Modified CV Regimen in Optic Pathway Glioma

Inclusion Criteria: * Age ≥ 3months and ≤21years; * Patients with optic pathway gliomas diagnosed by histopathology or characteristic brain MRI and clinical features; * Measurable lesions, surgical resection degree \< 95% or postoperative residual tumor ≥1.5cm\^2; * KPS score ≥50 (age \>12 years) or Lansky score ≥50 (age ≤12 years); * Clinical symptoms such as decreased visual acuity, visual field defect, optic disc edema, exophthalmia, increased intracranial pressure, diencephalic syndrome, etc; * No dysfunction of major organs. Exclusion Criteria: * MRI examination is not available. * Failing to comply with the visual examination. * H3K27 mutations, even histopathological grade 1/2. * Receiving any other investigational agent. * History of allergic reactions attributed to compounds of similar chemical or biologic composition to the drugs used in this study. * Patients who have received organ transplants. * Patients infected with HIV or treponema pallidum. * Suffering from serious cardiovascular disease;T wave inversion or elevation or ST segment changes. * Patients who had coagulation disorder and were being treated with thrombolytic or anticoagulant drugs. Patients with significant clinical bleeding symptoms or clear bleeding tendency occurred within 3 months before enrollment, such as gastrointestinal bleeding, hemorrhagic gastric ulcer, gastrointestinal perforation, baseline fecal occult blood ++ or above, intratumoral or intracranial bleeding, or vasculitis, etc. Arteriovenous thrombosis events (such as cerebrovascular accident (including transient ischemic attack, cerebral hemorrhage and cerebral infarction), deep vein thrombosis and pulmonary embolism) occurred within 6 months before enrollment. * Pregnant or breastfeeding. * Other conditions considered inappropriate by the researcher for inclusion.