Posterior Fossa Brain Tumors Research Articles

The Pediatric Physiatric Posterior Fossa Symptoms scale (3PFSs): Impairments and outcome in pediatric inpatient rehabilitation for posterior fossa brain tumors.

Clinical recognition of the post-operative neurologic sequelae of posterior fossa tumors is inconsistent. This study aimed to characterize functional impairments and recovery trajectories in pediatric patients admitted to inpatient rehabilitation following surgical resection of posterior fossa brain tumors. This study also introduces the Pediatric Physiatric Posterior Fossa Symptom scale (3PFSs) for serial assessment of post-operative symptoms in pediatric posterior fossa brain tumors. This retrospective cohort study included 49 patients aged 1.1 to 19.9 years admitted to a pediatric unit of a free-standing rehabilitation hospital following resection of a posterior fossa brain tumor. Functional Independence Measure for Children (WeeFIM) and 3PFSs scores at admission and discharge were the primary outcome measures. Across the group, WeeFIM score improved from 51.5±23.5 points at admission to 74.2±28.2 points at discharge (t=4.34, p<0.001). The 3PFSs score also showed improvement from 10[IQR=9-12] points at admission to 8[7-10] points at discharge (t=9.3, p<0.0001). While change in both the WeeFIM and 3PFSs captured statistically significant improvement in function, there was low inter-rating correlation (p>0.7). In addition, mortality was correlated with higher discharge 3PFSs score (p=0.007) but not discharge WeeFIM score. In pediatric patients with post-operative neurologic sequelae due to posterior fossa brain tumors, inpatient rehabilitation resulted in global and domain specific functional improvements. This initial application of the 3PFSs demonstrates potential applicability for stratifying patients to appropriate levels of rehabilitation, capturing functionally relevant response to rehabilitation treatment, and prognosticating long-term outcomes. These initial results are promising but require additional validation in a larger cohort.

An international study presenting a federated learning AI platform for pediatric brain tumors

While multiple factors impact disease, artificial intelligence (AI) studies in medicine often use small, non-diverse patient cohorts due to data sharing and privacy issues. Federated learning (FL) has emerged as a solution, enabling training across hospitals without direct data sharing. Here, we present FL-PedBrain, an FL platform for pediatric posterior fossa brain tumors, and evaluate its performance on a diverse, realistic, multi-center cohort. Pediatric brain tumors were targeted due to the scarcity of such datasets, even in tertiary care hospitals. Our platform orchestrates federated training for joint tumor classification and segmentation across 19 international sites. FL-PedBrain exhibits less than a 1.5% decrease in classification and a 3% reduction in segmentation performance compared to centralized data training. FL boosts segmentation performance by 20 to 30% on three external, out-of-network sites. Finally, we explore the sources of data heterogeneity and examine FL robustness in real-world scenarios with data imbalances.

Dose-dependent cranial irradiation associations with brain structures and neuropsychological outcomes in children with posterior fossa brain tumors.

Posterior fossa irradiation with or without whole brain irradiation results in high doses of radiation to the thalamus, hippocampus, and putamen, structures critical to cognitive functioning. As a result, children with brain tumors treated with cranial irradiation (CRT) may experience significant cognitive late effects. We sought to determine the effect of radiation to those structures on neuropsychological outcome. Forty-seven children with a history of posterior fossa tumor (17 treated with surgery; 11 with surgery and chemotherapy; and 19 with surgery, chemotherapy, and CRT) underwent neuroimaging and neuropsychological assessment at a mean of 4.8 years after treatment, along with 17 healthy sibling controls. The putamen, thalamus, and hippocampus were segmented on each participant's magnetic resonance imaging for diffusion indices and volumes, and in the radiation treatment group, radiation dose to each structure was calculated. Performance on visuoconstruction and spatial learning and memory was lower in patient groups than controls. Volume of the thalamus, when controlling for age, was smaller in the patient group treated with CRT than other groups. Higher radiation doses to the putamen correlated with higher fractional anisotropy in that structure. Higher radiation dose to the hippocampus correlated with lower spatial learning, and higher dose to thalami and putamina to lower verbal and nonverbal reasoning. All children with posterior fossa tumors, regardless of treatment modality, had cognitive deficits compared to their sibling controls. Posterior fossa irradiation may affect thalamic volume and aspects of verbal and nonverbal cognitive functioning.

