Systemic Biological Mechanisms of Neurocognitive Dysfunction in Long-Term Survivors of Childhood Hodgkin Lymphoma

PURPOSE

Hodgkin lymphoma (HL) survivors experience neurocognitive impairment despite receiving no central nervous system-directed therapy, though little is known about the underlying mechanisms.

EXPERIMENTAL DESIGN

HL survivors (n = 197) and age-, sex- and race/ethnicity frequency-matched community controls (n = 199) underwent standardized neurocognitive testing, and serum collection. Luminex multiplex or ELISA assays measured markers of inflammation and oxidative stress. Linear regression models compared biomarker concentrations between survivors and controls and with neurocognitive outcomes, adjusting for age, sex, race, body mass index, anti-inflammatory medication, and recent infections.

RESULTS

HL survivors [mean (SD) current age 36 (8) years, 22 (8) years after diagnosis] demonstrated higher concentrations of interleukin-6 (IL6), high-sensitivity c-reactive protein (hs-CRP), oxidized low-density lipoprotein, and glutathione peroxidase (GPx), compared with controls (P's < 0.001). Among survivors, higher concentrations of IL6 were associated with worse visuomotor processing speed (P = 0.046). hs-CRP ≥3 mg/L was associated with worse attention, processing speed, memory, and executive function (P's < 0.05). Higher concentrations of malondialdehyde were associated with worse focused attention and visual processing speed (P's < 0.05). Homocysteine was associated with worse short-term recall (P = 0.008). None of these associations were statistically significant among controls. Among survivors, hs-CRP partially mediated associations between cardiovascular or endocrine conditions and visual processing speed, whereas IL6 partially mediated associations between pulmonary conditions and visuomotor processing speed.

CONCLUSIONS

Neurocognitive function in long-term survivors of HL appears to be associated with inflammation and oxidative stress, both representing potential targets for future intervention trials.

High-grade glioma in infants and young children is histologically, molecularly, and clinically diverse: Results from the SJYC07 trial and institutional experience

BACKGROUND

High-grade gliomas (HGG) in young children pose a challenge due to favorable but unpredictable outcomes. While retrospective studies broadened our understanding of tumor biology, prospective data is lacking.

METHODS

A cohort of children with histologically diagnosed HGG from the SJYC07 trial was augmented with nonprotocol patients with HGG treated at St. Jude Children's Research Hospital from November 2007 to December 2020. DNA methylome profiling and whole genome, whole exome, and RNA sequencing were performed. These data were integrated with histopathology to yield an integrated diagnosis. Clinical characteristics and preoperative imaging were analyzed.

RESULTS

Fifty-six children (0.0-4.4 years) were identified. Integrated analysis split the cohort into four categories: infant-type hemispheric glioma (IHG), HGG, low-grade glioma (LGG), and other-central nervous system (CNS) tumors. IHG was the most prevalent (n = 22), occurred in the youngest patients (median age = 0.4 years), and commonly harbored receptor tyrosine kinase gene fusions (7 ALK, 2 ROS1, 3 NTRK1/2/3, 4 MET). The 5-year event-free (EFS) and overall survival (OS) for IHG was 53.13% (95%CI: 35.52-79.47) and 90.91% (95%CI: 79.66-100.00) vs. 0.0% and 16.67% (95%CI: 2.78-99.74%) for HGG (p = 0.0043, p = 0.00013). EFS and OS were not different between IHG and LGG (p = 0.95, p = 0.43). Imaging review showed IHGs are associated with circumscribed margins (p = 0.0047), hemispheric location (p = 0.0010), and intratumoral hemorrhage (p = 0.0149).

CONCLUSIONS

HGG in young children is heterogeneous and best defined by integrating histopathological and molecular features. Patients with IHG have relatively good outcomes, yet they endure significant deficits, making them good candidates for therapy de-escalation and trials of molecular targeted therapy.

