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.

Neurocognitive Outcomes in Multiethnic Pediatric Brain Tumor Patients Treated With Proton Versus Photon Radiation

BACKGROUND

We analyzed post-radiation (RT) neurocognitive outcomes in an ethnically diverse pediatric brain tumor population undergoing photon radiotherapy (XRT) and proton radiotherapy (PRT).

PROCEDURE

Post-RT neurocognitive outcomes from 49 pediatric patients (37% Hispanic/Latino) with primary brain tumors were analyzed. Tests included cognitive outcomes, behavioral outcomes, and overall intelligence. For each outcome, proportion of patients with cognitive impairment (scores <1.5 SD) was calculated. The Fisher exact tests compared proportion of patients with impairment and t tests compared T-scores between XRT (n=32) and PRT (n=17) groups. Linear regression assessed associations between radiation modality and outcomes.

RESULTS

Median follow-up was 3.2 and 1.8 years in the XRT and PRT groups, respectively. The median RT dose was 54.0 Gy. We found impairment in 16% to 42% of patients across most neurocognitive domains except executive function. There was no difference in scores between XRT and PRT groups. Regression analyses revealed no association of neurocognitive outcomes with radiation modality. Non-Hispanic patients had better Verbal Comprehension Index and General Ability Index scores than Hispanic patients ( P <0.05).

CONCLUSIONS

Among pediatric patients with brain tumors receiving RT, all cognitive domains were affected except executive function. Radiation modality was not associated with neurocognitive outcomes. Hispanic patients may be more vulnerable to posttreatment cognitive effects that warrant further study.

Genetic susceptibility to cognitive decline following craniospinal irradiation for pediatric central nervous system tumors

BACKGROUND

Survivors of pediatric central nervous system (CNS) tumors treated with craniospinal irradiation (CSI) exhibit long-term cognitive difficulties. Goals of this study were to evaluate longitudinal effects of candidate and novel genetic variants on cognitive decline following CSI.

METHODS

Intelligence quotient (IQ), working memory (WM), and processing speed (PS) were longitudinally collected from patients treated with CSI (n = 241). Genotype-by-time interactions were evaluated using mixed-effects linear regression to identify common variants (minor allele frequency > 1%) associated with cognitive performance change. Novel variants associated with cognitive decline (P < 5 × 10-5) in individuals of European ancestry (n = 163) were considered replicated if they demonstrated consistent genotype-by-time interactions (P < .05) in individuals of non-European ancestries (n = 78) and achieved genome-wide statistical significance (P < 5 × 10-8) in a meta-analysis across ancestry groups.

RESULTS

Participants were mostly males (65%) diagnosed with embryonal tumors (98%) at a median age of 8.3 years. Overall, 1150 neurocognitive evaluations were obtained (median = 5, range: 2-10 per participant). One of the five loci previously associated with cognitive outcomes in pediatric CNS tumors survivors demonstrated significant time-dependent IQ declines (PPARA rs6008197, P = .004). Two variants associated with IQ in the general population were associated with declines in IQ after Bonferroni correction (rs9348721, P = 1.7 × 10-5; rs31771, P = 7.8 × 10-4). In genome-wide analyses, we identified novel loci associated with accelerated declines in IQ (rs116595313, meta-P = 9.4 × 10-9), WM (rs17774009, meta-P = 4.2 × 10-9), and PS (rs77467524, meta-P = 1.5 × 10-8; rs17630683, meta-P = 2.0 × 10-8; rs73249323, meta-P = 3.1 × 10-8).

CONCLUSIONS

Inherited genetic variants involved in baseline cognitive functioning and novel susceptibility loci jointly influence the degree of treatment-associated cognitive decline in pediatric CNS tumor survivors.

No clinically relevant effect on cognitive outcomes after low-dose radiation to the infant brain: a population-based cohort study in Sweden

While the detrimental effects of cranial radiotherapy on the developing brain are well known, the effects on cognitive performance of low doses of ionizing radiation is less studied. We performed a population-based cohort study to determine whether low doses of ionizing radiation to the brain in infancy affects cognitive function later in life. Further we hypothesized that the dose to the hippocampus predicts cognitive late side effects better than the anterior or the posterior brain doses.

Material and methods

During 1950–1960 3860 boys were treated with radiation in Sweden for cutaneous hemangiomas before the age of 18 months. Of these, 3030 were analyzed for military test scores at the age of 18 years and 2559 for the highest obtained educational level.

Results

Logical, spatial and technical test scores were not affected by increasing irradiation doses. The verbal test scores displayed a significant trend for decreasing scores with increasing doses to the hippocampus (p = 0.005). However, the absolute mean difference between the zero dose and the highest dose category (median 680 mGy) was very small, only 0.64 stanine points, and the significance was dependent on the highest dose category, containing few subjects. The educational level was not affected by brain irradiation. Overall, the hippocampal dose was a better predictor of late cognitive side effects than the doses to the anterior or the posterior brain. In conclusion, there was no decrease in logical, spatial and technical verbal or global test scores after ionizing radiation doses up to 250 mGy, but a subtle decrease in verbal test scores if the highest dose category was included (median 680 mGy). However, the clinical relevance of this decline in the highest dose group is questionable, since we could not find any effect on the highest obtained educational level.

Long-term decline in intelligence among adult survivors of childhood acute lymphoblastic leukemia treated with cranial radiation

Survivors of childhood acute lymphoblastic leukemia (ALL) treated with cranial radiation therapy (CRT) are at risk for cognitive impairment, although whether impairment progresses with age into adulthood is unknown. We report change in intelligence for 102 adult survivors of childhood ALL (age range, 26.6-54.7 years) during a median interval of 28.5 years. Survivors demonstrated lower Performance intelligence (mean, 95.3; standard deviation, 16.5; P = .005) but not Verbal IQ (mean, 97.4; standard deviation, 15.44; P = .09) at initial testing. Verbal intelligence declined an average of 10.3 points (P < .0001) during the follow-up interval with no decline in Performance intelligence. Decline was associated with current attention problems (P = .002) but not gender, CRT dose, age at CRT exposure, or years between testing. Results suggest long-term survivors of childhood ALL treated with CRT are at risk for progressive decline in verbal intellect, which may be driven by attention deficits. This trial was registered at clinicaltrials.gov as no. NCT00760656.

Longitudinal investigation of adaptive functioning following conformal irradiation for pediatric craniopharyngioma and low-grade glioma

PURPOSE

Children treated for brain tumors with conformal radiation therapy experience preserved cognitive outcomes. Early evidence suggests that adaptive functions or independent-living skills may be spared. This longitudinal investigation prospectively examined intellectual and adaptive functioning during the first 5 years following irradiation for childhood craniopharyngioma and low-grade glioma (LGG). The effect of visual impairment on adaptive outcomes was investigated.

METHODS AND MATERIALS

Children with craniopharyngioma (n=62) and LGG (n=77) were treated using conformal or intensity modulated radiation therapy. The median age was 8.05 years (3.21-17.64 years) and 8.09 years (2.20-19.27 years), respectively. Serial cognitive evaluations including measures of intelligence quotient (IQ) and the Vineland Adaptive Behavior Scales (VABS) were conducted at preirradiation baseline, 6 months after treatment, and annually through 5 years. Five hundred eighty-eight evaluations were completed during the follow-up period.

RESULTS

Baseline assessment revealed no deficits in IQ and VABS indices for children with craniopharyngioma, with significant (P<.05) longitudinal decline in VABS Communication and Socialization indices. Clinical factors associated with more rapid decline included females and preirradiation chemotherapy (interferon). The only change in VABS Daily Living Skills correlated with IQ change (r=0.34; P=.01) in children with craniopharyngioma. Children with LGG performed below population norms (P<.05) at baseline on VABS Communication, Daily Living Indices, and the Adaptive Behavior Composite, with significant (P<.05) longitudinal decline limited to VABS Communication. Older age at irradiation was a protective factor against longitudinal decline. Severe visual impairment did not independently correlate with poorer adaptive outcomes for either tumor group.

