Age at treatment and long-term performance results in medulloblastoma

Medulloblastomas in Pediatric and Adults

Medulloblastoma is the primary malignant embryonic tumor of the cerebellum and the most common malignant tumor of childhood, accounting up to 25% of all CNS tumors in children, but is extremely rare in adults. Despite the fact that medulloblastomas are one of the most malignant human tumors, it is worthy to note that a great breakthrough has been achieved in our understanding of oncogenesis and the development of real methods of treatment. The main objective of surgical treatment is a maximum resection of tumor with minimal impairment of neurological functions, in order to reduce the volume, remove tumor tissue, get the biopsy, and restore the cerebrospinal fluid flow. The progress of surgical techniques (using a microscope, ultrasound suction), anesthesiology, and intensive care has significantly decreased surgical mortality and increased radicality of tumor removal. Postoperative mortality is less than one percent in most studies, while neurological complications have been reported between 5-10%. Radiotherapy is the main method of treatment in patients older than 3 years, which dramatically improved the recurrence-free survival. Nevertheless, the radiation therapy without systemic chemotherapy leads to a high risk of systemic metastases. After the role of chemotherapy was statistically proven, investigations of the optimal combination of different chemotherapy regimens continued around the world. Currently, 80% of patients can already be cured, however, the quality of life of patients in the long-term period remains quite low, which depends on many factors including endocrinological, cognitive, neurological, and otoneurologic aspects. Thus, the main strategic goal of the development of neuro-oncology is to reduce the doses of radiation therapy to the CNS and the main task of international research is to optimize existing protocols and develop fundamentally new ones based on molecular genetic research in order to improve the quality of life.

The multiple roles of GH in neural ageing and injury

Advanced age is typically associated with a decrease in cognitive function including impairment in the formation and retention of new memories. The hippocampus is critical for learning and memory, especially spatial learning, and is particularly affected by ageing. With advanced age, multiple neural components can be detrimentally affected including a reduction in the number of neural stem and precursor cells, a decrease in the formation of adult born neurons (neurogenesis), and deficits in neural circuitry, all of which ultimately contribute to impaired cognitive function. Importantly, physical exercise has been shown to ameliorate many of these impairments and is able to improve learning and memory. Relevantly, growth hormone (GH) is an important protein hormone that decreases with ageing and increases following physical exercise. Originally described due to its role in longitudinal growth, GH has now been identified to play several additional key roles, especially in relation to the brain. Indeed, the regular decrease in GH levels following puberty is one of the most well documented components of neuroendocrine ageing. Growth hormone deficiency (GHD) has been described to have adverse effects on brain function, which can be ameliorated via GH replacement therapy. Physical exercise has been shown to increase circulating GH levels. Furthermore, we recently demonstrated the increase in exercise-mediated GH is critical for improved cognitive function in the aged mouse. Here we examine the multiple roles that GH plays, particularly in the aged brain and following trauma, irradiation and stroke, and how increasing GH levels can ameliorate deficits in cognition.

Partial-Brain Radiation-Induced Microvascular Cognitive Impairment in Juvenile Murine Unilateral Hippocampal Synaptic Plasticity

PURPOSE

Radiation-induced cognitive deficits have a severe negative impact on pediatric brain tumor patients. The severity of cognitive symptoms is related to the age of the child when radiation was applied, with the most severe effects seen in the youngest. Previous studies using whole-brain irradiation in mice confirmed these findings. To understand ipsilateral and contralateral changes in the hippocampus after partial-brain radiation therapy (PBRT) of the left hemisphere, we assessed the neuroplasticity and changes in the microvasculature of the irradiated and nonirradiated hippocampus in juvenile mice.

METHODS AND MATERIALS

The left hemispheres of 5-week-old mice were irradiated with 2, 8, and 20 Gy and a fractionated dose of 8 Gy in 2 fractions using a computed tomography image guided small animal radiation research platform. Long-term potentiation (LTP) has been monitored ex vivo in the hippocampal cornu ammonis 1 (CA1) region and was assessed 3 days and 5 and 10 weeks after PBRT in both hemispheres and compared to a sham group. Irradiation effects on the hippocampus microvasculature were quantified by efficient tissue clearing and multiorgan volumetric imaging.

RESULTS

LTP in irradiated hippocampal slices of juvenile mice declines 3 days after radiation, lasts up to 10 weeks in the irradiated part of the hippocampus, and correlates with a significantly reduced microvasculature length. Specifically, LTP inhibition is sustained in the irradiated (20 Gy, 8 Gy in 2 fractions, 8 Gy, 2 Gy) hippocampus, whereas the contralateral hippocampus remains unaffected after PBRT. LTP inhibition in the irradiated hemisphere after PBRT might be associated with an impaired microvascular network.

CONCLUSION

PBRT induces a long-lasting impairment in neuroplasticity and the microvessel network of the irradiated hippocampus, whereas the contralateral hippocampus remains unaffected. These findings provide insight into the design of PBRT strategies to better protect the young developing brain from cognitive decline.

Height after photon craniospinal irradiation in pediatric patients treated for central nervous system embryonal tumors

BACKGROUND

We modeled height after craniospinal irradiation (CSI) in pediatric patients with central nervous system (CNS) embryonal tumors to identify factors that impair stature.

PROCEDURE

During 1996-2012, 212 pediatric patients (131 male) with CNS embryonal tumors received postoperative CSI: 23.4 Gy (n = 147) or ≥36 Gy (n = 65), similar postirradiation chemotherapy, and were followed for at least 5 years without tumor progression or other event. The group was further characterized by age at CSI and hormone-replacement therapy received. Models were developed to identify factors associated with growth impairment and estimate final height.

RESULTS

With median follow up of 10.2 years (range 5.0-20.4 years), the mean final height z-scores at 18 years of age, compared to United States standards, were -1.3 for female and -1.5 for male survivors. Younger age at the time of CSI, higher CSI dose, and female sex were associated with height impairment. Factors associated with higher growth rates before 15 years of age were older age at CSI, male sex, CSI dose < 36 Gy, replacement therapy for growth hormone (GH) and central adrenal insufficiency, and white race. Growth after age 15 in male survivors was associated with treatment of gonadotropin deficiency. Linear mixed-effects models were developed using clinical factors to estimate final height, demonstrate the unique growth curve of this cohort, and interactions between clinical variable and radiation dose.

CONCLUSIONS

CSI significantly impaired height at current doses used to treat standard- or high-risk CNS embryonal tumors. Measures to reduce the impact of CSI on height should be sought, with our models serving as benchmarks.

