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Updated: Dec 10, 2025
Whole-body PET/MRI of Pediatric Patients: The Details That Matter
Published on: December 19, 2017
Whole-body MRI versus an FDG-PET/CT-based reference standard for staging of paediatric Hodgkin lymphoma: a
Suzanne Spijkers1, Annemieke S Littooij2,3, Thomas C Kwee4
1Department of Radiology and Nuclear Medicine, University Medical Center Utrecht/Wilhelmina Children's Hospital, Utrecht University, Heidelberglaan 100, 3584 CX, Utrecht, The Netherlands. suzannespijkers@outlook.com.
Insights
Whole-body MRI with diffusion-weighted imaging (DWI) shows excellent agreement with FDG-PET/CT for staging pediatric Hodgkin lymphoma. Adding DWI to MRI significantly improves staging accuracy, making it a valuable tool for initial assessment.
Area of Science:
- Radiology and Imaging
- Pediatric Oncology
- Nuclear Medicine
Background:
- Accurate initial staging is crucial for effective treatment of pediatric Hodgkin lymphoma (HL).
- FDG-PET/CT is the established reference standard for staging HL.
- Whole-body MRI (WB-MRI) is an emerging imaging modality for staging HL.
Purpose of the Study:
- To evaluate the concordance of WB-MRI with an FDG-PET/CT reference standard for initial staging of pediatric HL.
- To determine the added value of diffusion-weighted imaging (DWI) to WB-MRI for staging pediatric HL.
Main Methods:
- Prospective, multicentre international study including children with newly diagnosed HL.
- Patients underwent both WB-MRI and FDG-PET/CT for staging.
- Independent image evaluation by radiologists and a nuclear medicine physician, with discrepancies resolved by an expert panel.
Main Results:
- WB-MRI with DWI demonstrated excellent agreement (96%) with the FDG-PET/CT reference standard for disease staging, compared to 88% for WB-MRI without DWI.
- Agreement for nodal and extra-nodal staging was high (98% and 100%, respectively) between WB-MRI DWI and the reference standard.
- Good inter-observer agreement (κ = 0.74) was observed for disease stage using WB-MRI DWI.
Conclusions:
- WB-MRI with DWI shows excellent agreement with FDG-PET/CT for staging pediatric Hodgkin lymphoma.
- The inclusion of DWI in WB-MRI protocols enhances staging accuracy and concordance with the reference standard.
- WB-MRI DWI is a valuable tool for the initial staging of pediatric HL.
Objectives:
To assess the concordance of whole-body MRI (WB-MRI) and an FDG-PET/CT-based reference standard for the initial staging in children with Hodgkin lymphoma (HL) METHODS: Children with newly diagnosed HL were included in this prospective, multicentre, international study and underwent WB-MRI and FDG-PET/CT at staging. Two radiologists and a nuclear medicine physician independently evaluated all images. Discrepancies between WB-MRI and FDG-PET/CT were assessed by an expert panel. All FDG-PET/CT errors were corrected to derive the FDG-PET/CT-based reference standard. The expert panel corrected all reader errors in the WB-MRI DWI dataset to form the intrinsic MRI data. Inter-observer agreement for WB-MRI DWI was calculated using overall agreement, specific agreements and kappa statistics. Concordance for correct classification of all disease sites and disease stage between WB-MRI (without DWI, with DWI and intrinsic WB-MRI DWI) and the reference standard was calculated as primary outcome. Secondary outcomes included positive predictive value, negative predictive value and kappa statistics. Clustering within patients was accounted for using a mixed-effect logistic regression model with random intercepts and a multilevel kappa analysis.
Results:
Sixty-eight children were included. Inter-observer agreement between WB-MRI DWI readers was good for disease stage (κ = 0.74). WB-MRI DWI agreed with the FDG-PET/CT-based reference standard for determining disease stage in 96% of the patients versus 88% for WB-MRI without DWI. Agreement between WB-MRI DWI and the reference standard was excellent for both nodal (98%) and extra-nodal (100%) staging.
Conclusions:
WB-MRI DWI showed excellent agreement with the FDG-PET/CT-based reference standard. The addition of DWI to the WB-MRI protocol improved the staging agreement.
Key Points:
• This study showed excellent agreement between WB-MRI DWI and an FDG-PET/CT-based reference standard for staging paediatric HL. • Diffusion-weighted imaging is a useful addition to WB-MRI in staging paediatric HL. • Inter-observer agreement for WB-MRI DWI was good for both nodal and extra-nodal staging and determining disease stage.
