Pediatric high-grade glioma (pedHGG) can occur as first manifestation of cancer predisposition syndromes resulting from pathogenic germline variants in the DNA mismatch repair (MMR) genes MSH2, MSH6, MLH1, and PMS2. The aim of this study was to establish a generalized screening for Lynch syndrome and constitutional MMR deficiency (CMMRD) in pedHGG patients, as the detection of MMR deficiencies (MMRD) may enable the upfront therapeutic use of checkpoint inhibitors and identification of variant carriers in the patients' families. We prospectively enrolled 155 centrally reviewed primary pedHGG patients for MMR-immunohistochemistry (IHC) as part of the HIT-HGG-2013 trial protocol. MMR-IHC results were subsequently compared to independently collected germline sequencing data (whole exome sequencing or pan-cancer DNA panel next-generation sequencing) available in the HIT-HGG-2013, INFORM, and MNP2.0 trials. MMR-IHC could be successfully performed in 127/155 tumor tissues. The screening identified all present cases with Lynch syndrome or CMMRD (5.5%). In addition, MMR-IHC also detected cases with exclusive somatic MMR gene alterations (2.3%), including MSH2 hypermethylation as an alternative epigenetic silencing mechanism. Most of the identified pedHGG MMRD patients had no family history of MMRD, and thus, they represented index patients in their families. Cases with regular protein expression in MMR-IHC never showed evidence for MMRD in DNA sequencing. In conclusion, MMR-IHC presents a cost-effective, relatively widely available, and fast screening method for germline MMRD in pedHGG with high sensitivity (100%) and specificity (96%). Given the relatively high prevalence of previously undetected MMRD cases among pedHGG patients, we strongly recommend incorporating MMR-IHC into routine diagnostics.

Diffuse pediatric-type high-grade gliomas (pedHGG), H3- and IDH-wildtype, encompass three main DNA-methylation-based subtypes: pedHGG-MYCN, pedHGG-RTK1A/B/C, and pedHGG-RTK2A/B. Since their first description in 2017 tumors of pedHGG-RTK2A/B have not been comprehensively characterized and clinical correlates remain elusive. In a recent series of pedHGG with a Gliomatosis cerebri (GC) growth pattern, an increased incidence of pedHGG-RTK2A/B (n = 18) was observed. We added 14 epigenetically defined pedHGG-RTK2A/B tumors to this GC series and provided centrally reviewed radiological, histological, and molecular characterization. The final cohort of 32 pedHGG-RTK2A/B tumors consisted of 25 pedHGG-RTK2A (78

Background:Our aim is to investigate the association of treatment with survival in patients with diffuse intrinsic pontine glioma (DIPG) by examining 6 historical treatment paths. Methods:We retrospectively analyzed data from 409 patients with radiologically centrally reviewed DIPG, sourced from the German Society of Pediatric Oncology and Hematology HIT-HGG trial database and the SIOPE-DIPG/DMG Registry. Survival outcomes were estimated using the Kaplan-Meier method, and univariable and multivariable Cox proportional hazard models were estimated to study treatment effects. Results:The median overall survival (OS) from diagnosis was 11.2 months (95% confidence interval [CI], 10.5-11.9). Patients who by choice received no frontline treatment had an OS of 3.0 months (95% CI, 2.0-4.0), while those treated with radiation therapy (RT) alone had a median OS of 10.4 months (95% CI, 9.1-11.8). Those receiving RT combined with chemotherapy had the longest median OS of 11.7 months (95% CI, 10.8-12.6). The median post-progression survival (PPS) was 4.1 months (95% CI, 3.5-4.7). Patients who relapsed and did not receive treatment had a PPS of 2.2 months (95% CI, 1.8-2.6), while those treated with chemotherapy alone had a PPS of 4.4 months (95% CI, 3.7-5.0), and those who underwent reirradiation, with or without chemotherapy, had the longest survival after relapse of 6.6 months (95% CI, 5.3-8.0). Treatment differences remained significant in multivariable analysis adjusted for age and symptom duration in both diagnosis and relapse setting. Conclusions:This study shows increased survival outcomes associated with radiation and chemotherapy treatment or a combination thereof, at diagnosis and relapse, in a historical DIPG cohort.