Cerebellar lesions at a young age predict poorer long-term functional recovery

Early studies on long-term functional recovery after motor and premotor lesions showed better outcomes in younger monkeys than in older monkeys. This finding led to the widespread belief that brain injuries cause less impairment in children than adults. However, this view has limitations and a large body of evidence now indicates that cerebral damages can be more harmful when inflicted at young age, during critical periods of neural development. To date, this issue has been mainly investigated in the context of focal and diffuse cortical lesions. Much less is known about the potential influence of early cerebellar damages. Several studies exist in survivor of posterior fossa tumours. However, in these studies, critical confounders were not always considered and contradictory conclusions were provided. We studied the impact or early cerebellar damage on long-term functional recovery in three groups of 15 posterior fossa survivors, comparable with respect to their tumour characteristics (type, size and location) but operated at different ages: young (≤7 years), middle (>7 and ≤13 years) and older (>13 years). Daily (health-related quality of life scale, performance status scale), motor (International Cooperative Ataxia Rating Scale, Pegboard Purdue Test) and cognitive (full-scale intelligence quotient) functioning were assessed. A general linear model controlling for age at surgery, radiotherapy, preservation of deep cerebellar nuclei, tumour volume and delay between surgery and assessment was used to investigate significant variations in outcome measures. Early age at surgery, lesion of deep cerebellar nuclei and postoperative radiotherapy had a significant, independent negative influence on long-term recovery. Tumour volume and delay between surgery and assessment had no statistically detectable impact. The negative influence of early age at surgery was significant in all domains: daily functioning (health-related quality of life scale, performance status scale), motor functioning (International Cooperative Ataxia Rating Scale, Pegboard Purdue Test) and cognitive functioning (full-scale intelligence quotient). These results support the existence of an early critical period of development during which the cerebellar ‘learning machine’ is of critical importance. Although the extent to which the early deficits here observed can be reversed needs now to be established, our data plead for the implementation of prompt and intense rehabilitation interventions in children operated before 7 years of age.

Preclinical Models of Craniospinal Irradiation for Medulloblastoma

Medulloblastoma is an embryonal tumor that shows a predilection for distant metastatic spread and leptomeningeal seeding. For most patients, optimal management of medulloblastoma includes maximum safe resection followed by adjuvant craniospinal irradiation (CSI) and chemotherapy. Although CSI is crucial in treating medulloblastoma, the realization that medulloblastoma is a heterogeneous disease comprising four distinct molecular subgroups (wingless [WNT], sonic hedgehog [SHH], Group 3 [G3], and Group 4 [G4]) with distinct clinical characteristics and prognoses has refocused efforts to better define the optimal role of CSI within and across disease subgroups. The ability to deliver clinically relevant CSI to preclinical models of medulloblastoma offers the potential to study radiation dose and volume effects on tumor control and toxicity in these subgroups and to identify subgroup-specific combination adjuvant therapies. Recent efforts have employed commercial image-guided small animal irradiation systems as well as custom approaches to deliver accurate and reproducible fractionated CSI in various preclinical models of medulloblastoma. Here, we provide an overview of the current clinical indications for, and technical aspects of, irradiation of pediatric medulloblastoma. We then review the current literature on preclinical modeling of and treatment interventions for medulloblastoma and conclude with a summary of challenges in the field of preclinical modeling of CSI for the treatment of leptomeningeal seeding tumors.

Subgroup-specific outcomes of children with malignant childhood brain tumors treated with an irradiation-sparing protocol

PURPOSE

Molecular subgroups of pediatric brain tumors associated with divergent biological, clinical, and prognostic features have been identified. However, data regarding the impact of subgroup affiliation on the outcome of children with malignant brain tumors treated with radiation-sparing protocol is limited. We report long-term clinical outcomes and the molecular subgroups of malignant brain tumors in young children whose first-line treatment was high-dose chemotherapy without irradiation.

METHODS

Tumor subclassification was performed using the Illumina HumanMethylation450 BeadChip (450k) genome-wide methylation array profiling platform. Clinical information was obtained from chart review.

RESULTS

Methylation array profiling yielded information on molecular subgroups in 22 children. Median age at surgery was 26 months (range 1-119 months). Among medulloblastomas (MB), all 6 children in the infant sonic hedgehog (SHH) subgroup were long-term survivors, whereas all 4 children in subgroup 3 MB died. There was one long-term survivor in subgroup 4 MB. One out of five children with ependymoma was a long-term survivor (RELPOS). Both children with primitive neuroectodermal tumors died. One child with ATRT TYR and one child with choroid plexus carcinoma were long-term survivors.

CONCLUSIONS

The efficacy of high-dose chemotherapy radiation-sparing treatment appears to be confined to favorable molecular subgroups of pediatric brain tumors, such as infant SHH MB. Identification of molecular subgroups that benefit from radiation-sparing therapy will aid in the design of prospective, "precision medicine"-driven clinical trials.

C3 deficiency ameliorates the negative effects of irradiation of the young brain on hippocampal development and learning

Radiotherapy in the treatment of pediatric brain tumors is often associated with debilitating late-appearing adverse effects, such as intellectual impairment. Areas in the brain harboring stem cells are particularly sensitive to irradiation (IR) and loss of these cells may contribute to cognitive deficits. It has been demonstrated that IR-induced inflammation negatively affects neural progenitor differentiation. In this study, we used mice lacking the third complement component (C3^−/−) to investigate the role of complement in a mouse model of IR-induced injury to the granule cell layer (GCL) of the hippocampus. C3^−/− and wild type (WT) mice received a single, moderate dose of 8 Gy to the brain on postnatal day 10. The C3^−/− mice displayed 55 % more microglia (Iba-1+) and a trend towards increase in proliferating cells in the GCL compared to WT mice 7 days after IR. Importantly, months after IR C3^−/− mice made fewer errors than WT mice in a reversal learning test indicating better learning capacity in C3^−/− mice after IR. Notably, months after IR C3^−/− and WT mice had similar GCL volumes, survival of newborn cells (BrdU), microglia (Iba-1) and astrocyte (S100β) numbers in the GCL. In summary, our data show that the complement system contributes to IR-induced loss of proliferating cells and maladaptive inflammatory responses in the acute phase after IR, leading to impaired learning capacity in adulthood. Targeting the complement system is hence promising for future strategies to reduce the long-term adverse consequences of IR in the young brain.

Changes in Imaging and Cognition in Juvenile Rats After Whole-Brain Irradiation

PURPOSE

In pediatric cancer survivors treated with whole-brain irradiation (WBI), long-term cognitive deficits and morbidity develop that are poorly understood and for which there is no treatment. We describe similar cognitive defects in juvenile WBI rats and correlate them with alterations in diffusion tensor imaging and magnetic resonance spectroscopy (MRS) during brain development.

METHODS AND MATERIALS

Juvenile Fischer rats received clinically relevant fractionated doses of WBI or a high-dose exposure. Diffusion tensor imaging and MRS were performed at the time of WBI and during the subacute (3-month) and late (6-month) phases, before behavioral testing.

RESULTS

Fractional anisotropy in the splenium of the corpus callosum increased steadily over the study period, reflecting brain development. WBI did not alter the subacute response, but thereafter there was no further increase in fractional anisotropy, especially in the high-dose group. Similarly, the ratios of various MRS metabolites to creatine increased over the study period, and in general, the most significant changes after WBI were during the late phase and with the higher dose. The most dramatic changes observed were in glutamine-creatine ratios that failed to increase normally between 3 and 6 months after either radiation dose. WBI did not affect the ambulatory response to novel open field testing in the subacute phase, but locomotor habituation was impaired and anxiety-like behaviors increased. As for cognitive measures, the most dramatic impairments were in novel object recognition late after either dose of WBI.

