Therapeutic schedules influence the pattern of intellectual decline after irradiation of posterior fossa tumors

Neurocognitive development after pediatric brain tumor - a longitudinal, retrospective cohort study

Survivors of Pediatric Brain Tumors (PBTs) treated with cranial radiation therapy (CRT) often experience a decline in neurocognitive test scores. Less is known about the neurocognitive development of non-irradiated survivors of PBTs. The aim of this study was to statistically model neurocognitive development after PBT in both irradiated and non-irradiated survivors and to find clinical variables associated with the rate of decline in neurocognitive scores. A total of 151 survivors were included in the study. Inclusion criteria: Diagnosis of PBT between 2001 and 2013 or earlier diagnosis of PBT and turning 18 years of age between 2006 and 2013. Exclusion criteria: Death within a year from diagnosis, neurocutaneous syndromes, severe intellectual disability. Clinical neurocognitive data were collected retrospectively from medical records. Multilevel linear modeling was used to evaluate the rate of decline in neurocognitive measures and factors associated with the same. A decline was found in most measures for both irradiated and non-irradiated survivors. Ventriculo-peritoneal (VP) shunting and treatment with whole-brain radiation therapy (WBRT) were associated with a faster decline in neurocognitive scores. Male sex and supratentorial lateral tumor were associated with lower scores. Verbal learning measures were either stable or improving. Survivors of PBTs show a pattern of decline in neurocognitive scores irrespective of treatment received, which suggests the need for routine screening for neurocognitive rehabilitation. However, survivors treated with WBRT and/or a VP shunt declined at a faster rate and appear to be at the highest risk of negative neurocognitive outcomes and to have the greatest need for neurocognitive rehabilitation.

Intelligence and executive function are associated with age at insult, time post-insult, and disability following chronic pediatric acquired brain injury

Background

Pediatric acquired brain injury (pABI) profoundly affects cognitive functions, encompassing IQ and executive functions (EFs). Particularly, young age at insult may lead to persistent and debilitating deficits, affecting daily-life functioning negatively. This study delves into the intricate interplay of age at insult, time post-insult, and their associations with IQ and EFs during chronic (>1 year) pABI. Additionally, we investigate cognitive performance across different levels of global function, recognizing the multifaceted nature of developmental factors influencing outcomes.

Methods

Drawing upon insult data and baseline information analyzing secondary outcomes from a multicenter RCT, including comprehensive medical and neuropsychological assessments of participants aged 10 to 17 years with pABI and parent-reported executive dysfunctions. The study examined associations between age at insult (early, EI; ≤7y vs. late, LI; > 7y) and time post-insult with IQ and EFs (updating, shifting, inhibition, and executive attention). Additionally, utilizing the Pediatric Glasgow Outcome Scale-Extended, we explored cognitive performance across levels of global functioning.

Results

Seventy-six participants, median 8 years at insult and 5 years post-insult, predominantly exhibiting moderate disability (n = 38), were included. Notably, participants with LI demonstrated superior IQ, executive attention, and shifting compared to EI, [adjusted mean differences with 95% Confidence Intervals (CIs); 7.9 (1.4, 14.4), 2.48 (0.71, 4.24) and 1.73 (0.03, 3.43), respectively]. Conversely, extended post-insult duration was associated with diminished performances, evident in mean differences with 95% CIs for IQ, updating, shifting, and executive attention compared to 1-2 years post-insult [-11.1 (-20.4, -1.7), -8.4 (-16.7, -0.1), -2.6 (-4.4, -0.7), -2.9 (-4.5, -1.2), -3.8 (-6.4, -1.3), -2.6 (-5.0, -0.3), and -3.2 (-5.7, -0.8)]. Global function exhibited a robust relationship with IQ and EFs.

Conclusion

Early insults and prolonged post-insult durations impose lasting tribulations in chronic pABI. While confirmation through larger studies is needed, these findings carry clinical implications, underscoring the importance of vigilance regarding early insults. Moreover, they dispel the notion that children fully recover from pABI; instead, they advocate equitable rehabilitation offerings for pABI, tailored to address cognitive functions, recognizing their pivotal role in achieving independence and participation in society. Incorporating disability screening in long-term follow-up assessments may prove beneficial.

Quality of life in survivors of pediatric medulloblastoma: a systematic review and meta-analysis

INTRODUCTION

Medulloblastoma (MB) is the most common malignant pediatric brain tumor. The mainstay of treatment is maximum surgical resection and craniospinal radiation, which may be followed by chemotherapy. The debilitating effect of the tumor and the intensive treatment approaches in MB lead to long-term neuropsychological, physical, and chronic medical problems. We conducted a systematic review to assess the quality of life (QoL) in the long-term survivors of MB and the factors leading to compromised QoL.

METHODS

We utilized the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines for our review. A comprehensive literature search was performed using PubMed, Cochrane Library, Digital Commons Network, and Wiley Online Library databases to search for articles having quality of life, medulloblastoma, and pediatric survivors in title or abstract. We removed duplicates and screened through titles, and full texts. Twelve articles were included in our study. Articles using and reporting all domains of PaedsQL were included in the meta-analysis. The PaedsQL scores of survivors and their caregivers were compared. Subgroup analysis was conducted for craniospinal and proton radiotherapy groups.

RESULTS

As compared to other posterior fossa tumors, MB survivors have the lowest QoL scores. There is a difference in the perception of QoL of survivors between caregivers and survivors themselves with survivors rating themselves higher in several domains. The overall PaedsQL scores were significantly different for both groups (p < 0.001). Subgroup analysis showed that the difference between those who were treated with craniospinal or proton radiation was not significant (p = 0.76). For the subscales, physical (p = 0.005), psychosocial (p = 0.0003), and school (p = 0.03) perceptions were significantly different for the survivors and their caregivers; however, psychosocial (p = 0.80) and emotional (p = 0.93) scales were not different for the survivors or caregivers. Patient characteristics related to a worse QoL included disease severity, metastatic disease, lesser family income, smaller current ventricle size, need for permanent hydrocephalus treatment, and lesser age at diagnosis.

