biostudies-literatureIvashchenko OVUniversitas IndonesiaDAAD (German Academic Exchange Service), Förderkennzeichene70043https://www.ebi.ac.uk/biostudies/studies/S-EPMC12464796biostudies-literatureUnknown52(10)<h4>Background</h4>The process of determining/calculating the time-activity curve (TAC) for radiopharmaceutical therapy (RPT) is generally heavily dependent on user- and site-dependent steps (e.g., the number and schedule of measurement points to be used, selection of the fit function), each having a notable effect on the determination of the time-integrated activity coefficient (TIAC) and thus on the calculated absorbed dose. Despite the high clinical importance of absorbed doses, there is no consensus on the methodology for processing time-activity data or even a clear understanding of the influence of various uncertainties and user-dependent variations in personalized RPT dosimetry on the accuracy of TAC calculations.<h4>Purpose</h4>To address this critical unmet need, the time-activityMedical physicsUnderstanding time-activity curve and time-integrated activity variations in radiopharmaceutical therapy challenge: Experience and results.PMC12464796NKB-739/UN2.RST/HKP.05.00/202357657089NKB‐739/UN2.RST/HKP.05.00/2023O'Doherty JHippelainen EGrassi ETran-Gia JGlatting GHeemskerk JWTSandstrom MHardiansyah DIvashchenko OVCremonesi MfalseUnderstanding time-activity curve and time-integrated activity variations in radiopharmaceutical therapy challenge: Experience and results.<h4>Background</h4>The process of determining/calculating the time-activity curve (TAC) for radiopharmaceutical therapy (RPT) is generally heavily dependent on user- and site-dependent steps (e.g., the number and schedule of measurement points to be used, selection of the fit function), each having a notable effect on the determination of the time-integrated activity coefficient (TIAC) and thus on the calculated absorbed dose. Despite the high clinical importance of absorbed doses, there is no consensus on the methodology for processing time-activity data or even a clear understanding of the influence of various uncertainties and user-dependent variations in personalized RPT dosimetry on the accuracy of TAC calculations.<h4>Purpose</h4>To address this critical unmet need, the time-activity2025-01-01T00:00:00Z2025 Oct2026-07-14T17:14:21.109Z2026-06-21T03:12:37.889ZS-EPMC124647964100003010.1002/mp.70043