CONCLUSIONS

The developing brains of juvenile rats given clinically relevant fractionated doses of WBI show few abnormalities in the subacute phase but marked late cognitive alterations that may be linked with perturbed MRS signals measured in the corpus callosum. This pathomimetic phenotype of clinically relevant cranial irradiation effects may be useful for modeling, mechanistic evaluations, and testing of mitigation approaches.

Quality of life and symptoms in pediatric brain tumor survivors: a systematic review

Little is known about the quality of life of children and youth under the age of 20 who have completed treatment for a pediatric brain tumor. This systematic review was conducted to (a) describe the health-related quality of life (HRQL) outcomes in pediatric brain tumor survivors, (b) identify instruments used to measure HRQL, and (c) determine the relationship between symptoms and HRQL. Using a systematic search and review methodology, databases searched included CINAHL, Medline, Embase, and PsycInfo. No date restrictions were used. Search results elicited 485 articles, of which16 met the inclusion criteria. Compared with their healthy peers, pediatric brain tumor survivors did worse on most measures of physical, psychosocial, social, and cognitive domains of HRQL. Compared with other cancer patients, survivors scored themselves significantly lower on the Pediatric Quality of Life Inventory (PedsQL) social functioning scale, and parents of brain tumor survivors reported lower PedsQL social and total functioning scores for their children. Other variables that were associated with decreased HRQL were degree of hypothalamic tumor involvement, osteopenia, need for special education, older age at diagnosis, greater than 1 year since treatment, and radiation treatment. In these studies, pediatric brain tumor survivors fared worse compared with other cancer survivors or healthy peers on several HRQL domains. Only 3 studies explored the relationship between symptoms, including pain or fatigue, and HRQL in pediatric brain tumor survivors. The relationship between symptoms and HRQL was not well elucidated. More research is needed to explore the multidimensional symptom experience and HRQL outcomes in pediatric brain tumor survivors.

Lipopolysaccharide sensitized male and female juvenile brains to ionizing radiation

Radiotherapy is an effective tool in the treatment of pediatric malignancies but it is associated with adverse side effects, both short- and long-term. One common long-term side effect after cranial radiotherapy is cognitive impairment and this is, at least partly, thought to be caused by reduced hippocampal neurogenesis. Neuroinflammation and a perturbed microenvironment are thought to be important in the dysregulation of neurogenesis seen after irradiation (IR). We investigated the effects of a pre-existing, lipopolysaccharide (LPS)-induced systemic inflammation at the time of IR in both males and females. A single dose of 8 Gy to the brain of postnatal day 14 mice caused an upregulation of cytokines/chemokines (IL-1β, MIP-1β, IL-12, GM-CSF, MIP-1α, IL-17, CCL2 and KC) 6 h after IR, more so in females. Caspase-3 activity, reflecting apoptosis and possibly microglia activation, was elevated 6 h after IR. Females treated with LPS before IR showed a higher caspase-3 activity compared with males. During the chronic phase (3 months post IR), we found that LPS-induced inflammation at the time of IR aggravated the IR-induced injury in both male and female mice, as judged by reduced bromodeoxyuridine incorporation and neurogenesis (doublecortin-positive cells) in the hippocampus. At this late time point, the microglia density was increased by IR, more so in females, indicating long-term effects on the microenvironment. IR increased anxiety-related behavior in vehicle-, but not LPS-, treated animals. However, exploratory behavior was affected by IR in both vehicle- and LPS-treated mice. In conclusion, we found that LPS administration before IR of the young mouse brain aggravated the injury, as judged by reduced hippocampal neurogenesis. This supports the clinical practice to postpone radiotherapy if the patient shows signs of infection. Systemic inflammation is not always obvious, though, for example because of concurrent corticosteroid treatment, so careful monitoring of inflammation is warranted.

Loss of hippocampal neurogenesis, increased novelty-induced activity, decreased home cage activity, and impaired reversal learning one year after irradiation of the young mouse brain

Radiotherapy is a major cause of long-term complications in survivors of pediatric brain tumors. These complications include intellectual and memory impairments as well as perturbed growth and puberty. We investigated the long-term effects of a single 8 Gy irradiation dose to the brains of 14-day-old mice. Behavior was assessed one year after irradiation using IntelliCage and open field, followed by immunohistochemical investigation of proliferation and neurogenesis in the dentate gyrus of the hippocampus. We found a 61% reduction in proliferation and survival (BrdU incorporation 4 weeks prior to sacrifice), 99% decrease in neurogenesis (number of doublecortin-positive cells) and gliosis (12% higher astrocyte density) one year following irradiation. Irradiated animals displayed increased activity in a novel environment but decreased activity in their home cage. Place learning in the IntelliCage was unaffected by irradiation but reversal learning was impaired. Irradiated animals persevered in visiting previously correct corners to a higher extent compared to control animals. Hence, despite the virtual absence of neurogenesis in these old mice, spatial learning could take place. Reversal learning however, where a previous memory was replaced with a new one, was partly impaired. This model is useful to study the so called late effects of radiotherapy to the young brain and to evaluate possible interventions.

Learning and activity after irradiation of the young mouse brain analyzed in adulthood using unbiased monitoring in a home cage environment

Cranial radiotherapy during the treatment of pediatric malignancies may cause adverse late effects. It is important to find methods to assess the functional effects of ionizing radiation in animal models and to evaluate the possible ameliorating effects of preventive or reparative treatment strategies. We investigated the long-term effects of a single 8-Gy radiation dose to the brains of 14-day-old mice. Activity and learning were evaluated in adulthood using open field and trace fear conditioning (TFC). These established methods were compared with the novel IntelliCage platform, which enables unbiased analysis of both activity and learning over time in a home cage environment. Neither activity nor learning was changed after irradiation, as judged by the open field and TFC analyses. The IntelliCage, however, revealed both altered activity and learning impairment after irradiation. Place learning and reversal learning were both impaired in the IntelliCage 3 months after irradiation. These results indicate that activity and learning should be assessed using multiple methods and that unbiased analysis over time in a home cage environment may offer advantages in the detection of subtle radiation-induced effects on the young brain.

Apoptosis-inducing factor deficiency decreases the proliferation rate and protects the subventricular zone against ionizing radiation

Cranial radiotherapy in children often leads to progressive cognitive decline. We have established a rodent model of irradiation-induced injury to the young brain. A single dose of 8 Gy was administered to the left hemisphere of postnatal day 10 (P10) mice. Harlequin (Hq) mice, carrying the hypomorphic apoptosis-inducing factor AIF^Hq mutation, express 60% less AIF at P10 and displayed significantly fewer dying cells in the subventricular zone (SVZ) 6 h after IR, compared with wild type (Wt) littermates. Irradiated cyclophilin A-deficient (CypA^−/−) mice confirmed that CypA has an essential role in AIF-induced apoptosis after IR. Hq mice displayed no reduction in SVZ size 7 days after IR, whereas 48% of the SVZ was lost in Wt mice. The proliferation rate was lower in the SVZ of Hq mice. Cultured neural precursor cells from the SVZ of Hq mice displayed a slower proliferation rate and were more resistant to IR. IR preferentially kills proliferating cells, and the slower proliferation rate in the SVZ of Hq mice may, at least partly, explain the protective effect of the Hq mutation. Together, these results indicate that targeting AIF may provide a fruitful strategy for protection of normal brain tissue against the detrimental side effects of IR.

