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4 slides generated from the cancer page, with a quiz from the open benchmark and speaker notes that cite the sources. Arrow keys move between slides; Print gives one slide per page.
Optic pathway glioma is a slow-growing childhood brain tumour of the nerves that carry sight, often in children with neurofibromatosis type 1. It rarely kills but can take away vision, so treatment aims to preserve sight: watching if stable, chemotherapy such as carboplatin and vincristine if vision is threatened, or the MEK-blocking tablet selumetinib, with radiotherapy avoided in young children.
Optic pathway gliomas are pilocytic or other low-grade astrocytomas of the optic nerves, chiasm and hypothalamus, sporadic or associated with neurofibromatosis type 1, and treated within the paediatric low-grade glioma pathway (NCI PDQ). Because visual acuity rather than tumour size is what matters, the Response Evaluation in Neurofibromatosis and Schwannomatosis committee recommended quantitative visual acuity (Teller cards, then HOTV) as the main functional outcome for trials (Neurology 2013). In a single-institution series of 43 children treated with chemotherapy or radiotherapy, about 14 percent improved their vision during therapy and site and age strongly predicted long-term visual outcome (Cancer 2015). The MEK inhibitor selumetinib produced responses in recurrent or progressive NF1-associated and BRAF-aberrant paediatric low-grade glioma in the Pediatric Brain Tumor Consortium phase 2 trial (Fangusaro 2019), and MEK and RAF inhibitors are now first-line options on the parent page.
How it differs from its parent: the goal is sight, not tumour shrinkage; NF1-associated tumours are usually not biopsied and follow a gentler course; radiotherapy is avoided because of vascular and second-tumour risks in NF1 and cognitive harm in young children.
| Setting | Approach | Guideline |
|---|---|---|
| Stable vision | Observation with ophthalmology and MRI follow-up. | not mapped |
| Threatened vision or progression | Carboplatin and vincristine, or selumetinib (phase 2, Fangusaro 2019), tovorafenib, or dabrafenib with trametinib for BRAF V600E; radiotherapy deferred. | not mapped |