Dataset Information

Whole-body MRI versus an FDG-PET/CT-based reference standard for staging of paediatric Hodgkin lymphoma: a prospective multicentre study.

ABSTRACT:

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 (? = 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.

SUBMITTER: Spijkers S

PROVIDER: S-EPMC7880958 | biostudies-literature | 2021 Mar

REPOSITORIES: biostudies-literature

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Publications

Whole-body MRI versus an FDG-PET/CT-based reference standard for staging of paediatric Hodgkin lymphoma: a prospective multicentre study.

Spijkers Suzanne S Littooij Annemieke S AS Kwee Thomas C TC Tolboom Nelleke N Beishuizen Auke A Bruin Marrie C A MCA Elias Sjoerd G SG van de Brug Tim T Enríquez Goya G Sábado Constantino C Miller Elka E Granata Claudio C de Lange Charlotte C Verzegnassi Federico F Greer Mary-Louise C MC de Keizer Bart B Nievelstein Rutger A J RAJ

European radiology 20200903 3

<h4>Objectives</h4>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. ...[more]

PMID: 32880696

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Project description:ObjectivesTo prospectively investigate concordance between whole-body MRI (WB-MRI) and a composite reference standard for initial staging and interim response evaluation in paediatric and adolescent Hodgkin's lymphoma.MethodsFifty patients (32 male, age range 6-19 years) underwent WB-MRI and standard investigations, including 18F-FDG-PET-CT at diagnosis and following 2-3 chemotherapy cycles. Two radiologists in consensus interpreted WB-MRI using prespecified definitions of disease positivity. A third radiologist reviewed a subset of staging WB-MRIs (n = 38) separately to test for interobserver agreement. A multidisciplinary team derived a primary reference standard using all available imaging/clinical investigations. Subsequently, a second multidisciplinary panel rereviewed all imaging with long-term follow-up data to derive an enhanced reference standard. Interobserver agreement for WB-MRI reads was tested using kappa statistics. Concordance for correct classification of all disease sites, true positive rate (TPR), false positive rate (FPR) and kappa for staging/response agreement were calculated for WB-MRI.ResultsThere was discordance for full stage in 74% (95% CI 61.9-83.9%) and 44% (32.0-56.6%) of patients against the primary and enhanced reference standards, respectively. Against the enhanced reference standard, the WB-MRI TPR, FPR and kappa were 91%, 1% and 0.93 (0.90-0.96) for nodal disease and 79%, < 1% and 0.86 (0.77-0.95) for extra-nodal disease. WB-MRI response classification was correct in 25/38 evaluable patients (66%), underestimating response in 26% (kappa 0.30, 95% CI 0.04-0.57). There was a good agreement for nodal (kappa 0.78, 95% CI 0.73-0.84) and extra-nodal staging (kappa 0.60, 95% CI 0.41-0.78) between WB-MRI reads CONCLUSIONS: WB-MRI has reasonable accuracy for nodal and extra-nodal staging but is discordant with standard imaging in a substantial minority of patients, and tends to underestimate disease response.Key points• This prospective single-centre study showed discordance for full patient staging of 44% between WB-MRI and a multi-modality reference standard in paediatric and adolescent Hodgkin's lymphoma. • WB-MRI underestimates interim disease response in paediatric and adolescent Hodgkin's lymphoma. • WB-MRI shows promise in paediatric and adolescent Hodgkin's lymphoma but currently cannot replace conventional staging pathways including 18F-FDG-PET-CT.