BACKGROUND:The term gliomatosis cerebri (GC), a radiology-defined highly infiltrating diffuse glioma, has been abandoned since molecular GC-associated features could not be established. METHODS:We conducted a multinational retrospective study of 104 children and adolescents with GC providing comprehensive clinical and (epi-)genetic characterization. RESULTS:Median overall survival (OS) was 15.5 months (interquartile range, 10.9-27.7) with a 2-year survival rate of 28%. Histopathological grading correlated significantly with median OS: CNS WHO grade II: 47.8 months (25.2-55.7); grade III: 15.9 months (11.4-26.3); grade IV: 10.4 months (8.8-14.4). By DNA methylation profiling (n = 49), most tumors were classified as pediatric-type diffuse high-grade glioma (pedHGG), H3-/IDH-wild-type (n = 31/49, 63.3%) with enriched subclasses pedHGG_RTK2 (n = 19), pedHGG_A/B (n = 6), and pedHGG_MYCN (n = 5), but only one pedHGG_RTK1 case. Within the pedHGG, H3-/IDH-wild-type subgroup, recurrent alterations in EGFR (n = 10) and BCOR (n = 9) were identified. Additionally, we observed structural aberrations in chromosome 6 in 16/49 tumors (32.7%) across tumor types. In the pedHGG, H3-/IDH-wild-type subgroup TP53 alterations had a significant negative effect on OS. CONCLUSIONS:Contrary to previous studies, our representative pediatric GC study provides evidence that GC has a strong predilection to arise on the background of specific molecular features (especially pedHGG_RTK2, pedHGG_A/B, EGFR and BCOR mutations, chromosome 6 rearrangements).

Abstract BACKGROUND We aimed to assess frequency, patterns and potential prognostic impact of initial and early dissemination in pediatric patients with diffuse intrinsic pontine glioma (DIPG) and diffuse midline glioma, H3K27-altered (DMG). METHODS 199 patients (age, 0-18 years) with DIPG/DMG and positive CSF cytology and/or metastases on MRI at diagnosis (Types 1-3) were identified within the SIOPE and International DIPG/DMG Registries. Data on metastatic first progression (PD) in DIPG/DMG (Type 4) were analyzed from the HIT-HGG-2007/2013 trials. RESULTS Dissemination at diagnosis was present in 5% of patients with DIPG/DMG (16.9% in non-pontine DMG). For all 199 patients with initially disseminated pontine (n=166) and non-pontine DMG (n=33), median overall survival (OS) was 10±0.5 months and progression-free survival (PFS) was 6.6±0.2 months. Tumor cells in the CSF without metastases on initial MRI (Type 1) were detected in 12 patients. Four patients had no primary tumor but primary extensive leptomeningeal dissemination resembling diffuse leptomeningeal glioneuronal tumor, molecularly confirmed as DMG, with aggressive course (Type 2). 183 DIPG/DMG patients were identified with primary tumor and metastases on MRI at diagnosis (Type 3). OS and PFS was superior in patients receiving additional treatment to radiotherapy (n=124), without significant differences between focal and craniospinal irradiation. Metastatic spread at first progression (Type 4) occurred in 32.1% (65.3% in non-pontine DMG) of 224 HIT-HGG patients with DMG and recorded PD. OS of patients with metastatic PD was inferior to local PD (median, 10.8±0.9 vs. 13.3±0.9 months, p=0.005), as was post-progression survival (median, 3.1±0.4 vs. 5.2±0.5 months, p=0.003). CONCLUSIONS We observed a propensity for early dissemination in (especially non-pontine) DMG. While additional treatment beyond radiotherapy seems beneficial, preventing dissemination at progression (e.g., by upfront CSI) may help to prolong survival of patients with DMG and possibly provide options for further therapy.

