{
  "abstract": "Background Brain tumours are the leading cause of cancer-related death in children. Surgical strategy depends on tumour type; in some entities gross total resection improves prognosis, while in others the risks outweigh the benefit. Intraoperative diagnosis, currently based on imaging and smear histology, is often insufficient. DNA methylation profiling has revolutionised tumour classification, but conventional methods take days to weeks. Nanopore sequencing offers a rapid alternative by directly measuring DNA methylation, offering the potential for intraoperative molecular diagnosis.Aims To implement an intraoperative DNA methylation profiling test for brain tumour classification and evaluate its potential clinical utility at Great Ormond Street Hospital. The objectives were to:Classify paediatric brain tumours within an intraoperative timeframe.Assess concordance with the final integrated diagnosis.Estimate the proportion of cases where intraoperative classification could alter surgical strategy.Methods Paediatric brain tumour samples for validating the test were analysed using a nanopore sequencing workflow (ROBIN). DNA was extracted from tumour tissue and underwent nanopore sequencing. DNA methylation profiles were used to classify tumours with machine learning algorithms. Results were compared against standard-of-care intraoperative smear histology and the final integrated diagnoses.Results Intraoperative nanopore classification achieved results within a surgical timeframe. In 83% (15/18) of cases a confident classification, concordant with the final diagnosis, was obtained within 1 hour of sequencing. Overall, classifications were concordant with the final integrated diagnosis in 94% (17/18) of cases. In 66% (10/15) of cases, intraoperative nanopore classification had the potential to alter surgical strategy compared with standard smear histology.Conclusion Intraoperative nanopore classification shows high concordance with integrated diagnoses and rapid turnaround within surgical timeframes. This approach could personalise surgical strategies, reduce neurological morbidity, avoid repeat surgeries, and accelerate delivery of definitive diagnoses. These findings provide translational evidence supporting the integration of rapid methylation profiling into routine clinical practice.Acknowledgements for Funding or Support The corresponding and presenting author is an ICA Pre-doctoral Clinical and Practitioner Academic Fellow supported by the National Institute for Health and Care Research. The views expressed in this publication are those of the author(s) and not necessarily those of the NHS, the National Institute for Health and Care Research or the Department of Health and Social Care.",
  "authors": [
    {
      "affiliations": [
        "Great Ormond Street Hospital for Children NHS Foundation Trust, UK"
      ],
      "name": "Julian Cano-Flanagan"
    },
    {
      "affiliations": [
        "Clinical Genomics Translational Research Laboratory, Royal Marsden Hospital, UK"
      ],
      "name": "Iman Awadh"
    },
    {
      "affiliations": [
        "Clinical Genomics Translational Research Laboratory, Royal Marsden Hospital, UK"
      ],
      "name": "Rosemary Bowers"
    },
    {
      "affiliations": [
        "Great Ormond Street Hospital for Children NHS Foundation Trust, UK"
      ],
      "name": "Luis Campos"
    },
    {
      "affiliations": [
        "Great Ormond Street Hospital for Children NHS Foundation Trust, UK"
      ],
      "name": "Matthew Clarke"
    },
    {
      "affiliations": [
        "Clinical Genomics Translational Research Laboratory, Royal Marsden Hospital, UK"
      ],
      "name": "Liam Johnson"
    },
    {
      "affiliations": [
        "Great Ormond Street Hospital for Children NHS Foundation Trust, UK"
      ],
      "name": "Atul Kumar"
    },
    {
      "affiliations": [
        "Great Ormond Street Hospital for Children NHS Foundation Trust, UK"
      ],
      "name": "Ashirwad Merve"
    },
    {
      "affiliations": [
        "Great Ormond Street Hospital for Children NHS Foundation Trust, UK"
      ],
      "name": "Nathaniel Storey"
    },
    {
      "affiliations": [
        "Great Ormond Street Hospital for Children NHS Foundation Trust, UK"
      ],
      "name": "Kristian Aquilina"
    },
    {
      "affiliations": [
        "School of Life Sciences, University of Nottingham, UK"
      ],
      "name": "Matthew Loose"
    },
    {
      "affiliations": [
        "Clinical Genomics Translational Research Laboratory, Royal Marsden Hospital, UK"
      ],
      "name": "Michael Hubank"
    },
    {
      "affiliations": [
        "Great Ormond Street Hospital for Children NHS Foundation Trust, UK"
      ],
      "name": "Thomas Jacques"
    }
  ],
  "title": "45 Rapid intraoperative DNA methylation profiling to guide surgery in paediatric brain tumours",
  "uid": "c8610b7a-b02c-57c2-8cc1-f2cb443d81b6"
}