Long-term cognitive outcome, brain computed tomography scan, and magnetic resonance imaging in children cured for acute lymphoblastic leukemia

Neurocognitive Effects and Necrosis in Childhood Cancer Survivors Treated With Radiation Therapy: A PENTEC Comprehensive Review

PURPOSE

A PENTEC review of childhood cancer survivors who received brain radiation therapy (RT) was performed to develop models that aid in developing dose constraints for RT-associated central nervous system (CNS) morbidities.

METHODS AND MATERIALS

A comprehensive literature search, through the PENTEC initiative, was performed to identify published data pertaining to 6 specific CNS toxicities in children treated with brain RT. Treatment and outcome data on survivors were extracted and used to generate normal tissue complication probability (NTCP) models.

RESULTS

The search identified investigations pertaining to 2 of the 6 predefined CNS outcomes: neurocognition and brain necrosis. For neurocognition, models for 2 post-RT outcomes were developed to (1) calculate the risk for a below-average intelligence quotient (IQ) (IQ <85) and (2) estimate the expected IQ value. The models suggest that there is a 5% risk of a subsequent IQ <85 when 10%, 20%, 50%, or 100% of the brain is irradiated to 35.7, 29.1, 22.2, or 18.1 Gy, respectively (all at 2 Gy/fraction and without methotrexate). Methotrexate (MTX) increased the risk for an IQ <85 similar to a generalized uniform brain dose of 5.9 Gy. The model for predicting expected IQ also includes the effect of dose, age, and MTX. Each of these factors has an independent, but probably cumulative effect on IQ. The necrosis model estimates a 5% risk of necrosis for children after 59.8 Gy or 63.6 Gy (2 Gy/fraction) to any part of the brain if delivered as primary RT or reirradiation, respectively.

CONCLUSIONS

This PENTEC comprehensive review establishes objective relationships between patient age, RT dose, RT volume, and MTX to subsequent risks of neurocognitive injury and necrosis. A lack of consistent RT data and outcome reporting in the published literature hindered investigation of the other predefined CNS morbidity endpoints.

Chemobrain in blood cancers: How chemotherapeutics interfere with the brain's structure and functionality, immune system, and metabolic functions

Cancer treatment brings about a phenomenon not fully clarified yet, termed chemobrain. Its strong negative impact on patients' well-being makes it a trending topic in current research, interconnecting many disciplines from clinical oncology to neuroscience. Clinical and animal studies have often reported elevated concentrations of proinflammatory cytokines in various types of blood cancers. This inflammatory burst could be the background for chemotherapy-induced cognitive deficit in patients with blood cancers. Cancer environment is a dynamic interacting system. The review puts into close relationship the inflammatory dysbalance and oxidative/nitrosative stress with disruption of the blood-brain barrier (BBB). The BBB breakdown leads to neuroinflammation, followed by neurotoxicity and neurodegeneration. High levels of intracellular reactive oxygen species (ROS) induce the progression of cancer resulting in increased mutagenesis, conversion of protooncogenes to oncogenes, and inactivation of tumor suppression genes to trigger cancer cell growth. These cell alterations may change brain functionality, as well as morphology. Multidrug chemotherapy is not without consequences to healthy tissue and could even be toxic. Specific treatment impacts brain function and morphology, functions of the immune system, and metabolism in a unique mixture. In general, a chemo-drug's effects on cognition in cancer are not direct and/or in-direct, usually a combination of effects is more probable. Last but not least, chemotherapy strongly impacts the immune system and could contribute to BBB disruption. This review points out inflammation as a possible mechanism of brain damage during blood cancers and discusses chemotherapy-induced cognitive impairment.

Advances of neuroimaging in chemotherapy related cognitive impairment (CRCI) of patients with breast cancer

BACKGROUND

Chemotherapy related cognitive impairment (CRCI) has seriously affected the quality of life (QOL) of patients with breast cancer (BCs), thus the neurobiological mechanism of CRCI attracted widespread attention. Previous studies have found that chemotherapy causes CRCI through affecting brain structure, function, metabolism, and blood perfusion.

FINDINGS

A variety of neuroimaging techniques such as functional magnetic resonance imaging (fMRI), event-related potential (ERP), near-infrared spectroscopy (NIRS) have been widely applied to explore the neurobiological mechanism of CRCI.

CONCLUSION

This review summarized the progress of neuroimaging research in BCs with CRCI, which provides a theoretical basis for further exploration of CRCI mechanism, disease diagnosis and symptom intervention in the future. Multiple neuroimaging techniques for CRCI research.

Radiation-Induced Brain Injury: Age Dependency of Neurocognitive Dysfunction Following Radiotherapy

Cranial radiotherapy is a known risk factor for neurocognitive impairment in cancer survivors. Although radiation-induced cognitive dysfunction is observed in patients of all ages, children seem to be more vulnerable than adults to suffering age-related deficits in neurocognitive skills. So far, the underlying mechanisms by which IR negatively influences brain functions as well as the reasons for the profound age dependency are still insufficiently known. We performed a comprehensive Pubmed-based literature search to identify original research articles that reported on age dependency of neurocognitive dysfunction following cranial IR exposure. Numerous clinical trials in childhood cancer survivors indicate that the severity of radiation-induced cognitive dysfunction is clearly dependent on age at IR exposure. These clinical findings were related to the current state of experimental research providing important insights into the age dependency of radiation-induced brain injury and the development of neurocognitive impairment. Research in pre-clinical rodent models demonstrates age-dependent effects of IR exposure on hippocampal neurogenesis, radiation-induced neurovascular damage and neuroinflammation.

Cranial MRI in Childhood Acute Leukemia during Treatment and Follow-Up Including the Impact of Intrathecal MTX-A Single-Center Study and Review of the Literature

Due to high survival rates, long-term sequelae, especially neurotoxicity, need to be considered in childhood acute leukemias. In this retrospective analysis of morphologic changes of the brain in children treated for acute leukemias, we included 94 patients (77 ALL, 17 AML; 51 male, 43 female; median age: 5 years) from a single center. We analyzed 170 cranial MRI scans (T2, FLAIR axial) for morphologic alterations of the brain and variations of the ventricular width (GDAH). In addition, the corresponding literature was reviewed. More than 50% of all patients showed cerebral pathomorphologies (CP). They were seen more often in children with ALL (55.8%), ≤ 6 years of age (60.8%), in relapse (58.8%) or after CNS irradiation (75.0%) and included white matter changes, brain atrophy, sinus vein thrombosis and ischemic events. GDAH significantly enlarged mainly in children up to 6 years, with relapse, high-risk leukemias or ALL patients. However, GDAH can normalize again. The number of intrathecal Methotrexate applications (≤12 vs. >12) showed no correlation to morphologic alterations besides a significant increase in GDAH (−0.3 vs. 0.9 mm) between the first and last follow-up MRI in ALL patients receiving >12 ith. MTX applications. The role of ith. MTX on CP needs to be further investigated and correlated to the neurocognitive outcome of children with acute leukemias.

The Psychoneuroimmunology of Stress Regulation in Pediatric Cancer Patients

Stress is a ubiquitous experience that can be adaptive or maladaptive. Physiological stress regulation, or allostasis, can be disrupted at any point along the regulatory pathway resulting in adverse effects for the individual. Children with cancer exhibit significant changes to these pathways in line with stress dysregulation and long-term effects similar to those observed in other early-life stress populations, which are thought to be, in part, a result of cytotoxic cancer treatments. Children with cancer may have disruption to several steps in the stress-regulatory pathway including cognitive-affective function, neurological disruption to stress regulatory brain regions, altered adrenal and endocrine function, and disrupted tissue integrity, as well as lower engagement in positive coping behaviours such as physical activity and pro-social habits. To date, there has been minimal study of stress reactivity patterns in childhood illness populations. Nor has the role of stress regulation in long-term health and function been elucidated. We conclude that consideration of stress regulation in childhood cancer may be crucial in understanding and treating the disease.

