Noise suppression of proton magnetic resonance spectroscopy improves paediatric brain tumour classification.

Proton magnetic resonance spectroscopy (1H-MRS) is increasingly used for clinical brain tumour diagnosis, but suffers from limited spectral quality. This retrospective and comparative study aims at improving paediatric brain tumour classification by performing noise suppression on clinical 1H-MRS. Eighty-three/forty-two children with either an ependymoma (ages 4.6 ± 5.3/9.3 ± 5.4), a medulloblastoma (ages 6.9 ± 3.5/6.5 ± 4.4), or a pilocytic astrocytoma (8.0 ± 3.6/6.3 ± 5.0), recruited from four centres across England, were scanned with 1.5T/3T short-echo-time point-resolved spectroscopy. The acquired raw 1H-MRS was quantified by using Totally Automatic Robust Quantitation in NMR (TARQUIN), assessed by experienced spectroscopists, and processed with adaptive wavelet noise suppression (AWNS). Metabolite concentrations were extracted as features, selected based on multiclass receiver operating characteristics, and finally used for identifying brain tumour types with supervised machine learning. The minority class was oversampled through the synthetic minority oversampling technique for comparison purposes. Post-noise-suppression 1H-MRS showed significantly elevated signal-to-noise ratios (P < .05, Wilcoxon signed-rank test), stable full width at half-maximum (P > .05, Wilcoxon signed-rank test), and significantly higher classification accuracy (P < .05, Wilcoxon signed-rank test). Specifically, the cross-validated overall and balanced classification accuracies can be improved from 81% to 88% overall and 76% to 86% balanced for the 1.5T cohort, whilst for the 3T cohort they can be improved from 62% to 76% overall and 46% to 56%, by applying Naïve Bayes on the oversampled 1H-MRS. The study shows that fitting-based signal-to-noise ratios of clinical 1H-MRS can be significantly improved by using AWNS with insignificantly altered line width, and the post-noise-suppression 1H-MRS may have better diagnostic performance for paediatric brain tumours.

Characterisation of paediatric brain tumours by their MRS metabolite profiles.

1H-magnetic resonance spectroscopy (MRS) has the potential to improve the noninvasive diagnostic accuracy for paediatric brain tumours. However, studies analysing large, comprehensive, multicentre datasets are lacking, hindering translation to widespread clinical practice. Single-voxel MRS (point-resolved single-voxel spectroscopy sequence, 1.5 T: echo time [TE] 23-37 ms/135-144 ms, repetition time [TR] 1500 ms; 3 T: TE 37-41 ms/135-144 ms, TR 2000 ms) was performed from 2003 to 2012 during routine magnetic resonance imaging for a suspected brain tumour on 340 children from five hospitals with 464 spectra being available for analysis and 281 meeting quality control. Mean spectra were generated for 13 tumour types. Mann-Whitney U-tests and Kruskal-Wallis tests were used to compare mean metabolite concentrations. Receiver operator characteristic curves were used to determine the potential for individual metabolites to discriminate between specific tumour types. Principal component analysis followed by linear discriminant analysis was used to construct a classifier to discriminate the three main central nervous system tumour types in paediatrics. Mean concentrations of metabolites were shown to differ significantly between tumour types. Large variability existed across each tumour type, but individual metabolites were able to aid discrimination between some tumour types of importance. Complete metabolite profiles were found to be strongly characteristic of tumour type and, when combined with the machine learning methods, demonstrated a diagnostic accuracy of 93% for distinguishing between the three main tumour groups (medulloblastoma, pilocytic astrocytoma and ependymoma). The accuracy of this approach was similar even when data of marginal quality were included, greatly reducing the proportion of MRS excluded for poor quality. Children's brain tumours are strongly characterised by MRS metabolite profiles readily acquired during routine clinical practice, and this information can be used to support noninvasive diagnosis. This study provides both key evidence and an important resource for the future use of MRS in the diagnosis of children's brain tumours.

The effectiveness and safety of proton beam radiation therapy in children and young adults with Central Nervous System (CNS) tumours: a systematic review.

