68Ga-HA-DOTATATE Imaging of Suspected Somatostatin Receptor Positive Tumors

Inclusion Criteria: * Patients with known or clinically suspected somatostatin receptor positive tumors including but not limited to: gastrointestinal neuroendocrine tumors, pancreatic neuroendocrine tumors, pulmonary neuroendocrine tumors, neuroendocrine tumors - primary unknown, pheochromocytoma, paraganglioma, medullary thyroid cancer, medulloblastoma, meningioma * A standard clinical CT or MRI is obtained within 6 months of enrollment * Ability to provide written informed consent prior to participation in the study (participant or if required a legal medical decision maker) Exclusion Criteria: * Weight \> 225 kg (weight limit of the PET/CT scanner) * Inability to scan (ie. extreme claustrophobia) or inability to lie still for imaging * Any additional medical condition, serious inter-current illness, or other extenuating circumstance that, in the opinion of the investigator or attending department physician, may significantly interfere with study performance or interpretation * Previous allergic reaction to DOTATATE or somatostatin analogues * Lack of intravenous access