Evolution of Proton Radiation Therapy Brainstem Constraints on the Pediatric Proton/Photon Consortium Registry

Increasing concern that brainstem toxicity incidence after proton radiation therapy might be higher than with photons led to a 2014 University of Florida (UF) landmark paper identifying its risk factors and proposing more conservative dose constraints. We evaluated how practice patterns changed among the Pediatric Proton/Photon Consortium Registry (PPCR). This prospective multicenter cohort study gathered data from patients under the age of 22 years enrolled on the PPCR, treated between 2002 and 2019 for primary posterior fossa brain tumors. After standardizing brainstem contours, we garnered dosimetry data and correlated those meeting the 2014 proton-specific brainstem constraint guidelines by treatment era, histology, and extent of surgical resection. A total of 467 patients with evaluable proton radiation therapy plans were reviewed. Median age was 7.1 years (range: <1-21.9), 63.0% (n = 296) were men, 76.0% (n = 357) were White, and predominant histology was medulloblastoma (55.0%, n = 256), followed by ependymoma (27.0%, n = 125). Extent of resection was mainly gross total resection (GTR) (67.0%, n = 312), followed by subtotal resection (STR) or biopsy (20.0%, n = 92), and near total resection (NTR) (9.2%, n = 43). The UF brainstem constraint metrics most often exceeded were the goal D50% of 52.4 gray relative biological equivalents (43.3%, n = 202) and maximal D50% of 54 gray relative biological equivalents (12.6%, n = 59). The compliance rate increased after the new guidelines (2002-2014: 64.0% vs 2015-2019: 74.6%, P = .02), except for ependymoma (46.3% pre- vs 50.0% post-guidelines, P = .86), presenting lower compliance (48.8%) in comparison to medulloblastoma/ primitive neuroectodermal tumors/pineoblastoma (77.7%), glioma (89.1%), and atypical teratoid/rhabdoid tumors (90.9%) (P < .001). Degree of surgical resection did not affect compliance rates (GTR/NTR 71.0% vs STR/biopsy 72.8%, P = .45), even within the ependymoma subset (GTR/NTR 50.5% vs STR/biopsy 38.1%, P = .82). Since the publication of the UF guidelines, the pediatric proton community has implemented more conservative brainstem constraints in all patients except those with ependymoma, irrespective of residual disease after surgery. Future work will evaluate if this change in practice is associated with decreased rates of brainstem toxicity.

NURS-06. MUSIC THERAPY: AN INTEGRAL PART OF REHABILITATION FOR CEREBELLAR MUTISM SYNDROME

Abstract BACKGROUND Cerebellar mutism syndrome (CMS) also known as posterior fossa syndrome (PFS), can occur in up to 25% of pediatric patients following surgical resection of posterior fossa brain tumors, particularly medulloblastoma. It is well recognized that intensive rehabilitation with physical therapy, occupational therapy and speech therapy are essential to recovery. Music therapy can be immensely helpful during rehabilitation to stimulate brain functions involved in movement, cognition, speech, emotions, and sensory perceptions. This case-based review aims at analyzing the available evidence to support our recommendation to include music therapy in the rehabilitation plan for all patients. METHODS We report on the case of a 4-year-old male with medulloblastoma and cerebellar mutism syndrome who began talking after just a few sessions with music therapy. We include an extensive review of the literature where multiple papers were found describing the positive effects of music therapy for management of neurologic diseases. RESULTS The pathophysiology of CMS is still poorly understood however, the most likely mechanism is injury along proximal components of the efferent cerebellar pathway. Intensive inpatient rehabilitation remains the standard of care. Music therapy uses and activates many different parts of the brain at the same time, promoting neuron repair and regeneration. Some of the advantages of music therapy are: it promotes plasticity in the brain and facilitates processing of sensory information and motor function; improves stress and helps patients adapt to stressful environments; facilitates more normative speech production for patients with dysarthria. CONCLUSIONS Despite efforts to identify preventative measures for CMS, it still occurs. Intensive rehabilitation remains the cornerstone of treatment. The case study as well as the review of the literature support our recommendation to include music therapy in the rehabilitation plan for patients with CMS. More studies are necessary to explore the therapeutic efficacy of music on patients with CMS.