Effects of chemotherapy for acute lymphoblastic leukemia on cognitive function in animal models of contemporary protocols: A systematic literature review

Survival rates of childhood acute lymphoblastic leukemia (ALL) have improved greatly due to advanced therapies and supportive care. Intrathecal chemotherapy replaced cranial radiation due to radiation-induced neurotoxicity and late-effects. Survivors treated with chemotherapy-only experience neurologic and cognitive problems following cessation of treatment. Very long-term cognitive outcomes remain unclear. Animal models are being generated to assess late-effects of chemotherapy on cognitive function. Although, few address juvenile models of chemotherapy-induced cognitive impairment (CICI) and developing brain, results of this review outline neurocognitive effects of chemotherapy consistent with childhood ALL therapy. Studies demonstrate deficits across cognitive domains including spatial memory, executive function, short-term memory, anxiety and depression. Inflammation, oxidative stress, excitotoxity, and other metabolic disruptions may lead to neurodegeneration associated with cognitive impairment observed in ALL survivors. Interventions directly targeting these mechanisms may prevent and/or promote recovery of cognitive function and improve long-term outcomes. Evidence suggests success of anti-inflammatory and antioxidant treatments in reducing cognitive decline. Animal models provide basis for assessing effects of chemotherapy on neurologic processes to guide future clinical investigations.

Brain Microstructural Changes Associated With Neurocognitive Outcome in Intracranial Germ Cell Tumor Survivors

Background

Childhood intracranial germ cell tumor (GCT) survivors are prone to radiotherapy-related neurotoxicity, which can lead to neurocognitive dysfunctions. Diffusion kurtosis imaging (DKI) is a diffusion MRI technique that is sensitive to brain microstructural changes. This study aimed to investigate the association between DKI metrics versus cognitive and functional outcomes of childhood intracranial GCT survivors.

Methods

DKI was performed on childhood intracranial GCT survivors (n = 20) who had received cranial radiotherapy, and age and gender-matched healthy control subjects (n = 14). Neurocognitive assessment was performed using the Hong Kong Wechsler Intelligence Scales, and functional assessment was performed using the Lansky/Karnofsky performance scales (KPS). Survivors and healthy controls were compared using mixed effects model. Multiple regression analyses were performed to determine the effects of microstructural brain changes of the whole brain as well as the association between IQ and Karnofsky scores and the thereof.

Results

The mean Intelligence Quotient (IQ) of GCT survivors was 91.7 (95% CI 84.5 – 98.8), which was below the age-specific normative expected mean IQ (P = 0.013). The mean KPS score of GCT survivors was 85.5, which was significantly lower than that of controls (P < 0.001). Cognitive impairments were significantly associated with the presence of microstructural changes in white and grey matter, whereas functional impairments were mostly associated with microstructural changes in white matter. There were significant correlations between IQ versus the mean diffusivity (MD) and mean kurtosis (MK) of specific white matter regions. The IQ scores were negatively correlated with the MD of extensive grey matter regions.

Conclusion

Our study identified vulnerable brain regions whose microstructural changes in white and grey matter were significantly associated with impaired cognitive and physical functioning in survivors of pediatric intracranial GCT.

Methylene tetrahydrofolate reductase A1298C polymorphisms influence the adult sequelae of chemotherapy in childhood-leukemia survivors

This retrospective correlation study investigated the putative link between methylene tetrahydrofolate reductase (MTHFR) A1298C mutations and chemotherapy-related brain function changes in adult childhood-leukemia survivors. To this end, we determined the relationship between the particular MTHFR1298 genotype (AA, AC or CC) of 31 adult childhood-leukemia survivors, and (1) their CSF Tau and phosphorylated Tau (pTau) levels at the time of treatment, (2) their adult performance intelligence quotient (PIQ), and (3) their regional brain connectivity using diffusion magnetic resonance imaging (dMRI) and resting-state functional MRI (rsfMRI). We confirmed that neuropathology markers Tau and pTau significantly increased in CSF of children after intrathecal methotrexate administration. Highest concentrations of these toxicity markers were found during the induction phase of the therapy. Moreover, CSF concentrations of Tau and pTau during treatment were influenced by the children’s particular MTHFR1298 genotype. CSF Tau (but not pTau) levels significantly dropped after folinic acid supplementation. At adult age (on average 13.1 years since the end of their treatment), their particular MTHFR1298 genotype (AA, AC or CC) influenced the changes in PIQ and cortical connectivity that we found to be related to their childhood exposure to chemotherapeutics. In summary, we suggest that homozygous MTHFR1298CC individuals are more vulnerable to the adult sequelae of antifolate chemotherapy.

Age- and Intravenous Methotrexate-Associated Leukoencephalopathy and Its Neurological Impact in Pediatric Patients with Lymphoblastic Leukemia

Simple Summary

In this study, we investigated standardized post-chemotherapy magnetic resonance (MR) scans for leukoencephalopathy and patient- and treatment-related risk factors in childhood leukemia patients. As prevalence numbers are limited, our study provides the required estimations for this population. Furthermore, we demonstrate that younger patients might be more at-risk for development of leukoencephalopathy (LE), and that a higher intravenous methotrexate (IV-MTX) dose has a cumulative toxic effect, while the number of intrathecal administrations was not significantly associated with the extent of LE. This can suggest we should modify chemotherapeutic treatment regimens by decreasing the number of IV-MTX applications, with special attention for younger patients.

Abstract

Methotrexate (MTX) is associated with leukoencephalopathy (LE) in children treated for lymphoblastic leukemia/lymphoma (ALL/LBL). However, large-scale studies with systematic MR acquisition and quantitative volumetric lesion information remain limited. Hence, the prevalence of lesion burdens and the potential risk factors of LE in this population are still inconclusive. FLAIR-MRI scans were acquired at the end of treatment in children who were treated for ALL/LBL, which were quantitatively analyzed for LE. Voxels were assigned to the lesion segmentation if indicated by two raters. Logistic and linear regression models were used to test whether lesion presence and size were predicted by risk factors such as age at diagnosis, gender, intrathecal (IT-) or intravenous (IV-)MTX dose, CNS invasion, and acute neurological events. Patients with a pre-existing neurological condition or low-quality MR scan were excluded from the analyses. Of the 129 patients, ten (8%) suffered from CNS invasion. Chemotherapy-associated neurological events were observed in 13 patients (10%) during therapy, and 68 patients (53%) showed LE post-treatment. LE was more frequent in cases of lower age and higher cumulative IV-MTX doses, while the extent of LE and neurological symptoms were associated only with IV-MTX doses. Neurological events were not significantly associated with LE, even though symptomatic patients demonstrated a higher ratio of LE (n = 9/13) than asymptomatic patients (n = 59/116). This study suggests leukoencephalopathy frequently occurs in both symptomatic and asymptomatic leukemia patients. Younger children and patients treated with higher cumulative IV-MTX doses might need more regular screening for early detection and follow-up of associated sequelae.

A Prospective Cohort Study of Neural Progenitor Cell-Sparing Radiation Therapy Plus Temozolomide for Newly Diagnosed Patients With Glioblastoma

BACKGROUND

In treating glioblastoma, irradiation of the neural progenitor cell (NPC) niches is controversial. Lower hippocampal doses may limit neurocognitive toxicity, but higher doses to the subventricular zones (SVZ) may improve survival.

OBJECTIVE

To prospectively evaluate the impact of limiting radiation dose to the NPC niches on tumor progression, survival, and cognition in patients with glioblastoma.