BACKGROUND: Central nervous system (CNS) tumours account for around 25% of childhood neoplasms. With multi-modal therapy, 5-year survival is at around 75% in the UK. Conventional photon radiotherapy has made significant contributions to survival, but can be associated with long-term side effects. Proton beam radiotherapy (PBT) reduces the volume of irradiated tissue outside the tumour target volume which may potentially reduce toxicity. Our aim was to assess the effectiveness and safety of PBT and make recommendations for future research for this evolving treatment. METHODS: A systematic review assessing the effects of PBT for treating CNS tumours in children/young adults was undertaken using methods recommended by Cochrane and reported using PRISMA guidelines. Any study design was included where clinical and toxicity outcomes were reported. Searches were to May 2021, with a narrative synthesis employed. RESULTS: Thirty-one case series studies involving 1731 patients from 10 PBT centres were included. Eleven studies involved children with medulloblastoma / primitive neuroectodermal tumours (n = 712), five ependymoma (n = 398), four atypical teratoid/rhabdoid tumour (n = 72), six craniopharyngioma (n = 272), three low-grade gliomas (n = 233), one germ cell tumours (n = 22) and one pineoblastoma (n = 22). Clinical outcomes were the most frequently reported with overall survival values ranging from 100 to 28% depending on the tumour type. Endocrine outcomes were the most frequently reported toxicity outcomes with quality of life the least reported. CONCLUSIONS: This review highlights areas of uncertainty in this research area. A well-defined, well-funded research agenda is needed to best maximise the potential of PBT. SYSTEMATIC REVIEW REGISTRATION: PROSPERO-CRD42016036802.

Proceedings of the first global meeting of the Posterior Fossa Society: state of the art in cerebellar mutism syndrome.

PURPOSE: The Posterior Fossa Society, an international multidisciplinary group, hosted its first global meeting designed to share the current state of the evidence across the multidisciplinary elements of pediatric post-operative cerebellar mutism syndrome (pCMS). The agenda included keynote talks from world-leading speakers, compelling abstract presentations and engaging discussions led by members of the PFS special interest groups. METHODS: This paper is a synopsis of the first global meeting, a 3-day program held in Liverpool, England, UK, in September 2022. RESULTS: Topics included nosology, patient and family experience, cerebellar modulation of cognition, and cerebellar cognitive affective syndrome. In addition, updates from large-scale studies were shared as well as abstracts across neuroradiology, neurosurgery, diagnosis/scoring, ataxia, and rehabilitation. CONCLUSIONS: Based on data-driven evidence and discussions, each special interest group created research priorities to target before the second global meeting, in the spring of 2024.

Medulloblastoma in a child with osteoma cutis - a rare association due to loss of GNAS expression.

OBJECTIVES: Inactivating GNAS mutations result in varied phenotypes depending on parental origin. Maternally inherited mutations typically lead to hormone resistance and Albright's hereditary osteodystrophy (AHO), characterised by short stature, round facies, brachydactyly and subcutaneous ossifications. Paternal inheritance presents with features of AHO or ectopic ossification without hormone resistance. This report describes the case of a child with osteoma cutis and medulloblastoma. The objective of this report is to highlight the emerging association between inactivating germline GNAS mutations and medulloblastoma, aiming to shed light on its implications for tumor biology and promote future development of targeted surveillance strategies to improve outcomes in paediatric patients with these mutations. CASE PRESENTATION: A 12-month-old boy presented with multiple plaque-like skin lesions. Biopsy confirmed osteoma cutis, prompting genetic testing which confirmed a heterozygous inactivating GNAS mutation. At 2.5 years of age, he developed neurological symptoms and was diagnosed with a desmoplastic nodular medulloblastoma, SHH molecular group, confirmed by MRI and histology. Further analysis indicated a biallelic loss of GNAS in the tumor. CONCLUSIONS: This case provides important insights into the role of GNAS as a tumor suppressor and the emerging association between inactivating GNAS variants and the development of medulloblastoma. The case underscores the importance of careful neurological assessment and ongoing vigilance in children with known inactivating GNAS variants or associated phenotypes. Further work to establish genotype-phenotype correlations is needed to inform optimal management of these patients.

SNO-EANO-EURACAN consensus on management of pineal parenchymal tumors.