QOL-26. SYTHESIS OF THE LITERATURE REVIEW ON PHYSICAL ACTIVITY IN PEDIATRIC NEURO-ONCOLOGY

Abstract BACKGROUND Physical Activity plays a vital role in physical, social, phychological wellbeing of pediatric neuro-oncologic group. However, the researches investigating the effects of physical activity on this group have been sparse. The purpose of this study was to identify studies conducted about the effects of physical activity on this population. METHODS PRISMA statement conduct review was followed in electronic database of Journal of Neuro-oncology. Two authors (SY, MT) independently conducted systematic literature searches February 2024. Keywords/Mesh terms: “physical activity’’. Randomized controlled English clinical trials are included; Studies that were published as “review”, “protocol”, “books”, “news”, not reach full text and not related to physical activity excluded. After articles had been reached, used QUADAS-2 checklist for methodological quality. RESULTS 29 articles were identified from 1721 articles, and 2 of them (published 2014-2023) were about pediatric age group. One of them was assessment (50%), while the other one was interventional study (50%). Assessment study was measured by using Bruininks-Osteretsky Test of Motor Performance, Second Edition (BOT-2) and online surveys. Interventional study analyzed the effects of aerobic exercises of three 90-minute sessions per week for 12 consecutive weeks primarily on cortical thickness, white matter, hippocampal volume and secondarily reaction time, accuracy across tests of attention, processing speed, and short term memory. CONCLUSION This abstract provides an initial scoping review of physical activity in pediatric neuro-oncology group. It demonstrates limited range of assessments, and interventions which highlights the lack of clinical evidence in this specific area. The results raise the need for further research in this field to help the development of physical activity guidelines for evaluation and physical activity methods in children with ataxia, and tumours expecially posterior fossa brain tumors. Investigation of different physical activity methods in a group of neuro-oncology children in need of support is major importance.

Outcome of Midline Posterior Cranial Fossa Tumor Surgery with Preoperative Ventriculo - Peritoneal (V-P) Shunt in Children

Introduction: Pediatric patients with midline posterior cranial fossa tumors present with features of raised intracranial pressure due to development of hydrocephalus. Due to the big size tumour and lack of facility we did Ventriculoperitoneal shunt before definitive surgery for all patients. Material and Methods: This cross-sectional experimental study was carried out on 55 consecutive patients with midline posterior cranial fossa brain tumors with obstructive hydrocephalus with age ranged from 3 to 15 years got admitted in the Department of Neurosurgery, Bangabandhu Sheikh Mujib Medical University from March 2021 to April 2023. We did preoperative ventriculoperitoneal shunt before definitive surgery but didn’t do the Endoscopic third ventriculostomy. Results: In this study, the age of the patients was 3-15 years, the mean age was 9.47+_3.18 and the peak incidence was 11-15 years which was 20(36.36%). Majority of the patients was male (56%), male female ratio was 1.27:1. Most of the children were presented with headache 51(92.73%) followed by papilloedema 47(85.45%), vomiting 46(83.64%), gait disturbance 37(67.27%), diminution of vision 31(56.36%), swallowing difficulty 12(21.82%), cranial nerve palsy 12(21.82%). 19 patients developed postoperative complications among them 15(27.27%) was meningitis followed by wound infection 7(12.73%), pseudomeningocele 8(14.55%), csf leakage 4(7.27%), hydrocephalous 3(5.45%). Logistic regression analysis was non-significant statistically in my study. Discussion and Conclusion: In conclusion we found satisfactory outcome of doing pr-operative VP Shunt in posterior fossa midline tumor causing obstructive Hydrocephalus in children, however major postoperative complications were development of hydrocephalus, CSF leak, pseudo meningocele, wound infection and meningitis. Future prospective studies with sufficient sample size are warranted to reach a definitive conclusion.