CONCLUSIONS

There was relative sparing of postirradiation functional outcomes over time in this sample. Baseline differences in functional abilities before the initiation of irradiation suggested that other factors influence functional outcomes above and beyond the effects of irradiation.

The Chornobyl accident and cognitive functioning: a follow-up study of infant evacuees at age 19 years

BACKGROUND

The cognitive and academic outcomes of infants exposed to radiation after the meltdown at Chornobyl have been intensely debated. Western-based investigations indicate that no adverse effects occurred, but local studies reported increased cognitive impairments in exposed compared with non-exposed children. Our initial study found that at age 11 years, school grades and neuropsychological performance were similar in 300 children evacuated to Kiev as infants or in utero compared with 300 classmate controls, yet more evacuee mothers believed that their children had memory problems. This study re-examined the children's performance and academic achievement at age 19 years.

METHOD

In 2005-2006, we conducted an 8-year follow-up of the evacuees (n=265) and classmate controls (n=261) assessed in Kiev in 1997. Outcomes included university attendance, tests of intelligence, attention, and memory, and subjective appraisals of memory problems. Scores were standardized using a local population-based control group (n=327). Analyses were stratified by parental education.

RESULTS

Evacuees and classmates performed similarly and in the normal range on all tests, and no differential temporal changes were found. The results were comparable for the in utero subsample. The rates of university attendance and self-reported memory problems were also similar. Nevertheless, the evacuee mothers were almost three times as likely to report that their children had memory problems compared with controls.

CONCLUSIONS

Chornobyl did not influence the cognitive functioning of exposed infants although more evacuee mothers still believed that their offspring had memory problems. These lingering worries reflect a wider picture of persistent health concerns as a consequence of the accident.

Brain Magnetic Resonance Imaging After High-Dose Chemotherapy and Radiotherapy for Childhood Brain Tumors

PURPOSE

Brain necrosis or other subacute iatrogenic reactions has been recognized as a potential complication of radiotherapy (RT), although the possible synergistic effects of high-dose chemotherapy and RT might have been underestimated.

METHODS AND MATERIALS

We reviewed the clinical and radiologic data of 49 consecutive children with malignant brain tumors treated with high-dose thiotepa and autologous hematopoietic stem cell rescue, preceded or followed by RT. The patients were assessed for neurocognitive tests to identify any correlation with magnetic resonance imaging (MRI) anomalies.

RESULTS

Of the 49 children, 18 (6 of 25 with high-grade gliomas and 12 of 24 with primitive neuroectodermal tumors) had abnormal brain MRI findings occurring a median of 8 months (range, 2-39 months) after RT and beginning to regress a median of 13 months (range, 2-26 months) after onset. The most common lesion pattern involved multiple pseudonodular, millimeter-size, T1-weighted unevenly enhancing, and T2-weighted hyperintense foci. Four patients with primitive neuroectodermal tumors also had subdural fluid leaks, with meningeal enhancement over the effusion. One-half of the patients had symptoms relating to the new radiographic findings. The MRI lesion-free survival rate was 74%+/-6% at 1 year and 57%+/-8% at 2 years. The number of marrow ablative courses correlated significantly to the incidence of radiographic anomalies. No significant difference was found in intelligent quotient scores between children with and without radiographic changes.

CONCLUSION

Multiple enhancing cerebral lesions were frequently seen on MRI scans soon after high-dose chemotherapy and RT. Such findings pose a major diagnostic challenge in terms of their differential diagnosis vis-à-vis recurrent tumor. Their correlation with neurocognitive results deserves further investigation.

Diffusion tensor imaging of white matter after cranial radiation in children for medulloblastoma: correlation with IQ

Treatment of children with cranial-spinal radiation (CSR) for brain tumors is associated with adverse intellectual outcome and white matter damage. However, the correlation between IQ and measures of white matter integrity has received little attention. We examined apparent diffusion coefficient (ADC), fractional anisotropy (FA), and intelligence in pediatric patients treated with CSR for medulloblastoma relative to control subjects. ADC and FA measures were obtained for eight patients and eight control children and evaluated in multiple regions of interest in the cerebral hemispheres. Mean ADC and mean FA for each region were calculated, group differences were evaluated, and the relationship between these measures and intelligence were examined. In our study group, decreased IQ was associated with increased ADC and decreased FA (P < 0.01). Mean IQ for the CSR group was lower than that for the control group, but the difference was not significant when controlling for overall mean FA or ADC (P > 0.10). Overall mean FA was lower and ADC was higher in the CSR group relative to controls (P < 0.01). Specifically, FA was lower in the genu of the corpus callosum, the anterior and posterior limbs of the internal capsule, inferior frontal white matter, and high frontal white matter, and ADC was higher in all regions in patients relative to controls (P < 0.01). Compromised white matter integrity was observed for multiple regions within the cerebral hemispheres following CSR. A novel finding was that microscopic damage in normal-appearing white matter, as indexed by higher ADC and lower FA, was related to poor intellectual outcome relative to age-matched controls.

Intelligence and adaptive function in children diagnosed with brain tumour during infancy

BACKGROUND

Late effects of treatment in children diagnosed and treated for brain tumours in infancy is a major concern. Assessment of infants presenting with brain tumours is difficult and there is little information available regarding the development of infants prior to treatment and hence the impact of the tumour itself on developmental outcomes.

AIM

To describe the development of children diagnosed with brain tumours in infancy and to document their cognitive and adaptive function at school entry.

METHOD

Infants were psychologically evaluated at the time of diagnosis of a brain tumour and during their fifth or sixth year in preparation for school entry.

RESULTS

Children diagnosed with brain tumours in infancy display developmental delays in a number of areas of adaptive function. By the time these children are school age they display further compromise in cognitive and academic skills and adaptive behaviour. Higher levels of deficit at follow-up were associated with tumour location in the supratentorium, younger age at diagnosis and longer time since diagnosis. The effect of radiotherapy could not be determined because of differing degrees of developmental compromise in the treatment groups at baseline.

CONCLUSION

Brain tumours in infancy confer a risk of poor developmental progress at the time of diagnosis. These children display additional compromise of development by the time they reach school age. Research protocols evaluating the impact of treatment in infants diagnosed with brain tumours need to take account of the developmental status of the child at diagnosis.

Limited-field radiation for bifocal germinoma

PURPOSE

To report the incidence, characteristics, treatment, and outcomes of bifocal germinomas treated with chemotherapy followed by focal radiation.

METHODS AND MATERIALS

This was a retrospective review. Inclusion criteria included radiologic diagnosis of bifocal germinoma involving the pineal and neurohypophyseal region, no evidence of dissemination on spinal MRI, negative results from cerebrospinal fluid cytologic evaluation, and negative tumor markers.

RESULTS

Between 1995 and 2004, 6 patients (5 male, 1 female; median age, 12.8 years) fulfilled the inclusion criteria. All had symptoms of diabetes insipidus at presentation. On MRI, 4 patients had a pineal and suprasellar mass, and 2 had a pineal mass associated with abnormal neurohypophyseal enhancement. All patients received chemotherapy followed by limited-field radiation and achieved complete remission after chemotherapy. The radiation field involved the whole ventricular system (range, 2,400-4,000 cGy) with or without a boost to the primary lesions. All patients remain in complete remission at a median follow-up of 48.1 months (range, 9-73.4 months).

CONCLUSIONS

This experience suggests that bifocal germinoma can be considered a locoregional rather than a metastatic disease. Chemotherapy and focal radiotherapy might be sufficient to provide excellent outcomes. Staging refinement with new diagnostic tools will likely increase the incidence of the entity.

Modeling radiation dosimetry to predict cognitive outcomes in pediatric patients with CNS embryonal tumors including medulloblastoma

PURPOSE

Model the effects of radiation dosimetry on IQ among pediatric patients with central nervous system (CNS) tumors.