METHODS

Patients with glioblastoma received resection followed by standard chemoradiation. Radiation dose to the NPC niches, including the bilateral hippocampi and SVZ, was minimized without compromising tumor coverage. The primary outcome was tumor progression in the spared NPC niches. Follow-up magnetic resonance imaging was obtained bimonthly. Neurocognitive testing was performed before treatment and at 6- and 12-mo follow-up. Cox regression evaluated predictors of overall and progression-free survival. Linear regression evaluated predictors of neurocognitive decline.

RESULTS

A total of 30 patients enrolled prospectively. The median age was 58 yr. Median mean doses to the hippocampi and SVZ were 49.1 and 41.8 gray (Gy) ipsilaterally, and 16.5 and 19.9 Gy contralaterally. Median times to death and tumor progression were 16.0 and 7.6 mo, and were not significantly different compared to a matched historical control. No patients experienced tumor progression in the spared NPC-containing regions. Overall survival was associated with neurocognitive function (P ≤ .03) but not dose to the NPC niches. Higher doses to the hippocampi and SVZ predicted greater decline in verbal memory (P ≤ .01).

CONCLUSION

In treating glioblastoma, limiting dose to the NPC niches may reduce cognitive toxicity while maintaining clinical outcomes. Further studies are needed to confirm these results.

A Review of Chronic Leukoencephalopathy among Survivors of Childhood Cancer

Currently, there are an estimated 400,000 long-term survivors of childhood cancer in the United States. Chronic leukoencephalopathy is a potential devastating late effect that can manifest as a range of neurological and neurocognitive sequelae. Survivors of the acute lymphocytic leukemia, central nervous system tumors, and stem cell transplant have frequently been exposed to cranial radiation, systemic and intrathecal chemotherapy, which places them at risk of developing chronic leukoencephalopathy. Defining leukoencephalopathy and its neuroimaging characteristics, the population of survivors at risk, its long-term consequences, and identifying prevention and intervention strategies can potentially mitigate the morbidity of these survivors. Better understanding of those at risk of leukoencephalopathy and its symptoms can lead to an improved quality of life for these cancer survivors.

Brain Connectivity and Cognitive Flexibility in Nonirradiated Adult Survivors of Childhood Leukemia

Background

This study aimed to assess functional and structural brain connectivity in adult childhood leukemia survivors and the link with cognitive functioning and previously identified risk factors such as intrathecal methotrexate dose and age at start of therapy.

Methods

Thirty-one nonirradiated adult childhood leukemia survivors and 35 controls underwent cognitive testing and multimodal magnetic resonance imaging (resting state functional MRI, T1-weighted, diffusion-weighted, and myelin water imaging [MWI]). Analyses included dual regression, voxel-based morphometry, advanced diffusion, and MWI modeling techniques besides stepwise discriminant function analysis to identify the most affected executive cognitive domain. Correlations with discrete intrathecal MTX doses and (semi)continuous variables were calculated using Spearman's rank and Pearson's correlation, respectively. All correlation tests were two-sided. Positive and negative T-contrasts in functional and structural MRI analysis were one-sided.

Results

Survivors demonstrated lower functional connectivity between the default mode network (DMN) and inferior temporal gyrus (ITG; P < .008). Additionally, we observed higher fractional anisotropy (FA; P = .04) and lower orientation dispersion index (ODI; P = .008) at the left centrum semiovale, which could-given that several fiber bundles cross this region-suggest selective reduced integrity of the respective white matter tracts. Set shifting reaction time, a measure of cognitive flexibility, was mostly impaired and correlated with lower FA (r = -0.53, P = .003) and higher ODI (r = 0.40, P = .04) in survivors but not with DMN-ITG connectivity. There were no statistically significant differences between survivors and controls in WM or GM volume, nor was there a statistically significant correlation between imaging measurements and age at start of therapy or intrathecal methotrexate dose.

Conclusions

Adult, nonirradiated childhood leukemia survivors show altered brain connectivity, which is linked with cognitive flexibility.

Neurocognitive Sequelae in Adult Childhood Leukemia Survivors Related to Levels of Phosphorylated Tau

Central nervous system-directed prophylactic chemotherapy increases survival in childhood leukemia, but possible late neurocognitive sequelae remain a concern. We compared intellectual performance (WAIS IV), memory (AVLT), and executive functioning (ANT) between adult leukemia survivors (n = 31) and control individuals (n = 35). In survivors, cerebrospinal fluid (CSF) levels of phosphorylated Tau (p-Tau) during treatment and total intrathecal methotrexate dose correlated with adult intellectual performance (Pearson's and Spearman's coefficients, respectively). Long-term memory and attentional control, both maturing before survivors' mean age at diagnosis, were unaffected (P > .05 on all four subtests), in contrast to cognitive flexibility and information processing (P < .05 for eight of the subtests), which mature during adolescence. CSF p-Tau and methotrexate dose negatively correlated with intellectual performance (r = -0.414, P = .04 and r = -0.484, P = .007, respectively), but not with each other (r = 0.219, P = .29). These data identify CSF p-Tau as a predictor of late neurocognitive sequelae (in addition to methotrexate dose). Early identification of children at risk could inspire interventions to prevent or remediate chemotherapy-induced cognitive sequelae.

Parent-reported cognitive function is associated with leukoencephalopathy in children with brain tumors

PURPOSE

Cognitive dysfunction is a major concern for children with brain tumors. A valid, user-friendly screening tool could facilitate prompt referral for comprehensive neuropsychological assessments and therefore early intervention. Applications of the pediatric perceived cognitive function item bank (pedsPCF) such as computerized adaptive testing can potentially serve as such a tool given its brevity and user-friendly nature. This study aimed to evaluate whether pedsPCF was a valid indicator of cerebral compromise using the criterion of structural brain changes indicated by leukoencephalopathy grades.

METHODS

Data from 99 children (mean age = 12.6 years) with brain tumors and their parents were analyzed. Average time since diagnosis was 5.8 years; time since last treatment was 4.3 years. Leukoencephalopathy grade (range 0-4) was based on white matter damage and degree of deep white matter volume loss shown on MRI. Parents of patients completed the pedsPCF. Scores were based on the US general population-based T-score metric (mean = 50; SD = 10). Higher scores reflect better function.

RESULTS

Leukoencephalopathy grade distributions were as follows: 36 grade 0, 27 grade 1, 22 grade 2, 13 grade 3, and 1 grade 4. The mean pedsPCF T-score was 48.3 (SD = 8.3; range 30.5-63.7). The pedsPCF scores significantly discriminated patients with different leukoencephalopathy grades, F = 4.14, p = 0.0084. Effect sizes ranged from 0.09 (grade 0 vs. 1) to 1.22 (grade 0 vs. 3/4).

CONCLUSION

This study demonstrates that the pedsPCF is a valid indicator of leukoencephalopathy and provides support for its use as a screening tool for more comprehensive neurocognitive testing.

Neuroradiology of Pediatric Hemolymphoproliferative Disease

Hemolymphoproliferative diseases (HLD) are among the most common causes of morbidity and mortality in children. In the past few years, the increased effectiveness of treatment modalities has significantly increased overall survival, but has also disclosed new aspects of the natural history of these disorders, among which central nervous system (CNS) involvement. CNS complications of HLD can basically be categorized into direct localization of primary disease, indirect effects of malignancy such as cerebrovascular or infectious complications, and iatrogenic side effects. Magnetic resonance imaging plays an important, often crucial role in the diagnosis of several of these disorders. Close interdisciplinary collaboration between hemato-oncologists and neuroradiologists is of paramount importance to provide affected children with an early diagnosis and proper treatment.

