6th ESACP Congress, Heidelberg, April 7-11, 1999

A065
EVALUATION OF A FULLY AUTOMATED SYSTEM FOR DNA IMAGE CYTOMETRY
Harmsen RJ, Belién JAM, Van Diest PJ, Baak JPA

Department of Pathology, Academic Hospital Vrije Universiteit, Amsterdam, Netherlands

Two systems for DNA Image Cytometry (ICM) are in use, the laboratory built PIPE system and the QPATH system, which uses a commercially available digital image processing computer (Q550, Leica Microsystems, Cambridge UK) and a fully automated microscope (DMRXA, Leica, Wetzlar, Germany). The aim of the present study was to evaluate DNA ploidy assessments of the QPATH system. To compare QPATH with flow cytometry, cell suspensions were prepared from paraffin blocks and equally split for FCM and Feulgen stained cytospins for ICM. With FCM at least 20,000 cells per case were measured. At least 1000 epithelial cells were fully automatically measured by ICM. All DNA histograms were interpreted with the MultiCycle« program (Phoenix flow systems, San Diego, California). Repeated DNA ploidy assessments with QPATH in multiple analyses showed a complete concordance. In total 116 cases were evaluated by both FCM and by QPATH-ICM. In 102 cases (88%) there was complete concordance between ICM and FCM determination of DNA diploidy versus DNA non-diploidy. In 10 cases, which were DNA diploid in FCM, a small DNA aneuploid peak was detected by ICM. The four other cases which were probably false tetraploid by FCM due to doublets, were diploid by ICM. The 30 cases measured on both DNA ICM systems showed a total agreement in 28 cases (93%), when divided as DNA diploid versus DNA non-diploid. Two cases showed histograms of low quality. In a multicenter EC analysis, the PIPE system was proven to meet the ESACP guidelines for DNA ICM. In view of the present results, the QPATH system seems to provide similar DNA ploidy results as the PIPE system. Further testing should be done in order to assess whether the QPATH system does meet the ESACP guidelines as well.