METHODS AND MATERIALS

Pediatric patients with CNS embryonal tumors (n = 39) were prospectively evaluated with serial cognitive testing, before and after treatment with postoperative, risk-adapted craniospinal irradiation (CSI) and conformal primary-site irradiation, followed by chemotherapy. Differential dose-volume data for 5 brain volumes (total brain, supratentorial brain, infratentorial brain, and left and right temporal lobes) were correlated with IQ after surgery and at follow-up by use of linear regression.

RESULTS

When the dose distribution was partitioned into 2 levels, both had a significantly negative effect on longitudinal IQ across all 5 brain volumes. When the dose distribution was partitioned into 3 levels (low, medium, and high), exposure to the supratentorial brain appeared to have the most significant impact. For most models, each Gy of exposure had a similar effect on IQ decline, regardless of dose level.

CONCLUSIONS

Our results suggest that radiation dosimetry data from 5 brain volumes can be used to predict decline in longitudinal IQ. Despite measures to reduce radiation dose and treatment volume, the volume that receives the highest dose continues to have the greatest effect, which supports current volume-reduction efforts.

Early patterns of verbal memory impairment in children treated for medulloblastoma

Children treated for medulloblastoma demonstrate a variety of cognitive deficits in addition to white matter and hippocampal neuropathology. This study examined 40 children treated for medulloblastoma as compared with 40 demographically matched controls on the California Verbal Learning Test-Children's Version (D. C. Delis, J. H. Kramer, E. Kaplan, & B. A. Ober, 1994). Results revealed significantly poorer performance on indices of word recall in the patient group as compared with the controls in addition to milder but still significantly poorer recognition memory. These findings suggest that children treated for medulloblastoma demonstrate a mixed profile of memory impairment consisting of both retrieval and recognition deficits. Implications of these findings for understanding neurobehavioral sequelae within pediatric medulloblastoma populations and for designing educational and remediation strategies to be used with these children are discussed.

Radiation dosimetry predicts IQ after conformal radiation therapy in pediatric patients with localized ependymoma

PURPOSE

To assess the effects of radiation dose-volume distribution on the trajectory of IQ development after conformal radiation therapy (CRT) in pediatric patients with ependymoma.

METHODS AND MATERIALS

The study included 88 patients (median age, 2.8 years +/- 4.5 years) with localized ependymoma who received CRT (54-59.4 Gy) that used a 1-cm margin on the postoperative tumor bed. Patients were evaluated with tests that included IQ measures at baseline (before CRT) and at 6, 12, 24, 36, 48, and 60 months. Differential dose-volume histograms (DVH) were derived for total-brain, supratentorial-brain, and right and left temporal-lobe volumes. The data were partitioned into three dose intervals and integrated to create variables that represent the fractional volume that received dose over the specified intervals (e.g., V(0-20 Gy), V(20-40 Gy), V(40-65 Gy)) and modeled with clinical variables to develop a regression equation to estimate IQ after CRT.

RESULTS

A total of 327 IQ tests were performed in 66 patients with infratentorial tumors and 20 with supratentorial tumors. The median follow-up was 29.4 months. For all patients, IQ was best estimated by age (years) at CRT; percent volume of the supratentorial brain that received doses between 0 and 20 Gy, 20 and 40 Gy, and 40 and 65 Gy; and time (months) after CRT. Age contributed significantly to the intercept (p > 0.0001), and the dose-volume coefficients were statistically significant (V(0-20 Gy), p = 0.01; V(20-40 Gy), p < 0.001; V(40-65 Gy), p = 0.04). A similar model was developed exclusively for patients with infratentorial tumors but not supratentorial tumors.

CONCLUSION

Radiation dosimetry can be used to predict IQ after CRT in patients with localized ependymoma. The specificity of models may be enhanced by grouping according to tumor location.

[The intellectual development of the children exposed to the influence of the ionizing radiation]

The mental development level of the children living in the territories polluted by the radioactive nuclide as the result of Cheernobil power plant damage, exposed to the prenatal irradiation, evacuated from the alienation zone, born from parents-liquidators (1st generation of the irradiated people) was evaluated. 177 children were examinated. The control group included 34 children not exposed to the radiation. The complex of psychometric methods--"D. Wexler children's intellectual test"--for 3-6-year-old children in the translation and adaptation of A.U. Panasyuk was applied for evaluating the intellect rate. In the structure of the observed groups the pathology diseases of nervous system, of digestion organs and the congenital anomalies prevailed. Clinical and instrumental investigation showed no differences in the neurology status between the observed and the control groups. It was proved that the intellect of the children exposed to the radiation corresponds the age standards. However, intellectual development of the children irradiated in the prenatal period and children evacuated from the 2nd zone of radioactive pollution (or living there) has a tendency to its decreasing. The determining role of social, of economic and of biologic factors (the parents' education, the region of living, the birth weight) in the intellect development was indicated.

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

BACKGROUND

To evaluate intellectual decline in children with posterior fossa (PF) tumors treated with different therapeutic protocols.

PROCEDURE

Forty children had a complete neuropsychological evaluation prospectively twice, at least 6 months year (y) after the end of their treatment. Patients were classified into four groups according to treatment schedules: Group 1 (n = 7) PF radiotherapy (PFRT) alone at 50 Gy; Group 2 (n = 13) reduced-dose cranio-spinal irradiation (CSI) at 25 Gy with a PF boost; Group 3 (n = 9) standard CSI at 35 Gy and a PF boost; and Group 4 (n = 11) high-dose chemotherapy with stem cell support followed by PFRT at 50 Gy.

RESULTS

At the first evaluation (mean interval since diagnosis 3.7 y), the mean Full-Scale Intellectual Quotient (FSIQ) was 80 (SD = 19). Only patients in Group 1 had a normal mean IQ score of 92 (SD = 14). At the second evaluation (mean interval since diagnosis 6.3 y), the mean FSIQ scores were significantly lower with a mean difference of 2.4 points, i.e., a yearly decline of one point. The magnitude of the FSIQ decline was positively correlated with the first IQ score (P = 0.0001) and inversely correlated with age at diagnosis (P = 0.0005). A FSIQ decline was observed in all treatment groups except Group 1 (P = 0.005). The differences in FSIQ observed initially between the four treatment groups persisted at the second evaluation.

CONCLUSIONS

This study shows that FSIQ continues to decline more than 4 years after the diagnosis but this yearly decline seems to decrease with time from diagnosis. Therapeutic schedules influence the magnitude of this decline. Long-term follow-up into adulthood is necessary to effectively adapt patient rehabilitation.

Long-term effects of radiation therapy on cognitive and endocrine function in children with leukemia and brain tumors

BACKGROUND

As the number of long-term survivors of childhood cancer has grown, it has become increasingly clear that central nervous system therapy may have serious long-term effects on cognition and endocrine function. These complications have been studied most extensively in children with brain tumors and leukemia.

REVIEW SUMMARY

Children with acute lymphoblastic leukemia previously treated with cranial irradiation are at risk for cognitive decline. Chemotherapy-only regimens, which rely on high-dose frequently administered methotrexate, are also associated with producing cognitive dysfunction. Children irradiated for brain tumors are even more vulnerable. Risk factors include perioperative morbidity, young age, large-volume high-dose cranial irradiation, supra-tentorial location of tumor, moyamoya syndrome, and leukoencephalopathy. Cognitive decline is progressive over at least a decade. The most common radiation-induced endocrinopathies are hypothyroidism and growth hormone deficiency. Treatment effects on growth are multifactorial and include growth hormone deficiency,spinal shortening, precocious puberty, undetected hypothyroidism,and poor nutrition. Fifty percent to 80% of children treated with craniospinal radiation for brain tumors will experience growth failure. In hopes of reducing neurotoxicity, current treatments limit the dose and volume of radiation while adding chemotherapy. Results have not been uniformly positive, however, and may increase toxicity in some cases.