Goal-directed therapeutic exercise for paediatric posterior fossa brain tumour survivors: a qualitative analysis of experiences

PurposeTo explore child and parent experiences of a 12-week goal-directed therapeutic exercise intervention in paediatric posterior fossa brain tumours survivors and to identify features of the program that influenced program adherence and acceptability.MethodsEleven interviews were conducted; five parent-child dyads (mothers = 83%) and one parent only (mean child age = 10.6 ± 3.0 years; 83% male). Posterior fossa brain tumour survivors, who participated in a weekly goal-directed exercise program for 12 weeks, completed semi-structured interviews to discuss their experience of the program. An inductive content analysis was undertaken. Interviews were transcribed, imported into NVivo and independently coded by two reviewers. Code and content categories were iteratively discussed and refined.ResultsFive content categories were generated: (1) perceived improvements, (2) program logistics, (3) activity selection, (4) connection with the therapist and (5) options for technology. All participants valued the tailored exercise program and described improvements in movement competence. Children and their parents discussed preferring home- and community-based locations and favoured face-to-face delivery. Occasionally, parents reported difficulty completing the home program due to low child motivation or family time restrictions. Multiple families suggested an interactive digital application would be an effective delivery channel for the supplemental home-based program.ConclusionA goal-directed exercise program delivered at home and in community-based locations was considered valuable and helpful for improving movement competence in paediatric survivors of posterior fossa brain tumour.Trial registrationACTRN12619000841178 June 12, 2019

Gross motor proficiency deficits among children and adolescents post posterior fossa brain tumor removal vs. traumatic brain injury in the chronic phase of recovery: a cross-sectional study.

Acquired brain injury (ABI) is a prevalent diagnosis in pediatric rehabilitation. Gross motor skills are often affected by ABI and limit the ability to participate in various physical activities. However, as ABI injury location is diverse, children and adolescents (youth) with localized ABI, such as ABI in the posterior fossa (ABI-PF) may present unique and different motor disabilities than youth with ABI on account of traumatic brain injury (TBI). The aims of the study were: (1) to compare gross motor deficits in youth with TBI vs. ABI-PF; and (2) to compare two methods on scoring BOT2 to determine which is better for identifying motor deficits. Participated in this study youth with TBI (N = 50) and ABI-PF (N = 30). Participants were tested on Bruininks-Oseretsky Test of Motor Proficiency-2nd Edition (BOT2) Upper-Limb Coordination, Balance, Strength, Running Speed and Agility, and Bilateral-Coordination subtests. Motor performance deficits were established using two-standard deviations (2SD) and age-equivalent methods. Between-group differences were assessed via independent t-tests and receiver operating characteristic curves (ROC). According to the 2SD method, motor deficits in the ABI-PF group ranged from 20% to 66.66%, whereas in the TBI group 8%-16%. According to the age-equivalent method, in the TBI and ABI-PF groups 40%-66.0% and 46.66%-76.66% of the youth presented motor deficits, respectively. Moreover, ROC analysis showed that motor performance deficits of both groups in all sub-scales except for Bilateral Coordination differed enough to result in medium area under the curve. Motor deficits post-pediatric ABI are prevalent. In comparison to the TBI group, deficits are greater in the ABI-PF group. Moreover, compared to the 2SD method, the extent of motor deficiency is greater in the age-equivalent method. Therefore, using the later might provide a more valid classification of deficits in gross motor proficiency for youth post-ABI.

A Pediatric Case of Extraneural Subcutaneous Metastasis of Ependymoma.

Ependymoma is the third most common brain tumor in children. Extracranial metastases of ependymomas are uncommon. A 21-month-old Japanese boy was diagnosed to be brain dead due to a posterior fossa (PF) brain tumor. Surgical resection of the tumor was not performed. Twenty-seven months later, he developed a truncal subcutaneous tumor, which was pathologically diagnosed as PF ependymoma group A. We observed the intracranial recurrence of the brain tumor, an invasion to the left orbit, and a neoplasm in his liver before he died. This case suggests that PF ependymoma group A can metastasize extracranially to various organs.

Corrigendum to: NCOG-45. Differential and dose-dependent effects of cranial irradiation on brain structures and neuropsychological outcomes in children with posterior fossa brain tumors treated with different modalities.

Corrigendum to: NCOG-45. Differential and dose-dependent effects of cranial irradiation on brain structures and neuropsychological outcomes in children with posterior fossa brain tumors treated with different modalities.