CONCLUSION

An analysis of various studies, using different measures of QoL, concludes that QoL is compromised in all pediatric survivors of MB; however, the perception of QoL of the survivors is better than objective or caretaker-rated QoL.

Clinical and molecular analysis of smoothened inhibitors in Sonic Hedgehog medulloblastoma

Background

Smoothened inhibitors (SMOi) have shown activity in Sonic Hedgehog (SHH) medulloblastoma, however this therapeutic class was not developed in children due to severe effects reported on growth. We hereby report long-term follow-up of young patients treated with SMOi for recurrent medulloblastoma.

Methods

Clinical data on response and toxicity from patients treated with vismodegib or sonidegib from 2011 to 2019 for a SHH medulloblastoma were retrospectively reviewed. Methylation analysis and whole exome sequencing were performed whenever possible.

Results

All patients with a somatic PTCH1 mutation responded to SMOi (6/8), including 2 prolonged complete responses. One patient was free of disease 8.2 years after treatment. SMOi was challenged again for 3 patients. Two of them had a response, one with SMOi alone, the other one in combination with temozolomide despite previous progression under monotherapy. SMO resistance mutations were found in patients from biopsy at relapse. Combination with temozolomide or surgery plus radiotherapy was associated with very long disease control in 2 patients. The most severe adverse events were myalgia and growth plate fusion with metaphyseal sclerosis. Normal growth velocity was recovered for 1 patient although her final height was below estimated target height.

Conclusions

Targeting SMO in mutated PTCH1 is an interesting strategy for long-term responses. Combination of SMOi with chemotherapy or surgery and local radiotherapy is an appealing strategy to prevent early resistance and diminish SMOi exposure, especially in young patients. Inhibition of SHH pathway causes growth and development impairment but partial recovery of the growth velocity is possible.

The role of cerebellum in the child neuropsychological functioning

This chapter proposes a review of neuropsychologic and behavior findings in pediatric pathologies of the cerebellum, including cerebellar malformations, pediatric ataxias, cerebellar tumors, and other acquired cerebellar injuries during childhood. The chapter also contains reviews of the cerebellar mutism/posterior fossa syndrome, reported cognitive associations with the development of the cerebellum in typically developing children and subjects born preterm, and the role of the cerebellum in neurodevelopmental disorders such as autism spectrum disorders and developmental dyslexia. Cognitive findings in pediatric cerebellar disorders are considered in the context of known cerebellocerebral connections, internal cellular organization of the cerebellum, the idea of a universal cerebellar transform and computational internal models, and the role of the cerebellum in specific cognitive and motor functions, such as working memory, language, timing, or control of eye movements. The chapter closes with a discussion of the strengths and weaknesses of the cognitive affective syndrome as it has been described in children and some conclusions and perspectives.

Exclusive Hyperfractionated Radiation Therapy and Reduced Boost Volume for Standard-Risk Medulloblastoma: Pooled Analysis of the 2 French Multicentric Studies MSFOP98 and MSFOP 2007 and Correlation With Molecular Subgroups

PURPOSE

Medulloblastoma has recently been characterized as a heterogeneous disease with 4 distinct molecular subgroups: wingless (WNT), sonic hedgehog (SHH), group 3, and group 4, with a new definition of risk stratification. We report progression-free survival, overall survival, and long-term cognitive effects in children with standard-risk medulloblastoma exclusively treated with hyperfractionated radiation therapy (HFRT), reduced boost volume, and online quality control, and we explore the prognostic value of biological characteristics in this chemotherapy-naïve population.

METHODS AND MATERIALS

Patients with standard-risk medulloblastoma were enrolled in 2 successive prospective multicentric studies, MSFOP 98 and MSFOP 2007, and received exclusive HFRT (36 Gy, 1 Gy/fraction twice daily) to the craniospinal axis followed by a boost at 68 Gy restricted to the tumor bed (1.5 cm margin), with online quality assurance before treatment. Patients with MYC or MYCN amplification were not excluded at the time of the study. We report progression-free survival and overall survival in the global population, and according to molecular subgroups as per World Health Organization 2016 molecular classification, and we present cognitive evaluations based on the Wechsler scale.

RESULTS

Data from 114 patients included in the MSFOP 98 trial from December 1998 to October 2001 (n = 48) and in the MSFOP 2007 from October 2008 to July 2013 (n = 66) were analyzed. With a median follow-up of 16.2 (range, 6.4-19.6) years for the MSFOP 98 cohort and 6.5 (1.6-9.6) years for the MSFOP 2007 cohort, 5-year overall survival and progression-free survival in the global population were 84% (74%-89%) and 74% (65%-81%), respectively. Molecular classification was determined for 91 patients (WNT [n = 19], SHH [n = 12], and non-WNT/non-SHH [n = 60]-including group 3 [n = 9], group 4 [n = 29], and not specified [n = 22]). Our results showed more favorable outcome for the WNT-activated subgroup and a worse prognosis for SHH-activated patients. Three patients had isolated extra-central nervous system relapse. The slope of neurocognitive decline in the global population was shallower than that observed in patients with a normofractionated regimen combined with chemotherapy.

CONCLUSIONS

HFRT led to a 5-year survival rate similar to other treatments combined with chemotherapy, with a reduced treatment duration of only 6 weeks. We confirm the MSFOP 98 results and the prognostic value of molecular status in patients with medulloblastoma, even in the absence of chemotherapy. Intelligence quotient was more preserved in children with medulloblastoma who received exclusive HFRT and reduced local boost, and intelligence quotient decline was delayed compared with patients receiving standard regimen. HFRT may be appropriate for patients who do not consent to or are not eligible for prospective clinical trials; for patients from developing countries for whom aplasia or ileus may be difficult to manage in a context of high cost/effectiveness constraints; and for whom shortened duration of RT may be easier to implement.

