{"entity":{"id":"in-111","kind":"isotope","name":"Indium-111","aka":["111In"],"tldr":"A radioactive metal used, attached to octreotide, as the original scan for neuroendocrine tumours (Octreoscan) before gallium-68 PET took over, and still used to label white blood cells for infection imaging.","summary":"Indium-111 decays by electron capture to stable cadmium-111 with a 2.805-day half-life, emitting gamma photons suited to gamma-camera and SPECT imaging. For two decades it was the standard somatostatin-receptor imaging agent as 111In-pentetreotide (Octreoscan), used to select neuroendocrine tumour patients before peptide receptor radionuclide therapy, first with 90Y-labelled and later with 177Lu-labelled somatostatin analogues; SPECT-based Octreoscan has since been largely replaced by 68Ga- or 64Cu-DOTATATE PET, which has better resolution and quantification, but 111In-pentetreotide remains on label and in use where PET access is limited.\n\nIt is produced on a cyclotron by proton bombardment of an enriched cadmium target, either 112Cd(p,2n)111In or 111Cd(p,n)111In, the latter giving higher radionuclidic purity. Its 2.8-day half-life is long enough to ship internationally and to track slower-clearing tracers such as labelled leukocytes and antibody fragments, which is why it is also used for infection and inflammation imaging (111In-labelled white cells) and in some antibody biodistribution and dosimetry studies.","status":"established","asOf":"2026-09-22","links":[{"label":"FDA/DailyMed label: OctreoScan (indium In 111 pentetreotide)","url":"https://dailymed.nlm.nih.gov/dailymed/fda/fdaDrugXsl.cfm?setid=93d8f3b2-1216-41dc-a63d-0e812b33891d"},{"label":"Wikipedia: indium-111 (production routes)","url":"https://en.wikipedia.org/wiki/Indium-111"}],"tags":["gamma emitter","legacy somatostatin imaging"],"related":["ga68-dotatate","lutathera"],"indications":["neuroendocrine"],"sections":[],"technologies":["spect","spect-ct","sstr-pet","cyclotron-isotope-production"],"targets":[],"drugs":[],"companies":[],"institutions":[],"pathways":[],"terms":[],"trials":[],"people":[],"bottlenecks":[],"keyPapers":[],"journals":[],"dependsOn":[],"notes":[],"symbol":"111In","element":"Indium","massNumber":111,"halfLife":"2.805 days","emissions":["γ 171 keV (90%)","γ 245 keV (94%)","electron capture"],"emissionClass":"gamma","use":"imaging","production":"Cyclotron: 111Cd(p,n)111In (higher purity) or 112Cd(p,2n)111In on enriched cadmium targets.","supply":"adequate","supplyNote":"Cyclotron-produced at a moderate number of sites; demand has fallen substantially since 68Ga/64Cu-DOTATATE PET replaced 111In-pentetreotide SPECT as the preferred somatostatin-receptor imaging test.","chelators":["DTPA"],"pairedWith":["y-90","lu-177"],"since":1994},"route":"/isotopes/in-111/","neighbours":{"drug":[{"id":"ac-225-fpi-2068","kind":"drug","name":"Actinium-225 FPI-2068","route":"/drugs/ac-225-fpi-2068/"},{"id":"ga68-dotatate","kind":"drug","name":"Gallium-68 DOTATATE (and Cu-64 DOTATATE)","route":"/drugs/ga68-dotatate/"},{"id":"in-111-pentetreotide","kind":"drug","name":"Indium-111 pentetreotide","route":"/drugs/in-111-pentetreotide/"},{"id":"lutathera","kind":"drug","name":"Lutetium-177 dotatate","route":"/drugs/lutathera/"},{"id":"tc-99m-psma-imaging","kind":"drug","name":"Technetium Tc-99m PSMA agents (PSMA-I&S)","route":"/drugs/tc-99m-psma-imaging/"}],"indication":[{"id":"neuroendocrine","kind":"indication","name":"Neuroendocrine tumours","route":"/indications/neuroendocrine/"}],"technology":[{"id":"auger-electron-therapy","kind":"technology","name":"Auger-electron therapy","route":"/technologies/auger-electron-therapy/"},{"id":"cyclotron-isotope-production","kind":"technology","name":"Cyclotron isotope production (F-18, Ga-68, Cu-64, Zr-89, At-211)","route":"/technologies/cyclotron-isotope-production/"},{"id":"sstr-pet","kind":"technology","name":"Somatostatin receptor PET (68Ga/64Cu-DOTATATE)","route":"/technologies/sstr-pet/"},{"id":"spect","kind":"technology","name":"SPECT & bone scan","route":"/technologies/spect/"},{"id":"spect-ct","kind":"technology","name":"SPECT/CT","route":"/technologies/spect-ct/"}],"trial":[{"id":"nct06549465","kind":"trial","name":"Study Evaluating Dosimetry, Randomized Dose Optimization, Dose Escalation and Efficacy of Ac-225 Rosopatamab Tetraxetan in Participants With PSMA PET-Positive Castration-Resistant Prostate Cancer (CRPC)","route":"/trials/nct06549465/"}],"company":[{"id":"bwxt-medical","kind":"company","name":"BWXT Medical","route":"/companies/bwxt-medical/"}],"pairing":[{"id":"ga68-dotatate-then-lutathera","kind":"pairing","name":"68Ga-DOTATATE PET before Lutathera (177Lu-DOTATATE)","route":"/pairings/ga68-dotatate-then-lutathera/"}],"roadmap":[{"id":"psma-theranostics-roadmap","kind":"roadmap","name":"PSMA theranostics roadmap: antigen discovery → PSMA PET → 177Lu-PSMA-617 → earlier lines and alpha","route":"/roadmaps/psma-theranostics-roadmap/"},{"id":"sstr-theranostics-roadmap","kind":"roadmap","name":"SSTR theranostics roadmap: octreotide scintigraphy → 68Ga-DOTATATE → 177Lu-DOTATATE → alpha","route":"/roadmaps/sstr-theranostics-roadmap/"}],"target":[{"id":"bradykinin-b1-receptor","kind":"target","name":"Bradykinin B1 receptor (B1R)","route":"/targets/bradykinin-b1-receptor/"},{"id":"cck2-receptor","kind":"target","name":"CCK2 receptor (gastrin receptor)","route":"/targets/cck2-receptor/"}],"term":[{"id":"chelator-term","kind":"term","name":"Chelator (bifunctional chelating agent)","route":"/terms/chelator-term/"},{"id":"krenning-score","kind":"term","name":"Krenning score","route":"/terms/krenning-score/"}]}}