{"entity":{"id":"sstr-pet-expression","kind":"biomarker","name":"Somatostatin receptor expression by PET (SSTR-positive)","aka":["SSTR PET positive","somatostatin receptor-positive","SSTR-positive","DOTATATE PET positive","Krenning score","SSTR2 expression","octreoscan positive"],"tldr":"Somatostatin receptor-positive means a neuroendocrine tumour takes up a DOTATATE tracer on PET. It is the requirement for lutetium-177 dotatate and the marker that predicts response to octreotide and lanreotide.","summary":"Gallium-68 or copper-64 DOTATATE PET (Netspot, Detectnet) images SSTR2; the Lutathera label covers somatostatin receptor-positive gastroenteropancreatic neuroendocrine tumours, including foregut, midgut and hindgut, in adults and children 12 and over, with the NETTER-1 trial requiring uptake at least equal to liver (Krenning score 2 or higher) on every lesion. The Krenning scale (0 to 4, from no uptake to greater than spleen or kidney) is the historic scintigraphy score carried over to PET. Actinium-225 DOTATATE and other radioligands in trials use the same selection.","asOf":"2026-09-23","links":[{"label":"Lutathera prescribing information (DailyMed)","url":"https://dailymed.nlm.nih.gov/dailymed/drugInfo.cfm?setid=72d1a024-00b7-418a-b36e-b2cb48f2ab55"}],"tags":["biomarker","pet"],"related":["psma-pet-expression","ki-67-index"],"cancers":["neuroendocrine","pancreatic-net","lung-net"],"sections":[],"technologies":[],"targets":[],"drugs":["lutathera","ga68-dotatate","ryz101"],"companies":[],"institutions":[],"pathways":[],"terms":["theranostics","prrt-term","net-grade-ki67"],"trials":[],"people":[],"bottlenecks":[],"keyPapers":[],"journals":[],"dependsOn":[],"notes":[],"target":"sstr2","measurement":"pet-tracer-expression","scoringRule":{"text":"Tumour uptake of a somatostatin receptor PET tracer at least equal to normal liver (Krenning score 2 or higher) in target lesions; the Lutathera label states 'somatostatin receptor-positive' without a numeric cut-off.","quote":"LUTATHERA is indicated for the treatment of adult and pediatric patients 12 years and older with somatostatin receptor-positive gastroenteropancreatic neuroendocrine tumors (GEP-NETs), including foregut, midgut, and hindgut neuroendocrine tumors.","source":"https://dailymed.nlm.nih.gov/dailymed/drugInfo.cfm?setid=72d1a024-00b7-418a-b36e-b2cb48f2ab55","sourceLabel":"Lutathera prescribing information"},"thresholds":[{"value":"Somatostatin receptor-positive by SSTR imaging","drugId":"lutathera","cancerId":"neuroendocrine","regulator":"FDA","source":"https://dailymed.nlm.nih.gov/dailymed/drugInfo.cfm?setid=72d1a024-00b7-418a-b36e-b2cb48f2ab55","quote":"LUTATHERA is indicated for the treatment of adult and pediatric patients 12 years and older with somatostatin receptor-positive gastroenteropancreatic neuroendocrine tumors (GEP-NETs), including foregut, midgut, and hindgut neuroendocrine tumors.","status":"current"}],"tests":[],"assays":[],"companionDiagnostics":[],"forPatient":"A DOTATATE PET scan that lights up your tumour at least as brightly as your liver makes it somatostatin receptor-positive, which is needed for lutetium-177 dotatate and predicts benefit from the monthly somatostatin injections. Tumours that do not take up the tracer, often the fast-growing ones, need a different plan."},"route":"/biomarkers/sstr-pet-expression/","neighbours":{"biomarker":[{"id":"ki-67-index","kind":"biomarker","name":"Ki-67 index (proliferation by IHC)","route":"/biomarkers/ki-67-index/"},{"id":"psma-pet-expression","kind":"biomarker","name":"PSMA expression by PET (PSMA-positive)","route":"/biomarkers/psma-pet-expression/"}],"cancer":[{"id":"lung-net","kind":"cancer","name":"Lung neuroendocrine tumours (typical and atypical carcinoid)","route":"/cancers/lung-net/"},{"id":"neuroendocrine","kind":"cancer","name":"Neuroendocrine tumours","route":"/cancers/neuroendocrine/"},{"id":"pancreatic-net","kind":"cancer","name":"Pancreatic neuroendocrine tumours","route":"/cancers/pancreatic-net/"}],"drug":[{"id":"ryz101","kind":"drug","name":"Actinium-225 DOTATATE","route":"/drugs/ryz101/"},{"id":"ga68-dotatate","kind":"drug","name":"Gallium-68 DOTATATE (and Cu-64 DOTATATE)","route":"/drugs/ga68-dotatate/"},{"id":"lutathera","kind":"drug","name":"Lutetium-177 dotatate","route":"/drugs/lutathera/"}],"term":[{"id":"net-grade-ki67","kind":"term","name":"Neuroendocrine tumour grade (Ki-67) and WHO classification","route":"/terms/net-grade-ki67/"},{"id":"prrt-term","kind":"term","name":"PRRT (peptide receptor radionuclide therapy)","route":"/terms/prrt-term/"},{"id":"theranostics","kind":"term","name":"Theranostics","route":"/terms/theranostics/"}],"target":[{"id":"sstr2","kind":"target","name":"Somatostatin receptor 2","route":"/targets/sstr2/"}]}}