[Brain injury after induction chemotherapy in children with acute lymphoblastic leukemia]

OBJECTIVE

To investigate the changes in brain injury after the induction chemotherapy in children with acute lymphoblastic leukemia (ALL) by cranial MRI.

METHODS

The clinical data and cranial MRI results of 62 children with ALL who were hospitalized from March 2014 to June 2015 were analyzed retrospectively.

RESULTS

Before chemotherapy, MRI showed bone marrow infiltration of the skull in 33 patients (53%); the children with WBC<20×10(9)/Lhad a significantly lower incidence rate of bone marrow infiltration of the skull than those with WBC≥20×10(9)/L (16 patients/42% vs 17 patients/71%; P<0.05), and the high-risk group had a significantly higher incidence rate of bone marrow infiltration of the skull than the non-high-risk group (71% vs 44%; P<0.05). Before chemotherapy, there were 4 cases (7%) of brain atrophy, and 2 cases (3%) of abnormal signals in the sensory conduction bundle. MRI reexamination in 28 patients after 3 months of chemotherapy showed 3 new cases (11%) of brain atrophy and 1 aggravated case of brain atrophy.

CONCLUSIONS

The children with ALL have bone marrow infiltration of the skull, brain atrophy, and abnormal signals in the sensory conduction bundle before chemotherapy, especially bone marrow infiltration of the skull, and some changes in brain injury disappear after treatment.

New considerations in radiation treatment planning for brain tumors: neural progenitor cell-containing niches

The purpose of this critical review is to explore the controversy regarding the relationship between radiation dose to the neural progenitor cell (NPC) niches and patient outcomes, in terms of both toxicity and tumor control. NPCs in the subventricular zone (SVZ) and hippocampus are paradoxically associated with long-term neurocognitive sequelae of brain irradiation, as well as resistance to therapy and tumor recurrence. The reconciliation of these somewhat opposing functions is challenging. Current literature suggests that radiation and other treatments against the NPC in the hippocampus and the SVZ may influence patient outcome. As a result, both the SVZ and the hippocampus could have important implications on radiation treatment planning strategies, and future laboratory and clinical evaluations will be critical in designing studies to optimize treatment outcome, effectiveness, and safety.

Increase in oxidative stress as measured by cerebrospinal fluid lipid peroxidation during treatment for childhood acute lymphoblastic leukemia

Five-year survival from childhood acute lymphoblastic leukemia (ALL) approaches 90%, but 40% of survivors experience central nervous system (CNS) treatment-related cognitive problems. Despite considerable evidence for cognitive problems, less is known about mechanisms of neurological injury. Our purpose was to investigate oxidative stress, measured by lipid peroxidation, as a mechanism of CNS treatment-related neurological injury. The sample included 55 children (mean age at diagnosis=6.84 y, SD=3.40) who received intrathecal and intravenous chemotherapy for CNS-directed treatment according to Children's Oncology Group protocols. Glycerophospholipids were extracted from cerebrospinal fluid samples obtained at diagnosis and during intrathecal chemotherapy administration. Unoxidized and oxidized phosphatidylcholine (PC) and phosphatidylinositol (PI) were measured by normal phase high-performance liquid chromatography with diode array detection, and analyzed with a general linear model for repeated measures analysis of variance. Compared with the diagnostic cerebrospinal fluid sample, unoxidized and oxidized PC and PI increased significantly across treatment phases. Amount of intravenous methotrexate received was significantly correlated with oxidized PI, and age at time of ALL diagnosis was significantly associated with oxidized PC. These findings support our hypothesis that oxidative stress is a mechanism of neurological injury associated with CNS-directed treatment for ALL.

Long-term outcome and risk factors for uncontrolled seizures after a first seizure in children with hematological malignancies

Long-term outcomes of seizures that develop during treatment of childhood hematological malignancies have not been described. We analyzed seizure outcome in 62 children with leukemia or lymphoma treated at our institution. There was a median follow-up of 6.5 years since first seizure. Seizure etiology included intrathecal or systemic methotrexate in 24, leucoencephalopathy in 11, brain hemorrhage or thrombosis in 11, meningitis in 4, and no identifiable cause in 12. Seizures remained uncontrolled in 18, and risk factors for poor control included female sex (P = .02), no seizure control with first antiseizure drug (P = .08), and longer interval between cancer diagnosis and seizure onset (P = .09). Poor seizure control after initial antiseizure drug also predicted recurrent seizure after drug withdrawal (P = .04). In conclusion, seizures are controlled with medications in a majority of patients with hematological cancer. After a period without seizures, antiseizure drug withdrawal in appropriately selected patient has a high success rate.

Neurocognitive outcome and white matter anisotropy in childhood acute lymphoblastic leukemia survivors treated with different protocols

Neurocognitive outcome affects the quality of life of ALL survivors. This study is aimed to assess the prevalence of neurocognitive dysfunction by psychometric and imaging tools in survivors of childhood ALL, treated with 3 different protocols and the effect of time elapsed since the end of chemotherapy. Sixty-two ALL survivors aged 6-18 years and treated in the period 1997-2007 and 60 healthy age and sex matched controls were subjected to neurocognitive testing using Wechsler Intelligence Scale for Children, Benton visual retention (BVRT) and Trail Making test (TMT), followed by diffusion weighed and diffusion tensor MRI for calculation of fraction anisotropy (FA). Survivors underwent revision of protocol and type of CNS therapy. Three different protocols were used: modified BFM 83, BFM 90, and CCG. Survivors treated with modified CCG protocol showed a significant decrease in all cognitive tests compared to control (p<.05); BFM 90 group had a significant lower IQ and longer TMT compared to both control and BFM 83 group and no significant difference was found in results of cognitive tests between BFM 83 and control group. Frontal FA was lower in CCG treated group compared to control, BFM 90 and BFM 83 groups (p<.05); meanwhile it was significantly lower in BFM 90 and BFM 83 groups compared to control group. We concluded that patients treated with modified CCG protocol showed the worst neurocognitive outcome among three assessed protocols. Frontal lobe FA might be an early marker for predicting the neurotoxicity in childhood ALL survivors.

Central neurotoxicity of standard treatment in patients with newly-diagnosed high-grade glioma: a prospective longitudinal study

Following tumor resection, the majority of high-grade glioma (HGG) patients are treated with a combined modality regimen of radiotherapy and temozolomide. As a result of the tumor itself or as treatment-related neurotoxic side-effects, these patients may experience cognitive deficits. Additionally, radiological abnormalities expressed as white matter hyperintensities (WMH) and cerebral atrophy (CA) can develop. In this study, these functional and morphological parameters are evaluated, and their relation is investigated. After surgery, HGG patients underwent chemo-irradiation for six weeks, followed by six cycles of temozolomide. Assessments were performed before chemo-irradiation, post-concomitantly, after the third and sixth adjuvant cycle, and 3 and 7 months after treatment. Degree of WMH and CA was scored on MRI. Patients' neuropsychological performance was compared to healthy matched controls, yielding six cognitive domain z-scores. Development or progression of pre-existing WMH and CA during follow-up was observed in 36 and 45 % of the patients (n = 39) respectively. Cognitive functioning remained stable or improved in 70 % of the patients and deteriorated in 30 % of the patients (n = 33). Of the cognitive decliners, 80 % had tumor progression within 4 months thereafter. No clear association between cognitive functioning and WMH or CA was found. Central neurotoxic effects of combined modality treatment in HGG patients expressed by radiological abnormalities are encountered in approximately 40 % of patients. However, functional impact as indexed by cognitive functioning was found to be limited. Furthermore, development or progression of pre-existing WMH and CA does not consistently result in functional impairment as measured by cognitive tests.

