Expanded Access Protocol Using 131I-MIBG

Primary Objectives: * To provide 131I-MIBG for compassionate use in patients with neuroblastoma, who otherwise do not qualify for inclusion or cannot participate in the sponsor's pivotal Phase II, FDA-approved, clinical trial. * To provide 131I-MIBG for compassionate use in patients with neuroblastoma in the absence of a commercially available FDA approved product for the indication. * Provide palliative therapy with 131I-MIBG for patients with advanced neuroblastoma. * To provide alternative therapeutic 131I-MIBG options for patients with pheochromocytoma / paraganglioma, not qualifying for FDA-approved MIBG treatment. * To provide alternative therapeutic 131I-MIBG options for patients with pheochromocytoma / paraganglioma, in the absence of a commercially available FDA-approved product for that indication. * Gain more information about acute and late toxicity of 131I-MIBG therapy for patients with refractory neuroblastoma, pheochromocytoma, or paraganglioma. Patients will receive a therapeutic dose at the investigator's discretion (5-18 mCi/kg). However, a dose of 12 mCi/kg or higher requires stored stem cells. Patients may be eligible for additional 131I-MIBG treatments (up to a cumulative total of 3 treatments) if they meet certain criteria. Treatments with 131I-MIBG must be separated by a minimum of six weeks from previous 131I-MIBG therapy. Post-treatment evaluation will be performed 5-9 weeks (35-63 days) post treatment, and patients will be followed every 6 months until 2 years from therapy. All patients will have toxicity monitoring for 2 years following 131I-MIBG therapy, or until going off study.