SSTR Antagonist PET/CT Unveils Occult Hepatic Metastases in Rectal Neuroendocrine Tumor: Superiority Over 68Ga-DOTANOC and Clinical Upstaging.

68Gallium NODAGA-JR11, a somatostatin receptor (SSTR) antagonist, exhibits superior sensitivity in detecting hepatic metastases of neuroendocrine tumors compared with the agonist tracer 68Ga-DOTANOC PET/CT. In the presented case of rectal neuroendocrine tumor, both tracers identified the primary lesion and regional lymph node involvement; however, NODAGA-JR11 PET/CT revealed multiple hepatic metastases not visualized on DOTANOC imaging, resulting in disease upstaging. The enhanced lesion detection is attributed to the antagonist's ability to bind a greater number of receptor sites and reduced hepatic background uptake. These findings highlight the potential impact of NODAGA-JR11 PET/CT on clinical staging and therapeutic decision-making in metastatic neuroendocrine tumors.