Background and Objectives: Medulloblastoma is the most common malignant brain tumor in children. In recent decades, the therapeutic landscape has undergone significant changes, with stereotactic radiosurgery (SRS) emerging as a promising treatment for recurrent cases. Our study provides a comprehensive analysis of the long-term efficacy and safety of SRS in recurrent medulloblastomas across both pediatric and adult patients at a single institution. Methods: We retrospectively reviewed the clinical and radiological records of patients who underwent CyberKnife SRS for recurrent cranial medulloblastomas at our institution between 1998 and 2023. Follow-up data were available for 15 medulloblastomas in 10 patients. The cohort comprised 8 pediatric patients (ages 3-18) and 2 adult patients (ages 19-75). Median age at the time of SRS was 13 years, median tumor volume accounted for 1.9 cc, median biologically equivalent dose (BED) was 126 Gy, and single-fraction equivalent dose (SFED) was 18 Gy. The SRS was administered at 75% of the median isodose line. Results: Following a median follow-up of 39 months (range: 6-78), 53.3% of the medulloblastomas progressed, 13.3% regressed, and 33.3% remained stable. The 3-year local tumor control (LTC) rate for all medulloblastomas was 65%, with lower rates observed in the adult cohort (50%) and higher rates in pediatric patients (67%). The 3-year overall survival (OS) rate was 70%, with significantly higher rates in pediatric patients (75%) compared to adult patients (50%). The 3-year progression-free survival (PFS) rate was 58.3%, with higher rates in pediatric patients (60%) compared to adult patients (50%). Two pediatric patients developed radiation-induced edema, while two adult patients experienced radiation necrosis at the latest follow-up, with both adult patients passing away. Conclusion: Our study provides a complex perspective on the efficacy and safety of CyberKnife SRS in treating recurrent cranial medulloblastomas across pediatric and adult populations. The rarity of adverse radiation events (ARE) underscores the safety profile of SRS, reinforcing its role in enhancing treatment outcomes. The intricacies of symptomatic outcomes, intertwined with factors such as age, tumor location, and prior surgeries, emphasize the need for personalized treatment approaches. Our findings underscore the imperative for ongoing research and the development of more refined treatment strategies for recurrent medulloblastomas. Given the observed disparities in treatment outcomes, a more meticulous tailoring of treatment approaches becomes crucial.

Medulloblastoma (MB) is the second most prevalent brain tumor in children. Although the current cure rate stands at approximately 70%, the existing treatments that involve a combination of radio- and chemotherapy are highly detrimental to the patients’ quality of life. These aggressive therapies often result in a significant reduction in the overall well-being of the patients. Moreover, the most aggressive forms of MB frequently relapse, leading to a fatal outcome in a majority of cases. However, MB are highly vascularized, and both angiogenesis and lymphangiogenesis, are believed to play crucial roles in tumor development and spread. In this context, our objective is to provide a comprehensive overview of the current research progress in elucidating the functions of these two pathways. Specifically, we will focus on the role and mechanism of action of VEGFC, one of the key players in lymphangiogenesis.

Pediatric brain tumors are the most common solid tumors in children, causing the highest number of cancer-related deaths at young ages. Although existing therapies have improved the 5-year overall survival rate of PBT patients, some high-risk brain tumors continue to resist current treatments. Additionally, the survivors endure devastating long-term side effects, including cognitive defects and sensory and endocrinal dysfunctions. In the past two decades, immunotherapies have evolved significantly, with great success in many cancers. Immunotherapies developed specifically for PBTs also show promising results. Currently, scores of clinical trials are underway to evaluate the safety and feasibility of a wide-range of immunotherapeutics for PBTs, and this review overviews the most recent advances, including the exciting progress made toward treating medulloblastoma, pediatric glioma, and ependymoma. We summarized the cutting-edge immunotherapies under development, including immune checkpoint blockade, chimeric antigen receptor (CAR)-T cell therapy, natural killer (NK)-cell therapy, cancer vaccines, and oncolytic virus therapy. We find that the results from the recently concluded or ongoing clinical trials on safety and feasibility are very encouraging; however, non-responsiveness and tumor recurrence still haunt them. While this review judges the scope of the current immunotherapies, it also lays out strategies to find alternate solutions for persisting issues.

Pediatric brain tumors are the leading cause of cancer-related death in children. Diagnosis cur-rently relies on surgical biopsy to obtain tumor tissue for histological analysis. There is a great need for less invasive approaches to molecularly profile tumors and monitor therapeutic response. Liquid biopsy analysis of circulating tumor biomarkers in biofluids like cerebrospinal fluid (CSF) and blood offers a promising minimally invasive strategy. This review discusses recent advances in developing liquid biopsy assays using next-generation sequencing, digital PCR, and emerging techniques to detect circulating tumor DNA (ctDNA), cells (CTCs), and exosomes in pediatric brain tumors. The ability to use these circulating biomarkers for non-invasive diagnosis, thera-peutic targeting, tracking response to therapy, and understanding resistance mechanisms is ex-amined. Technical and clinical validation challenges to translate liquid biopsies into routine clin-ical practice are also discussed.