Longitudinal language outcomes following intrathecal chemotherapy for acute lymphoblastic leukaemia

Intrathecal chemotherapy (ITC) is the treatment option for acute lymphoblastic leukaemia (ALL). Neurocognitive deficits have been described following ITC, but language status post-treatment is yet to be clarified. This study examined the language skills of nine children following ITC for ALL (mean age 7;8 years and 3;2 years post-diagnosis at baseline measurement) and nine age- and sex-matched controls, at baseline then 2 years later, using a battery of tests assessing general language skills. An assessment of cognitively-demanding high level language skills was undertaken on a sub-group of the children (n =12). Statistical analysis revealed no significant difference between children treated with ITC and controls when comparing change in performance scores from baseline measurement to 2 years post-baseline measurement. Descriptive analysis of three of the ALL participants in the Intermediate Stage survivorship at language re-assessment indicated no clinically-significant change in performance over 2 years for all measures except receptive language skills, which improved over the time for two of the children. As language skills continue to develop into late adolescence, the need for the monitoring of language abilities of children treated at a young age with ITC as they enter the Intermediate and Late Stages of survivorship is discussed.

Association between radiation dose to neuronal progenitor cell niches and temporal lobes and performance on neuropsychological testing in children: a prospective study

BACKGROUND

Neurocognitive toxicity from radiation therapy (RT) for brain tumors may be related to damage to neural progenitor cells that reside in the subventricular zone and hippocampus. This prospective study examines the relationship between RT dose to neural progenitor cell niches, temporal lobes, and cerebrum and neurocognitive dysfunction following cranial irradiation.

METHODS

Standardized assessments of motor speed/dexterity, verbal memory, visual perception, vocabulary, and visuospatial working memory were conducted in 19 pediatric patients receiving cranial RT and 55 controls at baseline and 6, 15, and 27 months following completion of RT. Prescription doses ranged from 12 Gy to 59.4 Gy. Linear mixed effects regression model analyses were used to examine the relationships among neuropsychological performance, age, and radiation dose to the subventricular zone, hippocampus, temporal lobes, and cerebrum.

RESULTS

Performance on all neuropsychological tests, except vocabulary, was significantly reduced in patients relative to controls, particularly among younger children. Performance on motor speed/dexterity decreased with increasing dose to hippocampus (P < .05) and temporal lobes (P < .035). There was also a significant relationship between (i) reduced performance on verbal learning and increasing dose to the cerebrum (P = .022) and (ii) reduced performance on visual perception and increasing dose to the left temporal lobe (P = .038). There was no association between radiation dose to evaluated structures and performance on vocabulary or visuospatial working memory.

CONCLUSIONS

These prospective data demonstrate a significant association between increasing RT dose to hippocampus and temporal lobes and decline in neurocognitive skills following cranial irradiation. These findings have important implications for trials, including RTOG 0933 (hippocampal-sparing whole brain radiation therapy for brain metastases).

Neurodevelopmental functioning in very young children undergoing treatment for non-CNS cancers

OBJECTIVE

We initiated a prospective study of very young children with cancer, in comparison with matched healthy children, to investigate neurodevelopmental consequences of non-CNS cancers and treatment.

METHODS

A total of 61 children (≤42 months) with non-CNS cancers and 61 matched controls underwent an identical age-appropriate neuropsychological test battery.

RESULTS

Children with cancer manifested deficits compared to healthy controls in motor, mental, and language development, but were similar to controls in cognitive representational abilities and emotional relationships in interaction with their mothers. Better physician-rated health status at diagnosis and mother-rated behavioral status 1 month prior to assessment were associated with better motor and mental performance in the cancer group.

CONCLUSIONS

This study identifies deficits as well as spared functions in children with non-CNS cancers; the results suggest ways parents and healthcare professionals may plan specific remediations to enhance quality of life in young cancer survivors.

Population-based exploration of academic achievement outcomes in pediatric acute lymphoblastic leukemia survivors

OBJECTIVE

Examine academic achievement among pediatric acute lymphoblastic leukemia survivors diagnosed during the years 1993-2008.

METHOD

A deterministic linkage of the Iowa Cancer Registry and Iowa Testing Programs databases was performed and yielded 147 survivors. Achievement data, in the form of Iowa Percentile Rank scores, were obtained and analyzed by grade and content domain.

RESULTS

Children diagnosed before age 5 evidenced more underachievement than those diagnosed later (p = .05). Underachievement was noted in mathematics in grades 8 and 11 (p's < .05), in addition to a longitudinal decrease in scores from grades 4 through 11 (p = .01). No differences were found in academic achievement between males and females.

CONCLUSIONS

Utilization of a population-based approach with a nationally recognized, standardized instrument indicates that academic underachievement is subtle yet exists, most notably in mathematics.

Expression of liquoral neuroprotection markers in children with acute lymphoblastic leukemia

Brain damage related to intrathecal methotrexate in children with acute lymphoblastic leukemia (ALL) is still unclear. Neuroinflammatory mechanisms and intracerebral production of specific biomarkers, play a key role in determining neuroprotective mechanisms after brain injury. To determine whether the CSF concentrations of neuron-specific enolase (NSE), neurotrophic factors and doublecortin (DCX) are influenced by repeated intrathecal methotrexate administrations, we prospectively collected CSF samples from 10 children with ALL and 10 controls. Our results showed an increased expression of the liquoral markers. This up-regulation could be interpreted as a neuroprotective response of the brain against the neuronal damages induced by MTX.

Magnetic resonance imaging in childhood leukemia survivors treated with cranial radiotherapy: a cross sectional, single center study

BACKGROUND

Children treated with cranial radiotherapy (CRT) for leukemia are at risk of developing central nervous system injuries. Magnetic resonance imaging (MRI) represents the examination method of choice for evaluating radiation-induced brain complications. The purpose of this report is to describe the spectrum of MRI abnormalities detected in a group of survivors of leukemia treated with cranial irradiation.

PROCEDURES

In this cross-sectional, single center study, 56 patients (median age at follow-up 19 years) receiving CRT as cranial prophylaxis (CP) included in the leukemia protocol (total dose 1,800-2,400 cGy) and/or in the total body irradiation regimen (990-1,200 cGy) before hematopoietic stem cell transplant, were evaluated by MRI after a median interval of 11 years (range 2-27) following CRT.

RESULTS

Fifty-nine MRI abnormalities (32 cavernomas, nine focal areas of gliosis, seven dystrophic mineralizations, five cerebral atrophies, four pituitary atrophies, one diffuse radiation leukoencephalopathy, and one meningioma) were found in 43 patients. The longest interval between CRT and MRI and oldest age at follow-up represented the two risk factors that were statistically associated with MRI lesions (P = 0.032 and 0.033, respectively). Cerebral cavernomas (CC) were the most frequent MRI abnormalities (57%). All patients with CC were asymptomatic at diagnosis and during follow-up, except one who had aspecific neurological manifestations and micro hemorrhages.

CONCLUSIONS

These results confirm that total doses and modalities of fractionation dose of CRT were not significantly associated with MRI abnormalities. Moreover, in our experience none of the patients developed neurological symptoms related to MRI abnormalities, and furthermore, the CC remained substantially stable during follow-up.

