Fully Automated Segmentation of [ 18 F]FDG and [ 68 Ga]/[ 18 F]PSMA PET/CT Images via Data-Centric Deep Learning
The purpose of this study was to develop and validate lesion identification in oncologic nuclear imaging (LION), an open-source PET-only tumor segmentation pipeline for [18F]FDG and prostate-specific membrane antigen (PSMA)–targeted PET/CT, and to investigate how training data characteristics influence segmentation performance. Methods: In this retrospective multicenter study, 5209 [18F]FDG PET/CT scans spanning 19 disease types and 2046 PSMA-targeted PET/CT scans were used to train PET-only segmentation models. Tumor segmentation incorporated organs with physiologic uptake as auxiliary classes to enable PET-only inference. Tumor occurrence maps (TOMs) quantified tumor spatial diversity across the training data. For [18F]FDG, disease-specific and mixed-disease models trained on progressively larger subsets were compared to test whether increasing spatial diversity improves generalization. Scanner-related domain shift was analyzed using DINOv2 embeddings. Models were evaluated on multicenter holdout cohorts (616 [18F]FDG scans across 4 diseases; 443 PSMA-targeted prostate cancer scans) and compared with 3 open-source tools. Results: Organ context improved median Dice from 0.62 to 0.71 for [18F]FDG and from 0.75 to 0.83 for PSMA, on the complete holdout cohorts. Spatial diversity measured by TOMs was strongly associated with Dice (Spearman ρ = 0.80, P = 0.003). A mixed-disease model trained on 500 patients matched the performance of a lymphoma specialist model trained on 3031 cases. DINOv2 embeddings revealed scanner-induced domain shift between same-disease cohorts. LION achieved median Dice scores of 0.71 for [18F]FDG and 0.85 for PSMA and outperformed other open-source approaches on the model-comparison test set, which excluded the AutoPET test cases. Conclusion: LION enables PET-only automated segmentation for [18F]FDG and PSMA-targeted PET. Training data composition, particularly spatial diversity quantified by TOMs, was strongly associated with segmentation performance.
Authors
- Michael Ingrisch (ORCID: https://orcid.org/0000-0003-0268-9078)
- Elisabetta Abenavoli
- Lorenzo Nardo (ORCID: https://orcid.org/0000-0002-0266-2708)
- Jukka Kemppainen (ORCID: https://orcid.org/0000-0001-9390-1198)
- Lalith Kumar Shiyam Sundar (ORCID: https://orcid.org/0000-0003-3004-7937)
- Fanny Orlhac (ORCID: https://orcid.org/0000-0002-5588-1867)
- Hande Nalbant (ORCID: https://orcid.org/0000-0002-8600-6707)
- Sebastian Gutschmayer (ORCID: https://orcid.org/0000-0002-7908-845X)
- Rodney Hicks
- Eduardo Calderón (ORCID: https://orcid.org/0009-0000-3837-7151)
- Ramsey Derek Badawi (ORCID: https://orcid.org/0000-0002-9769-0292)
- Roberto Sciagrà (ORCID: https://orcid.org/0000-0003-0694-2552)
- Riku Klén (ORCID: https://orcid.org/0000-0002-0982-8360)
- Irene Johanna Virgolini (ORCID: https://orcid.org/0000-0001-7097-6170)
- Jakob Dexl (ORCID: https://orcid.org/0000-0002-0617-0460)
- Giulia Santo (ORCID: https://orcid.org/0000-0001-6565-0686)
- Liam Widjaja (ORCID: https://orcid.org/0000-0002-0243-9338)
- Miju Cheon (ORCID: https://orcid.org/0000-0001-7469-7769)
- Mej Kazazi
- Dominik Amereller
- Clemens C. Cyran (ORCID: https://orcid.org/0000-0001-5630-6242)
- Enrica Bergalla
- Iustin Tibu
- Anting Li
- Ariane Kronthaler (ORCID: https://orcid.org/0009-0007-9442-6158)
- Julie Auriac (ORCID: https://orcid.org/0000-0002-9165-3001)
- David Kersting
- Manuel Pires
- Sophie C. Siegmund
- Fabian Schmidt
- Irene Buvat
- Moon-Sung Kim
- Aleksa Lazarević
- Thomas Beyer
- Ahti Vehmanen (ORCID: https://orcid.org/0009-0006-4375-2861)
- Natalia Wegrzyn
- Philip Richter
- Ken Miller
- Maurice Heimer
- Romain-David Seban
- Jason Callahan
- Rudolf A. Werner
- Jonas Benecke
- Stephane Chauvie
- Yasser Gaber Abdelhafez
Institutions
- Centre National de la Recherche Scientifique (FR)
- Innsbruck Medical University (AT)
- Inserm (FR)
- Universität Innsbruck (AT)
- Université de Versailles Saint-Quentin-en-Yvelines (FR)
- Université Paris Sciences et Lettres (FR)
- Turku University Hospital (FI)
- LMU Klinikum (DE)
- St Vincent's Hospital Melbourne (AU)
- Veterans Health Service Medical Center (KR)
- Turku PET Centre (FI)
- Azienda Ospedaliero-Universitaria Careggi (IT)
- Essen University Hospital (DE)
- Azienda Sanitaria Ospedaliera S.Croce e Carle Cuneo (IT)
- University of Duisburg-Essen (DE)
- Medical University of Vienna (AT)
- Institut Curie (FR)
- University of Tübingen (DE)
- Ludwig-Maximilians-Universität München (DE)
- University of California, Davis (US)
- Assiut University (EG)
Publication Details
- Journal
- Journal of Nuclear Medicine
- Published
- 2026-09-30
- DOI
- https://doi.org/10.2967/jnumed.126.272852
- Primary Topic
- Prostate Cancer Treatment and Research
- Type
- article
- Field-Weighted Citation Impact
- 0.00