An international study of factors affecting variability of dosimetry calculations, part 5: impact of segmentation methods

Sara Kurkowska; Yuni K Dewaraja; Eric C Frey; Julia Brosch-Lenz; John Sunderland; Carlos Uribe

doi:10.1186/s40658-026-00848-6

Back

An international study of factors affecting variability of dosimetry calculations, part 5: impact of segmentation methods

Journal article

Open access

Peer reviewed

An international study of factors affecting variability of dosimetry calculations, part 5: impact of segmentation methods

Sara Kurkowska, Yuni K Dewaraja, Eric C Frey, Julia Brosch-Lenz, John Sunderland and Carlos Uribe

EJNMMI physics

03/12/2026

DOI: 10.1186/s40658-026-00848-6

PMID: 41817947

Files and links (1)

url

https://doi.org/10.1186/s40658-026-00848-6View

Published (Version of record) Open Access

Abstract

Individualized radiopharmaceutical therapies guided by patient-specific absorbed dose assessments using imaging have the potential to improve both efficacy and safety. Understanding sources of variability in absorbed dose 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 different steps within the dosimetry workflow. This work aimed to assess the variability in absorbed doses due to differences in segmentation methods. Anonymized datasets from two patients treated with Lu-DOTATATE, including serial SPECT/CT scans, were made available online. Participants were asked to segment healthy organs and lesions and perform dosimetry calculations. In a subsequent task, participants were provided with standardized segmented VOIs and asked to perform dosimetry based on these pre-defined regions. Variability in segmentation was assessed by comparing absorbed dose estimates across two scenarios: participant-generated segmentations versus predefined reference segmentations. Relative absorbed dose variability was quantified using the quartile coefficient of dispersion (QCD) and interquartile range. Variability in absorbed dose (measured as QCD difference between absorbed doses from participant-generated segmentations and those from reference segmentations) for kidneys was less than 5% in simple cases and 10.6% for more challenging scenarios (i.e. presence of intraparenchymal cysts, cortical defects). Lesion segmentation exhibited higher variability, with absorbed dose variability reaching up to 22.4%. Segmentation significantly contributes to variability in absorbed dose estimates, particularly for lesions and for kidneys with anatomical complexities. Standardizing segmentation protocols and providing training on advanced segmentation methods are essential to reduce variability.

Dosimetry

Radiopharmaceutical therapies

Segmentation

177Lu

SPECT/CT

Details

Title: Subtitle: An international study of factors affecting variability of dosimetry calculations, part 5: impact of segmentation methods
Creators: Sara Kurkowska - Pomeranian Medical University
Yuni K Dewaraja - University of Michigan
Eric C Frey - Johns Hopkins University
Julia Brosch-Lenz - Parents' Place of Maryland
John Sunderland - University of Iowa
Carlos Uribe - University of British Columbia
Resource Type: Journal article
Publication Details: EJNMMI physics
DOI: 10.1186/s40658-026-00848-6
PMID: 41817947
NLM abbreviation: EJNMMI Phys
ISSN: 2197-7364
eISSN: 2197-7364
Publisher: Springer Nature
Grant note: R01CA240706 / NCI NIH HHS R44CA291420 / NCI NIH HHS P01CA272222 / NCI NIH HHS R01CA24077 / NCI NIH HHS RGPIN-2021-02965 / Natural Sciences and Engineering Research Council R01CA289631 / NCI NIH HHS
Language: English
Electronic publication date: 03/12/2026
Academic Unit: Radiology; Physics and Astronomy; Radiation Oncology
Record Identifier: 9985147182902771

Metrics

1 Record Views