Long-term neurocognitive outcomes in young adult survivors of childhood acute lymphoblastic leukemia

Five-year survival rates of childhood acute lymphoblastic leukemia (ALL) exceed 80% due to central nervous system-directed treatment including cranial radiation (CRT) and chemotherapy. However, these treatments are associated with neurocognitive compromise, the extent of which is correlated with higher dose and younger age at treatment. The aims of this study were to explore long-term neurocognitive outcomes in adult survivors of childhood ALL, and to identify measures sensitive to neurotoxicity in long-term survivors. We examined 24 adults who received 18 Gy CRT and chemotherapy for treatment of ALL between ages 2 and 15 years (median, 5.5). Time since diagnosis ranged from 6 to 26 years (median, 16.6). Younger age at diagnosis and longer time since diagnosis were associated with lower scores on a computerized battery that requires speed and accuracy across a number of domains (MicroCog), and other standardized neurocognitive tests. When compared with population norms, MicroCog indices were below average in survivors diagnosed with ALL before age 5, but only the reasoning/calculation index was below average in survivors diagnosed with ALL after age 5. In contrast, intelligence quotient (IQ) scores were average. In addition to confirming earlier studies showing that younger children are more vulnerable to treatment-related neurotoxicity, here we show that deficits exist many years post treatment even with a relatively lower dose of CRT, and that these deficits are especially evident on tasks involving rapid processing of information.

Development of a parent-report cognitive function item bank using item response theory and exploration of its clinical utility in computerized adaptive testing

OBJECTIVE

The purpose of this study is to report the reliability, validity, and clinical utility of a parent-report perceived cognitive function (pedsPCF) item bank.

METHODS

From the U.S. general population, 1,409 parents of children aged 7-17 years completed 45 pedsPCF items. Their psychometric properties were evaluated using Item Response Theory (IRT) approaches. Receiver operating characteristic (ROC) curves and discriminant function analysis were used to predict clinical problems on child behavior checklist (CBCL) scales. A computerized adaptive testing (CAT) simulation was used to evaluate clinical utility.

RESULTS

The final 43-item pedsPCF item bank demonstrates no item bias, has acceptable IRT parameters, and provides good prediction of related clinical problems. CAT simulation resulted in correlations of 0.98 between CAT and the full-length pedsPCF.

CONCLUSIONS

The pedsPCF has sound psychometric properties, U.S. general population norms, and a brief-yet-precise CAT version is available. Future work will evaluate pedsPCF in other clinical populations in which cognitive function is important.

Pretreatment neuropsychological deficits in children with brain tumors

Treatment of childhood brain cancer has been associated with long-term cognitive morbidity in children. In the present study, the cognitive status of children with brain tumors was examined prior to any treatment to single out the role of tumor and tumor-related factors in cognitive deficits. Eighty-three children with newly diagnosed brain tumors (mean age, 8.6 years; range, 7 months to 16.6 years; median, 9.4 years) completed an extensive battery of age-related tests to assess cognitive function before any therapeutic intervention. Magnetic resonance imaging (MRI) was used to determine tumor site and volume and tumor-related factors. Performance under test was compared with symptom duration, neurological status, epilepsy, and MRI. Cognitive difficulties are detected at diagnosis in as many as 50% of patients for some cognitive domains; 6% of patients present with true-diagnosed mental retardation. The location of the tumor is the principal determinant of cognitive deficits, with major impairment in children with cortical tumors. Symptom duration and the presence of epilepsy are significantly associated with neuropsychological disabilities, while neuroradiological tumor-related variables do not correlate clearly with neurocognitive performance. The knowledge of the pre-existing cognitive deficits is critical to evaluate the results of treatment, providing a baseline for assessing the true impact of therapy in determining cognitive decline. In addition, the study suggests that some clinical variables require careful monitoring, because they could be specifically implicated in the neuropsychological outcome; the efforts to reduce the impact of these factors could ameliorate long-term prognosis.

A radiotherapy technique to limit dose to neural progenitor cell niches without compromising tumor coverage

Radiation therapy (RT) for brain tumors is associated with neurocognitive toxicity which may be a result of damage to neural progenitor cells (NPCs). We present a novel technique to limit the radiation dose to NPC without compromising tumor coverage. A study was performed in mice to examine the rationale and another was conducted in humans to determine its feasibility. C57BL/6 mice received localized radiation using a dedicated animal irradiation system with on-board CT imaging with either: (1) Radiation which spared NPC containing regions; (2) Radiation which did not spare these niches; or (3) Sham irradiation. Mice were sacrificed 24 h later and the brains were processed for immunohistochemical Ki-67 staining. For the human component of the study, 33 patients with primary brain tumors were evaluated. Two intensity modulated radiotherapy (IMRT) plans were retrospectively compared: a standard clinical plan and a plan which spares NPC regions while maintaining the same dose coverage of the tumor. The change in radiation dose to the contralateral NPC-containing regions was recorded. In the mouse model, non-NPC-sparing radiation treatment resulted in a significant decrease in the number of Ki67(+) cells in dentate gyrus (DG) (P = 0.008) and subventricular zone (SVZ) (P = 0.005) compared to NPC-sparing radiation treatment. In NPC-sparing clinical plans, NPC regions received significantly lower radiation dose with no clinically relevant changes in tumor coverage. This novel radiation technique should significantly reduce radiation doses to NPC containing regions of the brain which may reduce neurocognitive deficits following RT for brain tumors.

Cerebrospinal fluid oxidative stress during chemotherapy of acute lymphoblastic leukemia in children

In this study the authors addressed the question whether neurotoxicity due to the chemotherapy of acute lymphoblastic leukemia (ALL) is associated with cerebrospinal fluid (CSF) oxidative stress. Examination of 38 ALL patients revealed significant increases in 8-isoprostane concentration and important decreases in total antioxidative capacity of CSF during therapy. The mean 8-isoprostane level at diagnosis was 9.05 +/- 1.62 pg/mL, and no correlations with initial leukocytosis, organomegaly, and lactate dehydrogenase levels were noted. 8-Isoprostane concentrations were increased on the 59th day of treatment (mean level: 24.85 +/- 7.59 pg/mL [P < .01]) and remained elevated at 4 points of the consolidation phase (17.28 +/- 2.16 pg/mL [P < .05]; 22.72 +/- 6.04 pg/mL [P < .05]; 24.92 +/- 6.31 pg/mL [P < .01]; 32.32 +/- 7.94 pg/mL [P < .01]) as compared to their level at diagnosis. The mean total antioxidative capacity at diagnosis was 203.08 +/- 6.17 mumol/L and was remarkably decreased on the 59th day of treatment (189.76 +/- 1.9 mumol/L [P < .05]) and at one point of the consolidation phase (188.29 +/- 3.46 mumol/L [P < .05]) as compared to the level at diagnosis. This study indicates that neurotoxicity of standard ALL treatment may be related to oxidative stress.

Neuropsychological functioning of children treated with intensive chemotherapy followed by myeloablative consolidation chemotherapy and autologous hematopoietic cell rescue for newly diagnosed CNS tumors: an analysis of the Head Start II survivors

BACKGROUND

To evaluate the neuropsychological late effects amongst survivors treated on the Head Start II protocol between 1997 and 2003.

PROCEDURES

Forty-nine patients (mean age 2.9 years) diagnosed with a malignant brain tumor underwent baseline neuropsychological assessment prior to autologous hematopoietic cell transplantation (AuHCT). Twenty-six survivors were retested after 3 years of follow-up as 20 patients did not survive. Patients were evaluated for intelligence, academic achievement, receptive language, visual-motor integration (VMI), learning/memory, social-emotional and behavioral functioning based upon age at testing.

RESULTS

Overall intelligence and VMI at baseline were low average while verbal and non-verbal intelligence, academic achievement, and receptive vocabulary were in average range. Parents reported social-emotional and behavioral functioning within normal limits. Serial testing revealed Full Scale (FSIQ)/Mental Development Index (MDI), Verbal (VIQ), and Performance (PIQ) Intelligence to be generally stable over 3-year follow-up. Group-average analysis at follow-up demonstrated low average intelligence, academic achievement, receptive language, and VMI. Age at diagnosis was positively correlated with internalizing symptoms and visual immediate memory, while time since diagnosis was inversely correlated with FSIQ, VIQ, PIQ, reading and delayed verbal memory. Craniospinal irradiation (CSI) was avoided in two-thirds of patients.

