Impact of induction chemotherapy, hyperfractionated accelerated radiotherapy and high-dose thiotepa on brain volume loss and functional status of children with primitive neuroectodermal tumour

Holistic rehabilitation for children with cancer: The Chilean model

The increasingly positive outcomes of childhood cancer treatments are among the most inspiring stories in modern medicine. Many of the children and adolescents surviving cancer will have a healthy life; however, many others will suffer from physical, cognitive, psychological, and social sequelae. During treatment, many children experience multiple temporary and permanent side effects which negatively impact their quality of life. Low- and middle-income countries where childhood cancer treatment outcomes are improving are facing the reality of a growing population of teenagers and young adults suffering from long-term disease- and treatment-related consequences. In Chile, 500 children are diagnosed with cancer each year. Treatment is granted for all through public health policies and NGO collaboration. In order to address the complex problems from acute and long-term consequences of disease and treatment, the Oncological Rehabilitation Center Fundación Nuestros Hijos (CROFNH) provides multidisciplinary attention to an extensive variety of rehabilitation needs for children and adolescents with cancer. With its integrated services in the medical treatment of children and adolescents with cancer, the CROFNH helps reduce the impact of treatment-related side effects in children's daily lives, improves quality of life, and aims at contributing to these children becoming independent and functional adults to the maximum of their capacities. The aim of this article is to show the experience of the Chilean Oncological Rehabilitation Centre and its unique multidisciplinary approach. In addition, we discuss the successful telerehabilitation strategy implemented in response to the COVID-19 pandemic in order to secure continuity of treatment.

Neuroimaging Biomarkers and Neurocognitive Outcomes in Pediatric Medulloblastoma Patients: a Systematic Review

Medulloblastoma is a malign posterior fossa brain tumor, mostly occurring in childhood. The CNS-directed chemoradiotherapy treatment can be very harmful to the developing brain and functional outcomes of these patients. However, what the underlying neurotoxic mechanisms are remain inconclusive. Hence, this review summarizes the existing literature on the association between advanced neuroimaging and neurocognitive changes in patients that were treated for pediatric medulloblastoma. The PubMed/Medline database was extensively screened for studies investigating the link between cognitive outcomes and multimodal magnetic resonance (MR) imaging in childhood medulloblastoma survivors. A behavioral meta-analysis was performed on the available IQ scores. A total of 649 studies were screened, of which 22 studies were included. Based on this literature review, we conclude medulloblastoma patients to be at risk for white matter volume loss, more frequent white matter lesions, and changes in white matter microstructure. Such microstructural alterations were associated with lower IQ, which reached the clinical cut-off in survivors across studies. Using functional MR scans, changes in activity were observed in cerebellar areas, associated with working memory and processing speed. Finally, cerebral microbleeds were encountered more often, but these were not associated with cognitive outcomes. Regarding intervention studies, computerized cognitive training was associated with changes in prefrontal and cerebellar activation and physical training might result in microstructural and cortical alterations. Hence, to better define the neural targets for interventions in pediatric medulloblastoma patients, this review suggests working towards neuroimaging-based predictions of cognitive outcomes. To reach this goal, large multimodal prospective imaging studies are highly recommended.

Management of high-risk medulloblastoma

Medulloblastoma is the most common malignant brain tumors in children. Current management combines surgery, radiotherapy, and chemotherapy. Current treatment of medulloblastoma is based on a clinical risk-stratification system that takes into account age, extent of resection and metastatic status. High-risk medulloblastoma patients are defined by the presence of metastatic disease and/or an incomplete resection with a residual amount of tumour>1.5 cm². This review describes the evolution in the management of high-risk medulloblastoma patients during recent 4 decades and recent changes in the definition of high-risk patients as a result of major advances in the understanding of the molecular heterogeneity of medulloblastomas.

Selective Neural Deletion of the Atg7 Gene Reduces Irradiation-Induced Cerebellar White Matter Injury in the Juvenile Mouse Brain by Ameliorating Oligodendrocyte Progenitor Cell Loss

Radiotherapy is an effective tool for treating brain tumors, but irradiation-induced toxicity to the normal brain tissue remains a major problem. Here, we investigated if selective neural autophagy related gene 7 (Atg7) deletion has a persistent effect on irradiation-induced juvenile mouse brain injury. Ten-day-old Atg7 knockout under a nestin promoter (KO) mice and wild-type (WT) littermates were subjected to a single dose of 6 Gy whole-brain irradiation. Cerebellar volume, cell proliferation, microglia activation, inflammation, and myelination were evaluated in the cerebellum at 5 days after irradiation. We found that neural Atg7 deficiency partially prevented myelin disruption compared to the WT mice after irradiation, as indicated by myelin basic protein staining. Irradiation induced oligodendrocyte progenitor cell (OPC) loss in the white matter of the cerebellum, and Atg7 deficiency partly prevented this. The mRNA expression of oligodendrocyte and myelination-related genes (Olig2, Cldn11, CNP, and MBP) was higher in the cerebellum in Atg7 KO mice compared with WT littermates. The total cerebellar volume was significantly reduced after irradiation in both Atg7 KO and WT mice. Atg7-deficient cerebellums were in a regenerative state before irradiation, as judged by the increased OPC-related and neurogenesis-related transcripts and the increased numbers of microglia; however, except for the OPC parameters these were the same in both genotypes after irradiation. Finally, there was no significant change in the number of astrocytes in the cerebellum after irradiation. These results suggest that selective neural Atg7 deficiency reduces irradiation-induced cerebellar white matter injury in the juvenile mouse brain, secondary to prevention of OPC loss.