{"entity":{"id":"idea-total-body-pet-dosimetry","kind":"idea","name":"Total-body PET for personalised radioligand dosing","aka":[],"tldr":"Ultra-sensitive whole-body scanners can measure exactly where a radioactive drug goes at tiny tracer doses, allowing each patient's therapeutic dose to be tailored.","summary":"Radioligand therapy is given at fixed activity despite wide variation in tumour and kidney dose, so this idea uses ultra-sensitive total-body PET with 44Sc- or 89Zr-labelled analogues to measure each patient's pharmacokinetics before treatment and tailor the therapeutic dose. Dosimetry-guided prescription of 177Lu-PSMA is expected to raise tumour absorbed dose and response without exceeding kidney and marrow limits. Personalised dosimetry is established in radioiodine and SIRT, and total-body scanners from United Imaging and Siemens Healthineers remove the imaging-time and dose barriers. The test is a randomised trial of dosimetry-guided versus fixed-dose Pluvicto in prostate cancer with PSA50 and rPFS endpoints. At early-clinical maturity it addresses the bottleneck Wrong doses.","asOf":"2026-09-04","links":[{"label":"VISION: lutetium-177 PSMA-617 radioligand therapy extends survival in advanced prostate cancer (New England Journal of Medicine 2021)","url":"https://doi.org/10.1056/NEJMoa2107322"}],"tags":[],"related":["zr-89","sc-44","lu-177"],"indications":["prostate"],"sections":[],"technologies":["pet-ct","radioligand-therapy","spect"],"targets":[],"drugs":["pluvicto"],"companies":["united-imaging","siemens-healthineers"],"institutions":[],"pathways":[],"terms":["dosimetry"],"trials":[],"people":[],"bottlenecks":[],"keyPapers":[],"journals":[],"dependsOn":[],"notes":[],"hypothesis":"Dosimetry-guided activity prescription for 177Lu-PSMA increases tumour absorbed dose and response without exceeding kidney and marrow limits, compared with fixed 7.4 GBq.","rationale":"Established in radioiodine and SIRT; total-body PET removes the imaging-time and dose barriers to pre-therapy dosimetry.","test":"Randomised dosimetry-guided vs fixed-dose Pluvicto trial with PSA50 and rPFS endpoints.","maturity":"early-clinical"},"route":"/ideas/idea-total-body-pet-dosimetry/","neighbours":{"isotope":[{"id":"lu-177","kind":"isotope","name":"Lutetium-177","route":"/isotopes/lu-177/"},{"id":"sc-44","kind":"isotope","name":"Scandium-44","route":"/isotopes/sc-44/"},{"id":"zr-89","kind":"isotope","name":"Zirconium-89","route":"/isotopes/zr-89/"}],"indication":[{"id":"prostate","kind":"indication","name":"Prostate cancer","route":"/indications/prostate/"}],"technology":[{"id":"pet-ct","kind":"technology","name":"PET/CT","route":"/technologies/pet-ct/"},{"id":"radioligand-therapy","kind":"technology","name":"Radioligand therapy (beta emitters)","route":"/technologies/radioligand-therapy/"},{"id":"spect","kind":"technology","name":"SPECT & bone scan","route":"/technologies/spect/"}],"drug":[{"id":"pluvicto","kind":"drug","name":"Lutetium-177 vipivotide tetraxetan","route":"/drugs/pluvicto/"}],"company":[{"id":"siemens-healthineers","kind":"company","name":"Siemens Healthineers","route":"/companies/siemens-healthineers/"},{"id":"united-imaging","kind":"company","name":"United Imaging","route":"/companies/united-imaging/"}],"term":[{"id":"dosimetry","kind":"term","name":"Dosimetry","route":"/terms/dosimetry/"},{"id":"fixed-versus-personalised-dosing","kind":"term","name":"Fixed versus personalised (dosimetry-guided) dosing","route":"/terms/fixed-versus-personalised-dosing/"}],"idea":[{"id":"idea-tr2-psma-volume-qualification","kind":"idea","name":"Qualify PSMA PET tumour volume as a validated imaging biomarker","route":"/ideas/idea-tr2-psma-volume-qualification/"},{"id":"idea-total-body-pet-lower-dose-tracers","kind":"idea","name":"Using total-body PET's sensitivity to cut diagnostic tracer dose, not just scan time","route":"/ideas/idea-total-body-pet-lower-dose-tracers/"}],"bottleneck":[{"id":"b-dosimetry-standardisation","kind":"bottleneck","name":"Dosimetry standardisation for radioligand therapy","route":"/bottlenecks/b-dosimetry-standardisation/"},{"id":"b-dose-optimisation","kind":"bottleneck","name":"Wrong doses","route":"/bottlenecks/b-dose-optimisation/"}],"roadmap":[{"id":"dosimetry-roadmap","kind":"roadmap","name":"Dosimetry roadmap: MIRD schema → fixed dosing → personalised, image-based dose","route":"/roadmaps/dosimetry-roadmap/"}]}}