Project description:ObjectivesTo compare WB-MRI with an [18F]FDG-PET/CT-based reference for early response assessment and restaging in children with Hodgkin's lymphoma (HL).MethodsFifty-one children (ages 10-17) with HL were included in this prospective, multicentre study. All participants underwent WB-MRI and [18F]FDG-PET/CT at early response assessment. Thirteen of the 51 patients also underwent both WB-MRI and [18F]FDG-PET/CT at restaging. Two radiologists independently evaluated all WB-MR images in two separate readings: without and with DWI. The [18F]FDG-PET/CT examinations were evaluated by a nuclear medicine physician. An expert panel assessed all discrepancies between WB-MRI and [18F]FDG-PET/CT to derive the [18F]FDG-PET/CT-based reference standard. Inter-observer agreement for WB-MRI was calculated using kappa statistics. Concordance, PPV, NPV, sensitivity and specificity for a correct assessment of the response between WB-MRI and the reference standard were calculated for both nodal and extra-nodal disease presence and total response evaluation.ResultsInter-observer agreement of WB-MRI including DWI between both readers was moderate (κ 0.46-0.60). For early response assessment, WB-MRI DWI agreed with the reference standard in 33/51 patients (65%, 95% CI 51-77%) versus 15/51 (29%, 95% CI 19-43%) for WB-MRI without DWI. For restaging, WB-MRI including DWI agreed with the reference standard in 9/13 patients (69%, 95% CI 42-87%) versus 5/13 patients (38%, 95% CI 18-64%) for WB-MRI without DWI.ConclusionsThe addition of DWI to the WB-MRI protocol in early response assessment and restaging of paediatric HL improved agreement with the [18F]FDG-PET/CT-based reference standard. However, WB-MRI remained discordant in 30% of the patients compared to standard imaging for assessing residual disease presence.Key points• Inter-observer agreement of WB-MRI including DWI between both readers was moderate for (early) response assessment of paediatric Hodgkin's lymphoma. • The addition of DWI to the WB-MRI protocol in early response assessment and restaging of paediatric Hodgkin's lymphoma improved agreement with the [18F]FDG-PET/CT-based reference standard. • WB-MRI including DWI agreed with the reference standard in respectively 65% and 69% of the patients for early response assessment and restaging.

Project description:PurposeTo investigate the possibility of reducing the injected activity for whole-body [18F]FDG-PET/CT studies of paediatric oncology patients and to assess the usefulness of time-of-flight (TOF) acquisition on PET image quality at reduced count levels.ProceduresTwenty-nine paediatric oncology patients (12F/17M, 3-18 years old (median age 13y), weight 45±20 kg, BMI 19±4 kg/m2), who underwent routine whole-body PET/CT examinations on a Siemens Biograph mCT TrueV system with TOF capability (555ps) were included in this study. The mean injected activity was 156 ± 45 MBq (3.8 ± 0.8 kg/MBq) and scaled to patient weight. The raw data was collected in listmode (LM) format and pre-processed to simulate reduced levels of [18F]FDG activity (75, 50, 35, 20 and 10% of the original counts) by randomly removing events from the original LM data. All data were reconstructed using the vendor-specific e7-tools with standard OSEM only, with OSEM plus resolution recovery (PSF). The reconstructions were repeated with added TOF (TOF) and PSF+TOF. The benefit of TOF together with the reduced count levels was evaluated by calculating the gains in signal-to-noise ratio (SNR) in the liver and contrast-to-noise ratio (CNR) in all PET-positive lesions before and after TOF employed at every simulated reduced count level. Finally, the PSF+TOF images at 50, 75 and 100% of counts were evaluated clinically on a 5-point scale by three nuclear medicine physicians.ResultsThe visual inspection of the reconstructed images did not reveal significant differences in image quality between 75 and 100% count levels for PSF+TOF. The improvements in SNR and CNR were the greatest for TOF reconstruction and PSF combined. Both SNR and CNR gains did increase linearly with the patients BMI for both OSEM only and PSF reconstruction. These benefits were observed until reducing the counts to 50 and 35% for SNR and CNR, respectively.ConclusionsThe benefit of using TOF was noticeable when using 50% or greater of the counts when evaluating the CNR and SNR. For [18F]FDG-PET/CT, whole-body paediatric imaging the injected activity can be reduced to 75% of the original dose without compromising PET image quality.

Dataset Information

Whole-body MRI versus an FDG-PET/CT-based reference standard for staging of paediatric Hodgkin lymphoma: a prospective multicentre study.

Objectives

Results

Conclusions

Key points

Publications

Whole-body MRI versus an FDG-PET/CT-based reference standard for staging of paediatric Hodgkin lymphoma: a prospective multicentre study.

Similar Datasets

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