CONCLUSIONS

The standard of care in 2004 is that children who have been treated for brain tumors and leukemia should be monitored for cognitive and endocrine dysfunction. Until effective non-neurotoxic treatment is identified, long-term effects assessments are essential to maximize the quality of life of survivors of childhood cancer.

[The electromagnetic fields of cellular phones and the health of children and of teenagers (the situation requiring to take an urgent measure)]

The problem of the influence of electromagnetic fields (EMF) of cellular phones (CP) on the health of children and teenagers is considered in this article. The results of the researchs indicate the increased sensitivity of the children and of the teenagers to this kind of radiation. Direct indicators of electromagnetic influence can be infringement of sleep, decrease of the memory, fatigue, breach of a blood-brain barrier permeability, changes in nervous cells of a brain. As the remote consequences the development of tumors of a brain and acoustic nerve are predicted. However all these results require the realization of independent repeated researches. WHO (World Health Organization) recommends to use "Precautionary principle" with the purposes of decreasing of the risk. Russian National Committee of Non-Ionizing Radiation Protection recommended to limit the use of CP by children and teenagers under 16 years old (2002, February 2004). The corresponding recommendations were included into SunPin H2.1.8/2.2.4.1190-03/(2003).

Vagus nerve stimulation therapy: 2-year prospective open-label study of 40 subjects with refractory epilepsy and low IQ who are living in long-term care facilities

Treating seizures among patients with mental retardation/developmental disabilities (MR/DD) is difficult owing in large part to the presence of additional comorbidities and the resulting need for polytherapy. Therefore, a nonpharmacological treatment option is needed for this population. This prospective, open-label study documented the long-term outcome of 40 low-IQ (<70) patients living in long-term care facilities who received vagus nerve stimulation (VNS) therapy for pharmacoresistant epilepsy. Subjects were seen every 1 to 3 months by their neurologist (R.H.). Seizure frequency, antiepileptic medication, and quality-of-life information were documented preimplantation and quarterly thereafter through 2 years. The surgery and therapy were well tolerated. Seizures were reduced by at least 50% for 11 subjects. Antiepileptic medications were reduced from 3.3 per subject at baseline to an average of 2.3 per subject after 2 years. According to caregiver reports, overall quality of life improved for the majority of subjects; also, using the Client Development Evaluation Report (CDER), statistically significant improvements were reported at both 1 and 2 years in attention span, word usage, clarity of speech, standing balance, washing dishes, and household chores. VNS is a viable treatment option for low-IQ patients with pharmacoresistant epilepsy who are living in long-term care facilities.

The Early Effects of Radiotherapy on Intellectual and Cognitive Functioning in Patients with Frontal Brain Tumours: The Use of a New Neuropsychological Methodology

Investigations of the effects of radiation on neuropsychological functions have revealed variable outcomes, ranging from no effect to severe cognitive impairment. However, many of the previous studies have relied on retrospective data or have been limited by methodological problems. In this study, prospective neuropsychological assessments were compared at baseline (after surgery and before radiotherapy) and within 4 months of completion of radiotherapy (except one case), to examine early-delayed effects of radiation on intellectual and cognitive functioning. Sixteen adult patients with either low- or high-grade brain tumours, 15 of whom were treated with radiotherapy, were compared with 8 control participants with nonmalignant brain tumours whom did not undergo radiotherapy. All participants had lesions situated mainly in the frontal lobes. All groups of patients had evidence of intellectual and cognitive impairment at baseline. The low- and high-grade brain tumour groups showed a differential pattern of performance following radiotherapy, with the low-grade tumour group's performance being more competent on all of the five main neuropsychological measures. Their pattern of improvement was very similar to that of the nonmalignant brain tumour group who had not undergone radiotherapy. The present study provides some preliminary information about the neuropsychological deficits associated with primary brain tumours, their severity, and the relationship between neuropsychological functioning and brain tumours and radiotherapy.

Change in Neurocognitive Functioning After Treatment With Cranial Radiation in Childhood

Purpose

To evaluate the pattern of stability and change over time across multiple domains of neurocognitive function in radiated survivors of posterior fossa (PF) tumors.

Patients and Methods

Thirty-four children (25 males) treated for malignant PF tumors were observed with serial clinical neuropsychologic assessments. Thirty patients were treated for medulloblastoma and four patients were treated for ependymoma. Twelve patients were treated with reduced-dose and 21 patients were treated with standard-dose cranial radiation. All patients received an additional boost to the PF. One patient was treated with PF radiation only. Standardized neuropsychologic tests were administered at different times after diagnosis for each child. The rate of change in scores was determined using a mixed model regression.

Results

Results showed a 2- to 4-point decline per year in intelligence scores. For our relatively young sample, intellectual function declined quickly in the first few years after treatment, and then more gradually. Significant declines in visual-motor integration, visual memory, verbal fluency, and executive functioning were also documented. No decline was evident for verbal memory and receptive vocabulary.

Conclusion

Cranial radiation is associated with a decline in multiple neurocognitive domains, with a few notable exceptions. Our results must be interpreted in the context of common limitations of clinical research, including patient variability, changes in test versions, small sample size, and clinical referral bias.

Effect of low doses of ionising radiation in infancy on cognitive function in adulthood: Swedish population based cohort study

OBJECTIVE

To determine whether exposure to low doses of ionising radiation in infancy affects cognitive function in adulthood.

DESIGN

Population based cohort study.

SETTING

Sweden.

PARTICIPANTS

3094 men who had received radiation for cutaneous haemangioma before age 18 months during 1930-59.

MAIN OUTCOME MEASURES

Radiation dose to frontal and posterior parts of the brain, and association between dose and intellectual capacity at age 18 or 19 years based on cognitive tests (learning ability, logical reasoning, spatial recognition) and high school attendance.

RESULTS

The proportion of boys who attended high school decreased with increasing doses of radiation to both the frontal and the posterior parts of the brain from about 32% among those not exposed to around 17% in those who received > 250 mGy. For the frontal dose, the multivariate odds ratio was 0.47 (95% confidence interval 0.26 to 0.85, P for trend 0.0003) and for the posterior dose it was 0.59 (0.23 to 1.47, 0.0005). A negative dose-response relation was also evident for the three cognitive tests for learning ability and logical reasoning but not for the test of spatial recognition.

CONCLUSIONS

Low doses of ionising radiation to the brain in infancy influence cognitive abilities in adulthood.

Human intelligence: the brain, an electromagnetic system synchronised by the Schumann Resonance signal

The human brain is a biological organ. On one hand it is soft, flexible and adaptive, but on the other hand is relatively stable and coherent with well developed intelligence. In order to retain intelligent thinking in a soft and adaptive organ there needs to be a constant, globally available, synchronization system that continuously stabilizes the brain. Rapid intelligence and reactions requires and electromagnetic signalling system, supported by a biochemical system. The Schumann Resonance signal provides a brain frequency range matching electromagnetic signal, providing the synchronization needed for intelligence.

Predicting Intellectual Outcome Among Children Treated With 35-40 Gy Craniospinal Irradiation for Medulloblastoma

Fifty children diagnosed with medulloblastoma completed 188 psychological evaluations using the Wechsler Intelligence Scales for Children (D. Wechsler, 1974, 1991) over a 7-year study period following 35-40 Gy postoperative craniospinal irradiation. Random coefficient models were used to predict the trend in the children's intellectual performance as a function of time since diagnosis, with both patient and treatment variables as parameters of this function. A quadratic model demonstrated a delay prior to decline in performance for older patients, whereas the younger patients showed an immediate loss of performance with a plateau at approximately 6 years postdiagnosis. A steeper decline was found for those with higher baseline performance. Clinicians may use the proposed predictive model to identify those patients who are at risk of significant intellectual decline.

Craniopharyngioma: the St. Jude Children's Research Hospital experience 1984-2001

PURPOSE

To review our institution's experience in the treatment of craniopharyngioma and assess the merits of initial therapy with limited surgery and irradiation.