Background: Medulloblastoma (MB) comprises four broad molecular subgroups - wingless (WNT), sonic hedgehog (SHH), Group 3, and Group 4 respectively with subgroup-specific developmental origins, unique genetic profiles, distinct clinico-demographic characteristics, and diverse clinical outcomes. WNT-MB has the best outcomes (5-year survival >90%) with contemporary multi-modality treatment prompting attempts at treatment de-intensification to reduce late toxicity. This is a retrospective audit of clinical outcomes in WNT-MB patients treated at a tertiary-care comprehensive cancer centre. Methods: Patients with molecularly confirmed WNT-MB treated with maximal safe resection followed by post-operative standard-of-care risk-stratified adjuvant radio(chemo)therapy were identified retrospectively via electronic search of the neuro-oncology database. Data regarding clinico-demographic characteristics, histo-molecular features, treatment details, patterns of failure, and survival outcomes was retrieved from electronic medical records and/or hospital case files. Time-to-event outcomes were analyzed using Kaplan-Meier methods and compared with the log-rank test. Results: Between 2004 to 2020, 74 patients with WNT-MB were registered in the neuro-oncology unit of the institute. Seven patients treated on a prospective clinical trial of therapy de-intensification were excluded leaving 67 patients that constitute the present study cohort. Median age at presentation was 12 years (inter-quartile range 9-18 years) with a male preponderance (2:1). Six patients (1 post-operative mortality and 5 without adequate details of treatment or outcomes) were excluded from the survival analysis which was restricted to 61 patients. At a median follow-up of 72 months, Kaplan-Meier estimates of 5-year progression-free survival and overall survival were 87.7% and 91.2% respectively. Traditional high-risk features such as large residual tumor (≥1.5cm2) and leptomeningeal metastases (M+) did not significantly impact upon survival in this molecularly-characterized WNT-MB cohort. Conclusions: This retrospective clinical audit confirms excellent survival in WNT-MB patients treated with contemporary multi-modality therapy. Lack of prognostic impact of conventional high-risk features suggests the need for refined risk-stratification and potential de-intensification of therapy.

Epigenetic mechanisms, including post-translational modifications of DNA and histones that influence chromatin structure, regulate gene expression during normal development, and are also involved in carcinogenesis and cancer progression. The histone methyltransferase G9a (euchromatic histone lysine methyltransferase 2, EHMT2), which mostly mediates mono- and dimethylation by histone H3 lysine 9 (H3K9), influences gene expression involved in embryonic development and tissue differentiation. Overexpression of G9a has been observed in several cancer types, and different classes of G9a inhibitors have been developed as potential anticancer agents. Here, we review the emerging evidence suggesting the involvement of changes in G9a activity in brain tumors, namely glioblastoma (GBM), the main type of primary malignant brain cancer in adults, and medulloblastoma (MB), the most common type of malignant brain cancer in children. We also discuss the role of G9a in neuroblastoma (NB) and the drug development of G9a inhibitors.

A recent paradigm shift in diagnostics of medulloblastoma allows the distinction of four major groups defined by genetic data rather than histology. This new molecular classification correlates better with prognosis and will allow better clinical management for therapies targeting druggable mutations, but also offers a new combination of monitoring tumor development in real-time and treatment response by sequential liquid biopsy. This review highlights recent developments after a century of milestones in neurosurgery, radio- and chemotherapy, but also controversial theories on the cell of origin, animal models and the use of liquid biopsy.

The molecular evolution of medulloblastoma is more complex than was previously imagined as emerging evidence suggests that multiples interactions between the tumor cells and components of the tumor microenvironment (TME) are important for tumor promotion and progression. The identification of several molecular networks within the TME, which interact with tumoral cells, has provided new clues to understand the tumorigenic roles of many TME components as well as potential therapeutic targets. In this review, we discuss the most recent studies regarding the roles of astrocytes in supporting the sonic hedgehog (SHH)–activated medulloblastoma molecular subgroup, and provide an overview of medulloblastoma progression through SHH expression and signal transduction mechanisms into the complex tumor microenvironment. In addition, we highlight the associations between tumor and stromal cells as possible prognostic markers and new therapeutic strategies.

Objective: The causes of vertigo and dizziness in children are diverse and require attention from various specialists. Numerous authors have reported that the commonest type of vertigo in children is migraine-associated vertigo (vestibular migraine and benign paroxysmal vertigo of childhood - BPV). We aimed to check whether this could be applied to our group of patients. Materials and methods: A retrospective case series of 257 consecutive pediatric vertigo and diz-ziness patients referred to the tertiary pediatric ENT clinic from 2015 to 2020. Patients received a complete audiovestibular workup and were referred to pediatric neurologists and other special-ists depending on the signs and symptoms. Results: Of 257 children aged 1-17 years, almost one fifth of them, 49/257 (19.1 %) had a central type of vertigo, 20/257 of them (7.8%) had benign paroxysmal vertigo of childhood and 4/257 (1.6%) had a migrainous type of vertigo. Most of the children, 112/257 (43.6%), remained unclas-sified, without a final diagnosis. Conclusion: Due to the numerous possible causes, a child presenting with dizziness and vertigo requires a multidisciplinary approach. In the majority of cases, vertigo spells are self-limiting. They stop spontaneously and sometimes remain clinically undiagnosed. The most prevalent reasons for pediatric vertigo may be temporary hemodynamic (vaso-vagal) and psychological imbalance.