Journal article
An International Study of Factors Affecting Variability of Dosimetry Calculations, Part 4: Impact of Fitting Functions in Estimated Absorbed Doses
The Journal of nuclear medicine (1978), Vol.66(3), pp.441-448
03/01/2025
DOI: 10.2967/jnumed.124.268612
PMCID: PMC11876727
PMID: 39978818
Abstract
Individualized radiopharmaceutical therapies guided by patient-specific absorbed dose (AD) assessments using nuclear medicine imaging have the potential to improve both efficacy and safety. Understanding sources of variability in AD calculations is critical for standardization. The Society of Nuclear Medicine and Molecular Imaging Dosimetry Task Force launched the
Lu Dosimetry Challenge to evaluate variability across steps within the dosimetry workflow. This work aimed to assess the variability in ADs due to different fitting and integration methods.
Anonymized datasets from 2 patients treated with
Lu-DOTATATE, including serial SPECT/CT scans, segmented organs and lesions, and time-integrated activity maps, were made available online. Participants were invited to perform dosimetry calculations and submit their results using standardized submission spreadsheets. Fitting approaches were categorized, and relative AD variability was analyzed using the quartile coefficient of dispersion and interquartile range.
The variability in AD due to the fitting step for patient A's kidneys was less than 1%. In contrast, patient B's kidneys showed higher variability, with values below 10%. Lesions exhibited more variability in fitting than did kidneys, with variability within 25%.
The contribution of variability caused by fitting and integration is small for healthy organs. By following recommendations such as selection of appropriate functions, pharmacokinetic modeling, and sanity checks, this variability can be further reduced.
Details
- Title: Subtitle
- An International Study of Factors Affecting Variability of Dosimetry Calculations, Part 4: Impact of Fitting Functions in Estimated Absorbed Doses
- Creators
- Sara Kurkowska - Pomeranian Medical UniversityJulia Brosch-Lenz - Parents' Place of MarylandYuni K Dewaraja - University of MichiganEric Frey - Johns Hopkins UniversityJohn Sunderland - University of IowaCarlos Uribe - University of British Columbia
- Resource Type
- Journal article
- Publication Details
- The Journal of nuclear medicine (1978), Vol.66(3), pp.441-448
- DOI
- 10.2967/jnumed.124.268612
- PMID
- 39978818
- PMCID
- PMC11876727
- NLM abbreviation
- J Nucl Med
- ISSN
- 0161-5505
- eISSN
- 1535-5667
- Publisher
- SOC NUCLEAR MEDICINE INC
- Grant note
- Natural Science and Engineer Research Council: RGPIN-2021-02965
acknowledges funding from Natural Science and Engineer Research Council discovery grant RGPIN-2021-02965. No other potential conflict of interest relevant to this article was reported.r acknowledges funding from Natural Science and Engineer Research Council discovery grant RGPIN-2021-02965. No other potential conflict of interest relevant to this article was reported.
- Language
- English
- Electronic publication date
- 02/20/2025
- Date published
- 03/01/2025
- Academic Unit
- Radiology; Physics and Astronomy; Radiation Oncology
- Record Identifier
- 9984793878002771
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