METHODS AND MATERIALS

The data of 30 patients (median age 8.6 years) with a diagnosis of craniopharyngioma between April 1984 and September 1997 were reviewed. Their course of treatment, neurologic, endocrine, and cognitive function, and quality of life at last follow-up were compared.

RESULTS

Fifteen patients were initially treated with surgery (8 required irradiation after relapse) and 15 with limited surgery and irradiation (2 required additional treatment for tumor progression). Only 1 patient died of tumor progression. The surgery group lost a mean of 9.8 points in full-scale IQ, and the combined-modality group lost only 1.25 points (p <0.063). Patients in the surgery group who had relapses (n = 9) lost a mean of 13.1 points (p <0.067). A loss of 10 points was considered clinically significant. The surgery group also had more frequent neurologic, ophthalmic, and endocrine complications. The mean Health Utility Index (a functional quality-of-life index) was higher for the combined-modality group (0.85) than for the surgery group (0.71; p <0.063, one-sided t test).

CONCLUSIONS

The acute neurologic, cognitive, and endocrine effects of surgery often affect long-term function and quality of life. Our experience suggests that limited surgery and radiotherapy cause lesser or comparable sequelae. Diabetes insipidus was the only endocrine deficiency that differed substantially in frequency between the two groups. Newer radiation planning and delivery techniques may make a combined-modality approach a good initial option for most patients.

[Assessment of cognitive function after preventive and therapeutic whole brain irradiation using neuropsychological testing]

PURPOSE

Aim of this study was the assessment of neuropsychological changes after whole brain irradiation.

PATIENTS AND METHOD

64 patients were tested before, and 29 after whole brain irradiation, including 28 patients with small cell lung cancer (SCLC) before prophylactic cranial irradiation (PCI) and 36 patients with cerebral metastases before therapeutic cranial irradiation (TCI), as well as 14 patients after PCI and 15 after TCI (Table 1). Intelligence, attention and memory were assessed applying a 90-minute test battery of standardized, neuropsychological tests (Table 3).

RESULTS

Patients with SCLC showed test results significantly below average before PCI (n = 28, mean IQ = 83, SD = 17). Neither after PCI, nor after TCI the tested neuropsychological functions decreased significantly (Tables 4, 5). A comparison between SCLC-patients with and without cerebral metastases before whole brain irradiation showed better test-results in patients with cerebral metastases and fewer cycles of preceding chemotherapy (Table 7).

CONCLUSION

Neuropsychological capacity in patients with SCLC was impaired even before PCI. Possible reason is the preceding chemotherapy. Whole brain irradiation did not induce a significant decline of cognitive functions in patients with PCI or TCI. A decline in a longer follow-up nevertheless seems possible.

[Pregnancy and medical irradiation; summary and conclusions from the International Commission on Radiological Protection, Publication 84]

Prenatal exposure to ionising radiation as used during most diagnostic procedures generally presents no increased risk of prenatal death, malformation or impairment of mental development (i.e. deterministic effects) compared to the background incidence of these entities. Higher doses of radiation used in therapeutic procedures can result in significant foetal harm. In general, malformations only occur above a threshold dose of 100-200 mGy. These doses are not normally reached with most properly executed diagnostic procedures. During the period from 8 to 25 weeks after conception, the central nervous system is particularly sensitive to radiation. Foetal doses in excess of about 100 mGy may result in a decrease in IQ. Between 8-15 weeks after conception, a foetal dose of 1000 mGy (1 Gy) reduces IQ by about 30 points. This reduction is less marked during the period from 16-25 weeks. At foetal doses of 1000 mGy in the period from 8 to 15 weeks after conception the risk of severe mental retardation is about 40%. During the period from 16 to 25 weeks, this risk is practically zero at a dose of 1000 mGy. Radiation exposure of the embryo/foetus is associated with an increased risk of tumour induction (stochastic effect). Recent absolute risk estimates for fatal cancer risk for ages 0-15 year after in utero irradiation have been estimated to be 6% per Gy (0.06% per 10 mGy). For the whole life span this risk is about 15% per Gy (0.15% per 10 mGy). Pre-conception irradiation of either parent's gonads has not been shown to result in increased cancer or malformations in the children.

[Neuropsychological sequelae in children with AML treated with or without prophylactic CNS-irradiation]

BACKGROUND

In study AML-BFM 87 the relapse rate was lower in patients receiving cranial irradiation (CRT). However, CRT has always been associated with adverse cognitive side effects. Therefore, the impact of CRT on neuropsychological function in children with AML was retrospectively evaluated.

PATIENTS

We tested 53 children (30 boys, 23 girls) treated according to the AML-BFM-87 protocol (median age at diagnosis: 8.5 years, range 0.3 - 17.5; median time since diagnosis: 5.7 yrs, 3.8 - 10.7 yrs). To avoid any bias from additional therapy elements, patients with relapse or initial CNS involvement and transplanted patients were excluded (n=32). Our cohort was representative of the total group of 104 long term survivors of study AML-BFM 87. CNS prophylaxis consisted of ARA-C i.th., high dose ARA-C i. v. and either no CRT (n=15) or CRT (n=38) at a dose of 12 - 18 Gy depending on age.

METHODS

Neuropsychological function was evaluated by psychological tests of attention and concentration (test d2 by Brickenkamp) and an intelligence test (Progressive Matrices by Raven). In addition, patients and their parents were interviewed about the occurrence of learning problems, subjective deficits in concentration and physical impairment.

RESULTS

In the total group, no significant differences were seen between irradiated and non-irradiated patients regarding the psychological tests. However, the irradiated patients scored below the non-irradiated control group in test "d2" (concentration: 41st vs. 59th percentile). In the interview, irradiated patients tended to report more learning problems (lp) (10/36 vs. 1/14; p=0.15) and subjective deficits in concentration (con). In irradiated girls (con: 6/15 vs. 0/8; p=0.06; lp: 5/15 vs. 0/8; p=0.12) and younger patients (0 - 5 years at diagnosis; con: 7/12 vs. 2/9; p=0.18; lp 3/10 vs. 1/9; p=0.18) this trend was even more pronounced.

CONCLUSION

Children with AML and CRT had no significant intellectual impairment in standardized tests when compared to non-irradiated patients. However, more irradiated patients reported learning problems and subjective concentration deficits.

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.

Learning difficulties in children treated for acute lymphoblastic leukaemia (ALL)

Concern about the adverse affects of brain irradiation used in treatment for childhood leukaemia on children's learning have been put forward since the 1960s. Early work based on assessment of IQ suggested considerable problems associated with CNS irradiation of 2400cGy, and that children who were younger on diagnosis (below 5 years) were particularly at risk. Consequently, new protocols were introduced in which the amount of irradiation was reduced, or children were treated by chemotherapy alone. There is some evidence that reduction from 2400 to 1800cGy irradiation is beneficial, especially for younger children, as is treatment by chemotherapy alone. Methodological problems in conducting this work and limitations in relying on IQ tests are discussed. Where there are no indications of differences in survival, there would seem to be implications for reducing as far as possible the use of CNS directed therapy among young children treated for leukaemia.

Prospective evaluation of delayed central nervous system (CNS) toxicity of hyperfractionated total body irradiation (TBI)

PURPOSE

Prospective evaluation of chronic radiation effects on the healthy adult brain using neuropsychological testing of intelligence, attention, and memory.

METHODS AND MATERIALS

58 patients (43 +/- 10 yr) undergoing hyperfractionated total body irradiation (TBI) (TBI, 14.4 Gy, 12 x 1.2 Gy in 4 days) before bone marrow or peripheral blood stem cell transplantation were prospectively included. Twenty-one recurrence-free long-term survivors were re-examined 6-36 months (median 27 months) after completion of TBI. Neuropsychological testing included assessment of general intelligence, attention, and memory using normative, standardized psychometric tests. Mood status was controlled, as well. Test results are given as IQ scores (population mean 100) or percentiles for attention and memory (population mean 50).