NCOG-45. DIFFERENTIAL AND DOSE-DEPENDENT EFFECTS OF CRANIAL IRRADIATION ON BRAIN STRUCTURES AND NEUROPSYCHOLOGICAL OUTCOMES IN CHILDREN WITH POSTERIOR FOSSA BRAIN TUMORS TREATED WITH DIFFERENT MODALITIES

Abstract BACKGROUND Studies investigating dose-dependent effects of cranial irradiation (CRT) in children with posterior fossa brain tumors are limited by examining combined effects of surgery, chemotherapy, and radiation. We aimed to determine alterations in brain volume and microstructure, and neuropsychological outcomes in children with posterior fossa tumors treated with surgery alone, surgery and chemotherapy, and surgery, chemotherapy, and CRT combined. We explored the relationship of radiation dose to the thalamus, putamen, and hippocampus to outcomes of intelligence, processing speed, executive functions, memory, and social/emotional functioning. METHODS Forty-seven children with treated posterior fossa tumors (17 with surgery; 11 with surgery and chemotherapy; 19 with surgery, chemotherapy, and CRT) underwent neuroimaging and neuropsychological assessment a mean of 4.8 years after treatment, along with 17 healthy sibling controls (n=64). The putamen, thalamus and hippocampus were manually segmented on MRI, and structural mean radiation doses were calculated. Differences in demographics and medical history were evaluated using χ2 and t-tests. Linear regression examined differences in neuropsychological performance, structural volumes, and diffusion indices. Pearson correlation explored relationships of structural radiation doses to diffusion indices and neuropsychological outcomes. RESULTS All patients scored lower on Block Design than controls (p=0.01), and the surgery and chemotherapy group scored the lowest. There was no significant difference in mean fractional anisotropy (FA) values in the thalamus, hippocampus and putamen between the three patient groups and controls. Hippocampal volume and mean radiation dose approached significant correlation (r= -0.49; p=0.07). Right putamen FA correlated with mean radiation dose (r=0.56; p=0.02). When controlling for age, thalamic volume was lowest in the irradiated group (p=0.02). CONCLUSIONS Treatment of pediatric posterior fossa brain tumors with surgery, chemotherapy, and CRT impacts thalamic volume and may have a dose-dependent effect on the microstructure of the putamen compared to treatment with surgery/chemotherapy.

White matter tract changes in pediatric posterior fossa brain tumor survivors after surgery and chemotherapy.

Survivors of pediatric posterior fossa brain tumors are susceptible to the adverse effects of treatment as they grow into adulthood. While the exact neurobiological mechanisms of these outcomes are not yet understood, the effects of treatment on white matter (WM) tracts in the brain can be visualized using diffusion tensor (DT) imaging. We investigated these WM microstructural differences using the statistical method tract-specific analysis (TSA). We applied TSA to the DT images of 25 children with a history of posterior fossa tumor (15 treated with surgery, 10 treated with surgery and chemotherapy) along with 21 healthy controls. Between these 3 groups, we examined differences in the most used DTI metric, fractional anisotropy (FA), in 11 major brain WM tracts. Lower FA was found in the splenium of the corpus callosum (CC), the bilateral corticospinal tract (CST), the right inferior frontal occipital fasciculus (IFOF) and the left uncinate fasciculus (UF) in children with brain tumors as compared to healthy controls. Lower FA, an indicator of microstructural damage to WM, was observed in 4 of the 11 WM tracts examined in both groups of children with a history of posterior fossa tumor, with an additional tract unique to children who received surgery and chemotherapy (left UF). Our findings indicate that a history of tumor in the posterior fossa and surgical resection may have effects on the WM in other parts of the brain.

Pediatric Posterior Fossa Brain Tumor Surgical Outcome

Objective: The study analyzed the complications and satisfactory surgical outcomes of posterior fossa brain tumor surgery in Lahore Medical City Lahore.&#x0D; Materials and Methods: A prospective study was conducted and included 40 children who were diagnosed with posterior fossa brain tumors by history, physical examination, and later radiologically were admitted and operated on at the Pediatric Neurosurgery Department in Lahore medical City Lahore between the period of March 2021 and March 2022.&#x0D; Results: There were 26 (65%) male and 14 (35% females) individuals among the 40 patients. The average age was 12.5 years. This study found that great surgical outcomes were observed in 10 instances (25 percent), good outcomes in 20 cases (50%), and bad outcomes in 10 cases (25%). The most frequent clinical manifestations were headache (38%), vomiting (30%), ataxia (10%), blurred vision (10%), and cranial nerve palsy (12.5%). The best prognosis is shown in children with Pilocytic astrocytoma, followed by ependymoma, while the poorest outcome is seen in children with medulloblastoma.&#x0D; Conclusion: Pediatric neurosurgeons continue to face particular difficulty in the surgical treatment of posterior fossa brain tumors. Our study compares the outcomes, complications, and surgical outcomes to prior clinical investigations.

