Whole-body MRI versus an [18F]FDG-PET/CT-based reference standard for early response assessment and restaging of paediatric Hodgkin’s lymphoma: a prospective multicentre study

Child; Diffusion magnetic resonance imaging; Whole-body imagingNiño; Imágenes por resonancia magnética de difusión; Imágenes de cuerpo enteroNen; Imatge per ressonància magnètica de difusió; Imatge de cos sencerObjectives To compare WB-MRI with an [18F]FDG-PET/CT-based reference for early response assessment and restaging in children with Hodgkin’s lymphoma (HL). Methods Fifty-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. Results Inter-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. Conclusions The 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.This project was financially supported by the Stichting Kinderen Kankervrij (KiKa, project number 87). The data collection, analysis and interpretation of data, the writing of the paper and the decision to submit were not influenced by KiKa

Whole-body MRI versus an [F-18]FDG-PET/CT-based reference standard for early response assessment and restaging of paediatric Hodgkin's lymphoma:a prospective multicentre study

Objectives To compare WB-MRI with an [F-18]FDG-PET/CT-based reference for early response assessment and restaging in children with Hodgkin's lymphoma (HL). Methods Fifty-one children (ages 10-17) with HL were included in this prospective, multicentre study. All participants underwent WB-MRI and [F-18]FDG-PET/CT at early response assessment. Thirteen of the 51 patients also underwent both WB-MRI and [F-18]FDG-PET/CT at restaging. Two radiologists independently evaluated all WB-MR images in two separate readings: without and with DWI. The [F-18]FDG-PET/CT examinations were evaluated by a nuclear medicine physician. An expert panel assessed all discrepancies between WB-MRI and [F-18]FDG-PET/CT to derive the [F-18]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. Results Inter-observer agreement of WB-MRI including DWI between both readers was moderate (kappa 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. Conclusions The addition of DWI to the WB-MRI protocol in early response assessment and restaging of paediatric HL improved agreement with the [F-18]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

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

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 (kappa= 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

Whole-body MRI in paediatric Hodgkin lymphoma

Lymphomas (lymph node cancer) are the third most common form of cancer in children. About a third of the lymphomas are Hodgkin lymphomas. Medical imaging plays an important role in determining disease progression (staging), assessment of response to therapy, and follow-up of children with Hodgkin lymphoma. Over the past few years, the use of imaging studies in Hodgkin lymphoma has shifted from Computed Tomography (CT) to the addition of Positron Emission Tomography (PET) and most recently, whole-body Magnetic Resonance Imaging (MRI). This thesis focuses on determining the diagnostic accuracy of whole-body MRI for staging, early assessment of response to therapy and assessment of remission at the end of therapy in children with Hodgkin lymphoma. In addition, normal values of lymph nodes in children are investigated. In summary, the studies show that data on the normal size of the lymph nodes by age is very important for a correct diagnosis of pathological lymph nodes. This is especially relevant in children. In addition, the studies presented in this thesis show that it is still challenging to determine the optimal role of whole-body MRI in imaging protocols for paediatric Hodgkin lymphoma. The results indicate that whole-body MRI is a very suitable radiation-free alternative to anatomical imaging by CT. In addition, this thesis shows that whole-body MRI can be a good alternative to FDG-PET/CT for the staging of Hodgkin lymphoma in children. Whole-body MRI (including visual assessment of DWI), however, did not correlate sufficiently with FDG-PET/CT for (early) response assessment

Measurements of cervical lymph nodes in children on computed tomography

Background: No normal measurements or specific size criteria have been described for cervical lymph nodes in children. Objective: To determine the normal measurements of cervical lymph nodes in children on CT. Materials and methods: We included 142 children (ages 1–17 years) who underwent cervical CT examination after high-energy trauma. We evaluated axial and coronal 2-mm reconstructions for lymph nodes at six cervical levels. For the largest lymph node at each level, we measured diameters in both the long and short axial axes and the long coronal axis. Results: A total of 733 lymph nodes were measured in 142 children (62% boys, 38% girls). The greatest measured diameters were 14 mm for the short axis in the axial plane, 24 mm for the long axis in the axial plane and 28 mm for the long axis in the coronal plane. The Pearson correlation coefficient for age and lymph node size at Levels IV–VI was in the range of 0.19–0.47. Conclusion: Lymph nodes with an axial short-axis diameter exceeding 15 mm for Level II and 10 mm for all other cervical levels are uncommon in otherwise healthy children

Fresh and Frozen-Thawed Embryo Transfer Compared to Natural Conception: Differences in Perinatal Outcome