Abstract Gliomatosis cerebri (GC), a radiologically defined highly infiltrating supratentorial glioma, is no longer considered a distinct entity since the 2016 WHO classification for tumors of the central nervous system (CNS). So far, neither prognostic factors, nor molecular GC-associated features have been established. We conducted a multinational retrospective study of 104 children and adolescents with GC providing comprehensive radiological, clinical and (epi-)genetic characterization. Within a median follow-up of 15.5 months (range, 2.3–138.8), 93 patients (89.4%) had died, four (3.8%) were lost to follow-up and seven (6.8%) were alive with stable/progressive disease. Median progression-free- (PFS) and overall survival (OS) were 8.6 months (interquartile range, 4.3–14.0) and 15.5 months (10.9–27.7), respectively. Available histopathological grading correlated significantly with median OS: CNS-WHO grade II: 47.8 months (25.2–55.7); grade III: 15.9 months (11.4–26.3); grade IV: 10.4 months (8.8–14.4). In GC with high-grade features, radiochemotherapy achieved longest PFS (median 9.6 months [5.7–14.0]). According to methylation profiling [n=49] and exome-sequencing [n=45], most cases were considered as IDH-/H3-wildtype gliomas (n=32/52, 61.5%) enriched with the subclasses pedHGG_RTK2A/B (n=19), pedHGG_A/B (n=6) and pedHGG_MYCN (n=5), but exhibited only one pedHGG_RTK1A/B/C case. Within the IDH-/H3-wildtype gliomas, EGFR-alterations were most common (n=10). Expected genetic alterations of unselected hemispheric pedHGG affecting CDKN2A/B, ATRX or PDGFRA were virtually absent. Additionally, we observed structural aberrations in chromosome 6 comprising complex genomic rearrangements, large areas of loss, or even gain/amplification at similar breakpoints in 16/49 cases (32.7%). We assembled the largest pediatric GC cohort providing evidence that GC may have a strong predilection to arise on the background of specific molecular features (pedHGG_RTK2A/B, pedHGG_A/B and pedHGG_MYCN; EGFR- and chromosome 6-alterations). Taken together, these findings expand on the current understanding of GC and provide insight into disease biology of extensively infiltrating gliomas in children.

Supplementary Methods and Materials, Tables 1-3 from A Functional Polymorphism in the NAD(P)H Oxidase Subunit CYBA Is Related to Gene Expression, Enzyme Activity, and Outcome in Non–Hodgkin Lymphoma

Abstract The aim of the HIT-HGG-2007 trial (ISRCTN19852453) was to demonstrate therapeutic non-inferiority of temozolomide radiochemotherapy for pediatric patients (3-18 years) with high-grade gliomas (pedHGG) in comparison to the cisplatinum-based radiochemotherapy of the two previous clinical trials HIT-GBM-C/-D. Between 06/2009 and 12/2016, 456 patients were enrolled at 79 centers in Germany, Austria, and Switzerland (n=18 dropouts, remaining patients for confirmatory analysis: n=438). 438 patients from HIT-GBM-C/-D served as historical control. All pedHGG diagnoses had been confirmed by central neuroradiological and neuropathological review. Primary objective was achieved since non-inferiority of HIT-HGG-2007 in comparison to HIT-GBM-C/-D as indicated by 6 months event-free survival (EFS) was statistically confirmed (p=0.0125). Statistical survival analyses even revealed a better overall survival (OS) and EFS for HIT-HGG-2007 patients in comparison to their HIT-GBM-C/-D counterparts (EFS: p<0.0001; OS: p=0.0328). While EFS subgroup analyses for pontine and non-pontine pedHGG also showed a better survival of HIT-HGG-2007 patients (median EFS pontine pedHGG: 8.2 (n=152; confidence interval (CI): 7.6-9.4) versus 6.2 (n=170; CI: 5.5-6.9) months, p=0.0079; median EFS non-pontine pedHGG: 10.7 (n=276; CI: 9.6-12.4) versus 7.4 (n=267; CI: 6.4-9.2) months, p<0.0001), OS was only improved in HIT-HGG-2007 patients with non-pontine pedHGG (median OS non-pontine pedHGG: 19.3 (CI: 16.8-23.3) versus 16.2 (CI: 14.2-19.1) months; p=0.0181) but not with pontine pedHGG (median OS pontine pedHGG: 11.4 months versus 11.3 months, p=0.4021) Toxicity profile of HIT-HGG-2007 seemed very favorable with most CTCAE (common toxicity criteria adverse event) ≥ grade 3 as hematological toxicity, hepatotoxicity, and neurotoxicity. Less toxicity was observed during concomitant radiochemotherapy in comparison to HIT-GBM-C/-D. Further subgroup survival analyses as well as the assessment of the impact of MGMT promoter methylation are ongoing. In conclusion, our data show non-inferiority of the HIT-HGG-2007 trial with increased survival and less toxicity when compared with previous trials HIT-GBM-C/-D.