Neurocognitive impairment associated with chronic morbidity in long-term survivors of Hodgkin Lymphoma

Thoracic radiation is associated with significant cardiopulmonary morbidities in survivors of long-term Hodgkin lymphoma and may affect neurocognitive outcomes. Survivors (N = 204; 52.5% female; mean [standard deviation] age, 36.6 [8.01] years) treated with thoracic radiation and age-, sex-, and race/ethnicity-matched community controls (N = 205; 51.7% female; age, 36.7 [9.17] years) completed standardized neurocognitive testing, echocardiography, pulmonary function tests, and vascular studies during the same visit. Treatments were abstracted from medical records. Cardiac (ie, left ventricular ejection fraction [LVEF], global longitudinal strain [GLS]), vascular (ie, large and small artery elasticity [SAE]), pulmonary (ie, diffusing capacity of the lungs for carbon monoxide [DLCO] and forced expiratory volume [FEV1]), and chronic health conditions were evaluated for associations with age-adjusted neurocognitive performance using multivariable linear regression. Compared with controls, survivors had lower performance (P < 0.05) in visuomotor (0.11 vs 0.41), visual processing speed (0.25 vs 0.64), short-term recall (-0.24 vs 0.12), and flexibility (-0.04 vs 0.28). Survivors had lower pulmonary (FEV1, DLCOcorr), cardiac (LVEF, GLS), and vascular function (SAE) than controls (all P < 0.001). FEV1 was associated with visuomotor (P = .008) and visual processing speed (P = .05), and flexibility (P = .05). GLS was associated with short-term recall (P = .03). SAE was associated with flexibility (P = .007). Neurocognitive outcomes were also associated with moderate-to-severe neurologic chronic conditions (P < .05). Findings suggest a link between subclinical cardiopulmonary and vascular findings, neurologic morbidity, and neurocognitive impairments. Prevention of health morbidity may benefit neurocognitive outcomes.

Review of imaging recommendations from Response Assessment in Pediatric Neuro-Oncology (RAPNO)

The Response Assessment in Pediatric Neuro-Oncology (RAPNO) working group includes neuroradiologists, neuro-oncologists, neurosurgeons, radiation oncologists, and clinicians in various additional specialties. This review paper will summarize the imaging recommendations from RAPNO for the six RAPNO publications to date covering pediatric low-grade glioma, pediatric high-grade glioma, medulloblastoma and other leptomeningeal seeding tumors, diffuse intrinsic pontine glioma, ependymoma, and craniopharyngioma.

Imaging of pediatric brain tumors: A COG Diagnostic Imaging Committee/SPR Oncology Committee/ASPNR White Paper

Tumors of the central nervous system are the most common solid malignancies in children and the most common cause of pediatric cancer-related mortality. Imaging plays a central role in diagnosis, staging, treatment planning, and response assessment of pediatric brain tumors. However, the substantial variability in brain tumor imaging protocols across institutions leads to variability in patient risk stratification and treatment decisions, and complicates comparisons of clinical trial results. This White Paper provides consensus-based imaging recommendations for evaluating pediatric patients with primary brain tumors. The proposed brain magnetic resonance imaging protocol recommendations balance advancements in imaging techniques with the practicality of deployment across most imaging centers.

Proton therapy and limited surgery for paediatric and adolescent patients with craniopharyngioma (RT2CR): a single-arm, phase 2 study

BACKGROUND

Compared with photon therapy, proton therapy reduces exposure of normal brain tissue in patients with craniopharyngioma, which might reduce cognitive deficits associated with radiotherapy. Because there are known physical differences between the two methods of radiotherapy, we aimed to estimate progression-free survival and overall survival distributions for paediatric and adolescent patients with craniopharyngioma treated with limited surgery and proton therapy, while monitoring for excessive CNS toxicity.

