Evidence map›Paper›PMID 41000030›Full record

ArticleMedical physics2025

Understanding time-activity curve and time-integrated activity variations in radiopharmaceutical therapy challenge: Experience and results.

Oleksandra V Ivashchenko, Jim O'Doherty, Deni Hardiansyah, Elisa Grassi, Johannes Tran-Gia, Johannes W T Heemskerk, Eero Hippeläinen, Mattias Sandström, Marta Cremonesi, Gerhard Glatting

Erratum issuedAbstract read
In one paragraph

Article in Medical physics, 2025. The graph could read no effect estimate from its abstract, so it casts no vote on the map. An erratum has been issued. Cited by 1 paper.

0numbers the graph read from it
0cells of the map it votes in
1citing papers in PubMed
–field-weighted citation impact
1 · What the graph read from it

What it found

Each row is one number read from the abstract, on the scale the paper reported it, with its interval. Left of the dashed line favours the treatment, right favours the comparator. Under each row is the sentence it came from. New to these charts? A ten-minute tutorial.

The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.

2 · The registry

The trial behind it

Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.

Neither the registry nor the abstract names a trial number. If this is a trial report, that itself is worth knowing.

3 · Its place in the literature

Who cites it

1 citing paper in PubMed.

  1. Article
4 · The record

Corrections and comments

5 · Who and what money

Authors and funding

10 authors.

Oleksandra V IvashchenkoDepartment of Nuclear Medicine and Molecular Imaging, University Medical Center Groningen, Groningen, The Netherlands.
Jim O'DohertyR&D Collaborations, Siemens Medical Solutions, Malvern, Pennsylvania, USA.
Deni HardiansyahDepartment of Physics, FMIPA, Universitas Indonesia, Depok, Indonesia.
Elisa GrassiMedical Physics Unit, Azienda USL-IRCCS di Reggio Emilia, Reggio Emilia, Italy.
Johannes Tran-GiaDepartment of Nuclear Medicine, University Hospital Würzburg, Würzburg, Germany.
Johannes W T HeemskerkDepartment of Radiology, Leiden University Medical Center, Leiden, South Holland, The Netherlands.
Eero HippeläinenDepartment of Physics, University of Helsinki and Helsinki University Hospital, Helsinki, Finland.
Mattias SandströmDepartment of Radiology, Uppsala University, Uppsala, Sweden.
Marta CremonesiRadiation Research Unit, European Institute of Oncology, Milan, Italy.
Gerhard GlattingDepartment of Nuclear Medicine, Ulm University, Ulm, Germany.

Funding

DAAD (German Academic Exchange Service), Förderkennzeichen 57657089Universitas Indonesia NKB-739/UN2.RST/HKP.05.00/2023
6 · The paper itself

Abstract

backgroundThe 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. PURPOSE: To address this critical unmet need, the time-activity curve and time-integrated activity variations (TACTIC) AAPM Grand Challenge was designed to explore the variations in TAC modeling for RPT applications.

methodsLaunched in January 2023, the TACTIC challenge consisted of three phases: i) warm-up phase (phase 0, to gain familiarity with the logistics and the modalities of the challenge), ii) TAC fitting based on data from individual patients (phase 1, rated to determine winner 1), and iii) TAC fitting using population-based data (phase 2, rated to determine winner 2). Based on the distributed synthetic biokinetic data of [

resultsA total of 132 teams from over 30 countries registered for this data-driven challenge, of which 95 individual groups submitted their results throughout the challenge. By presenting participants with an identical set of measurement points previously generated from measured biokinetic data and providing additional a priori information about the procedure at different stages of the challenge, we could assess the degree of variation within the TIAC estimation. We investigated which of the commonly used TIAC estimation methods performs best and could therefore be used to harmonize TAC modeling in RPT dosimetry.

conclusionThe results of the TACTIC challenge demonstrate the large variability in TAC fitting despite the participants receiving identical input data. This highlights the fundamental role of TAC fitting methodology selection in the calculation of absorbed doses in RPT and successfully raises awareness of the need for greater harmonization in dosimetric approaches.

Indexed as

RadiopharmaceuticalsHumansRadiometryTime FactorsRadiopharmaceuticalsdosimetryradiopharmaceutical therapytime–activity curve

Identifiers

PMID41000030
PMCPMC12464796

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Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.