Effects of supratentorial and infratentorial tumor location on cognitive functioning of children with brain tumor

PURPOSE

Effects of tumor location on cognitive performance of patients with brain tumor are controversial: some studies reported higher risks related to supratentorial locations, some to infratentorial locations, and still others did not find any differences. We aimed to address this issue by comparing school-aged children with supratentorial or infratentorial tumor with respect not only to cognitive outcomes but also to the associations between core cognitive domains and academic abilities.

METHODS

32 children with infratentorial tumor and 22 with supratentorial tumor participated in the study. To detect relationships among cognitive domains, we tested which neuropsychological variable(s) predicted academic skills, controlling for the effects of radiotherapy and time since diagnosis.

RESULTS

Radiotherapy and time since diagnosis, but not tumor location, predicted cognitive outcomes. Radiotherapy negatively influenced attention and executive functioning, as well as reading speed and arithmetic operations accuracy. Unexpectedly, longer time since diagnosis was associated with improvement in attention and reading speed. Tumor location showed an effect on the relationships between core cognitive domains and academic skills: verbal and visual-spatial memory influenced reading and mathematical performance in supratentorial patients; in infratentorial patients, an only effect of visual-spatial memory on mathematical performance was detected.

CONCLUSIONS

Tumor location seems not to influence cognitive performance, while radiotherapy constitutes a key risk factor for cognitive impairment. Attentional and reading abilities may improve over time, possibly due to the weakening of cancer care effects. Different patterns of cognitive associations seem to characterize supratentorial and infratentorial patients, probably associated with different neuroplastic reorganization processes after tumor occurrence.

The European Society of Paediatric Oncology Ependymoma-II program Core-Plus model: Development and initial implementation of a cognitive test protocol for an international brain tumour trial

It is increasingly accepted that survival alone is an inadequate measure of the success of childhood brain tumour treatments. Consequently, there is growing emphasis on capturing quality of survival. Ependymomas are the third most frequently occurring brain tumours in childhood and present significant clinical challenges. European Society of Paediatric Oncology Ependymoma II is a comprehensive international program aiming to evaluate outcomes under different treatment regimens and improve diagnostic accuracy. Importantly, there has been agreement to lower the age at which children with posterior fossa ependymoma undergo focal irradiation from three years to either eighteen months or one year of age. Hitherto radiotherapy in Europe had been reserved for children over three years due to concerns over adverse cognitive outcomes following irradiation of the developing brain. There is therefore a duty of care to include longitudinal cognitive follow-up and this has been agreed as an essential trial outcome. Discussions between representatives of 18 participating European countries over 10 years have yielded European consensus for an internationally accepted test battery for follow-up of childhood ependymoma survivors. The 'Core-Plus' model incorporates a two-tier approach to assessment by specifying core tests to establish a minimum dataset where resources are limited, whilst maintaining scope for comprehensive assessment where feasible. The challenges leading to the development of the Core-Plus model are presented alongside learning from the initial stages of the trial. We propose that this model could provide a solution for future international trials addressing both childhood brain tumours and other conditions associated with cognitive morbidity.

Intellectual, educational, and situation-based social outcome in adult survivors of childhood medulloblastoma

PURPOSE

To investigate intellectual and situation-based social outcome and educational achievement in adult survivors of childhood medulloblastoma and analyse factors influencing outcome Methods: We collected demographic, medical and cognitive data, and social and educational outcome at a mean time since the end of treatments of 14.9 years in 58 adults, aged 19-35 years, consecutively treated in a single cancer center between 1989 and 2005.

RESULTS

Ten survivors had severe intellectual disability, 12 were still studying, 23 had a regular employment and 13 were unemployed. Full Scale Intellectual Quotient, assessed 6.6 years after the end of treatments, ranged from 46 to 131. It was strongly associated with educational achievement and significantly lower in patients who experienced postoperative cerebellar mutism, and when parental education level was low.

CONCLUSION

These factors should be systematically considered at diagnosis in order to offer adequate and timely assessments and interventions.

Cognitive functioning of pediatric patients with brain tumor: an investigation of the role of gender

PURPOSE

The female gender has been considered a risk factor for cognitive impairment in pediatric brain tumor survivors. However, it is still unknown which specific cognitive domains are at greater risk of impairment in females. The aim of this study was to explore differences between male and female children in distinct domains of cognitive functioning, in order to deepen knowledge on the topic.

METHODS

The cognitive performance of 100 males and 71 females aged 6-16 years was assessed by Wechsler Intelligence Scales for Children-Third Edition (WISC-III). Differences between males and females were tested not only on intellectual quotients, but also on WISC-III subtests, which allow the evaluation of different cognitive domains. Analyses were performed in the whole sample and dividing children based on the supratentorial vs. infratentorial location of the tumor.

RESULTS

Gender was the only predictor of VIQ in the whole group and in children with supratentorial tumor. Female children with supratentorial tumor performed significantly worse than males in four out of six verbal subtests. However, even among children with infratentorial tumor, females performed worse than males on two verbal subtests.

CONCLUSIONS

Overall, findings of this study suggest that females may have more difficulties than males at manipulating verbal oral material. A possible explanation of these findings could be that females present a greater vulnerability to white matter damage due to the illness and post-adjuvant therapies, in line with reports of the literature on female children with lymphoblastic leukemia.