The growth hormone secretagogue hexarelin increases cell proliferation in neurogenic regions of the mouse hippocampus

OBJECTIVE

Radiation therapy (RT) to the brain is often used in the treatment of children with different types of malignant diseases affecting the brain. However, RT in childhood may also have severe side effects including impaired brain maturation and intellectual development. For childhood cancer survivors these adverse effects of RT can cause lifelong disability and suffering. Therefore, there is an unmet need to limit late effects after RT. Precursor cells in the subgranular zone of the dentate gyrus (DG) in the hippocampus are particularly sensitive to irradiation (IR). This may be of significance as newly generated neurons in the DG are important for memory and learning. GH secretagogues (GHS) have previously been shown to promote neurogenesis and to have neuroprotective effects. In addition, several parts of the brain, including the hippocampus, have been shown to express the GHS receptor 1a (GHS-R1a). The aim of this study was to evaluate the potential effect of the GHS hexarelin on proliferation and survival of progenitor cells in the hippocampus after brain IR in a mouse model.

DESIGN

In the present study, 10-day-old male mice received 6Gy cranial IR. Non-irradiated sham animals were used as controls. We treated one group of irradiated and one sham group with hexarelin (100microg/kg/day) for 28days and used immunohistochemical labeling of bromo-deoxy uridine (BrdU) and phospho-histone H3 of the granular cell layer of the DG to evaluate proliferation and cell survival after IR at postnatal day ten.

RESULTS

Our results show that hexarelin significantly increased the number of BrdU-positive cells in the granule cell layer by approximately 50% compared to controls.

CONCLUSION

The increased number of BrdU-positive cells in the granule cell layer suggests a partial restoration in the pool of proliferating cells by hexarelin after IR.

Irradiation to the immature brain attenuates neurogenesis and exacerbates subsequent hypoxic-ischemic brain injury in the adult

Cranial radiotherapy is common in pediatric oncology. Our purpose was to investigate if irradiation (IR) to the immature brain would increase the susceptibility to hypoxic-ischemic injury in adulthood. The left hemisphere of postnatal day 10 (P10) mice was irradiated with 8 Gy and subjected to hypoxia-ischemia (HI) on P60. Brain injury, neurogenesis and inflammation were evaluated 30 days after HI. IR alone caused significant hemispheric tissue loss, or lack of growth (2.8 +/- 0.42 mm(3), p < 0.001). Tissue loss after HI (18.2 +/- 5.8 mm(3), p < 0.05) was synergistically increased if preceded by IR (32.0 +/- 3.5 mm(3), p < 0.05). Infarct volume (5.1 +/- 1.6 mm(3)) nearly doubled if HI was preceded by IR (9.8 +/- 1.2 mm(3), p < 0.05). Pathological scoring revealed that IR aggravated hippocampal, cortical and striatal, but not thalamic, injury. Hippocampal neurogenesis decreased > 50% after IR but was unchanged by HI alone. The number of newly formed microglia was three times higher after IR + HI than after HI alone. In summary, IR to the immature brain produced long-lasting changes, including decreased hippocampal neurogenesis, subsequently rendering the adult brain more susceptible to HI, resulting in larger infarcts, increased hemispheric tissue loss and more inflammation than in non-irradiated brains.

Differential recovery of neural stem cells in the subventricular zone and dentate gyrus after ionizing radiation

Radiation therapy is a widely used treatment for malignant central nervous system tumors. Mature neurons are terminally differentiated, whereas stem and progenitor cells have a prominent proliferative capacity and are therefore highly vulnerable to irradiation. Our aim was to investigate how cranial radiation in young rats would affect stem/progenitor cells in the two niches of adult neurogenesis, the subventricular zone (SVZ) and the dentate gyrus of the hippocampal formation. Nine weeks after irradiation we found that in irradiated animals, hippocampal neurogenesis was reduced to 5% of control levels. Similarly, the numbers of actively proliferating cells and radial glia-like stem cells (nestin+/glial fibrillary acidic protein [GFAP]+) in the dentate gyrus were reduced to 10% and 15% of control levels, respectively. In the irradiated olfactory bulb, neurogenesis was reduced to 40% of control levels, and the number of actively proliferating cells in the SVZ was reduced to 53% of control levels. However, the number of nestin+/GFAP+ cells in the SVZ was unchanged compared with controls. To evaluate the immediate response to the radiation injury, we quantified the amount of proliferation in the SVZ and dentate gyrus 1 day after irradiation. We found an equal reduction in proliferating cells both in dentate gyrus and SVZ. In summary, we show an initial response to radiation injury that is similar in both brain stem cell niches. However, the long-term effects on stem cells and neurogenesis in these two areas differ significantly: the dentate gyrus is severely affected long-term, whereas the SVZ appears to recover with time.

Transient inflammation in neurogenic regions after irradiation of the developing brain

We characterized the inflammatory response after a single dose of 8 Gy to the brains of postnatal day 9 rats. Affymetrix gene chips revealed activation of multiple inflammatory mechanisms in the acute phase, 6 h after irradiation. In the subacute phase, 7 days after irradiation, genes related to neurogenesis and cell cycle were down-regulated, but glial fibrillary acidic protein (GFAP) was up-regulated. The concentrations of 14 different cytokines and chemokines were measured using a microsphere-based xMAP technology. CCL2, Gro/KC and IL-1alpha were the most strongly up-regulated 6 h after irradiation. CCL2 was expressed in astrocytes and microglia in the dentate gyrus and the subventricular zone (SVZ). Hypertrophy, but not hyperplasia, of astrocytes was demonstrated 7 days after irradiation. In summary, we found transient activation of multiple inflammatory mechanisms in the acute phase (6 h) after irradiation and activation of astrocytes in the subacute phase (7 days) after irradiation. It remains to be elucidated whether these transient changes are involved in the persistent effects of radiation observed on neurogenesis and cognition in rodents.

Irradiation-induced loss of microglia in the young brain

Irradiation-induced loss of neural stem and progenitor cells may contribute to cognitive deficits. Furthermore, subsequent inflammation inhibits neural progenitor cell differentiation. Here we have characterized the microglia response after a single dose of 8 Gy to the brains of postnatal day 9 or 21 rats. The number of Iba-1-positive microglia increased 6 h after IR but had decreased 7 days later, below control levels, and this decrease was more pronounced in P9 rats. Active caspase-3 and TUNEL staining revealed irradiation-induced microglia death. This age-dependent IR-induced loss of microglia likely affects both the response to IR and further brain development.