RESULTS

The 21 patients showed normal baseline test results of IQ (101 +/- 13) and attention (53 +/- 28), with memory test scores below average (35 +/- 21). Test results of IQ (98 +/- 17), attention (58 +/- 27), and memory (43 +/- 28) showed no signs of clinically measurable radiation damage to higher CNS (central nervous system) functions during the follow-up. The mood status was improved.

CONCLUSION

The investigation of CNS toxicity after hyperfractionated TBI showed no deterioration of test results in adult recurrence-free patients with tumor-free CNS. The median follow-up of 27 months will be extended.

Processing speed, working memory, and IQ: a developmental model of cognitive deficits following cranial radiation therapy

IQ decrements following cranial radiation therapy (CRT) for acute lymphoblastic leukemia (ALL) are most apparent years after treatment. The authors examined a developmental model for delayed deficits by evaluating the relationship between processing speed, working memory, and IQ in long-term survivors of childhood ALL (n = 27) compared with demographically matched controls (n = 27). The ALL group treated with CRT showed deficits in IQ, working memory, and processing speed relative to controls. Differences in IQ between the CRT group and controls were mediated by differences in working memory. Processing speed did not fully account for the working memory deficit in the CRT group. Participants with ALL treated only with chemotherapy showed similar working memory and processing speed as matched controls. Data suggest that deficits in processing speed and working memory following CRT may underlie declines in IQ.

EEG, cognitive and psychopathological abnormalities in children irradiated in utero

Computerised EEG, a clinical neuropsychiatric examination, and IQ tests were examined in 50 randomly selected prenatally irradiated 9-10-year-old children and compared with 50 randomly selected non-exposed control children of the same age. In the prenatally irradiated children a disorganised EEG-pattern with slow and paroxysmal activity (acute and high-voltage delta-waves, sometimes: spike-waves) in the left fronto-temporal region was disclosed. There was also a significant predominance of delta- and beta (dominant frequency: 20 Hz)-power in the frontal lobe, particularly, in the left fronto-temporal region, together with depressed spectral theta-power. The more disorganised EEG-patterns were observed in those children exposed at 8-15 weeks of prenatal development, while left-hemisphere abnormalities were more typical for those exposed later at 16-25 weeks of gestation. There was also a significant increase of borderline and low range (70-90) IQ scores and a significant decrease of high verbal (> 110) IQ scores. Disorders of psychological development, particularly specific developmental disorders of speech, language, and scholastic skills were more common and correlated with left-sided slow- and fast-wave activity. Behavioural and emotional disorders (social estrangement, exhaustion, emotional lability, tearfulness, apathy) were also more common and associated with a L > R imbalance in arousal. We hypothesise that the cerebral basis of mental disorders in the prenatally irradiated children is the malfunction of the left hemisphere limbic-reticular structures, particularly in those exposed at the most critical period of cerebrogenesis (16-25 weeks of gestation). We propose that the left hemisphere is more vulnerable to prenatal irradiation than the right.

Long-term intellectual outcome in children with posterior fossa tumors according to radiation doses and volumes

PURPOSE

To analyze the relationship between craniospinal irradiation (CSI) and intellectual outcome in children with posterior fossa (PF) tumors.

METHODS AND MATERIALS

A neuropsychological evaluation was performed retrospectively in 31 children, aged 5-15 years, who had received radiotherapy for PF tumors, and who had been off therapy for at least 1 year. Factors evaluated for impact on intellectual outcome were: socioeconomic status, disease presentation, histology, complications, chemotherapy, age at radiotherapy, interval between radiotherapy and testing, and radiation doses and volumes. Patients were divided into 3 subgroups according to the CSI doses (0 Gy [i.e., PF irradiation only], 25 Gy, and 35 Gy), with 11, 11, and 9 patients, respectively.

RESULTS

Long-term cognitive impairment occurred in most of the patients, even after PF irradiation only. Moreover, there was a significant correlation between the full-scale IQ score (FSIQ) and the CSI dose, with mean FSIQ scores at 84.5 (SD = 14.0), 76.9 (SD = 16.6), and 63.7 (SD = 15.4) for 0 Gy, 25 Gy, and 35 Gy of CS1, respectively. A marked drop in verbal comprehension scores was noted in children who had received the higher dose.

CONCLUSION

This preliminary study further supports the rationale for de-escalation of CSI doses and volumes in standard-risk PF tumors.

Cognitive function and prenatal exposure to ionizing radiation

It is clear from the many studies of the prenatally exposed survivors of the atomic bombing of Hiroshima and Nagasaki that exposure to ionizing radiation during gestation has harmful effects on the developing human brain, particularly if that exposure occurs at critical stages in the development of the neocortex. Data on a variety of measures of cognitive function, including the occurrence of severe mental retardation as well as variation in the intelligence quotient (IQ) and school performance, show significant effects on those survivors exposed 8-15 weeks and 16-25 weeks after ovulation. Studies of seizures, primarily those without known precipitating cause, also exhibit a radiation effect on those individuals exposed in the first 16 weeks after ovulation. The cellular and molecular events that subtend these abnormalities are still largely unknown although some progress toward an understanding has occurred. For example, magnetic resonance imaging of the brain of some of the mentally retarded survivors has revealed a large region of abnormally situated gray matter, suggesting an abnormality in neuronal migration, but cell killing could also contribute importantly to the effects on cognitive function that have been seen. The retardation of growth in stature observed in individuals exposed in the first and second trimesters of pregnancy suggests that the development of an atypically small head size, without conspicuously impaired cognitive function, may reflect a generalized retardation of growth.

Preirradiation evaluation and technical assessment of involved-field radiotherapy using computed tomographic (CT) simulation and neoadjuvant chemotherapy for intracranial germinoma

PURPOSE

To investigate the importance of preirradiation mental and endocrinological evaluation, and the effectiveness of involved-field radiotherapy following neoadjuvant chemotherapy.

METHODS AND MATERIALS

Following etoposide and cisplatin with or without ifosfamide, 13 patients with nondisseminated disease received involved-field irradiation of 24 Gy in 12 fractions within 3 weeks and 2 patients with disseminated germinoma received 24 Gy craniospinal irradiation (CSI). CT simulation was used to cover the tumor bed.

RESULTS

Full-scale intelligence quotient (IQ) tests given at the time of the initial radiotherapy showed less than 90 in 7 of 11 patients who had tumors involving the neurohypophyseal region, but the 4 patients who had solitary pineal tumors showed higher scores. Panhypopituitarism was observed in 9 patients with tumors involving the neurohypophyseal region. All patients are alive without disease, with a median follow-up period of 40 months. No in-field relapse was noted after the involved-field radiotherapy. One patient experienced a recurrence outside of the planning target volume.

CONCLUSION

Decline of neurocognitive and endocrine functions were often seen in patients with tumors involving the hypophyseal region, but not in patients with solitary pineal germinoma before radiotherapy. Involved-field radiotherapy using 24 Gy is effective with the help of CT simulation and neoadjuvant chemotherapy.

