LG-61DEVELOPING RISK-BASED SELECTION CRITERIA FOR THE NEXT SIOP TRIAL OF “SIGHT-SAVING THERAPY” FOR CHILDREN WITH NF1-ASSOCIATED OPTIC PATHWAY GLIOMA (NF1-OPG) - A MULTI-DISCIPLINARY CONSENSUS WORKSHOP

Abstract

Introduction: The natural history of children with NF1‐OPG is unpredictable. The indications for therapy to save vision, using patient, imaging and visual factors, have not been studied in European trials. AIM: To promote a revised and standardised approach for the next SIOP NF1‐OPG trial. Methods: A multi‐disciplinary workshop involving specialists in neuro‐radiology (n = 4), ophthalmology (n = 8), NF genetics (n = 1) and neuro‐oncology (n = 11) from nine SIOP‐LGG2004 centres was conducted. Imaging, visual and clinical datasets from 83 NF1‐OPG patients were collated (38 observation only, 23 treated at diagnosis and 22 treated after observation; median age at diagnosis 4.8 years, range 1.1‐13.1 years; m:f 37:46, median follow‐up 19.2 months, range 1.8‐121 months). Results: Consensus was achieved on Methods for conversion of different visual acuity measurements to LogMAR, a schematic to record visual acuity over time and the application of the modified Dodge classification (PLAN score) to classify OPGanatomical involvement of visual pathways. At diagnosis/last follow up, median LogMAR was 0.2/0.1 for best eye, 0.3/0.4 for worst eye; severe visual impairment/blindness (LogMAR.= 1.0) was: unilateral 16/21; bilateral 3/7, respectively. Posterior visual pathway involvement (Dodge C) was correlated with visual deterioration; but there was no correlation between visual outcome and tumour imaging response after treatment or observation. Conclusions: After case based discussion, agreed criteria for future case selection within trials were age, history of, or documented visual decline, presence of severe visual symptoms, unreliable visual assessment, proptosis, and posterior radiation tumour involvement.