Visual perception and spatial transformation of the body in children and adolescents with brain tumor

Representations of own and others' body play a crucial role in social interaction. While extensive knowledge has been gathered on the neuropsychological deficits affecting body representation in adult brain lesion patients, little is known on how acquired damage to a developing brain may affect this process. We tested it on pediatric brain tumor survivors, comparing the abilities of 30 children and adolescents (aged 8-16 years) surviving from a supratentorial tumor (STT) or an infratentorial tumor (ITT) in two different tasks of body representation. Thirty children with typical development (TD) served as control group. In the first task, we tested configural (body inversion effect) and holistic (composite illusion effect) processing of others' bodies. In the second task, we tested the ability to perform first-person and object-based mental spatial transformations of own body and external objects, respectively. Configural processing was spared in all patients. Conversely, ITT, but not STT patients, were impaired in the holistic processing of body stimuli. STT patients performed overall worse than both controls and ITT patients at mental spatial transformations of both own body and external objects. ITT children presented selective alteration in using the first-person transformation strategies with body stimuli. Results suggest that body-representation abilities may be heavily affected in pediatric brain tumor survivors. STTs may be associated to greater difficulties in mental visuo-spatial transformation abilities, likely reflecting damage to fronto-parietal circuits. Conversely, ITTs may be associated to specific disturbances of visual body perception abilities that require motor simulation processes, reflecting direct or indirect damage to cerebellar areas.

Cerebellar mutism syndrome

Cerebellar mutism most commonly, but not exclusively, develops in children after surgery for midline cerebellar or intraventricular tumors in the posterior fossa, typically medulloblastoma. Cerebellar mutism syndrome (CMS) comprises a complex set of neurologic and neurocognitive signs and symptoms, the cardinal and central component of which is an initially profound but usually reversible speech disorder. As such, CMS is currently recognized as an extreme form of the so-called cerebellar cognitive affective syndrome (Schmahmann syndrome). The putative cause of CMS is a substantial surgical injury to the proximal components of the bilateral efferent cerebellar pathways, disrupting cerebellar input to the supratentorial brain. The resultant cerebellocerebral diaschisis may lead to supratentorial cortical perfusion depression with frontal predominance. The speech disorder is, therefore, likely an apraxia. As our understanding of the mechanism and the clinical spectrum of CMS evolves, clinically useful preoperative risk stratification schemes, adjustments to surgical strategies and techniques, and possible early therapeutic-rehabilitative measures are being sought and developed to reduce the burden of this severe and particularly handicapping chronic morbidity on affected individuals and their families.

Multidisciplinary rehabilitation for children with brain tumors: A systematic review

BACKGROUND

There is an increasing need to assess the evidence of a multidisciplinary approach for both short-term and long-term management of neurological sequelae arising from the diagnosis and treatment of brain tumors in childhood.

METHODS

We performed a systematic review of the evidence base for multidisciplinary paediatric brain tumor rehabilitation using seven databases. PRISMA guidelines were adhered to and the review was registered with the PROSPERO international prospective register of systematic reviews (registration number CRD42014015070).

RESULTS

The literature search identified 3,061 results. Three service evaluations were included. The review identified limited evidence in favor of multidisciplinary rehabilitation for children with brain tumors. Due to the lack of controlled trial data and heterogeneity of the interventions and outcome measures, no meta-analysis could be performed.

CONCLUSIONS

Studies utilising a coordinated multi-centre approach with standardized outcome measures are recommended in order to enable robust assessment of the efficacy of multidisciplinary rehabilitation services.

Neurocognitive Function and Health-Related Quality of Life in Pediatric Korean Survivors of Medulloblastoma

The neurocognitive function and quality of life of 58 Korean survivors of childhood medulloblastoma were assessed after surgery, cranial radiation and chemotherapy. All patients were evaluated with a battery of neurocognitive function tests and the Pediatric Functional Assessment of Cancer Therapy-Brain Tumor Survivors, which consists of self-report questionnaires on quality of life. The mean full-scale intelligence quotient (IQ), verbal IQ, and performance IQ scores were 90.2, 97.1, and 84.16, respectively. The mean memory quotient (MQ) score was 86.78, which was within 1 standard deviation of the average score of 100. Processing speed, attention, and executive function showed mild to moderate deficits. Intelligence, memory, executive function, visuospatial function, and simple motor function were significantly lower in the patients diagnosed before 8 years of age compared with those diagnosed after 8. The cognitive deficits in the patients diagnosed at younger ages might be related to earlier exposure to craniospinal irradiation and chemotherapy. The patient and parent proxy evaluations of attention, fine motor function, and quality of life did not differ. We found significant neurocognitive changes in a wide range of neurocognitive functional domains in Korean survivors of childhood medulloblastoma. Long-term follow-up studies of survivors of childhood medulloblastoma beginning at the time of their first diagnosis are required to better understand the deficits exhibited by survivors of childhood medulloblastoma, so that intervention strategies and treatment refinements that reduce the long-term neurocognitive decline can be developed.

Measurement of neurodevelopmental changes in children treated with radiation for brain tumors: what is a true 'baseline?'

OBJECTIVE

To review the various ways in which baseline neuropsychological functioning is measured in the extant literature on pediatric brain tumors, describe the pros and cons of each approach, and increase the awareness of researchers as to the implications of each.

METHOD

We reviewed the literature from 1993 to 2013, and classified studies by baseline approach and explicitness of selection of approach.

RESULTS

There are multiple approaches to operationalizing baseline levels of ability and to assess change from baseline. Each approach has strengths and weaknesses, and selection may depend on the question under investigation. Approaches to baseline estimation varied widely with a trend over time toward reliance on statistical modeling. Researchers were often insufficiently explicit about the reasons for adopting a particular approach. The common use of standardized scores requires caution as they obscure critical inferential limitations about change and magnitude of change. Some viable approaches were infrequently used, such as actuarial prediction formulas. Multiple simultaneous methods akin to theory testing and formal methods of construct validation could enhance scientific yield since all approaches are fallible.

CONCLUSIONS

Estimating baseline neuropsychological functioning is very challenging, particularly when it concerns children in the preschool years. Nevertheless, it is a crucial methodological decision with important implications for the interpretation of research findings that needs to be dealt with explicitly.