CONCLUSION

Induction, with or without intensification using intravenous methotrexate, followed by myeloablative consolidation chemotherapy with AuHCT, may avoid or delay CSI, with possible stabilization of neuropsychological functioning, including those younger at diagnosis. Continued follow-up is necessary to determine the preservation of neuropsychological, academic, social-emotional and behavioral functioning.

Comparison of neurocognitive functioning in children previously randomly assigned to intrathecal methotrexate compared with triple intrathecal therapy for the treatment of childhood acute lymphoblastic leukemia

PURPOSE

For the majority of children with acute lymphoblastic leukemia (ALL), CNS prophylaxis consists of either intrathecal (IT) methotrexate or triple IT therapy (ie, methotrexate with both cytarabine and hydrocortisone). The long-term neurotoxicities of these two IT strategies have not yet been directly compared.

PATIENTS AND METHODS

In this multisite study, 171 children with standard-risk ALL, age 1 to 9.99 years at diagnosis, previously randomly assigned to IT methotrexate (n = 82) or to triple IT therapy (n = 89) on CCG 1952, underwent neurocognitive evaluation by a licensed psychologist at a mean of 5.9 years after random assignment.

RESULTS

Patients who received IT methotrexate had a mean Processing Speed Index that was 3.6 points lower, about one fourth of a standard deviation, than those who received triple IT therapy (P = .04) after analysis was adjusted for age, sex, and time since diagnosis. Likewise, 19.5% of children in the IT methotrexate group had a Processing Speed Index score in the below-average range compared with 6.9% in the triple IT therapy group (P = .02). Otherwise, the groups performed similarly on tests of full-scale intelligence quotient, academic achievement, attention/concentration, memory, and visual motor integration. The association of treatment with measures of cognitive functioning was not modified by sex or age at diagnosis. In the post-therapy period, there were no group differences in special education services, neurologic events, or use of psychotropic medications.

CONCLUSION

This study did not show any clinically meaningful differences in neurocognitive functioning between patients previously randomly assigned to IT methotrexate or triple IT therapy except for a small difference in processing speed in the IT methotrexate group.

Sex-specific attention problems in long-term survivors of pediatric acute lymphoblastic leukemia

BACKGROUND

Neurocognitive problems are a frequent outcome of chemotherapy for pediatric leukemia, although individual differences exist in patient outcome. Sex of the patient and age at diagnosis are 2 characteristics that have been associated with differential outcomes. The relation between these patient characteristics and specific attention deficits (ie, initiating, inhibiting, shifting, focusing, sustaining attention, and working memory) has not been well researched. The purpose of this study was to evaluate the pattern of attention problems in male and female long-term survivors of pediatric acute lymphoblastic leukemia (ALL).

METHODS

One hundred three long-term survivors (ie, >or=5 years from diagnosis; 51% boys, mean age at diagnosis of 3.9 years, and mean time since diagnosis 7.5 years) completed standardized measures of basic and complex attention skills related to anterior (ie, inhibition, shifting attention, working memory), posterior (ie, focusing), and subcortical brain systems (ie, sustaining).

RESULTS

Treatment intensity was related to sustained attention, with those patients treated on high-risk protocols displaying significantly lower performance. Girls performed worse than boys on measures related to the anterior attention system (ie, shifting attention, P<.042) and the subcortical attention system (ie, sustained attention, P<.001), whereas boys performed worse than girls on different measures of anterior control (ie, inhibition, P<.039; working memory, P<.003).

CONCLUSIONS

The results of this study suggest that children diagnosed with and treated for pediatric ALL perform poorly on select measures of attention and executive control, and that this performance is influenced by sex and treatment intensity.

Cognitive and radiological effects of radiotherapy in patients with low-grade glioma: long-term follow-up

BACKGROUND

Our previous study on cognitive functioning among 195 patients with low-grade glioma (LGG) a mean of 6 years after diagnosis suggested that the tumour itself, rather than the radiotherapy used to treat it, has the most deleterious effect on cognitive functioning; only high fraction dose radiotherapy (>2 Gy) resulted in significant added cognitive deterioration. The present study assesses the radiological and cognitive abnormalities in survivors of LGG at a mean of 12 years after first diagnosis.

METHODS

Patients who have had stable disease since the first assessment were invited for follow-up cognitive assessment (letter-digit substitution test, concept shifting test, Stroop colour-word test, visual verbal learning test, memory comparison test, and categoric word fluency). Compound scores in six cognitive domains (attention, executive functioning, verbal memory, working memory, psychomotor functioning, and information processing speed) were calculated to detect differences between patients who had radiotherapy and patients who did not have radiotherapy. White-matter hyperintensities and global cortical atrophy were rated on MRI scans.

FINDINGS

65 patients completed neuropsychological follow-up at a mean of 12 years (range 6-28 years). 32 (49%) patients had received radiotherapy (three had fraction doses >2 Gy). The patients who had radiotherapy had more deficits that affected attentional functioning at the second follow-up, regardless of fraction dose, than those who did not have radiotherapy (-1.6 [SD 2.4] vs -0.1 [1.3], p=0.003; mean difference 1.4, 95% CI 0.5-2.4). The patients who had radiotherapy also did worse in measures of executive functioning (-2.0 [3.7] vs -0.5 [1.2], p=0.03; mean difference 1.5, 0.2-2.9) and information processing speed (-2.0 [3.7] vs -0.6 [1.5], p=0.05; mean difference 0.8, 0.009-1.6]) between the two assessments. Furthermore, attentional functioning deteriorated significantly between the first and second assessments in patients who had radiotherapy (p=0.25). In total, 17 (53%) patients who had radiotherapy developed cognitive disabilities deficits in at least five of 18 neuropsychological test parameters compared with four (27%) patients who were radiotherapy naive. White-matter hyperintensities and global cortical atrophy were associated with worse cognitive functioning in several domains.

INTERPRETATION

Long-term survivors of LGG who did not have radiotherapy had stable radiological and cognitive status. By contrast, patients with low-grade glioma who received radiotherapy showed a progressive decline in attentional functioning, even those who received fraction doses that are regarded as safe (</=2 Gy). These cognitive deficits are associated with radiological abnormalities. Our results suggest that the risk of long-term cognitive and radiological compromise that is associated with radiotherapy should be considered when treatment is planned.

FUNDING

Kaptein Fonds; Schering Plough.

Negative correlation between cerebrospinal fluid tau protein and cognitive functioning in children with acute lymphoblastic leukemia

The aim of the study was to assess whether cerebrospinal fluid tau protein is associated with cognitive changes in children with acute lymphoblastic leukemia (ALL). Examination of 38 ALL patients revealed a statistically significant increase in tau protein on treatment day 59 and at two points during consolidation phase. Cognitive functioning was examined in 19 patients at an average of 3.7 years after diagnosis. The level of tau at the initiation of maintenance therapy was negatively correlated with verbal abilities measured on an intellectual scale. The study suggests that standard ALL treatment may cause a decline in cognitive functioning.

Neurodevelopmental sequelae of pediatric acute lymphoblastic leukemia and its treatment

This review will describe the neurocognitive outcomes associated with pediatric acute lymphoblastic leukemia (ALL) and its treatment. The literature is reviewed with the aim of addressing methodological issues, treatment factors, risks and moderators, special populations, relationship to neuroimaging findings, and directions for future research. It is concluded that neurocognitive outcomes for the majority of children with standard-risk ALL treated according to current chemotherapy protocols is relatively good, but subgroups of children are more significantly compromised. As medical treatments advance and survival rates continue to improve, neurocognitive outcomes and other quality of life indicators will become increasingly important. Preventing or ameliorating treatment-related neuropsychological sequelae represents the next major challenge in pediatric ALL.

