Abstract
At diagnosis 22% of colorectal cancer (CRC) patients have metastases and 50% later develop metastasis. Peptide receptor radionuclide therapy (PRRT) with lutetium-177 (177Lu)-PSMA-617 is employed to treat metastatic prostate cancer (PC). 177Lu-PSMA-617 targets Prostate Specific Membrane Antigen (PSMA) a cell surface protein enriched in PC and the neovasculature of other solid tumors including CRC. We performed gallium-68 (68Ga)-PSMA-11 PET-CT imaging of ten metastatic CRC patients to assess metastasis avidity. Eight patients had lesions lacking avidity and two had solitary metastases exhibiting very low avidity. Despite expression of PSMA in CRC neovasculature, none of the patients exhibited tumor avidity sufficient to be considered for 177Lu-PSMA-617 PRRT.
- Oncology: GI
- PET/CT
- Radionuclide Therapy
- metastatic colorectal cancer
- peptide receptor radionuclide therapy
- positron emission tomography
- theranostics
- Copyright © 2020 by the Society of Nuclear Medicine and Molecular Imaging, Inc.