The psychological development of children from Belarus exposed in the prenatal period to radiation from the Chernobyl atomic power plant

This study examined psychological development in 138 children at the age of 6-7 and 10-11 years, who had suffered prenatal radiation exposure at the time of the Chernobyl accident in 1986. These children were compared to a control group of 122 children of the same age from noncontaminated areas of Belarus. The examination included neurological and psychiatric examination, intellectual assessment, and clinical psychological investigation of parents as well as the estimation of thyroid exposure in utero. The exposed group manifested a relative increase in psychological impairment compared with the control group, with increased prevalence in cases of specific developmental speech-language disorders (18.1% vs. 8.2% at 6-7 years; 10.1% vs. 3.3% at 10-11 years) and emotional disorders (20.3% vs. 7.4% at 6-7 years; 18.1 vs. 7.4% at 10-11 years). The mean IQ of the exposed group was lower than that of the control group, and there were more cases of borderline IQ (IQ = 70-79) (15.9% vs. 5.7% at 6-7 years; and 10.1% vs. 3.3% at 10-11 years). The mean value of thyroid doses from 131I 0.4 Gy was estimated for children exposed in utero. No correlation was found between individual thyroid doses and IQ at age 6-7 years or 10-11 years. We notice a positive moderate correlation between IQ of children and the educational level of their parents. There was a moderate correlation between high personal anxiety in parents and emotional disorders in children. We conclude that a significant role in the genesis of borderline intellectual functioning, specific developmental disorders of speech, language and scholastic skills, as well as emotional disorders in the exposed group of children was played by unfavourable social-psychological and social-cultural factors such as a low educational level of parents, the break of microsocial contacts, and adaptational difficulties, which appear following the evacuation and relocation from the contaminated areas.

Assessment of neuropsychological changes in patients with arteriovenous malformation (AVM) after radiosurgery

PURPOSE

The purpose of this study was to investigate neuropsychological effects of radiosurgery in patients with cerebral arteriovenous malformation (AVM), with special focus on attention and memory. This report describes the study setup and presents the first results during a follow-up of up to 1 year.

MATERIALS AND METHODS

Seventy-nine patients were studied before, acutely after radiosurgery, and during the regular follow-up (subacute phase: Weeks 6-12, chronic phase: Months 6-12). Radiosurgery was performed using a modified linear accelerator (minimum doses to the target volume: 15-22 Gy, median 20 Gy). Estimated whole brain dose was 0.5 to 2 Gy. Neuropsychological testing included assessment of general intelligence (Wechsler Adult Intelligence Scale), attention (modified Trail-Making Test A, Digit Symbol Test, D2 Test, Wiener Determination Machine) and memory (Rey Auditory Verbal Learning Test, Benton Visual Retention Test). During follow-up, alternate test versions were used. Neuropsychological deficits were defined as a test score of at least one standard deviation (SD) below the mean of the normal distribution.

RESULTS

The pretherapeutic evaluation revealed marked deviations from the normal population; 24% had deficits in intelligence (range 23-31% in different subtests), attention (35%, 23-59%) and memory (48%, 31-61%). The overall percentage of aberrant results was reduced by 12% (memory) to 14% (attention) in the chronic phase up to 12 months after therapy. The improvement in test scores was significant (p < 0.05) in 3 of 4 subtests of attention functions.

CONCLUSIONS

The acute tolerance of radiosurgery seems to be very good in these patients, showing no relevant increase in number of patients with neuropsychological deficits. Although the long-term follow-up needs to be further increased, our data indicate a tendency to slight improvement in the overall neuropsychological performance of AVM patients in the chronic phase after radiosurgery.

Psychophysiologic aftereffects of prenatal irradiation

Prenatally irradiated children (n = 544), who were born between 26 April 1986 and 26 February 1987, in regions of the Ukraine which were radioactively contaminated as a result of the Chernobyl disaster, their mothers and teachers have been examined with psychometric tests. The control group of relevant children (n = 759), their mothers and teachers, were living at the radioecological 'clear' regions (Kharkov and Kharkov Region). Further, we randomly selected 50 prenatally irradiated children whose mothers were evacuated from the Chernobyl exclusion zone and 50 age-and-gender-matched non-exposed children. At this phase clinical examinations, psychometric tests, computerized EEG, thyroid function assessment and dosimetric reconstruction were used. We found a significant increase in mental retardation (IQ < 70) and of borderline and low range IQ, as well as emotional and behavioral disorders and a decrease in high IQ (IQ > 110) in children irradiated in utero as a result of the Chernobyl disaster, in comparison with the controls. One important biological mechanism in the genesis of mental disorders in prenatally irradiated children is the radiation-induced malfunction of the thyroid-pituitary system with the effect threshold of 0.30 Sv of thyroid exposure dose. We hypothesize that the cerebral basis of mental disorders in the prenatally irradiated children is the malfunction of the left hemisphere limbic-reticular structures, particularly in those exposed at the most critical period of cerebrogenesis (8-25 weeks of gestation). The data obtained reveal mental disorders in prenatally irradiated children and obviously reflect developmental abnormalities of brain structure and function as a result of the interaction of prenatal and post-natal factors where it is possible to assume radiation effects on the developing brain. A follow-up study of the children irradiated in utero, who may be at risk for schizophrenia, is proposed because of its particular importance to clinical medicine and neuroscience.

[Neuropsychological effects of preventive CNS irradiation in adult tumor patients]

Prophylactic cranial irradiation (PCI) has led to marked prolongation of survival, but also to intellectual and neuropsychological retardation in children with ALL. PCI has also been conducted in adult patients with small-cell bronchial carcinoma in the stage of minimal disease or with breast cancer. There are no studies assessing cognitive or other neuropsychological consequences of PCI in adult cancer patients. We report on a longitudinal prospective study of the effects of PCI on five major neuropsychological domains (intelligence, concentration, attention, memory and psychomotor performance). We report on our ongoing study, in which up to now 11 patients with small-cell lung cancer undergoing PCI have been investigated. Patients are assessed immediately before therapy started as well as 4 weeks and 3 months after onset of PCI. The used instruments are Standard Progressive Matrices (SPM), d2 Concentration Test, Minimental State, Verbal Learning Test and Psychomotor Tests (Steadiness, Aiming, Tapping, Tracking, Pursuit Rotor Test). Although our sample is small, results indicate that there is no evidence for a decrease in neuropsychological abilities in adults after three months. This is in contrast to the observed results after PCI in children. As compared to baseline measures, differences in memory, intelligence, concentration and attention were marginal over time. Moreover the progress of motor performance skills showed no clear tendency.

[Late sequelae of CNS recurrence of acute lymphoblastic leukemia in childhood]

Study objective was to evaluate retrospectively central nervous system (CNS) morbidity of children with acute lymphoblastic leukemia treated with intensive chemotherapy and cranial radiotherapy for a first isolated or combined CNS relapse. Neurological (Touwen), neuropsychological (CFT 20, Wechsler scales, d2 attention test) and neuromorphological (CT, MRI) assessments were performed in 17 children (9 girls, 8 boys) aged between 7 and 14 years. Patients were off therapy for median 4 years; cranial radiotherapy for CNS relapse (12-24 Gy) was given to all patients 2 to 9 years ago (median 5.5 years). Ten patients had received preventive cranial radiotherapy during front-line treatment, previously. In this group, the cumulative radiation dose ranged between 30 and 39 Gy. Patients received 12 to 30 intrathecal methotrexate doses (median 22). Compared with normative levels for age (100 points) performance IQ (89.9) and full scale IQ (92.0), Culture Fair IQ (88.3) and attention and concentration (90.9) were significantly impaired. Verbal IQ (95.5) was not significantly different from normal expectations. Neurological investigations of 16 patients showed mild signs in 7 (44%) of them, mostly of fine-motor skills and coordination, but no major motor disability. In MRI and CT, white matter changes or ventricular enlargement were noted in 10 of 16 patients (63%). Parent-completed questionnaires indicated problem behaviors in 5 children. Cumulative doses of methotrexate correlated significantly with neuropsychological test results. Children irradiated twice as well as girls had poorer cognitive functions, not being statistically significant. Despite pathological test results, all children attended a normal school and did not exhibit obvious impairment in daily life. In conclusion, CNS relapse and attendant therapy, mostly consisting of a second course of cranial radiotherapy, caused measurable intellectual deficits and CNS morbidity, which did not result in severely impaired performance. Periodic psychological und clinical examinations are recommended for recognition of delayed morbiditiy and early intervention.

Neuropsychologic functioning of survivors of childhood medulloblastoma randomized to receive conventional or reduced-dose craniospinal irradiation: a Pediatric Oncology Group study

PURPOSE

The purpose of this study was to test the hypothesis that survivors of medulloblastoma who were younger at diagnosis and those who received standard-dose cranial irradiation (SRT) of 36 Gy would have a lower performance on standardized tests of cognitive function and achievement than children who were older and those treated with reduced-dose cranial irradiation (RRT) of 23.4 Gy.

