Abstract for presentation at 38th Annual Scientific Meeting of the Australian and New Zealand Society of Nuclear Medicine 2008

FDG-PET Scans of Optic Nerve Gliomas in Children with NF1 and Tumour Response to Chemotherapy

  • Dr Kevin London, Department of Nuclear Medicine, The Children's Hospital, Westmead, Australia
  • Dr Mahendranath Moharir, Department of Neurogenetics, The Children's Hospital, Discipline of Paediatrics and Child Health, University of Sydney, Australia
  • Prof Kathryn North, Department of Neurogenetics, The Children's Hospital, Discipline of Paediatrics and Child Health, University of Sydney, Australia
  • Prof Robert Howman-Giles, Department of Nuclear Medicine, The Children's Hospital, Westmead and Discipline of Imaging, University of Sydney, Australia

    • Background: Optic nerve gliomas (OPGs) are frequently encountered in children with neurofibromatosis type-1 (NF1). Most are benign pilocytic astrocytomas that remain asymptomatic and are conservatively managed. But some are aggressive and cause visual impairment and may need chemotherapy. The natural history is still uncertain; hence controversies exist in the optimal frequency, duration and type of radiological modality for follow-up in asymptomatic children. The utility of FDG-PET for surveillance of OPGs in children with NF-1 has not been reported.
    Methods: Retrospective review of FDG-PET scans performed in two NF-1 children with symptomatic OPGs that required chemotherapy.
    Results: Two children (3y/M & 2y/F) with NF-1 had bilateral OPGs. Both had symptomatic right-sided OPG. Both these tumours were “hot” on baseline FDG-PET with standard uptake value (SUVmax) of 5.57 and 3.97 in the boy and the girl respectively. Chemotherapy resulted in clinical and radiological improvement. On follow-up FDG-PET, both tumors were “cold” with SUVmax of 1.74 and 2.67 in the boy and the girl respectively.
    Conclusions: Conversion of the “hot” OPG to a “cold” OPG associated with significant reduction in the FDG-uptake following chemotherapy in these children is a very interesting finding suggesting a potential role for FDG-PET in the monitoring of NF-1 related symptomatic OPGs. The role of FDG-PET could also, perhaps, be extended to the surveillance of pre-symptomatic children with NF-1 related OPGs. Long-term prospective studies are required to evaluate if FDG-PET is effective in predicting tumour progression that could be helpful in selecting patients for treatment.

    Conference Organiser - ICMS Pty Ltd