Abstract Purpose The techniques used previously to assess intracapsular pressures did not allow the assessment of pressure variations in both compartments throughout the entire range of motion without puncturing the capsular tissue. Our hypothesis was that the intra-capsular pressure would be different in the lateral and acetabular compartment depending on the movement assessed. Methods Eight hip joints from four cadaveric specimens (78.5 ± 7.9 years) were assessed using intra-osseous tunnels reaching the lateral and acetabular compartments. Using injector adaptors, 2.7 ml of liquid were inserted in both compartments to simulate synovial liquid. Optic pressure transducers were used to measure pressure variations. We manually performed hip adduction, abduction, extension, flexion and internal rotation at 90° of flexion. Results Hip extension and internal rotation show the highest intra-capsular pressures in the lateral compartment with increases of 20.56 ± 19.29 and 19.27 ± 18.96 mmHg, respectively. Hip abduction and hip internal rotation showed depressurisations of − 16.86 ± 18.01 and − 31.88 ± 30.71 mmHg in the acetabular compartment, respectively. The pressures measured in the lateral compartment and in the acetabular compartment were significantly (P < 0.05) different for the hip abduction, 90° of flexion and internal rotation. Pressure variations showed that maximum intracapsular fluid pressures in the lateral compartment occur at maximum range of motion for all movements. Conclusion As an increase in pressure may produce hip pain, clinician should assess pain at maximum range of motion in the lateral compartment. The pressure measured in the acetabular compartment vary depending on the hip position. The movements assessed are used in clinical practice to evaluate hip integrity and might bring pain. The pressure variations throughout the entire range of motion are a relevant information during hip clinical assessment and might help clinicians to better understand the manifestations of pain.

BACKGROUND: Gliomatosis cerebri (GC), a radiologically defined diffusely infiltrating glioma, is no longer considered a distinct entity since the 2016 WHO classification for tumors of the CNS. Due to its rarity and dismal prognosis treatment recommendations in children remain ambiguous. Using central neuroradiological review, we performed a multi-institutional, retrospective study of GC providing comprehensive radiological, clinical, and (epi)genetic characterization. RESULTS: We included 104 patients between 1-19 years. Within a median follow-up of 15.5 months (range, 2.3-138.8), 93 patients (89.4 %) had died, 4 (3.8 %) were lost to follow-up and 7 (6.8 %) were alive with stable/progressive disease. Median progression-free- (PFS) and overall survival (OS) were 8.6 months (interquartile range, 4.3-14.0) and 15.5 months (10.9-27.7), respectively. Former WHO grading correlated significantly with median OS: WHO °II: 47.8 months (25.2-55.7); WHO °III: 15.9 months (11.4-26.3); WHO °IV: 10.4 months (8.8-14.4) (p<0.001). In high-grade gliomas (HGG), radiochemotherapy showed best PFS (p=0.002). Compared to hemispheric pediatric non-GC HGG, GC phenotype was associated with decreased OS (p=0.001). Methylation-based classification and exome sequencing were possible for 49 and 45 patients, respectively. According to the 2021 WHO classification, most cases were considered as IDH-/H3-wildtype gliomas (n=37/49, 75.5 %), mostly with a pedRTK2 subtype (n=15, 30.6%), followed by pedMYCN (n=5, 10.2 %). Within the IDH-/H3-wildtype gliomas, EGFR-altered tumors (n=10) seemed overrepresented. Survival analyses revealed a better OS for IDH1-mutant tumors (n=6; 54.6 vs. 15.2 months in IDH-wildtype; p=0.015) and a worse OS for TP53-mutant tumors (n=6; p=0.001). Despite the potential overrepresentation of EGFR-altered tumors, no other specific molecular markers for GC could be identified so far. Further analyses are ongoing. CONCLUSIONS: GC in children is confirmed as a poor prognostic phenotype include various epigenetic pediatric glioma subtypes, without a proven (epi)genetic mark of its own. The relevance of overrepresented EGFR alterations has to be determined yet.

Background: Moment arms are an indicator of the role of the muscles in joint actuation. An excursion method is often used to calculate them, even though it provides 1D results. As shoulder movement occurs in three dimensions (combination of flexion, abduction and axial rotation), moment arms should be given in 3D. Our objective was to assess the 3D moment arms of the rotator cuff (infraspinatus and teres minor) and deltoid muscles for movements with high arm elevation. Methods: The 3D moment arms (components in plane of elevation, elevation and axial rotation) were assessed using a geometric method, enabling to calculate the moment arms in 3D, on five fresh post-mortem human shoulders. Movement with high range of motion were performed (including overhead movement). The humerus was elevated until it reaches its maximal posture in different elevation plane (flexion, scaption, abduction and elevation in a plane 30 degrees posterior to frontal plane). Findings: We found that the anterior deltoid was a depressor and contributes to move the elevation plane anteriorly. The median deltoid was a great elevator and the posterior deltoid mostly acted in moving the elevation plane posteriorly. The infraspinatus and teres minor were the greatest external rotator of the shoulder. The position of the glenohumeral joint induces changes in the muscular moment arms. The maximal shoulder elevation was 144 degrees (performed in the scapular plane). Interpretation: The knowledge of 3D moment arms for different arm elevations might help surgeons in planning tendon reconstructive surgery and help validate musculoskeletal models.