PATIENTS AND METHODS

Eligible patients had been treated on Pediatric Oncology Group (POG) study 8631 for low-risk medulloblastoma that randomized patients to receive RRT or SRT after surgical resection. Those who were alive and free of progressive disease 6.1 to 9.9 years from completion of treatment were eligible for this study. Of the 35 eligible patients, 22 patients (13 SRT, nine RRT) participated in a battery of tests that included intellectual and academic development as well as ratings of health-related quality of life.

RESULTS

Patients were stratified by treatment group (SRT v RRT) and into younger (Y) and older (O) groups by the median age at diagnosis (8.85 years), which resulted in four groups that we hypothesized would show neuropsychologic test scores in the following order: Y/SRT less than Y/RRT less than O/SRT less than O/RRT. Evidence to support the hypothesized ordering of groups in terms of neuropsychologic toxicity was obtained with regard to Performance Intelligence Quotient (IQ), Full Scale IQ, Attention, Reading, and Arithmetic.

CONCLUSION

Children treated for medulloblastoma experienced less severe neuropsychologic toxicity when treated with 23.4 Gy instead of 36 Gy cranial irradiation. Older children experienced less toxicity than children who were younger at the time of irradiation.

[Neurological and psychological sequelae in children with acute lymphoblastic leukemia who had received radiotherapy and intrathecal methotrexate]

Our objective was to compare the neurologic and psychological sequelae of children with acute lymphoblastic leukemia (ALL) after three or more years without antineoplasic treatment who underwent cranial irradiation plus intrathecal methotrexate (Group 1) or just intrathecal methotrexate (Group 2). In both groups, a neurologic evaluation, electroencephalogram (EEG) and cranial computed tomography (CCT) were performed. Intellectual quotient and the Bender test were done for the psychological evaluation. Investigators did not know the kind of treatment of each patient.

STATISTICS

Fisher's exact test and Mann-Whitney U. There were fourteen patients in group 1 and eight patients in group 2. Intellectual quotient was statistically lower in the first group (median 83.5) than in the second (90.5). Neurologic impairments were found in one patient of each group, alterations of the EEG were found in 6 and 4 in group 1 and 2, respectively, and in the CCT of two patients in group 2 without statistical difference. Children with ALL after cranial irradiation have a greater alteration of intellectual performance than children with intrathecal methotrexate. Neurologic alterations were seen in both groups.

[Some aspects of reproductive function and social adaptation after comprehensive therapy of childhood Hodgkin's disease]

An analysis of the data available on the reproductive status and social adjustment of 443 children who received three modalities of complex treatment for Hodgkin's disease in 1976-1994 established no impairment of reproductive function or its formation, although full therapeutic effect had been achieved. Nor were their intelligence or professional and social function affected in any way.

Neurobehavioural sequelae following cranial irradiation and chemotherapy in children: an analysis of risk factors

Neurobehavioural deficits are commonly reported following treatment for childhood cancers. This study examined the impact of cranial irradiation (CRT) and chemotherapy in children, aiming to identify factors detrimental to long-term outcome. The study compared survivors of acute lymphoblastic leukemia (ALL), treated with CRT and chemotherapy (CRT group: n = 100), survivors of cancers treated with chemotherapy only (n = 50) and healthy controls (n = 100) for intelligence, academic achievement, information processing, learning, and executive function. CRT and chemotherapy in combination were associated with reduced intelligence, educational skill, immediate memory, processing speed, and executive function. Children treated with chemotherapy alone exhibited subtle information processing deficits. Within the CRT group, younger age at treatment was predictive of deficits in non-verbal ability, educational skills and executive functions. High dose CRT was associated with poorer information processing and lower arithmetic ability.

Neuropsychological sequelae after treatment for medulloblastoma in childhood--the Taiwan experience

The purpose of this study was to investigate the functional independence, intellectual performance and academic achievement of children treated for medulloblastoma at the Veterans General Hospital-Taipei. Adverse factors that it was thought would result in significant intellectual impairment were also studied. Nineteen patients with medulloblastoma located over the posterior fossa were enrolled in this study. Their mean age at tumor removal was 6.16 +/- 3.30 (range 2-14) years. Mean full intelligent quotient (FIQ) was 86.00 +/- 22.66, performance intelligent quotient (PIQ) was 85.29 +/- 21.23, and verbal intelligent quotient (VIQ) was 90.50 +/- 23.50. In 11 cases academic achievement at school was poor. Sixteen patients received radiation therapy after tumor removal. Significant negative correlations were noted between IQ and whole-brain irradiation dose (r = -0.72) and between IQ and years after radiation therapy (r = -0.63). The results indicate a need for ongoing attention and intervention to prevent, remedy or minimize deficits produced by the tumor itself and by the cancer treatment.

Progressive deterioration of intellect and motor function occurring several decades after cranial irradiation. A new facet in the clinical spectrum of radiation encephalopathy

OBJECTIVE

To report the cases of 2 patients who developed the features of radiation encephalopathy 33 and 28 years after cranial irradiation.

DESIGN

Case reports; clinical data were available for 2 years in each instance.

CONCLUSION

Latent intervals approaching 2 decades have been reported in cases of radiation necrosis following cranial irradiation, but a similar or greater delay before the onset of radiation encephalopathy has not been described previously. This report indicates that a diagnosis of radiation encephalopathy must be considered when any individual who has received cranial irradiation presents with deterioration in intellectual or motor function, whatever the interval.

Neuropsychologic late effects in children with malignant brain tumors treated with surgery, radiotherapy and "8 in 1" chemotherapy

Sixty-eight children with malignant brain tumors were treated with the "8 in 1" chemotherapy protocol from 1986 to 1993 in Finland. The overall 5-year survival rate was 43%. Thirty-one children are still alive and tumor-free, and have been evaluated in the present study. Of these 31 children, 26% had hemi- or tetraplegia, 13% intractable seizures, and 30% attend special schools. The mean full scale (FS) IQ was 85 (range 45-138), 24% had an FSIQ value less than 70, and 36% more than 90. One-half of the survivors were placed in Bloom's group I or II, are able to lead an active life, and have only mild neurologic disabilities. In the other, neurologic late complications accumulated and these children were relegated to Bloom's group III or IV, with major disabilities such as hemiplegia, intractable epilepsy, or mental retardation. The most important prognostic factors were severe perioperative complications, young age at diagnosis, and cranial irradiation.

Risk factors for intellectual and educational sequelae of cranial irradiation in childhood acute lymphoblastic leukaemia

Long-term cognitive and educational sequelae have been inconsistently reported in children who received cranial irradiation (CRT) to prevent central nervous system (CNS) disease in acute lymphoblastic leukaemia (ALL). This study investigates a large and representative sample of survivors of ALL and compares them with non-irradiated survivors of cancer and healthy control children to determine the effect of CRT on cognitive and educational ability. Three groups of children were studied: Group 1 (n=100) survivors of ALL treated with chemotherapy and CRT, group 2 (n=50) children with a variety of malignancies treated with chemotherapy alone, group 3(n=100) healthy children. Cognitive and educational abilities of these groups were evaluated using standardised psychometric techniques. Significant differences in cognitive and educational abilities were found between the children in group 1 (chemotherapy + CRT) and the two control groups, with the children receiving CRT performing less well in a range of tests. Greatest differences were detected for tasks dependent on language function including verbal IQ, reading and spelling. Within group 1 a younger age at treatment (less than 5 years) and a higher dose of CRT (24 Gy vs 18 Gy) were predictive of poor long-term outcome for cognitive and education ability. In contrast, children who received chemotherapy alone, with or without intrathecal methotrexate, performed similarly to healthy controls. No gender differences were detected for these measures.