Core deficits and quality of survival after childhood medulloblastoma: a review

Background

Medulloblastoma is the most common malignant central nervous system tumor in children. Treatment most often includes surgical resection, craniospinal irradiation, and adjuvant chemotherapy. Although survival has improved dramatically, the tumor and its treatments have devastating long-term side effects that negatively impact quality of survival (QoS). The objective was to review the literature on QoS following childhood medulloblastoma.

Methods

This narrative review is based on a Medline database search and examination of the reference lists of papers selected.

Results

Frequent problems after medulloblastoma treatment include medical complications, such as long-term neurological and sensory (hearing loss) impairments; endocrine deficits, including growth problems; and secondary tumors. Neurocognitive impairment is repeatedly reported, with decreasing cognitive performances over time. Although all cognitive domains may be affected, low processing speed, attention difficulties, and working memory difficulties are described as the core cognitive deficits resulting from both cerebellar damage and the negative effect of radiation on white matter development. Long-term psychosocial limitations include low academic achievement, unemployment, and poor community integration with social isolation. Important negative prognostic factors include young age at diagnosis, conventional craniospinal radiotherapy, presence of postoperative cerebellar mutism, and perioperative complications. The influence of environmental factors, such as family background and interventions, remains understudied.

Conclusion

Future studies should focus on the respective impact of radiation, cerebellar damage, genomic and molecular subgroup parameters, and environmental factors on cognitive and psychosocial outcomes. Long-term (probably lifelong) follow-up into adulthood is required in order to monitor development and implement timely, suitable, multi-disciplinary rehabilitation interventions and special education or support when necessary.

A chemical screen for medulloblastoma identifies quercetin as a putative radiosensitizer

Treatment of medulloblastoma in children fails in approximately 30% of patients, and is often accompanied by severe late sequelae. Therefore, more effective drugs are needed that spare normal tissue and diminish long-term side effects. Since radiotherapy plays a pivotal role in the treatment of medulloblastoma, we set out to identify novel drugs that could potentiate the effect of ionizing radiation.Thereto, a small molecule library, consisting of 960 chemical compounds, was screened for its ability to sensitize towards irradiation. This small molecule screen identified the flavonoid quercetin as a novel radiosensitizer for the medulloblastoma cell lines DAOY, D283-med, and, to a lesser extent, D458-med at low micromolar concentrations and irradiation doses used in fractionated radiation schemes. Quercetin did not affect the proliferation of neural precursor cells or normal human fibroblasts. Importantly, in vivo experiments confirmed the radiosensitizing properties of quercetin. Administration of this flavonoid at the time of irradiation significantly prolonged survival in orthotopically xenografted mice. Together, these findings indicate that quercetin is a potent radiosensitizer for medulloblastoma cells that may be a promising lead for the treatment of medulloblastoma in patients.

Functional and neuropsychological late outcomes in posterior fossa tumors in children

Tumors of the posterior fossa (PF) account for up to 60 % of all childhood intracranial tumors. Over the last decades, the mortality rate of children with posterior fossa tumors has gradually decreased. While survival has been the primary objective in most reports, quality of survival increasingly appears to be an important indicator of a successful outcome. Children with a PF tumor can sustain damage to the cerebellum and other brain structures from the tumor itself, concomitant hydrocephalus, the consequences of treatment (surgery, chemotherapy, radiotherapy), or a combination of these factors. Together, these contribute to long-term sequelae in physical functioning, neuropsychological late outcomes (including academic outcome, working memory, perception and estimation of time, and selective attention, long-term neuromotor speech deficits, and executive functioning). Long-term quality of life can also be affected by endocrinological complication or the occurrence of secondary tumors. A significant proportion of survivors of PF tumors require long-term special education services and have reduced rates of high school graduation and employment. Interventions to improve neuropsychological functioning in childhood PF tumor survivors include (1) pharmacological interventions (such as methylphenidate, modafinil, or donepezil), (2) cognitive remediation, and (3) home-based computerized cognitive training. In order to achieve the best possible outcome for survivors, and ultimately minimize long-term complications, new interventions must be developed to prevent and ameliorate the neuro-toxic effects experienced by these children.

Disrupted sensorimotor synchronization, but intact rhythm discrimination, in children treated for a cerebellar medulloblastoma

The aim of this study was to investigate the temporal abilities of children treated by surgery for a malignant tumor in the cerebellum, both in the perception and the production of rhythm. Children with a diagnosed medulloblastoma and age-matched control children were tested in a rhythm discrimination task and a sensorimotor synchronization task. Their motor and cognitive capabilities were also assessed through a battery of age-adapted neuropsychological tests. The results did not show any significant difference in performance between groups for the discrimination task. On the contrary, children with cerebellar lesions produced longer and more variable inter-tap intervals (ITI) in their spontaneous motor tempo (SMT) than did the control children. However, the length and, to a lesser extent, the variability of their SMT decreased after a synchronization phase, when they had been instructed to tap in synchrony with a beep. During the synchronization task, the children with medulloblastoma succeeded to modify the length of their ITI in response to an auditory rhythm, although with better success when the inter-stimuli intervals (ISI) were shorter than when they were longer than the ITIs of their own SMT. Correlational analyses revealed that children's poorer synchronization performance was related to lower scores in neuropsychological tests assessing motor dexterity and processing speed.

Tandem high-dose chemotherapy and autologous stem cell rescue in children with newly diagnosed high-risk medulloblastoma or supratentorial primitive neuro-ectodermic tumors

BACKGROUND

To assess the feasibility and effectiveness of high-dose chemotherapy (HDC) with stem cell support followed by conventional craniospinal radiotherapy (RT) as treatment for children older than 5 years of age with newly diagnosed high-risk medulloblastoma (MB) or supratentorial PNET (sPNET).