METHODS

In this single-arm, phase 2 study, patients with craniopharyngioma at St Jude Children's Research Hospital (Memphis TN, USA) and University of Florida Health Proton Therapy Institute (Jacksonville, FL, USA) were recruited. Patients were eligible if they were aged 0-21 years at the time of enrolment and had not been treated with previous radiotherapeutic or intracystic therapies. Eligible patients were treated using passively scattered proton beams, 54 Gy (relative biological effect), and a 0·5 cm clinical target volume margin. Surgical treatment was individualised before proton therapy and included no surgery, single procedures with catheter and Ommaya reservoir placement through a burr hole or craniotomy, endoscopic resection, trans-sphenoidal resection, craniotomy, or multiple procedure types. After completing treatment, patients were evaluated clinically and by neuroimaging for tumour progression and evidence of necrosis, vasculopathy, permanent neurological deficits, vision loss, and endocrinopathy. Neurocognitive tests were administered at baseline and once a year for 5 years. Outcomes were compared with a historical cohort treated with surgery and photon therapy. The coprimary endpoints were progression-free survival and overall survival. Progression was defined as an increase in tumour dimensions on successive imaging evaluations more than 2 years after treatment. Survival and safety were also assessed in all patients who received photon therapy and limited surgery. This study is registered with ClinicalTrials.gov, NCT01419067.

FINDINGS

Between Aug 22, 2011, and Jan 19, 2016, 94 patients were enrolled and treated with surgery and proton therapy, of whom 49 (52%) were female, 45 (48%) were male, 62 (66%) were White, 16 (17%) were Black, two (2%) were Asian, and 14 (15%) were other races, and median age was 9·39 years (IQR 6·39-13·38) at the time of radiotherapy. As of data cutoff (Feb 2, 2022), median follow-up was 7·52 years (IQR 6·28-8·53) for patients who did not have progression and 7·62 years (IQR 6·48-8·54) for the full cohort of 94 patients. 3-year progression-free survival was 96·8% (95% CI 90·4-99·0; p=0·89), with progression occurring in three of 94 patients. No deaths occurred at 3 years, such that overall survival was 100%. At 5 years, necrosis had occurred in two (2%) of 94 patients, severe vasculopathy in four (4%), and permanent neurological conditions in three (3%); decline in vision from normal to abnormal occurred in four (7%) of 54 patients with normal vision at baseline. The most common grade 3-4 adverse events were headache (six [6%] of 94 patients), seizure (five [5%]), and vascular disorders (six [6%]). No deaths occurred as of data cutoff.

INTERPRETATION

Proton therapy did not improve survival outcomes in paediatric and adolescent patients with craniopharyngioma compared with a historical cohort, and severe complication rates were similar. However, cognitive outcomes with proton therapy were improved over photon therapy. Children and adolescents treated for craniopharyngioma using limited surgery and post-operative proton therapy have a high rate of tumour control and low rate of severe complications. The outcomes achieved with this treatment represent a new benchmark to which other regimens can be compared.

FUNDING

American Lebanese Syrian Associated Charities, American Cancer Society, the US National Cancer Institute, and Research to Prevent Blindness.

Primary hypothyroidism in childhood cancer survivors: Prevalence, risk factors, and long-term consequences

BACKGROUND

Data on primary hypothyroidism and its long-term impact on the health, cognition, and quality of life (QOL) of childhood cancer survivors are limited. This study examined the prevalence of and risk factors for primary hypothyroidism and its associations with physical, neurocognitive, and psychosocial outcomes.

METHODS

This was a retrospective study with a cross-sectional health outcome analysis of an established cohort comprising 2965 survivors of childhood cancer (52.8% male; median current age, 30.9 years, median time since cancer diagnosis, 22.3 years). Multivariable logistic regression estimated odds ratios (ORs) and 95% confidence intervals (CIs) for associations between primary hypothyroidism and cancer-related risk factors, cardiovascular disease risk factors, frailty, neurocognitive and QOL outcomes, social attainment, and subsequent thyroid carcinoma. Associations between serum free thyroxine and thyrotropin levels at assessment and health outcomes were explored.