Magnetic resonance and diffusion tensor imaging in pediatric white matter diseases

The central nervous system undergoes profound and predictable developmental changes during the first few years of life that provide the structural and functional elements necessary for normal neurological development. The establishment and maturation of white matter pathways is a critical component of the developing nervous system. Diffusion tensor imaging (DTI) offers a noninvasive and quantitative means for the evaluation of white matter changes. DTI has contributed to the evaluation of a number of childhood leukoencephalopathies; it has also been used to follow brain maturation in abnormal states, such as premature birth or early brain injury. Furthermore, it has helped characterize the relation between white matter integrity and cognitive abilities. In the future, DTI is expected to play an increasingly large role in defining developmental abnormalities at an early age and in assessing therapies for pediatric disorders such as leukodystrophies.

Intellectual and functional outcome of children 3 years old or younger who have CNS malignancies

PURPOSE

To evaluate the impact of tumor location, clinical parameters, and therapy on neurocognitive, neuroendocrine, and functional outcomes in children < or = 3 years old with intracranial CNS malignancies who survived at least 2 years after diagnosis.

PATIENTS AND METHODS

Records were retrospectively reviewed for 194 children diagnosed from 1985 to 1999 at St Jude Children's Research Hospital (Memphis, TN).

RESULTS

The median age at diagnosis was 1.8 years (range, 0.1 to 3.5 years). Median follow-up was 7.64 years (2.0 to 19.4 years). Tumors were infratentorial (102), diencephalic (53), and hemispheric (39); 47% required ventriculoperitoneal shunts, 36% developed seizure disorders, and 20% developed severe ototoxicity. Therapy included no radiation therapy (RT) in 57 (30%), local RT in 87 (45%), and craniospinal irradiation (CSI) in 49 (25%). Overall survival at 10 years was 78 +/- 4%. In a longitudinal analysis of 126 patients with at least one neurocognitive evaluation (NE), the mean rate of intelligence quotient (IQ) change for patients who received CSI (-1.34 points per year) and local RT (-0.51 points per year) was significantly different from the no RT group (0.91 points per year; P = .005 and P = .036, respectively). Patients with hemispheric tumors had a significantly greater IQ decline (-1.52 points per year) than those with midline tumors (0.59 points per year; P = .038). Among those with NE > or = 5 years after diagnosis, 71.4% of CSI recipients compared with 23% of local RT recipients had IQ less than 70 (P = .021). Patients undergoing CSI were more likely to develop endocrinopathies (P < .0001) and to require special education (P = .0007).

CONCLUSION

In young children with CNS tumors, CSI and hemispheric location are associated with significant declines in IQ scores.

Progenitor cell injury after irradiation to the developing brain can be modulated by mild hypothermia or hyperthermia

Ionizing radiation induced acute cell death in the dentate gyrus subgranular zone (SGZ) and the subventricular zone (SVZ). Hypomyelination was also observed. The effects of mild hypothermia and hyperthermia for 4 h after irradiation (IR) were studied in postnatal day 9 rats. One hemisphere was irradiated with a single dose of 8 Gy and animals were randomized to normothermia (rectal temperature 36 degrees C for 4 h), hypothermia (32 degrees C for 4 h) or hyperthermia (39 degrees C for 4 h). Cellular injury, e.g. chromatin condensation and nitrotyrosine formation, appeared to proceed faster when the body temperature was higher. Caspase-3 activation was more pronounced in the hyperthermia group and nuclear translocation of p53 was less pronounced in the hypothermia group 6 h after IR. In the SVZ the loss of nestin-positive progenitors was more pronounced (48%) and the size was smaller (45%) in the hyperthermia group 7 days post-IR. Myelination was not different after hypo- or hyperthermia. This is the first report to demonstrate that hypothermia may be beneficial and that hyperthermia may aggravate the adverse side-effects after radiation therapy to the developing brain.

Lack of benefit of spinal irradiation in the primary treatment of intracranial germinoma: a multiinstitutional, retrospective review of 180 patients

BACKGROUND

The current study assessed the contribution of spinal irradiation to the treatment outcome of patients with intracranial germinoma.

METHODS

Clinical data from 180 patients with intracranial germinoma, who were treated with radiotherapy and/or chemotherapy from 1980 to 2001, were collected from 6 institutions. The patients' median age was 16 years (range, 1-47 yrs), and the male-to-female ratio was 133:47. Pathologic verification was obtained in 88 patients. A solitary tumor was seen in 129 patients, and multifocal or disseminated tumors were detected in 51 patients. The median tumor size was 2.5 cm (range, 0.6-7.0 cm). Local field and/or whole brain irradiation was performed in 114 patients, and craniospinal irradiation was performed in 66 patients. Fifty-five patients were treated with chemotherapy. The median follow-up time was 89 months (range, 3-297 mos).

RESULTS

Eight-year overall and event-free survival rates were 91% and 89%, respectively. The 8-year recurrence rates at the primary site, intracranial space, and the spinal space were 1%, 6%, and 6%, respectively. Cox regression analysis showed that spinal irradiation (hazard ratio, 1.050; 95% confidence interval [CI], 0.355-3.170) did not contribute to a favorable event-free survival.

CONCLUSIONS

Spinal irradiation did not contribute to favorable event-free survival in patients with intracranial germinoma.

Age-dependent sensitivity of the developing brain to irradiation is correlated with the number and vulnerability of progenitor cells

In a newly established model of unilateral, irradiation (IR)-induced injury we compared the outcome after IR to the immature and juvenile brain, using rats at postnatal days 9 or 23, respectively. We demonstrate that (i) the immature brains contained more progenitors in the subventricular zone (SVZ) and subgranular zone (SGZ) compared with the juvenile brains; (ii) cellular injury, as judged by activation of caspase 3 and p53, as well as nitrotyrosine formation, was more pronounced in the SVZ and SGZ in the immature brains 6 h after IR; (iii) the number of progenitor and immature cells in the SVZ and SGZ decreased 6 h and 7 days post-IR, corresponding to acute and subacute effects in humans, respectively, these effects were more pronounced in immature brains; (iv) myelination was impaired after IR at both ages, and much more pronounced after IR to immature brains; (v) the IR-induced changes remained significant for at least 10 weeks, corresponding to late effects in humans, and were most pronounced after IR to immature brains. It appears that IR induces both an acute loss of progenitors through apoptosis and a perturbed microenvironment incompatible with normal proliferation and differentiation, and that this is more pronounced in the immature brain.

Irradiation-induced progenitor cell death in the developing brain is resistant to erythropoietin treatment and caspase inhibition

One hemisphere of postnatal day 8 (P8) rats or P10 mice was irradiated with a single dose of 4-12 Gy, and animals were killed from 2 h to 8 weeks after irradiation (IR). In the subventricular zone (SVZ) and the granular cell layer (GCL) of the dentate gyrus, harboring neural and other progenitor cells, nitrosylation and p53 peaked 2-12 h after IR, followed by markers for active caspase-3, apoptosis-inducing factor and TUNEL (6-24 h). Ki67-positive (proliferating) cells had disappeared by 12 h and partly reappeared by 7 days post-IR. The SVZ and GCL areas decreased approximately 50% 7 days after IR. The development of white matter was hampered, resulting in 50-70% less myelin basic protein staining. Pretreatment with erythropoietin did not confer protection against IR. Caspase inhibition by overexpression of XIAP prevented caspase-9 and caspase-3 activation but not cell death, presumably because of increased caspase-independent cell death.