PROCEDURE

Between May 2001 and April 2010, 24 children older than 5 years of age (MB = 21; sPNET = 3), fulfilling inclusion criteria at diagnosis, were treated at Gustave Roussy. After conventional chemotherapy, they received two courses of high-dose thiotepa (600 mg/m(2)) followed by craniospinal RT.

RESULTS

The median follow-up was 4.4 years (range, 0.8-11.3 years). For children with metastatic MB, the 5-year event-free survival (EFS) and overall survival (OS) were 72% and 83%, respectively. The toxicity was manageable. No toxic death occurred. At the most recent evaluation, among the 24 children who had at least one Full Scale Intellectual Quotient (FSIQ) examination at a median follow-up of 3.79 years after diagnosis, the mean estimated FSIQ was 82 (range, 56-114).

CONCLUSIONS

In children with metastatic MB, tandem HDCT with ASCT followed by conventional craniospinal RT proved its feasibility without jeopardizing survival.

Conceptions of time in children treated for malignant cerebellar tumours

PRIMARY OBJECTIVE

Conceptions of time in children having survived malignant cerebellar tumours (CT) and healthy children matched for chronological age (HCCA) were compared, knowing that the cerebellum has been involved in time perception.

METHODS AND PROCEDURE

Study participants included 20 children with CT (13 boys) and 20 HCCA (10 boys) aged 6-12 years. All children with CT were at least 1 year after the end of treatment without relapse. A time questionnaire (TQ) exploring duration of daily activities, time units, planning and diachronic thinking was used, as well as a video animation (VA) displaying cyclic and linear time.

MAIN OUTCOMES AND RESULTS

Children with CT obtained similar results as HCCA for time units, planning and diachronic thinking, but showed more difficulties than controls in estimating the duration of daily activities and understanding linear and cyclic time concepts (VA).

CONCLUSIONS

These findings are not in favour of impaired time conceptions in children with CT and are probably linked to the specific life experience among children treated for a malignant pathology, rather than to the role of the cerebellum in time processing.

Central nervous system tumors

Central nervous system tumors are the most frequent malignant tumor in children and the main cause of death in this age group after traffic accidents. The current estimates are that one adult in 2500 is a survivor of a brain tumor that occurred during childhood. These tumors are particularly heterogeneous in terms of histology/biology, treatment, and outcome. They share, however, a high risk of neurological and cognitive morbidity due to the disease itself and the treatment modalities (radiotherapy, surgery, and chemotherapy). Diagnosis is frequently delayed because symptoms are usually nonspecific at the beginning of the evolution. Posterior fossa is the most frequent site and the tumors present most frequently with signs of intracranial hypertension. Supratentorial tumors are more frequent in infants and in adolescents; seizures are not uncommon, especially for benign tumors. When adjuvant treatment is needed, radiotherapy is usually the mainstay apart from some histologies where chemotherapy may be sufficient: low-grade gliomas, desmoplastic medulloblastomas, malignant glial tumors in infants. Multidisciplinary care is best performed in tertiary care centers and should include early rehabilitation programs soon after surgery.

Estimated clinical benefit of protecting neurogenesis in the developing brain during radiation therapy for pediatric medulloblastoma

We sought to assess the feasibility and estimate the benefit of sparing the neurogenic niches when irradiating the brain of pediatric patients with medulloblastoma (MB) based on clinical outcome data. Pediatric MB survivors experience a high risk of neurocognitive adverse effects, often attributed to the whole-brain irradiation that is part of standard management. Neurogenesis is very sensitive to radiation, and limiting the radiation dose to the hippocampus and the subventricular zone (SVZ) may preserve neurocognitive function. Radiotherapy plans were created using 4 techniques: standard opposing fields, intensity-modulated radiotherapy (IMRT), intensity-modulated arc therapy (IMAT), and intensity-modulated proton therapy (IMPT). Mean dose to the hippocampus and SVZ (mean for both sites) could be limited to 88.3% (range, 83.6%-91.0%), 77.1% (range, 71.5%-81.3%), and 42.3% (range, 26.6%-51.2%) with IMAT, IMRT, and IMPT, respectively, while maintaining at least 95% of the prescribed dose in 95% of the whole-brain target volume. Estimated risks for developing memory impairment after a prescribed dose of 23.4 Gy were 47% (95% confidence interval [CI], 21%-69%), 44% (95% CI, 21%-65%), 41% (95% CI, 22%-60%), and 33% (95% CI, 23%-44%) with opposing fields, IMAT, IMRT, and IMPT, respectively. Neurogenic niche sparing during cranial irradiation of pediatric patients with MB is feasible and is estimated to lower the risks of long-term neurocognitive sequelae. Greatest sparing is achieved with intensity-modulated proton therapy, thus making this an attractive option to be tested in a prospective clinical trial.

[Medulloblastomas: review]

INTRODUCTION

The term of "medulloblastoma" refers to cerebellar tumors belonging to the family of primitive neuro-ectodermic tumors (PNET). Medulloblastomas represent 40% of cerebellar tumors, 15 to 20% of brain tumors and the first cause of malignant brain tumors in childhood. Seventy to 80% of cases are diagnosed in children versus 20 to 30% in adults.

UPDATED KNOWLEDGE

Diagnosis is based on clinical and radiological exams, and proved on pathological analysis in association with molecular biology. Treatment comprises surgery, craniospinal radiotherapy except for children under five years of age and chemotherapy according to age and high-risk criteria. Medulloblastoma is a rare case of a central nervous system tumor which is radio- and chemo-sensitive. Treatment goals are, on one hand, to improve the survival rates and, on the other hand, to avoid late neurocognitive, neuroendocrine and orthopedic side effects related to radiation therapy, notably in children. The prognosis is relatively good, with a five year survival rate over 75% after complete resection of a localized tumor although sequelae may still compromise outcome.

