SSTR2 and neuroendocrine carcinoma: One of the first examples was [68Ga]Ga-DOTA-TOC, a tracer that binds to somatostatin receptor 2 (SSTR2)-expressing tumors, such as neuroendocrine carcinomas or meningiomas, and it is also used for therapy in DOTA-TOC-positive tumors labeled with beta emitters as 90Y or 177Lu.