Intellectual outcome after reduced-dose radiation therapy plus adjuvant chemotherapy for medulloblastoma: a Children's Cancer Group study

PURPOSE

To investigate the intellectual outcomes of children with medulloblastomas/primitive neuroectodermal tumors (MB/PNET) treated with reduced-dose craniospinal radiotherapy (RT) plus adjuvant chemotherapy.

PATIENTS AND METHODS

Forty-three children with average-risk posterior fossa MB/PNETs underwent longitudinal intelligence testing. All had been treated with a reduced-dose craniospinal RT regimen (23.4 Gy to the neuraxis, 32.4-Gy boost to the posterior fossa) and adjuvant chemotherapy.

RESULTS

The estimated rate of change from baseline was significant for Full Scale Intelligence Quotient (FSIQ), Verbal IQ (VIQ), and Nonverbal IQ (NVIQ) (P <.001 for all three outcomes). The rate of change was estimated to be -4.3 FSIQ points per year, -4.2 VIQ points per year, and -4.0 NVIQ points per year. Females were more subject to VIQ decline than were males (P =.008), and young children (< 7 years of age) were more negatively affected than were older children, with a significant decline in NVIQ (P =.016). Finally, patients with higher baseline evaluations suffered greater declines in IQ than did those with lower baseline scores.

CONCLUSION

This study represents the largest series of patients with average-risk MB/PNETs treated with a combination of reduced-dose RT and adjuvant chemotherapy whose intellectual development has been followed prospectively. Intellectual loss was substantial but suggestive of some degree of intellectual preservation compared with effects associated with conventional RT doses. However, this conclusion remains provisional, pending further research.

Neurocognitive development of children after a cerebellar tumor in infancy: A longitudinal study

PURPOSE

To assess the long-term neuropsychologic effects experienced by children who have tumors in the cerebellum that are diagnosed and treated during infancy.

PATIENTS AND METHODS

Twenty-seven children with posterior fossa tumors diagnosed at less than 36 months of age were assessed prospectively with a comprehensive set of age-appropriate tests. Group means and SDs are reported for assessments conducted at diagnosis (analysis 1) and at the most recent follow-up appointment (analysis 2). Cognitive developmental growth curves were derived from the prospective data (analysis 3) using mixed model regression analyses and controlling for age at diagnosis and socioeconomic status.

RESULTS

In the first analysis, eight of 11 infants at diagnosis scored within normal limits on all neuropsychologic domains, except for motor skills, which were impaired. In the second analysis, mean scores at the most recent follow-up of 21 of 27 patients were mostly in the normal range; however, group comparisons between those who had (n = 7) and had not (n = 14) been treated with cranial radiation therapy (CRT) showed that patients in the irradiated (CRT) group scored significantly lower than those in the nonirradiated (No-CRT) group on verbal intelligence quotient (IQ) and in the motor domain. In the third analysis (growth curves of CRT and No-CRT groups), statistically significant differences in slope were found on verbal IQ, performance IQ, perceptual-motor skills, language, and attention/executive skills. Slopes on the fine-motor domain were similar; both groups declined at approximately the same rate.

CONCLUSION

Neurocognitive development and outcome of children with cerebellar tumors diagnosed in infancy is very positive among those who were treated with surgery and chemotherapy. Declines in performance across time were minimal, and scores tended to remain within normal limits. By itself, a cerebellar tumor in infancy does not seem to have a significant impact on children. However, those who received CRT as part of their treatment are likely to have neurocognitive and psychosocial deficits that require remediational interventions.

Marriage in the survivors of childhood cancer: a preliminary description from the Childhood Cancer Survivor Study

BACKGROUND

The goal of this paper is to provide a preliminary description of the marital status for a large number of childhood cancer survivors participating in the Childhood Cancer Survivor Study (CCSS).

PROCEDURE

This report includes children and adolescents (< 21 years of age) diagnosed with cancer between 1970 and 1986 at 25 oncology centers in the United States and Canada who survived at least 5 years from diagnosis. Self-reported data from 10,425 survivors are used in this preliminary descriptive summary. The proportion of survivors ever married and divorced/separated is compared to the U.S. population according to age-specific groups. The median age of the survivor population at diagnosis was 7 years and 26 years at the time martial status was ascertained. Excluded from this assessment are children < 15 years of age at the time of study, those whose martial status was unknown, and those married prior to diagnosis. Data for marital status of the U.S. population, as tabulated in the Bureau of Census 1995 Update, is used as a general comparison to the survivor population.

RESULTS

Overall, 32% of the survivors reported being married or living as married, 6% being divorced or separated, 0% being widowed, and 62% having never been married. In general, compared to the U.S. population, survivors were less likely to have ever married, particularly females and whites, but, once married, were less likely to divorce/separate, again particularly females and whites. Black survivors were generally found to be more likely to have married, with males and blacks more likely to divorce/separate once married. Comparison of childhood tumor types suggested that survivors of CNS tumors, particularly males, were less likely to have ever married and more likely to divorce/separate compared to those with other cancer diagnoses and the general U.S. population.

CONCLUSIONS

This interim evaluation of the CCSS cohort provided preliminary data describing a suggested decreased likelihood of marriage, which may be influenced by gender and/or race. These patterns must be confirmed within the entire CCSS cohort and comparisons made with an appropriate sibling comparison group before making final conclusions.

Neuropsychological sequelae of medulloblastoma in adults

PURPOSE

To investigate the neuropsychological consequences of medulloblastoma in adults.

METHODS

Patients 18 years of age or older who had medulloblastoma and at least 3 years of disease-free survival were eligible. A battery of tests was conducted to assess global intellectual functioning, verbal ability, visuospatial ability, memory, reasoning, and academic proficiency. For the verbal memory performance, each patient was matched with two normal controls selected on the basis of age, sex, and level of education.

RESULTS

Review of the Neuro-Oncology database revealed 24 patients eligible for the study. Of these, 10 patients (6 good-risk and 4 poor-risk) agreed to participate; 7 patients were lost to follow-up; 5 lived too far away to come to the testing site, and 2 refused testing. There were four men and six women; their mean age was 36.5 years at testing and 29.9 years at surgical diagnosis. Mean dose of whole brain radiation was 34.5 Gy. Mean interval between diagnosis and testing was 79.1 months. Test results demonstrated below average intelligence quotients (mean intelligence quotient 90.2; range 67-103) and specific deficits in memory, reasoning, visuospatial ability, and arithmetic.

CONCLUSION

Adults with medulloblastoma in a prolonged disease-free status may suffer significant cognitive deficits. We recommend further controlled, prospective studies to evaluate cognitive outcomes in this patient population in the hope that interventional strategies could be developed, or treatment modified to minimize such toxicities.