PERSPECTIVES AND CONCLUSION

Management of patients with medulloblastoma implies a multidisciplinary approach combining the contributions of neurosurgery, neuroradiology, pediatric oncology, neuro-oncology and radiotherapy teams.

Survival and prognostic factors of early childhood medulloblastoma: an international meta-analysis

PURPOSE

To assess the prognostic role of clinical parameters and histology in early childhood medulloblastoma.

PATIENTS AND METHODS

Clinical and histologic data from 270 children younger than age 5 years diagnosed with medulloblastoma between March 1987 and July 2004 and treated within prospective trials of five national study groups were centrally analyzed.

RESULTS

Two hundred sixty children with medulloblastoma and specified histologic subtype were eligible for analysis (median age, 1.89 years; median follow-up, 8.0 years). Rates for 8-year event-free survival (EFS) and overall survival (OS) were 55% and 76%, respectively, in 108 children with desmoplastic/nodular medulloblastoma (DNMB) or medulloblastoma with extensive nodularity (MBEN); 27% and 42%, respectively, in 145 children with classic medulloblastoma (CMB); and 14% and 14%, respectively, in seven children with large-cell/anaplastic (LC/A) medulloblastoma (P < .001). Histology (DNMB/MBEN: hazard ratio [HR], 0.44; 95% CI, 0.31 to 0.64; LC/A medulloblastoma: HR, 2.27; 95% CI, 0.95 to 5.54; P < .001 compared with CMB), incomplete resection and metastases (M0R1: HR, 1.86; 95% CI, 1.29 to 2.80; M+: HR, 2.28; 95% CI, 1.50 to 3.46; P < .001 compared with M0R0), and national group were independent prognostic factors for EFS, and OS. The HRs for OS ranged from 0.14 for localized M0 and DNMB/MBEN to 13.67 for metastatic LC/A medulloblastoma in different national groups.

CONCLUSION

Our results confirm the high frequency of desmoplastic variants of medulloblastomas in early childhood and histopathology as a strong independent prognostic factor. A controlled de-escalation of treatment may be appropriate for young children with DNMB and MBEN in future clinical trials.

A comprehensive model of care for rehabilitation of children with acquired brain injuries

BACKGROUND

Acquired brain injury (ABI) is a leading cause of death and lifelong acquired disability in children and remains a significant public health issue. Deficits may only become fully apparent when developmental demands increase and once cognitive processes are expected to be fully developed. It is therefore necessary to provide organized long-term follow-up for children post ABI. Despite these recommendations, it has been shown that only a small proportion of children received specialized rehabilitation and adequate follow-up after ABI.

AIMS

The aims are: (i) to describe a comprehensive model of care devoted to children with acquired brain injuries; and (ii) to provide descriptive data analysing the characteristics of children followed up, the type/amount of services provided and general outcomes.

PROGRAMME DESCRIPTION

The programme features an in- and outpatient rehabilitation facility, where multidisciplinary rehabilitation and specialized schooling are provided. The ultimate goal of the programme is to promote each child's successful reintegration in school and in the community. Adequate preparation of discharge is essential, long-term follow-up is organized, and an outreach programme has been developed to deal with the complex delayed psychosocial issues.

RESULTS

Overall outcome, as measured by the Glasgow Outcome Scale, improved dramatically between admission (3.3; SD = 0.45) and discharge (2.15; SD = 0.74). Most of the children were discharged home with an adequate personalized plan for ongoing rehabilitation and school adaptations. Analysis of the outreach programme underlines the more challenging issues arising in late adolescence-early adulthood.

CONCLUSION

Given the specificities of childhood ABI, long-term specific care must be organized and co-ordinated, regardless of injury severity.

Rehabilitation for survivors of pediatric brain tumors: our work has just begun

CNS tumors are the second most common childhood cancer, and survival rates for children with these tumors have increased over the last few decades. Children are often treated with a combination of neurosurgery, chemotherapy and cranial radiation. Both the tumors and these therapies can lead to cognitive challenges, decreased social participation or coping, and physical dysfunction, which can impede a child’s ability to complete daily activities and participate in his or her environment. This review describes these late effects in the framework of the International Classification of Functioning, Disability and Health, and discusses the few studies that have attempted to improve children’s functioning in their environment beyond just survival.

Investigating verbal and visual auditory learning after conformal radiation therapy for childhood ependymoma

PURPOSE

The primary objective of this study was to determine whether children with localized ependymoma experience a decline in verbal or visual-auditory learning after conformal radiation therapy (CRT). The secondary objective was to investigate the impact of age and select clinical factors on learning before and after treatment.

METHODS AND MATERIALS

Learning in a sample of 71 patients with localized ependymoma was assessed with the California Verbal Learning Test (CVLT-C) and the Visual-Auditory Learning Test (VAL). Learning measures were administered before CRT, at 6 months, and then yearly for a total of 5 years.

RESULTS

There was no significant decline on measures of verbal or visual-auditory learning after CRT; however, younger age, more surgeries, and cerebrospinal fluid shunting did predict lower scores at baseline. There were significant longitudinal effects (improved learning scores after treatment) among older children on the CVLT-C and children that did not receive pre-CRT chemotherapy on the VAL.

CONCLUSION

There was no evidence of global decline in learning after CRT in children with localized ependymoma. Several important implications from the findings include the following: (1) identification of and differentiation among variables with transient vs. long-term effects on learning, (2) demonstration that children treated with chemotherapy before CRT had greater risk of adverse visual-auditory learning performance, and (3) establishment of baseline and serial assessment as critical in ascertaining necessary sensitivity and specificity for the detection of modest effects.

Online quality control, hyperfractionated radiotherapy alone and reduced boost volume for standard risk medulloblastoma: long-term results of MSFOP 98

PURPOSE

To determine event free and overall survival, and long-term cognitive sequelae of children with standard-risk medulloblastoma (SRM) treated with hyperfractionated radiotherapy, conformal reduced boost volume without chemotherapy, and online quality assurance.

