SSTR PET → PRRT

This diagnostic-therapeutic pairing links somatostatin receptor PET, using gallium-68 or copper-64 DOTATATE, to peptide receptor radionuclide therapy with lutetium-177 dotatate or 177Lu-edotreotide in neuroendocrine tumours. Because the imaging and therapeutic agents share identical peptide chemistry, the biodistribution seen on the scan predicts where the therapy will be delivered, which is the founding logic of theranostics. Every pivotal PRRT trial, including NETTER-1, NETTER-2 and COMPETE, required SSTR-avid disease on imaging, and both the intensity of uptake, graded on the Krenning scale, and the absence of FDG-avid lesions lacking SSTR predict benefit. The same template was later copied by PSMA theranostics in prostate cancer.