Background Flexion-Abduction-External-Rotation and Flexion-Adduction-Internal-Rotation tests are used to reproduce pain at the hip during clinical assessment. As pain can be elicited by high intracapsular pressure, no information has been provided regarding intracapsular pressure during these pain provocative tests. Methods Eight hip joints from four cadaveric specimens (78.5 +/- 7.9 years) were assessed using intra-osseous tunnels reaching the lateral and acetabular compartments. To simulate synovial liquid, 2.7 ml of liquid were inserted in both compartments using adaptor injectors. Optic pressure transducers were used to measure pressure variations. Pressures were compared between compartments in each test and between tests for each compartment. Both tests were compared with uniplanar movements. Findings The Flexion-Adduction-Internal-Rotation test showed a significant difference between pressure measured in the lateral (27.17 +/- 42.63 mmHg) and acetabular compartment (-26.80 +/- 29.26 mmHg) (P < 0.006). The pressure measured in the lateral compartment during the Flexion-Adduction-Internal-Rotation test (27.17 +/- 42.63 mmHg) was significantly higher than in the Flexion-Abduction-External-Rotation test (-8.09 +/- 15.09 mmHg) (P < 0.010). The pressure measured in the lateral compartment in the Flexion-Abduction-ExternalRotation test was significantly lower than during internal rotation (P = 0.011) and extension (P = 0.006). Interpretation High intracapsular pressure is correlated with greater pain at the hip. Clinicians should assess pain with caution during the Flexion-Adduction-Internal-Rotation test as this test showed high intracapsular pressures in the lateral compartment. The Flexion-Abduction-External-Rotation is not influenced by high intra-capsular pressures.

Purpose Recent research identified histone H3 K27M mutations to be associated with a dismal prognosis in pediatric diffuse midline glioma (pDMG); however, data on detailed MRI characteristics with respect to H3 K27 mutation status and molecular subgroups (H3.1 and H3.3 K27M mutations) are limited. Methods Standardized magnetic resonance imaging (MRI) parameters and epidemiologic data of 68 pDMG patients (age <18 years) were retrospectively reviewed and compared in a) H3 K27M mutant versus H3 K27 wildtype (WT) tumors and b) H3.1 versus H3.3 K27M mutant tumors. Results Intracranial gliomas (n = 58) showed heterogeneous phenotypes with isointense to hyperintense signal in T2-weighted images and frequent contrast enhancement. Hemorrhage and necrosis may be present. Comparing H3 K27M mutant to WT tumors, there were significant differences in the following parameters: i) tumor localization (p = 0.001), ii) T2 signal intensity (p = 0.021), and iii) T1 signal homogeneity (p = 0.02). No significant imaging differences were found in any parameter between H3.1 and H3.3 K27M mutant tumors; however, H3.1 mutant tumors occurred at a younger age (p = 0.004). Considering spinal gliomas (n = 10) there were no significant imaging differences between the analyzed molecular groups. Conclusion With this study, we are the first to provide detailed MR imaging data on H3 K27M mutant pDMG with respect to molecular subgroup status in a large patient cohort. Our findings may support diagnosis and future targeted therapeutic trials of pDMG within the framework of the radiogenomics concept.

Accurate muscle geometry is essential to estimate moment arms in musculoskeletal models. Given the complex interactions between shoulder structures, we hypothesized that finite element (FE) modelling is suitable to obtain physiological muscle trajectory. A FE glenohumeral joint model was developed based on medical imaging. Moment arms were computed and compared to literature and MRI-based estimation. Our FE model produces moment arms consistent with the literature and with MRI data (max 17 mm differences). The inferior and superior fibres of a same muscle can have opposite action; predictions of moment arms are sensitive to muscle insertion (up to 20 mm variation).

Experimental data enabling to validate musculoskeletal models are essential to ensure a physiological behaviour with an accurate prediction of muscle parameters like muscle trajectory. Some musculo...

As the efficacy of all pediatric high-grade glioma (HGG) treatments is similar and still disappointing, it is essential to also investigate the toxicity of available treatments.