Neuropsychological sequelae of the treatment of children with medulloblastoma

When a malignant tumor invades the child's cerebellum, the cost of successful treatment is often significant cognitive morbidity. A review of neuropsychological outcome revealed that survivors of childhood medulloblastoma (MB) have long-term deficits in intelligence, memory, language, attention, academic skills, psychosocial function, and a compromised quality of life. These deficits varied with chronological age at tumor diagnosis and/or adjuvant treatment, type and duration of presenting symptoms, tumor extension beyond the cerebellum, a history of adjuvant radiation treatment, and time since treatment. The effects on neuropsychological outcome of other factors, such as post-surgical hydrocephalus, were less clear. To understand the interaction between two factors predictive of outcome, age at diagnosis and time since treatment, we analyzed IQ results for a new sample of 25 surgically-treated and radiated MB survivors, and found that age at diagnosis and time since treatment made separable contributions to intellectual morbidity. PIQ appeared to measure some general effects of diffuse cerebral insult because it varied with chronological age of the child at tumor diagnosis but was relatively constant in magnitude, once established. VIQ, in contrast, was somewhat less sensitive to age at diagnosis in treated MB survivors, but declined with time since treatment. These results are important for understanding the academic attainments and continuing rehabilitation needs of childhood MB survivors, because they suggest that these children progressively fail to assimilate new verbally-based knowledge at a developmentally-appropriate rate.

Hearing loss in children with brain tumors treated with cisplatin and carboplatin-based high-dose chemotherapy with autologous bone marrow rescue

Carboplatin is less ototoxic than cisplatin, but ototoxicity may occur with carboplatin at higher doses. We evaluated hearing in children with brain tumors treated with conventional dose cisplatin followed by high-dose carboplatin. Children under 6 years of age, newly diagnosed with brain tumors, were treated after surgery with cisplatin, Etoposide, cyclophosphamide, and vincristine, followed by consolidation with carboplatin, ThioTEPA, Etoposide, and autologous bone marrow rescue. Hearing was assessed before and after consolidation, utilizing standard audiometric techniques. Seven of the 11 evaluable patients developed high-frequency sensorineural hearing loss after induction therapy. Hearing deteriorated after consolidation in five patients, with pure tone threshold shifts of up to 65 dB between 2,000 and 8,000 Hz. Of these five patients, audiological abnormalities were documented in four prior to consolidation, one received cranial irradiation after consolidation, and all five received aminoglycoside antibiotics for at least 2 weeks, with toxic drug levels in four. Three patients have subsequently required hearing aids. Significant ototoxicity is common in these patients. Ototoxicity related to consolidation therapy is likely due to the high dose of carboplatin used, prior cisplatin therapy, aminoglycosides, and, in one patient, cranial irradiation. Audiological assessment is essential in children treated with dose-intensive chemotherapy regimens containing cisplatin and carboplatin for identification and rehabilitation of ototoxicity.

Will high dose chemotherapy followed by autologous bone marrow transplantation supplant cranio-spinal irradiation in young children treated for medulloblastoma?

Cranio-spinal irradiation is the gold standard treatment used in non metastatic medulloblastoma as prophylaxis against central nervous system (CNS) metastases. However, given the severe late effects caused by this procedure in children under 3 years of age, most pediatric oncologists are currently treating these patients with conventional chemotherapy in order to postpone or even avoid irradiation. In the French Society of Pediatric Oncology (SFOP) this attitude has been adopted since 1987. Among the patients treated without radiotherapy, 20 relapsed while on conventional chemotherapy and were entered in a study of high-dose chemotherapy (HDC) followed by ABMT. Their median age at diagnosis was 23 months (R5-71) and the relapse occurred at a median time of 6.3 months after the initiation of chemotherapy. Complete surgical removal of the local relapse was the first treatment in 4/20 patients who were not evaluable for response. Sixteen of the twenty patients had measurable disease at the primary site (9 patients), or at metastatic sites (3 patients) or both (4 patients). The conditioning regimen consisted of combination Busulfan 600 mg/m2 over 4 days and Thiotepa 900 mg/m2 over three days. After recovery from aplasia, patients with a local relapse received local radiotherapy limited to posterior fossa.

RESULTS

among the 16 patients with measurable disease, 6 CR, 6 PR, 3 NR, were observed following HDC (response rate 75%). One patient was not evaluable. For the 20 patients, the EFS is 50%. Among the surviving patients, the median follow up is 31 months post BMT (R12-82). Ten patients who developed a local relapse or local progression are alive with NED without craniospinal irradiation. Among the 7 patients who developed metastases or progression of metastases, only one is alive. Toxicity was high but manageable: the median duration of granulocytopenia < 0.5 x 109/l and thrombocytopenia < 50 x 10(9)/l was 13 and 41 days respectively. Bacteremia was documented in 4 cases. Grade > 2 mucositis and diarrhea were observed in 60% of patients. One complication-related death occurred 1 month post BMT.

CONCLUSION

With a 75% response rate, this HDC proved to be very efficient in relapsed medulloblastoma. A longer follow up is necessary to demonstrate whether, after a local relapse, HDC could replace craniospinal irradiation as prophylaxis against CNS metastases.

Radiotherapy in the treatment of low-grade astrocytomas. II. The physical and cognitive sequelae

The purpose of the present study was to define the late effects, both physical and psychological, of treating low-grade astrocytomas with radiotherapy. Fifty patients, half of whom received radiotherapy, underwent an assessment of neurological and neuropsychological function. There was no difference in neurological function between the two groups. The radiotherapy recipients, including those with cerebellar tumours, performed significantly worse on measures of intelligence and information processing. In addition, there was a greater incidence of special education needs in the irradiated group. We conclude that children with low-grade astrocytomas who receive radiotherapy have no greater neurological deficit but that the use of radiotherapy carries a penalty in terms of long-term cognitive function and confirmed the findings of many previous reports that supratentorial irradiation is detrimental. More surprisingly, it has been demonstrated that local field irradiation to the posterior fossa can also produce significant cognitive impairment.

Medulloblastoma in pediatric age: a single-institution review of prognostic factors

We report a retrospective study of 35 cases of medulloblastoma in pediatric patients treated at our institution during an 18-year period. Ten of the patients were infants (age < 2 years) and 25 were children (age > 2 years). The main factors affecting prognosis were total removal of the tumor (P < 0.01) and tumor stage (P < 0.01). There were no differences between the survival rate of infants and children, infants had a worse prognosis in regard to quality of life than children.

