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

A067
QUALITY STATUS OF DNA IMAGE CYTOMETRY IN EUROPEAN LABORATORIES
Haroske G, Meyer W, Kunze KD

Inst. Pathology, Dresden University of Technology, Germany

Aim: A Remote Quantitation Server EUROQUANT allows DNA-measurements obtained from different DNA cytometry devices to be analysed in a standardized way, concerning parameters, algorithms, statistical tests and diagnostic classifications. According to the 1997 ESACP consensus on diagnostic DNA image cytometry a framework of quality control measures should be tested at this server. Material & Methods: In 17 laboratories a total of about 1700 tumour specimens from different sites were measured. Those laboratories used 12 different types of cytometry workstations. Further 300 measurements on specimens of non-pathological cells were performed for the evaluation of the stability of the machinery and of the preparation process. Afterwards the measurement data from the cytometry devices have been transferred to the EUROQUANT and analyzed automatically. Results & Conclusions: Besides the DNA histograms a set of evaluations was performed as to detect optical errors as well as inhomogeneities in the measurements. Levy-Jennings-charts for several variables were computed as to control the stability of the entire methodology over the time. The sampling and diagnostic skillness of five users was tested by special server functions. The study demonstrates both the effects of a server-based quality control and the current state in DNA ploidy analysis. It is also demonstrated, how the quality control tests reflect the process performance of the ploidy analysis in its different levels. The study makes clear that the quality control must be an immanent part of the daily routine as to allow a reliable diagnostic interpretation and as to assure a steadily high product quality.