MRI-based whole-tumor radiomics to classify the types of pediatric posterior fossa brain tumor

BackgroundDifferential diagnosis between medulloblastoma (MB), ependymoma (EP) and astrocytoma (PA) is important due to differing medical treatment strategies and predicted survival. The aim of this study was to investigate non-invasive MRI-based radiomic analysis of whole tumors to classify the histologic tumor types of pediatric posterior fossa brain tumor and improve the accuracy of discrimination, using a random forest classifier. MethodsMRI images of 99 patients, with 59 MBs, 13 EPs and 27 PAs histologically confirmed by surgery and pathology before treatment, were included in this retrospective study. Registration was performed between the three sequences, and high- throughput features were extracted from manually segmented tumors on MR images of each case. The forest-based feature selection method was adopted to select the top ten significant features. Finally, the results were compared and analyzed according to the classification. ResultsThe top ten contributions according to the classifier of wavelet features all came from the ADC sequence. The random forest classifier achieved 100% accuracy on the training data and validated the best accuracy (0.938): sensitivity=1.000, 0.948 and 0.808, specificity=0.952, 0.926 and 1.000 for EP, MB and PA, respectively. ConclusionA random forest classifier based on the ADC sequence of the whole tumor provides more quantitative information than TIWI and T2WI in differentiating pediatric posterior fossa brain tumors. In particular, the histogram percentile value showed great superiority, which added diagnostic value in pediatric neuro-oncology.

Endoscopic third ventriculostomy for the management of hydrocephalus secondary to posterior fossa tumors: A retrospective study.

Background: Endoscopic third ventriculostomy (ETV) is an effective alternative to ventriculoperitoneal shunting as well as external ventricular drainage for the urgent management of acute hydrocephalus. We performed this study to investigate the efficacy and safety of ETV before tumor resection in managing hydrocephalus in patients with posterior fossa brain tumors (PFBT) in our neurosurgery department.Methods: We conducted this retrospective observational study between February 2018 and February 2020 on all cases diagnosed with PFBT associated with triventricular obstructive hydrocephalus. We retrospectively reviewed the demographic characteristics, operative procedures, and radiological investigations of all cases. During the follow-up period, clinical, as well as radiological success were evaluated.Results: Twenty-two ETV procedures were performed in 22 cases of PFBT (mean age = 22.1 years, SD = 11.4). Of the 22 cases, 8 cases (36.4%) had ependymoma, 7 cases (31.8%) had cerebellar astrocytoma, and 5 cases (22.7 %) had medulloblastoma, while 2 cases (9.1%) had diffuse pontine gliomas. The median follow-up duration was 9 months (range 3–13 months). The most commonly reported clinical presentation was the significant intracranial pressure increase. All operations were performed successfully in all cases. Only two ETV post-tumor resection failures were documented during the follow-up period.Conclusion: Preoperative ETV has shown to be an effective long-term cerebrospinal fluid diversion procedure to manage PFBT-associated hydrocephalus, with a relatively low rate of complications. Further prospective studies are required to assess the regular use of ETV before complete tumor resection.

Co-Existent Rhabdoid Tumor of the Brain and the Kidney in Newborn Girl: A Case Report

Malignant rhabdoid tumor of kidney (MRTK) is highly aggressive tumor of infancy and childhood. MRTK is unique in its significant association with primary brain tumours or brain metastases. We describe a case of malignant rhabdoid tumor of kidney, who first presented as posterior fossa brain tumor. Renal tumor was discovered incidentally during cerebral medullary MRI.

