Convection-Enhanced Delivery of 124I-Omburtamab for Patients With Non-Progressive Diffuse Pontine Gliomas Previously Treated With External Beam Radiation Therapy

Prior to treatment children will be pre-medicated with super-saturated potassium iodide \& liothyronine to prevent thyroid uptake of the therapeutic radioisotopes. The proposed intervention is a surgical procedure using interstitial infusion of the radiolabeled monoclonal antibody 124I-omburtamab into the brain stem tumor. This will be performed by stereotactic placement of a small caliber infusion cannula into the tumor followed by a slow infusion (CED) of 124I-omburtamab. Following treatment, these children will be monitored during inpatient hospitalization with clinical evaluations \& PET/CT or PET/MRI scans of the brain \& other organs. Clinical observations, intensive care unit monitoring, routine blood \& interval imaging studies (MRI \& PET/CT or PET/MRI scans) will be performed at predetermined time points. If the PET/CT scan happens to fall on a weekend or holiday, the scan may be done before or after at the discretion of the Study PI. This will not affect dosimetry interpretation.

Standard radiation therapy is given 4-6 weeks prior to study entry.