Patient description: The patient is a 14-year-old boy complaining of scoliosis and back pain. He has no other medical condition. He used to be able to play routine activities such as basketball and soccer, however, he recently has problem doing them. The pain is in his leg and back and aggravated by physical activities. He prefer lying down most of the time. He is not happy with his body gesture and complaints of shoulder imbalance and shifting his head to right. Patient is a well-dressed and well-nourished adolescent who is alert and cooperative. The left shoulder is slightly higher than the right shoulder. The scoliotic curve is measured as 45 degree. The patients is candidate for scoliosis surgery according to perioperative MEP monitoring

Clinical trial eligibility criteria: eligible ages (years): 1.0-18.0,  Low-Grade Gliomas Malignant Neoplasms, Brain Soft Tissue Neoplasms Patients with recurrent or progressive disease, as defined in the following three strata below, will be eligible. For determination, tumor imaging from at least two time-points must be available to document radiographic progression or recurrence. Patients with non-progressive refractory tumors will not be eligible Stratum 1: patients with LGG with a BRAF truncated fusion that is measurable in at least two dimensions on imaging Stratum 2: patients with NF1 and LGG that is measurable in at least two dimensions on imaging Stratum 3: Pediatric patients with a recurrent or progressive tumor thought to involve the Ras/Raf/ERK pathway but not included in strata 1 or 2 that is measurable in at least two dimensions on imaging. This includes any LGG not included in strata 1 or 2 (i.e., any LGG without a BRAF truncated fusion in a patient without NF1), any tumor other than LGG in a patient with NF1, and any other tumor with a documented activating BRAF, NRAS, or KRAS mutation Stratum 4 (surgical arm, target validation): Patients who meet for stratum 1, 2, or 3 for whom tumor biopsy and/or resection is clinically indicated Tumor tissue for correlative studies must be available for all patients except those with NF1 and LGG (stratum 2) or any patient with optic pathway glioma (stratum 2 or 3), for whom tumor tissue is optional Patients must have received at least one prior chemotherapy or radiation regimen prior to progression At the time of enrollment, at least 6 weeks must have elapsed since the last dose of any nitrosourea, and the longer of 2 weeks or 3 half-lives must have elapsed since the last dose of any other tumor-directed medication. or biologic therapy At least 3 months must have elapsed since the last dose of irradiation to the target tumor(s) at the time of enrollment Patients must be >1 year and <18 years old  Patients with any of the following characteristics will not be eligible Patients for whom other curative or established standard-of-care therapeutic options with acceptable morbidity exist Patients with any significant medical illnesses that in the investigator's opinion cannot be adequately controlled with appropriate therapy or would compromise the patient's ability to tolerate this therapy History of Gilbert's syndrome Patients receiving any other anticancer or experimental drug therapy Use of hematopoietic growth factors within 2 weeks prior to initiation of therapy Any other investigational agents within 2 weeks or ≤ 3 half-lives (whichever is longer) before start of study therapy Patients who have undergone surgery ≤ 3 weeks or who have not recovered from side effects of this procedure prior to receiving study drug Uncontrolled intercurrent illness including, but not limited to, ongoing or active infection, symptomatic congestive heart failure, unstable angina pectoris, cardiac arrhythmia, impaired gastrointestinal function, or psychiatric illness/social situations that would limit compliance with study requirements History or current evidence of retinal vein occlusion (RVO) or predisposing factors to RVO (e.g. uncontrolled glaucoma or ocular hypertension, history of hyperviscosity or hypercoagulability syndromes)