This study is testing a new PET/CT scan that uses a special tracer called \[⁶⁸Ga\]Ga-DLL3 nanobody to see if it can better detect cancer spread (metastases) in people with neuroendocrine tumors than the standard scans currently used (FDG PET/CT or PSMA PET/CT). DLL3 is a protein found on the surface of many neuroendocrine tumor cells, and the new tracer is designed to stick to this protein, making tumors visible on the scan. The goal is to find out whether this new imaging method can give doctors more accurate information about where the cancer has spread and help them choose the most appropriate treatment for each patient.
The study is prospective, multi-center, and self-controlled, meaning each participant will receive both the new scan and the standard scan, allowing a direct side-by-side comparison in the same person. Depending on the type of neuroendocrine tumor, participants will be assigned to one of two groups: one group will be compared with FDG PET/CT and the other with PSMA PET/CT. The two scans will be performed within two weeks of each other, and all images will be read by independent experts who do not know the patient's clinical history, to ensure objective and unbiased results.
The investigators plan to enroll about 180-200 patients aged 18 or older who have confirmed neuroendocrine tumors with at least two metastatic sites. The total duration of participation is approximately 6 months, consisting of a screening period of up to 14 days, two imaging scans completed within 2 days, and a final follow-up visit at 6 months to evaluate participants' health and disease progression. Participation is entirely voluntary, and participants may withdraw at any time without affecting participants' standard medical care.