99mTc-Tektrotyd SPECT/MRI in the Diagnosis of a Gastroenteropancreatic Neuroendocrine Tumor

Tc-99m-tektrotyd is a recently developed tracer for imaging neuroendocrine tumors. We report the case of a patient with a history of prostate cancer and chronic lymphocytic leukemia, who presented with a liver biopsy showing leukemic infiltration associated with chromogranin and CDX2 positivity, suggestive of metastases from an intestinal neuroendocrine tumor. While diagnostic CT did not detect the primary tumor and showed only some liver metastases, Tc-99m-tektrotyd SPECT/MRI fusion identified a pancreatic head tumor and several liver metastases. This case illustrates the feasibility and clinical value of SPECT/MRI fusion using Tc-99m-tektrotyd in neuroendocrine tumor patients.