OP23A CONSENSUS WORKSHOP TO DEVELOP RISK-BASED SELECTION CRITERIA FOR THE NEXT SIOP TRIAL OF “SIGHT-SAVING THERAPY” FOR CHILDREN WITH NF1-ASSOCIATED OPTIC PATHWAY GLIOMA (NF1-OPG)

Abstract

INTRODUCTION: The natural history of children with NF1-OPG is unpredictable, indications for therapy to save vision, using patient, imaging and visual factors have not been studied in Europe. The aim of this multi-disciplinary workshop was to promote a revised and standardised approach for the next SIOP LGG trial. METHOD: Eight SIOP-LGG2004 centres contributed 83 NF1-OPG cases with complete imaging, visual and clinical datasets (age at diagnosis: median 4.8 yrs range 1.1-13.1; m:F 37:46, median follow-up 19.2 months range 1.8-121 months). Severe visual impairment/blindness (LogMAR >= 1.0) at diagnosis and last follow up, respectively: unilateral 16,21; bilateral 3,7. Anatomical distribution at diagnosis: Dodge Stage A (nerves) 35; Stage B (chiasm) 16; Stage C (nearby structures) 32. Imaging evidence of: response 31: no change:46; progression 6. Analysis of this dataset informed consensus discussion and voting of representative cases for proposed trial criteria for observation, treatment and randomisation. RESULTS: Consensus on imaging and visual classification was achieved, including a schematic for recording patient, visual and imaging details. Criteria for case selection were: age, history of visual decline, presence of severe visual symptoms, unreliable visual assessment, proptosis and post-chiasmatic tumour involvement. A subsequent 19 case web-based questionnaire was completed by 15 workshop participants. The respondents allocated 8 cases to observation; 8 to immediate treatment and 3 for consideration for randomisation. CONCLUSION: A new consensus on selection criteria using a contemporary trial cohort was reached. We have piloted a web-based questionnaire to assess feasibility of a randomised trial.