Quality of long-term survival in young children with medulloblastoma

The reported success of treatment for children with medulloblastoma must be balanced against the effect that treatment has on the quality of life of long-term survivors. The outcome of long-term survivors reported in previous studies has been conflicting. The authors evaluate the mental and behavioral skills of a group of medulloblastoma survivors from their institution, all of whom had survived for more than 5 years postdiagnosis. A review of the institutional records yielded 32 patients. Twenty-three families were interviewed by telephone and, of these, 13 subjects came to the hospital for detailed neuropsychological and neurological evaluations. Intelligence quotient (IQ) was less than 90 for all participants tested, and patients diagnosed before the age of 3 years had lower IQ scores on average than those diagnosed later. Mean IQ and achievement test scores in reading, spelling, and mathematics were all higher in survivors who had undergone shunting. Achievement test results were often not in accord with intellectual potential, and individual intellectual skills varied widely. Perceptual-motor task performance was below average in more than 50% of the participants, but motor dexterity was more severely affected than perception. Problems in learning and a delay in both physical growth and development were seen in a majority of participants. This study directs attention to the serious difficulties faced by long-term survivors of medulloblastoma and their families, and underscores the importance of routine neuropsychological testing. Moreover, the study provides further impetus to seek alternatives to irradiation in the treatment of malignant brain tumors.

Long-term effects of radiation for medulloblastoma on intellectual and physical development. A case report of monozygotic twins

BACKGROUND

Recent advances in treatment have improved the prognosis for medulloblastoma. Although postoperative radiation of the central nervous system (CNS) is widely practiced, late radiation sequelae, especially in long-term survivors, pose a constant risk.

METHODS

To assess the long-term effects of CNS radiation, a monozygotic twin girl with medulloblastoma was compared with her normal twin. Treatment included total removal of the mass, postoperative chemotherapy, and CNS radiation with 47.8 Gy directed to the posterior fossa, 30.2 Gy to the cerebral hemispheres, and 20 Gy to the whole spine.

RESULTS

Not only the radiated patient's spine but also the unradiated upper and lower limbs were shorter than the control subject's. The patient's thyroid hormone level was within normal range; however, thyroid-stimulating hormone was higher than normal. The patient's intellectual ability deteriorated, and cognitive dysfunction has not improved as of 6 years after treatment.

CONCLUSIONS

Treatment systems that do not cause late sequelae affecting physical and intellectual development should be pursued.

Long-term neurobehavioral outcome in pediatric brain-tumor patients: review and methodological critique

This paper provides an overview of pediatric brain tumors and reviews the literature on long-term neurobehavioral outcomes for these children. Progress in this area has been slow due to numerous methodological and practical complications. While some general conclusions can be drawn, the development of comprehensive models awaits more research into the multiplicity of biological and nonbiological events, and their interactions, potentially affecting outcome. Increased theoretical and methodological sophistication will be needed to address this complex classification of diseases. Barriers to research in this area are enumerated as are suggestions for future efforts.

Scale for assessing quality of life of children survivors of cranial posterior fossa tumors

BACKGROUND

Evaluation of quality of life of survivors of brain tumors is an important aspect of outcome that must be included in clinical studies.

METHODS

We have developed a new scale for assessing quality of life (QL) of pediatric long-term survivors of posterior fossa tumors based on their physical, psychointellectual, and endocrine/growth status. We have studied 39 patients, with a median follow-up of 9 years. Twenty-five had cerebellar astrocytoma (CA), 6 medulloblastoma (MDB), 5 brain-stem glioma (BSG) and 3 ependymoma of IV ventricle (EPD).

RESULTS

Sixty-six percent of children showed neurologic and/or visual sequelae. Little or no significant disability (Bloom's levels I-II) were present in 66%. Psychointellectual dysfunction was present in 44%, with an IQ < 90 in 39%. Endocrine and growth disorders were found in 26%, mostly stature anomalies. According to our scale, QL scores were high in 19 patients (49%), intermediate in 8 (20%), and low in the remaining 12 (31%). Unfavourable outcomes were related to age of less than 4 years, tumors other than CA (MDB, BSG, EPD), incomplete tumoral resection, and employment of radiotherapy and chemotherapy.

CONCLUSION

Our results are comparable to others previously reported, and this supports the validity of our scale. We consider that this scale is applicable to evaluate QL of children survivors of cranial tumors.

Primary intraspinal soft-tissue sarcoma in childhood: report of two cases with a review of the literature

Two young children who presented with lower spinal cord dysfunction manifested by bilateral leg weakness and urinary retention were diagnosed with intraspinal soft-tissue sarcoma. Neither patient had a significant extradural mass. Both tumors had histochemical features of rhabdomyosarcoma. Temporary responses were noted after combination chemotherapy either with vincristine, actinomycin D, and cyclophosphamide or with ifosfamide/mesna and etoposide. However, both patients developed uncontrollable cerebrospinal fluid (CSF) dissemination of tumor and died within 6 months of diagnosis, despite intrathecal chemotherapy and irradiation for one and very high-dose intravenous methotrexate (33 g/m2) for the other. This rare tumor can respond to parenteral antisarcoma chemotherapy, but better strategies are needed to prevent CSF spread and ultimate demise. Early institution of intrathecal cytostatic agents may retard or prevent CSF dissemination and prolong survival.

Brain tumors in children and adolescents--III. Effects of radiation and hormone status on intelligence and on working, associative and serial-order memory

The effects on intelligence and memory of two post-surgical conditions (radiation treatment, hormone deficiency and supplementation) were explored in 46 children and adolescents with tumors in a variety of brain sites. Verbal intelligence, but not non-verbal intelligence, varied positively with age at radiation treatment. Memory for word meanings was unrelated to either radiation history or to hormone status. Severe deficits in serial position memory occurred with impaired hormone function and an older age at tumor onset. Severe deficits in working memory were associated with a history of radiation and a principal tumor site that involved thalamic/epithalamic brain regions. Radiation treatment and hormone status affect later cognitive function in children and adolescents with brain tumors. Although the greater vulnerability of the verbal intelligence of the younger radiated child and the serial order memory of the child with later tumor onset and hormone disturbances remain to be explained, and although the form of the relationship between radiation and tumor site is not fully understood, the data highlight the need to consider the cognitive consequences of pediatric brain tumors according to a set of markers that include maturational rate, hormone status, radiation history, and principal site of the tumor.

Neuropsychological status of children treated for brain tumors: a critical review and integrative analysis

The literature on the neuropsychological status of children with primary brain tumors was reviewed to identify English-language publications reporting the results of standardized, quantitative measures of patient function. The 22 studies that met these review criteria, representing 544 patients, were evaluated to assess the relationship between traditional risk factors (age at diagnosis, tumor location, radiation therapy, and time since completion of treatment), as well as subsequent intellectual development, academic achievement, psychosocial adjustment, and neuropsychological status. The impact of other potentially salient factors, such as seizures and sensory and motor deficits, was evaluated when possible. Despite inconsistent reporting of demographic and treatment-related effects across studies which precluded formal meta-analysis, we were able to confirm the primary importance of radiation therapy volume and age at treatment on IQ. No effects were detected for tumor location. Younger children treated with cranial (whole brain) irradiation showed a 14-point deficit in IQ as compared with their older counterparts. No significant differences were noted between older children receiving local or cranial irradiation, although both groups had IQ levels 12-14 points lower than those not irradiated. The high-risk groups identified in this study require increased clinical surveillance. Definitive evaluation of potential risk factors for neuropsychological impairment will depend on more complete reporting of relevant patient characteristics and interinstitutional studies.