Pineal parenchymal tumors are rare neoplasms for which evidence-based treatment recommendations are lacking. These tumors vary in biology, clinical characteristics, and prognosis, requiring treatment that ranges from surgical resection alone to intensive multimodal antineoplastic therapy. Recently, international collaborative studies have shed light on the genomic landscape of these tumors, leading to refinement in molecular-based disease classification in the 5th edition of the World Health Organization (WHO) classification of tumors of the central nervous system. In this review, we summarize the literature on diagnostic and therapeutic approaches, and suggest pragmatic recommendations for the clinical management of patients presenting with intrinsic pineal region masses including parenchymal tumors (pineocytoma, pineal parenchymal tumor of intermediate differentiation, and pineoblastoma), pineal cyst, and papillary tumors of the pineal region.

Metabolite profiles of medulloblastoma for rapid and non-invasive detection of molecular disease groups.

BACKGROUND: The malignant childhood brain tumour, medulloblastoma, is classified clinically into molecular groups which guide therapy. DNA-methylation profiling is the current classification 'gold-standard', typically delivered 3-4 weeks post-surgery. Pre-surgery non-invasive diagnostics thus offer significant potential to improve early diagnosis and clinical management. Here, we determine tumour metabolite profiles of the four medulloblastoma groups, assess their diagnostic utility using tumour tissue and potential for non-invasive diagnosis using in vivo magnetic resonance spectroscopy (MRS). METHODS: Metabolite profiles were acquired by high-resolution magic-angle spinning NMR spectroscopy (MAS) from 86 medulloblastomas (from 59 male and 27 female patients), previously classified by DNA-methylation array (WNT (n = 9), SHH (n = 22), Group3 (n = 21), Group4 (n = 34)); RNA-seq data was available for sixty. Unsupervised class-discovery was performed and a support vector machine (SVM) constructed to assess diagnostic performance. The SVM classifier was adapted to use only metabolites (n = 10) routinely quantified from in vivo MRS data, and re-tested. Glutamate was assessed as a predictor of overall survival. FINDINGS: Group-specific metabolite profiles were identified; tumours clustered with good concordance to their reference molecular group (93%). GABA was only detected in WNT, taurine was low in SHH and lipids were high in Group3. The tissue-based metabolite SVM classifier had a cross-validated accuracy of 89% (100% for WNT) and, adapted to use metabolites routinely quantified in vivo, gave a combined classification accuracy of 90% for SHH, Group3 and Group4. Glutamate predicted survival after incorporating known risk-factors (HR = 3.39, 95% CI 1.4-8.1, p = 0.025). INTERPRETATION: Tissue metabolite profiles characterise medulloblastoma molecular groups. Their combination with machine learning can aid rapid diagnosis from tissue and potentially in vivo. Specific metabolites provide important information; GABA identifying WNT and glutamate conferring poor prognosis. FUNDING: Children with Cancer UK, Cancer Research UK, Children's Cancer North and a Newcastle University PhD studentship.

The Utility of the Liverpool Adverse Drug Reaction Assessment Tools in the Evaluation of Chemotherapy-Induced Nausea and Vomiting in Children / Utilidade das Ferramentas de Avaliação de Reações Adversas a Medicamentos de Liverpool na Análise de Náuseas e Vômitos Induzidos por Quimioterapia em Crianças / La Utilidad de las Herramientas de Evaluación de Reacciones Adversas a Medicamentos de Liverpool en la Evaluación de Náuseas y Vómitos Inducidos por Quimioterapia en Niños

Introduction: Chemotherapy-induced nausea and vomiting (CINV) are common adverse drug reactions (ADR) experienced by children undergoing treatment for cancer. New paediatric ADR Assessment Causality and Avoidability tools (LCAT and LAAT) of Liverpool are suitable for categorizing factors related to ADR prevention and improving patient care. Still, no studies to date have compared the utility and results of its application for CINV in countries with different levels of development. Objective: To investigate the utility of the Liverpool Adverse Drug Reaction Causality and Avoidability Assessment Tools (LCAT and LAAT) in assessing CINV in children. Method: Prospective observational study of CINV assessment in children aged 4 to 16 years from Alder Hey Children's Hospital (Liverpool, UK) and "Instituto de Puericultura e Pediatria Martagão Gesteira" (Rio de Janeiro, Brazil). Children (helped by the parents) completed a symptom diary during chemotherapy and for 24 hours after treatment. Information regarding underlying diagnosis, past medical history, and medications administered was collected from the patient record. Case reports were prepared, and the temporal relationship between nausea and vomiting and exposure to chemotherapy, including any strategy to prevent CINV, was recorded. The causality and avoidability were assessed with LCAT and LAAT, respectively. Results: There were 26 reports of CINV in 36 chemotherapy cycles. The causality assessment was 'definite' for 24 cases. Twenty ADRs were deemed 'definitely avoidable' and four 'not avoidable'. Selection of inappropriate therapeutic options and non-administration of antiemetic were the most common factors observed in the hospitals studied. Conclusion: The LCAT and LAAT were helpful for assessing CINV in children in two different hospitals.

