no longer sustainable • Adopt a modified NHS Cervical Screening Programme model
Internal quality control • Rapid pre-view/review v FOV review • Jury still out • The potential weak link! • Are we checking screener or imager performance? • Scotland doing rapid pre/rescreen • USA doing 10% rescreen
Confidence/Trust levels • Long learning curve for some screeners • Partly dependant on pre-imager staining • Variation in screener review times depends on existing manual times • Consultant led review sessions vital • Hologic led review sessions • Practice makes perfect!
Ergonomics • Review scope is ergonomic but….. • Can only adjust height of head • Not as ergonomic as existing microscopes • Existing RSI symptoms • One size fits all! • New desks and spacers solved many issues • Manual + RS to the rescue!
Autoscan facility • Any slide requiring full review must go through autoscan • Can adjust speed and motion • Can slow the process down • Variable screener/lab referral for autoscan • Variation reflects existing screener/lab profiles • Part of the learning curve
Integration of Multicyte • CD transfer not the final solution • Can download data at hub and email (within secure NHS) to spoke where CD can be burned • Back up of imager data • Direct transfer of data from hub to spoke is the aim but Hologic need roll out commitment
Very early unvalidated data • HG/LG disease at least equal to comparator • Average screening time productivity gain Phase one - 20% . • Screener perceptions survey – 86% response rate. Negative opinion on 22FOV Abnormality present it is picked up on 22FOV • HG/LG false negative rate comparable • Referral for checking rates comparable
Phase Two • Improve screener perception • Full review of all abnormal slides on manual microscope • 10,000 slides on each arm • Report - phase one and two • Testing of Manual plus microscope • Phase two - 32% Screening time productivity gain (Very early data)
Long learning curve….. • Issues will arise at the beginning that appear to be “show-stoppers” • Don’t panic! • Don’t make hasty decisions based on early results/feedback • Limit the numbers trained at the beginning (37-30) • Consolidate then cascade!
Take home message • Meticulous planning • Be prepared for early difficulties • Record everything! • Think about alternatives to CD’s • Ergonomic issues • Slow confidence building