Background/Aim: To compare the pregnancy outcome of singletons conceived after transfer of cryopreserved and thawed embryos (frozen embryo transfer [FET]) to singletons conceived after fresh embryo transfer (fresh ET) and natural conceived singletons. Methods: Using a retrospective data analysis on a study population consisting of 1,261 singletons born after FET and 2,519 singletons born after fresh ET between 2006 and 2015. The control group consisted of singletons born after natural conception. Main outcome measures consisted of birth weight (in grams), gestational age, preterm birth (<37 weeks of gestation), being large for gestational age (LGA, above 90th weight percentile adjusted for gestational age) and Apgar scores. Results: Babies born after FET had an increased risk of high birth weight (adjusted OR [AOR]) 2.92; 1.503-3.482) and being LGA (AOR fresh ET vs. FET 1.47; 1.210-1.787) compared to singletons born after fresh ET, as well as higher birth weights compared to natural conceived children. Conclusions: Singletons born after FET have a higher risk of high birth weight and being LGA compared to singletons after fresh ET and compared to natural conceived singletons. We assume that the freezing process might be the underlying cause

Mentoring in radiology: An asset worth exploring!

Residents experience high pressure to be successful in both their career and in keeping up an optimal work-life balance. With a mentoring program, faculties can alleviate stress and provide help for their residents. It is now well established that mentor-mentee relationships during medical school, have influence in career decisions and professional identity formation. The same can be said for mentor-mentee relationships during radiology residency. In general, universal rules of mentoring are also useful and applicable in the field of radiology. These universal rules for establishing a successful mentoring relationship include creating a relationship of trust and confidentiality, clearly defining roles and responsibilities, establishing short- and long-term goals, using open and supportive communication, and collaboratively solving problems. The institutions and the radiology departments should be well prepared and aware of the responsibility to have trainees, providing time for mentors to dedicate to their academic duties. They have to implement strategies to effective mentor matching and orientation as well as the ability to provide evaluation with qualitative feedback. Periodic assessment should be warranted together with the incorporation of new technology as it plays a critical role in the training of millennial radiologists as they take the profession into a technology-laden future of medical imaging

Imaging features of extranodal involvement in paediatric Hodgkin lymphoma

Detecting extranodal disease in paediatric Hodgkin lymphoma is of great importance for both treatment and prognosis. Different imaging techniques can be used to identify these extranodal sites. This pictorial essay provides an overview of imaging features of extranodal disease manifestation in paediatric Hodgkin lymphoma

Fused high b-value diffusion weighted and T2-weighted MR images in staging of pediatric Hodgkin's lymphoma : A pilot study

Purpose: To evaluate the value of fused high b-value diffusion weighted and T2-weighted MRI compared to T1-weighted imaging, T2-weighted imaging and DWI for staging pediatric Hodgkin's lymphoma. Method: 21 consecutive pediatric patients who underwent whole-body MRI at Hodgkin's lymphoma staging were included. Fused, colorized DWI/T2-weighted images were created. Image sets consisting of (a) T1-weighted, T2-weighted and DWI images and (b) T1-weighted, T2-weighted, DWI and DWI/T2-weighted fused images were reviewed by a radiologist using a cross-over design with blinding and randomization. Scoring was performed using a standardized form, based on detection, characterization and reading time, using a FDG-PET/CT based reference standard. Test characteristics, test agreement to a FDG-PET/CT based reference standard and reading times were calculated. Results: Agreement for whole-body MRI without fused images and FDG-PET/CT was very good for nodal staging (κ = 0.86, 95% CI 0.78-0.93) and extra-nodal staging (κ = 0.90, 95% CI 0.71–1.09). Agreement improved with the addition of the fused DWI/T2-weighted images (κ = 0.92 95% CI 0.87-0.97 (nodal staging), κ = 0.92 95% CI 0.76–1.08 (extra-nodal staging). Sensitivity and specificity for staging nodal disease were 99 % and 95% respectively for whole-body MRI including DWI/T2-weighted fused images (versus 88 % and 97 % without fused images) and 100 % and 99 % for extra-nodal disease (83 % and 100 % without fused images). Disease stage for MRI including fused DWI/T2-weighted images agreed with the reference standard in 18 out of 21 patients. Conclusions: The addition of DWI/T2-weighted fusion images to T1-weighted, T2-weighted and DWI whole-body MRI might shorten reading times and might improve the diagnostic performance of whole-body MRI in staging pediatric Hodgkin's lymphoma