This study is testing a two-step treatment for patients with large neuroendocrine tumors in the digestive system that can't be removed by surgery. First, patients receive SBRT (Stereotactic Body Radiation Therapy), a special type of external radiation that targets the tumor while sparing healthy tissue. After about 4-10 weeks, they receive PRRT (Peptide Receptor Radionuclide Therapy) using a drug called 177Lu-DOTATATE. This drug attaches to a specific protein on the tumor cells and releases radiation to help kill them. The study aims to see how safe and effective this combination is compared to using PRRT alone.
- Participants will need to visit for treatments over several months, including 5 radiation sessions and 4 PRRT doses.
- They will be closely monitored with CT or MRI scans and other tests.
- Regular check-ups will continue for about a year after treatment.
This study is open to adults with specific tumor types who meet health criteria. It excludes those who have had certain prior treatments or who cannot safely undergo radiation therapy.