This phase IV trial evaluates how well giving standard of care (SOC) peptide receptor radionuclide therapy (PRRT) after SOC surgical removal of as much tumor as possible (debulking surgery) works in treating patients with grade 1 or 2, somatostatin receptor (SSTR) positive, gastroenteropancreatic neuroendocrine tumors (GEP-NETs) that have spread from where they first started (primary site) to the liver (hepatic metastasis). Lutetium Lu 177 dotatate is a radioactive drug that uses targeted radiation to kill tumor cells. Lutetium Lu 177 dotatate includes a radioactive form (an isotope) of the element called lutetium. This radioactive isotope (Lu-177) is attached to a molecule called dotatate. On the surface of GEP-NET tumor cells, a receptor called a somatostatin receptor binds to dotatate. When this binding occurs, the lutetium Lu 177 dotatate drug then enters somatostatin receptor-positive tumor cells, and radiation emitted by Lu-177 helps kill the cells. Giving lutetium Lu 177 dotatate after surgical debulking may better treat patients with grade 1/2 GEP-NETs

This study aims to establish a safe and well tolerated dose of \[177Lu\]Lu-DOTA-TATE in combination with carboplatin, etoposide and atezolizumab in this setting and to assess preliminary efficacy of this combination treatment versus the combination of carboplatin, etoposide, and atezolizumab.The study will be essential to assess a new potential therapeutic option in participants with this aggressive cancer type.