A pilot study of on-site evaluation as external quality assessment for ISO 15189 accreditation of laboratories performing next-generation sequencing oncology tests

BackgroundAs next-generation sequencing (NGS) oncology tests vary by platform, application, and target of genes, specific methods for external quality assessment (EQA) have not been universally applied. Hence, we have attempted to implement on-site evaluation as EQA in the accreditation program under ISO 15189 for laboratories that perform NGS oncology tests. MethodsA total of 10 laboratories that performed NGS oncology tests were enrolled. Two types of EQA samples were prepared (Acrometrix Oncology Hotspot Control DNA and OncoSpan gDNA DNA samples), and the variant allele frequency of targeted genes was assigned. The samples were subjected to NGS oncology tests in participant laboratories according to their routine protocols. Based on the result reports, auditors visited the participant laboratories to perform on-site evaluations and provided feedback regarding possible laboratory process improvement. ResultsThe participant laboratories identified the targeted variants in the Acrometrix Oncology Hotspot Control DNA and OncoSpan gDNA samples with a success rate of 31-100% and 9.5-100%, respectively, compared with reference information, depending on their sequencing systems, and reported a few lower-variant allele frequencies. Six of the eight evaluated laboratories failed to report at least three pathogenic variants due to errors in wet-lab and/or dry-lab processes. Based on the feedback reports and self-assessment, auditors and laboratory staff discussed potential improvements to processes during on-site evaluations for laboratory accreditations. ConclusionsOn-site evaluation as EQA for NGS oncology tests in the laboratory accreditation program under ISO 15189 was successfully implemented and proved applicable to a broad spectrum of NGS tests.