{"entity":{"id":"ga68-dotatate-then-lutathera","kind":"pairing","name":"68Ga-DOTATATE PET before Lutathera (177Lu-DOTATATE)","aka":[],"tldr":"Before starting the neuroendocrine tumour treatment Lutathera, patients get a somatostatin-receptor PET scan to confirm the tumour actually has the right target for the drug to lock onto. Lutathera's approval and use are built around this scan-first rule.","summary":"Lutathera (177Lu-dotatate) is FDA-approved for somatostatin receptor-positive gastroenteropancreatic neuroendocrine tumours, and its own label states that eligibility in the pivotal programme required 'confirmed presence of somatostatin receptors on all lesions,' historically demonstrated with OctreoScan (111In-pentetreotide) uptake at least equal to normal liver, and now more commonly with PET agents such as 68Ga-DOTATATE, 68Ga-DOTATOC or 64Cu-DOTATATE, which have largely replaced OctreoScan because of higher sensitivity and better lesion detectability. Lesions with tracer uptake less than liver activity are considered somatostatin-receptor-negative and are not expected to respond to Lutathera; patients with significant somatostatin-receptor-negative (and, where available, FDG-positive) disease are generally excluded from treatment because such discordant lesions predict poor response to PRRT.\n\nThis is a drug-specific instance of the broader diagnostic-therapeutic 'theranostic' pairing between somatostatin-receptor PET and peptide receptor radionuclide therapy: the same molecular target (SSTR2) is imaged with a gallium-68- or copper-64-labelled diagnostic tracer and then treated with the lutetium-177-labelled therapeutic analogue, so the scan used for staging doubles as the biomarker test that selects patients for, and later monitors response to, Lutathera. SNMMI/EANM and society guidance recommend repeat somatostatin-receptor PET roughly 3-6 months after completing PRRT to assess response.\n\nEligibility based on receptor imaging (Krenning score equivalent, uptake greater than liver) sits alongside other selection criteria in the Lutathera label and NET treatment guidelines, including Ki-67 index, performance status, renal function and prior PRRT exposure. This record is specific to the Lutathera-DOTATATE PET pairing and is distinct from the generic sstr-pet-to-prrt technology-level pairing already in this graph, which covers somatostatin receptor PET's relationship to PRRT as a modality rather than the specific FDA-labelled drug requirement.","asOf":"2026-09-22","links":[{"label":"FDA label: Lutathera (lutetium Lu 177 dotatate), 2024 revision, eligibility criteria","url":"https://www.accessdata.fda.gov/drugsatfda_docs/label/2024/208700Orig1s032lbl.pdf"},{"label":"SNMT practical considerations for 177Lu-DOTATATE programmes: SSTR imaging and patient selection","url":"https://tech.snmjournals.org/content/jnmt/early/2022/06/14/jnmt.122.263813.full.pdf"},{"label":"Clinical guide to PRRT with 177Lu-DOTATATE (PMC9737149)","url":"https://pmc.ncbi.nlm.nih.gov/articles/PMC9737149/"}],"tags":["neuroendocrine tumours","theranostics","patient selection"],"related":["sstr2","neuroendocrine","sstr-pet","prrt","sstr-pet-to-prrt","richard-baum","ga-68","in-111","cu-64","lu-177"],"indications":[],"sections":[],"technologies":[],"targets":[],"drugs":[],"companies":[],"institutions":[],"pathways":[],"terms":[],"trials":[],"people":[],"bottlenecks":[],"keyPapers":[],"journals":[],"dependsOn":[],"notes":[],"a":"ga68-dotatate","b":"lutathera","rationale":"Lutathera targets the same somatostatin receptor (SSTR2) that 68Ga-DOTATATE PET images, so the diagnostic scan doubles as the biomarker test confirming a tumour expresses enough receptor to be worth treating, and later as the response-assessment tool.","evidence":"Lutathera's FDA label states eligibility required 'confirmed presence of somatostatin receptors on all lesions', historically shown by OctreoScan uptake at least equal to liver, now more often confirmed on 68Ga-DOTATATE PET; lesions with uptake below liver activity are considered SSTR-negative and unlikely to respond to PRRT.","pairingType":"diagnostic-therapeutic"},"route":"/pairings/ga68-dotatate-then-lutathera/","neighbours":{"target":[{"id":"sstr2","kind":"target","name":"Somatostatin receptor 2","route":"/targets/sstr2/"}],"indication":[{"id":"neuroendocrine","kind":"indication","name":"Neuroendocrine tumours","route":"/indications/neuroendocrine/"}],"technology":[{"id":"prrt","kind":"technology","name":"Peptide receptor radionuclide therapy (PRRT)","route":"/technologies/prrt/"},{"id":"sstr-pet","kind":"technology","name":"Somatostatin receptor PET (68Ga/64Cu-DOTATATE)","route":"/technologies/sstr-pet/"}],"pairing":[{"id":"sstr-pet-to-prrt","kind":"pairing","name":"SSTR PET → PRRT","route":"/pairings/sstr-pet-to-prrt/"}],"person":[{"id":"richard-baum","kind":"person","name":"Richard P. Baum","route":"/people/richard-baum/"}],"isotope":[{"id":"cu-64","kind":"isotope","name":"Copper-64","route":"/isotopes/cu-64/"},{"id":"ga-68","kind":"isotope","name":"Gallium-68","route":"/isotopes/ga-68/"},{"id":"in-111","kind":"isotope","name":"Indium-111","route":"/isotopes/in-111/"},{"id":"lu-177","kind":"isotope","name":"Lutetium-177","route":"/isotopes/lu-177/"}],"drug":[{"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/"}]}}