Phase I Trial to Determine the Dose and Evaluate the PK and Safety of Lutetium Lu 177 Edotreotide Therapy in Pediatric Participants With SSTR-positive Tumors

Determine the dose, pharmacokinetics and safety of Lutetium Lu 177 Edotreotide as monotherapy or following sequential standard of care in pediatric participants with recurrent, progressive or refractory NET, CNS, lymphoma and other solid tumors that express SSTRs by immunohistochemistry and demonstrate uptake by somatostatin receptor imaging. Lutetium Lu 177 Edotreotide will be given intravenously once every 8 weeks for a total of up to 6 doses over an average of 48 weeks in participants aged 2-18 years.