A prospective behavioral and imaging study exploring the impact on long-term memory of radiotherapy delivered for a brain tumor in childhood and adolescence

BackgroundPosterior fossa tumors represent two thirds of brain tumors in children. Although progress in treatment has improved survival rates over the past few years, long-term memory impairments in survivors are frequent and have an impact on academic achievement. The hippocampi, cerebellum and cerebellar-cortical networks play a role in several memory systems. They are affected not only by the location of the tumor itself and its surgical removal, but also by the supratentorial effects of complementary treatments, particularly radiotherapy. The IMPALA study will investigate the impact of irradiation doses on brain structures involved in memory, especially the hippocampi and cerebellum. Methods/designIn this single-center prospective behavioral and neuro-imaging study, 90 participants will be enrolled in three groups. The first two groups will include patients who underwent surgery for a posterior fossa brain tumor in childhood, who are considered to be cured, and who completed treatment at least 5 years earlier, either with radiotherapy (aggressive brain tumor; Group 1) or without (low-grade brain tumor; Group 2). Group 3 will include control participants matched with Group 1 for age, sex, and handedness. All participants will perform an extensive battery of neuropsychological tests, including an assessment of the main memory systems, and undergo multimodal 3 T MRI. The irradiation dose to the different brain structures involved in memory will be collected from the initial radiotherapy dosimetry. DiscussionThis study will provide long-term neuropsychological data about four different memory systems (working memory, episodic memory, semantic memory, and procedural memory) and the cognitive functions (attention, language, executive functions) that can interfere with them, in order to better characterize memory deficits among the survivors of brain tumors. We will investigate the correlations between neuropsychological and neuroimaging data on the structural (3DT1), microstructural (DTI), functional (rs-fMRI), vascular (ASL) and metabolic (spectroscopy) impact of the tumor and irradiation dose. This study will thus inform the setting of dose constraints to spare regions linked to the development of cognitive and memory functions. Trial registrationClinicalTrials.gov: NCT04324450, registered March 27, 2020, updated January 25th, 2021. Retrospectively registered, https://www.clinicaltrials.gov/ct2/show/NCT04324450.

Differentiation of Posterior Fossa Brain Tumors by Diffusion Weighted Imaging

Background: Diffusion Weighted Imaging (DWI) and Apparent Diffusion Coefficient (ADC) map provide information on Magnetic Resonance Imaging (MRI) about the cellularity of the tumor and have an important role in the pre-operative differentiation of different tumor types. The aim of the current study is to differentiate between pediatric and adult posterior fossa brain tumours using DWI calculation of ADC value of these tumours and correlate our findings with the histopathological reported data. Methods: Our study included a total of 34 patients with posterior fossa brain tumours. Conventional MRI and MRI DWI were applied for each patient. The calculation of the ADC value was performed for the pediatric and adult posterior fossa brain tumours. Results: This study included 34 patients with posterior fossa brain tumours,19 males and 15 females while the cases were selected randomly from the neurosurgery department. Our study has been divided into pediatric group which included 11 patients and adult group with 23 patients. We found a significant difference in 1 (regions of interest) ROI ADC values between all types of pediatric posterior fossa brain tumours (p&lt;0.001). Furthermore, there was a significant difference in 3 ROIs ADC values between all types of pediatric posterior fossa brain tumours (p&lt;0.001). There were no significant differences in 1 ROIs ADC values as well as 3 ROIs ADC values between the adult posterior fossa brain tumors (p value&gt; 0.05). Conclusion: ADC values are simple and readily available techniques for preoperative differentiation of the most common posterior fossa.

Posterior Fossa Tumors in Pediatric Age Group, an Epidemiological Study

Background: There are no data so far relating posterior fossa brain tumors in pediatric age group in Bangladesh. We are dealing with this type of tumors regularly. So an attempt has been made to document these tumors in respect to their incidence in our country, mode of presentation, age and sex distribution, treatment offered to them and their complication and outcome. Methods: This study was conducted in the Department of Pediatric Neurosurgery, National Institute of Neurosciences and Hospital. It was a retrospective study and cases were collected from 2013-2020. Result: We dealt with 60 cases of posterior fossa brain tumors. Out of them 21 were medulloblastoma,19 pilocytic astrocytoma, 11ependymoma and rest are other tumors. Almost all patients presented with hydrocephalus and in most cases CSF diversion was done before definitive tumors surgery. Conclusion: This is only a partial picture of total posterior fossa tumors in pediatric age group. This type of study should be done in a larger scale and newer modalities of diagnostics should be widely practiced for a better post-operative treatment and better prognosis. Bang. J Neurosurgery 2021; 10(2): 182-184