Parental needs for information related to neurocognitive late effects from pediatric cancer and its treatment

BACKGROUND

Parents' needs for information about neurocognitive late effects (NCLE) associated with cancer treatment may differ as to the preferred source, format, timing, and amount of information about potential NCLE from treatment. Parental characteristics, treatment variables, and other risk factors may also modulate the needs for information about NCLE.

PROCEDURE

A total of 90 parents completed a series of questionnaires related to their perceived knowledge of NCLE and need for further information about NCLE, coping style, stress, perceived risk for NCLE, and information related to their child's diagnosis and treatment.

RESULTS

These findings indicate that although parents report feeling knowledgeable about NCLE, they continue to have a need for further information. Many parents would prefer multi-modal presentation of this material, but they do not have a clear consensus about the optimal time to first discuss this risk. Parents who reported higher levels of emotional distress expressed a preference to receive information earlier. Stepwise regression analyses revealed that parents of children who received cranial radiation reported being well informed about NCLE, whereas parents of children who received chemotherapy reported wanting more information about NCLE.

CONCLUSIONS

It is important to recognize the high level of need for information about potential NCLE in caregivers of children with cancer. Further research is needed to understand how to tailor the timing and mode of presentation to individual families.

Folate homeostasis in cerebrospinal fluid during therapy for acute lymphoblastic leukemia

The neurotoxic effects of therapy for childhood acute lymphoblastic leukemia can result in leukoencephalopathy or measurable deficits in cognitive function. However, there are no validated biomarkers that allow the identification of those patients at greatest risk. With the objective of identifying such predictors, cerebrospinal fluid collected from 53 patients over 2.5 years of therapy for childhood acute lymphoblastic leukemia was retrospectively studied. Cerebrospinal fluid folate, concentrated relative to serum folate prior to therapy, dropped during the first month of therapy and remained below baseline throughout treatment. Cerebrospinal fluid homocysteine was inversely related to cognitive function prior to treatment. Oral methotrexate was associated with decreased cerebrospinal fluid folate and increased cerebrospinal fluid homocysteine, but these changes were not seen with oral aminopterin. Of 36 patients who had imaging after completion of therapy, 9 had periventricular or subcortical white matter abnormalities consistent with leukoencephalopathy. Peak cerebrospinal fluid tau concentrations during therapy were higher among patients who had leukoencephalopathy after completion of therapy than among those with normal imaging studies at the end of therapy. If confirmed prospectively, these markers may allow the identification of those patients at greatest risk of developing treatment-induced neurocognitive dysfunction, thus guiding preventive interventions.

White matter fractional anisotropy correlates with speed of processing and motor speed in young childhood cancer survivors

PURPOSE

To determine whether childhood medulloblastoma and acute lymphoblastic leukemia (ALL) survivors have decreased white matter fractional anisotropy (WMFA) and whether WMFA is related to the speed of processing and motor speed.

METHODS AND MATERIALS

For this study, 17 patients (6 medulloblastoma, 5 ALL treated with high-dose methotrexate (MTX) (4 x 5 g/m(2)) and 6 with low-dose MTX (3 x 2 g/m(2))) and 17 age-matched controls participated. On a 3.0-T magnetic resonance imaging (MRI) scanner, diffusion tensor imaging (DTI) was performed, and WMFA values were calculated, including specific regions of interest (ROIs), and correlated with the speed of processing and motor speed.

RESULTS

Mean WMFA in the patient group, mean age 14 years (range 8.9 - 16.9), was decreased compared with the control group (p = 0.01), as well as WMFA in the right inferior fronto-occipital fasciliculus (IFO) (p = 0.03) and in the genu of the corpus callosum (gCC) (p = 0.01). Based on neurocognitive results, significant positive correlations were present between processing speed and WMFA in the splenium (sCC) (r = 0.53, p = 0.03) and the body of the corpus callosum (bCC) (r = 0.52, p = 0.03), whereas the right IFO WMFA was related to motor speed (r = 0.49, p < 0.05).

CONCLUSIONS

White matter tracts, using a 3.0-T MRI scanner, show impairment in childhood cancer survivors, medulloblastoma survivors, and also those treated with high doses of MTX. In particular, white matter tracts in the sCC, bCC and right IFO are positively correlated with speed of processing and motor speed.

Preventing neurocognitive late effects in childhood cancer survivors

Neurocognitive late effects are common sequelae of cancer in children, especially in those who have undergone treatment for brain tumors or in those receiving prophylactic cranial radiation therapy to treat leukemia. Neurocognitive morbidity in attention, executive functioning, processing speed, working memory, and memory frequently occurs and contributes to declines in intellectual and academic abilities. Oncologists are faced with the challenge of using the most effective, often the most intense, therapy to achieve the primary goal of medical success, balanced with the desire to prevent adverse late effects. Not all children with similar diagnoses and treatment have identical neurocognitive outcomes; some do very poorly and some do well. Attention now turns to the reliable prediction of risk for poor outcomes and then, using risk-adapted therapy, to preserve neurocognitive function. Prevention of late effects through rehabilitative strategies, continuation of school, and pharmacotherapy will be explored.

Late structural alterations of cerebral white matter in long-term survivors of childhood leukemia

PURPOSE

To look for the presence and age-dependence of late structural alterations of otherwise normal-appearing cerebral gray and white matter after radiation and chemotherapy in adult survivors of acute lymphoblastic leukemia (ALL) during childhood.

MATERIALS AND METHODS

In a group of 13 adult survivors 17-37 years old, who had been treated by total brain radiation (18-24 Gy) and chemotherapy 16-28 years ago, prospective MR examinations including diffusion tensor imaging (DTI) were performed. Evaluation included volumetry, calculation of mean diffusivity (MD) and fractional anisotropy (FA), and comparison of results to an age-matched control group.

RESULTS

DTI showed significantly reduced FA values in the temporal lobes (difference of 0.069 units, P < 0.001), hippocampi (difference of 0.033 units, P < 0.001), and thalami (difference of 0.046 units, P = 0.001), which were accompanied by significant white matter volume loss (difference of 92 cm(3), P < 0.001). Significant elevations of MD were limited to the temporal white matter (difference of 42 x 10(-6) mm(2)/s, P = 0.005). Global and frontal white matter MD correlated negatively to increasing age of the survivors (P < 0.01).

CONCLUSION

With regard to structural white matter alterations, adult long-term survivors of childhood ALL, who had received total brain radiation and chemotherapy, apparently show the same overall age dependence as controls. Follow-up studies are needed for confirmation.

Detection and characterization of neurotoxicity in cancer patients using proton MR spectroscopy

OBJECTIVE

The study objective was to detect abnormalities and identify relationships between brain metabolic ratios determined by proton magnetic resonance spectroscopic imaging ((1)H-MRSI) and neuropsychological (NP) function in cancer patients at risk for neurotoxicity.

METHODS

Thirty-two patients received (1)H-MRSI using a multi-slice, multi-voxel technique on a 1.5T magnet. Cho/NAA, NAA/Cr, and Cho/Cr ratios were identified in seven pre-determined sites without tumor involvement. A battery of age-appropriate NP tests was administered within 7 days of imaging. Relationships were examined between test scores and metabolite ratios.

CONCLUSIONS

This study identifies relationships between brain metabolite ratios and cognitive functioning in cancer patients. (1)H-MRSI may be useful in early detection of neurotoxic effects, but prospective longitudinal studies in a homogeneous population are recommended to determine the prognostic value.