Introdução: Náuseas e vômitos induzidos por quimioterapia (NVIQ) são reações adversas a medicamentos (RAM) comuns em crianças em tratamento oncológico. Novas ferramentas de Avaliação de Causalidade e Evitabilidade de RAM de Liverpool (LCAT e LAAT) foram validadas e auxiliam a categorização de fatores de risco. Contudo, até o momento, nenhum estudo comparou a utilidade e os resultados de sua aplicação para NVIQ em países com diferentes níveis de desenvolvimento. Objetivo: Investigar a utilidade da LCAT e LAAT na avaliação de NVIQ. Método: Estudo observacional prospectivo com crianças de 4 a 16 anos do Alder Hey Children's Hospital (Liverpool, Reino Unido) e do Instituto de Puericultura e Pediatria Martagão Gesteira (Rio de Janeiro, Brasil). As crianças (ajudadas pelos pais) preencheram um diário de sintomas durante e até 24 horas após administração da quimioterapia. Informações sobre diagnóstico subjacente, história médica pregressa e medicamentos administrados foram coletadas do prontuário do paciente. Relatos de casos foram preparados e a relação temporal entre náuseas e vômitos e exposição à quimioterapia, incluindo qualquer estratégia para prevenir NVIQ, foi registrada para análise da causalidade e evitabilidade com o auxílio de LCAT e LAAT, respectivamente. Resultados: Houve 26 notificações de NVIQ em 36 ciclos de quimioterapia. A causalidade foi 'definida' para 24 casos. Foram consideradas 'definitivamente evitáveis' 20 RAM e 'não evitáveis', quatro. A seleção de opções terapêuticas inadequadas e a omissão de antieméticos foram os principais problemas evitáveis. Conclusão: O LCAT e o LAAT foram úteis para avaliar NVIQ em crianças em dois hospitais diferentes

Introducción: Las náuseas y vómitos inducidos por quimioterapia (NVIQ) son reacciones adversas a medicamentos (RAM) comunes en niños en tratamiento oncológico. Nuevas herramientas de Evaluación de Causalidad y Evitabilidad de RAM de Liverpool (LCAT y LAAT) han sido validadas y ayudan en la categorización de factores de riesgo. Sin embargo, ningún estudio ha comparado su utilidad y resultados para evaluación de NVIQ en países con diferentes niveles de desarrollo. Objetivo: Investigar la utilidad de LCAT y LAAT en la evaluación de NVIQ. Método: Estudio observacional prospectivo con niños de 4 a 16 años del Alder Hey Children's Hospital (Liverpool, Reino Unido) y del Instituto de Pediatría Martagão Gesteira (Río de Janeiro, Brasil). Los niños (ayudados por los padres) completaron un diario de síntomas durante y hasta 24 horas después de la quimioterapia. La información sobre el diagnóstico subyacente, la historia médica previa y los medicamentos se recopiló de la historia clínica médico del paciente. Se prepararon informes de casos y se registró la relación temporal entre las RAM y la exposición a la quimioterapia, incluyendo cualquier estrategia para prevenir NVIQ, para análisis de causalidad y evitabilidad con LCAT y LAAT, respectivamente. Resultados: Hubo 26 notificaciones de NVIQ en 36 ciclos de quimioterapia. La causalidad fue "definida" para 24 casos. Fueron consideradas "definitivamente evitables" 20 RAM y "no evitables", cuatro. La selección de opciones terapéuticas inadecuadas y la omisión de antieméticos fueron los principales problemas evitables. Conclusión: LCAT y LAAT fueron útiles para evaluar NVIQ en niños en dos hospitales diferentes