{"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":[],"cancers":["prostate"],"sections":[],"technologies":["pet-ct","radioligand-therapy","spect"],"targets":[],"drugs":["pluvicto"],"companies":["united-imaging","siemens-healthineers"],"institutions":[],"pathways":[],"terms":["dosimetry"],"trials":["nct06004661","psmaddition","psmafore","therap","vision"],"people":[],"bottlenecks":[],"keyPapers":["paper-lutetium-177-vipivotide-tetrax-prostate-oncol-ther-2025","paper-lutetium-177-vipivotide-tetrax-prostate-journal-2023"],"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":{"cancer":[{"id":"prostate","kind":"cancer","name":"Prostate cancer","route":"/cancers/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/"}],"trial":[{"id":"psmaddition","kind":"trial","name":"PSMAddition","route":"/trials/psmaddition/"},{"id":"psmafore","kind":"trial","name":"PSMAfore","route":"/trials/psmafore/"},{"id":"nct06004661","kind":"trial","name":"Study of Lutetium (177Lu) Vipivotide Tetraxetan in mCRPC Participants With Moderately and Severely Impaired and With Normal Renal Function","route":"/trials/nct06004661/"},{"id":"therap","kind":"trial","name":"TheraP (ANZUP 1603)","route":"/trials/therap/"},{"id":"vision","kind":"trial","name":"VISION","route":"/trials/vision/"}],"paper":[{"id":"paper-lutetium-177-vipivotide-tetrax-prostate-journal-2023","kind":"paper","name":"Lutetium-177 vipivotide tetraxetan for treating PSMA-positive hormone-relapsed metastatic prostate cancer after 2 or more treatments","route":"/key-papers/paper-lutetium-177-vipivotide-tetrax-prostate-journal-2023/"},{"id":"paper-lutetium-177-vipivotide-tetrax-prostate-oncol-ther-2025","kind":"paper","name":"Sequencing of Radium-223 and Lutetium-177 Vipivotide Tetraxetan: Maximizing the Benefit of Systemic Targeted Radiation Therapy in Metastatic Castration-Resistant Prostate Cancer","route":"/key-papers/paper-lutetium-177-vipivotide-tetrax-prostate-oncol-ther-2025/"}],"bottleneck":[{"id":"b-dose-optimisation","kind":"bottleneck","name":"Wrong doses","route":"/bottlenecks/b-dose-optimisation/"}],"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/"}]}}