[212Pb]VMT-Alpha-NET in Metastatic or Inoperable Somatostatin-Receptor Positive Gastrointestinal Neuroendocrine Tumors, Pheochromocytoma/Paragangliomas, Small Cell Lung, Renal Cell, and Head and Neck Cancers

Background: Some cancers have high levels of proteins called somatostatin receptors (SSTRs) on the surface of the tumors. These tumors can be in the lung, head and neck, digestive tract, kidneys, and in or near the adrenal glands. Researchers want to know if drug treatments that target SSTRs can help shrink these types of tumors. Objective: To test a study drug (\[212Pb\]VMT-Alpha-NET) in people with tumors that have SSTRs. Eligibility: People aged 18 years and older with tumors of the lung, kidneys, head and neck, digestive tract, or adrenal glands that have SSTRs. Their tumors must have spread to other organs and cannot be removed with surgery. Design: Participants will be screened. They will have a physical exam with blood and urine tests. They will have imaging scans and a test of their heart function. A sample of tumor tissue may be collected if one is not already available. \[212Pb\]VMT-Alpha-NET is given through a tube attached to a needle inserted into a vein. The drug will be given on the first day of four 8-week cycles. Participants will stay in the hospital for a few nights after each dose. They will have blood tests once a week during each cycle. Some participants will also get a related study drug (\[203Pb\]VMT-Alpha-NET). They will receive this drug a few days before the first 2 cycles. At 4, 24, and 48 hours after each infusion, they will have whole body scans. These scans will show where the study drug went in their body. Follow-up visits will continue up to 6 years after the last treatment.