PATIENTS AND METHODS

Forty-eight patients (age 5 to 18 years) were included in the Medulloblastoma-Société Française d'Oncologie Pédiatrique (MSFOP 98) protocol (December 1998 to October 2001). Patients received hyperfractionated radiotherapy (HFRT; 36 Gy, 1 Gy/fraction twice per day) to the craniospinal axis followed by a boost to the tumor bed (1.5-cm margin) to a dose of 68 Gy. Records of craniospinal irradiation were reviewed before treatment started. Neuropsychologic evaluations were done according to the protocol (1, 3, 5, and 7 years after irradiation). Cognitive outcomes were followed longitudinally with full-scale intelligence quotient (FSIQ) obtained with age-adapted Wechsler scales.

RESULTS

After a median follow-up of 77.7 months, 6-year overall survival (OS) and event-free survival (EFS) rates for the cohort were 78% (95% CI, 66% to 90%) and 75%, respectively (95% CI, 62% to 87%). Thanks to quality control, 14 major deviations were detected. Annual full scale IQ decline was 2 points over a 6-year period. Predicted change in FSIQ points per year was 2.15 (95% CI, -1.24 to 3.51) with an intercept (ie, predicted FSIQ) of 93.57 at baseline.

CONCLUSION

HFRT protocol with conformal reduced boost and online quality control allows excellent long-term OS and EFS in the absence of chemotherapy. In addition, FSIQ drops seem to be less pronounced than previously reported with standard irradiation regimens.

Role of the cerebellum in the neurocognitive sequelae of treatment of tumours of the posterior fossa: an update

The lengthened survival of patients with tumours of the posterior fossa has brought awareness of the neurocognitive deficits present in this patient population. In the past, these deficits were thought to be caused by radiotherapy damaging supratentorial structures known to be responsible for cognitive processing. This notion led to the development of new treatment protocols to restrict damage to supratentorial regions by decreasing the radiation dose and the irradiated volume. However, these treatment protocols have only resulted in marginal improvements, sometimes at the expense of long-term survival. Moreover, the current published work reports that non-irradiated patients with tumours of the posterior fossa exhibit similar cognitive impairments to irradiated patients. The growth and treatment of tumours of the posterior fossa also damage infratentorial structures, including the cerebellum. Findings from anatomical, clinical, and neuroimaging studies support a role for the cerebellum in cognitive functions similar to those impaired in patients with a tumour of the posterior fossa. Despite these findings, research focused on the treatment of these patients and on decreasing their cognitive impairments either ignores that the cerebellum has been implicated in non-motor functions or argues against the possibility that damage to the cerebellum might result in cognitive sequelae. Future studies need to address the possibility that the cognitive impairments of patients with tumours of the posterior fossa might be determined by a combination of factors, including damage to the cerebellum. Recognition of the important cognitive contributions of the cerebellum might lead to improved cognitive outcome and quality of life for this patient population.

Impairment of intellectual functions after surgery and posterior fossa irradiation in children with ependymoma is related to age and neurologic complications

Background

To investigate the neuropsychological outcome of children treated with surgery and posterior fossa irradiation for localized infratentorial ependymoma.

Methods

23 patients (age 0.3 – 14 years at diagnosis) who were treated with local posterior fossa irradiation (54 Gy) underwent one (4 patients) or sequential (19 patients) neuropsychologic evaluation. The last evaluation was performed at a median of 4.5 (1 to 15.5) years after RT.

Results

Mean last full scale IQ (FSIQ), verbal IQ (VIQ) and PIQ were 89.1, 94.0, and 86.2 respectively. All patients had difficulties with reading, and individual patients showed deficits in visuospatial, memory and attentional tasks. There was no trend for deterioration of intellectual outcome over time. All 5 children with IQ scores ≤ 75 were under the age of four at diagnosis. There was a significant association between the presence of cerebellar deficits and impaired IQ (72.0 vs 95.2, p < 0,001). The absence of hydrocephalus was an indicator of better neuropsychologic outcome (mean FSIQ of 102.6 vs 83.9, p = 0.025).

Conclusion

Within the evaluated cohort, intellectual functions were moderately impaired. Markedly reduced IQ scores were only seen with early disease manifestation and treatment, and postoperative neurological deficits had a strong impact on intellectual outcome.

Remediation of learning difficulties in children after treatment for a cerebellar medulloblastoma: a single-case study

In the process of establishing a methodology for individualized remediation programmes in children treated for cerebellar tumour, this study followed prospectively over 11 years a young child treated for a medulloblastoma at 18 months of age throughout the rehabilitation process. Repeated neuropsychological and academic evaluations evidenced temporary disruptive behaviour, deficient manual and visual abilities, attention and working memory difficulties, but preserved language abilities, in relation with vermian and left cerebellar damage. However, the described remediation programmes and interventions allowed the child to have fluent progression in school. Limits and benefits of rehabilitation are discussed.

Current treatment approaches to early childhood medulloblastoma

Treatment of medulloblastoma, the most common malignant brain tumor of childhood, is particularly challenging in very young children, owing to the increased susceptibility of the immature brain to treatment-induced neurocognitive deficits. Three promising strategies have been developed in combination with systemic postoperative chemotherapy, to avoid craniospinal irradiation for young children with nonmetastatic medulloblastoma, these include: high-dose chemotherapy, with and without local radiotherapy; intraventricular chemotherapy; and local radiotherapy. More intensified strategies may be required for metastatic medulloblastoma. Future studies will clarify the prognostic relevance of desmoplasia, postoperative residual tumor and biological markers to improve stratification criteria by risk-adapted treatment recommendations. An international Phase III trial for young children with nonmetastatic medulloblastoma, comparing survival rates and neurocognitive outcomes of different treatment strategies by standardized criteria, is under discussion.