RESULTS

The prevalence of primary hypothyroidism was 14.7% (95% CI, 13.5%-16.0%). It was more likely in females (OR, 1.06; 95% CI, 1.03-1.08), was less likely in non-Whites (OR, 0.96; 95% CI, 0.93-0.99), was associated with thyroid radiotherapy (higher risk at higher doses), and was more common if cancer was diagnosed at an age ≥ 15.0 years versus an age < 5 years (OR, 1.05; 95% CI, 1.01-1.09). Primary hypothyroidism was associated with frailty (OR, 1.54; 95% CI, 1.05-2.26), dyslipidemia (OR, 1.52; 95% CI, 1.14-2.04), impaired physical QOL (OR, 1.66; 95% CI, 1.12-2.48), and having health care insurance (OR, 1.51; 95% CI, 1.07-2.12).

CONCLUSIONS

Primary hypothyroidism is common in survivors and is associated with unfavorable physical health and QOL outcomes. The impact of thyroid hormone replacement practices on these outcomes should be investigated further.

Anatomic Neuroimaging Characteristics of Posterior Fossa Type A Ependymoma Subgroups

BACKGROUND AND PURPOSE

Posterior fossa type A (PFA) ependymomas have 2 molecular subgroups (PFA-1 and PFA-2) and 9 subtypes. Gene expression profiling suggests that PFA-1 and PFA-2 tumors have distinct developmental origins at different rostrocaudal levels of the brainstem. We, therefore, tested the hypothesis that PFA-1 and PFA-2 ependymomas have different anatomic MR imaging characteristics at presentation.

MATERIALS AND METHODS

Two neuroradiologists reviewed the preoperative MR imaging examinations of 122 patients with PFA ependymomas and identified several anatomic characteristics, including extension through the fourth ventricular foramina and encasement of major arteries and tumor type (midfloor, roof, or lateral). Deoxyribonucleic acid methylation profiling assigned ependymomas to PFA-1 or PFA-2. Information on PFA subtype from an earlier study was also available for a subset of tumors. Associations between imaging variables and subgroup or subtype were evaluated.

RESULTS

No anatomic imaging variable was significantly associated with the PFA subgroup, but 5 PFA-2c subtype ependymomas in the cohort had a more circumscribed appearance and showed less tendency to extend through the fourth ventricular foramina or encase blood vessels, compared with other PFA subtypes.

CONCLUSIONS

PFA-1 and PFA-2 ependymomas did not have different anatomic MR imaging characteristics, and these results do not support the hypothesis that they have distinct anatomic origins. PFA-2c ependymomas appear to have a more anatomically circumscribed MR imaging appearance than the other PFA subtypes; however, this needs to be confirmed in a larger study.

[11C]-Methionine PET for Identification of Pediatric High-Grade Glioma Recurrence

Differentiating tumor recurrence or progression from pseudoprogression during surveillance of pediatric high-grade gliomas (PHGGs) using MRI, the primary imaging modality for evaluation of brain tumors, can be challenging. The aim of this study was to evaluate whether ¹¹C-methionine PET, a molecular imaging technique that detects functionally active tumors, is useful for further evaluating MRI changes concerning for tumor recurrence during routine surveillance. Methods: Using ¹¹C-methionine PET during follow-up visits, we evaluated 27 lesions in 26 patients with new or worsening MRI abnormalities for whom tumor recurrence was of concern. We performed quantitative and qualitative assessments of both ¹¹C-methionine PET and MRI data to predict the presence of tumor recurrence. Further, to assess for an association with overall survival (OS), we plotted the time from development of the imaging changes against survival. Results: Qualitative evaluation of ¹¹C-methionine PET achieved 100% sensitivity, 60% specificity, and 93% accuracy to correctly predict the presence of tumors in 27 new or worsening MRI abnormalities. Qualitative MRI evaluation achieved sensitivity ranging from 86% to 95%, specificity ranging from 40% to 60%, and accuracy ranging from 85% to 89%. The interobserver agreement for ¹¹C-methionine PET assessment was 100%, whereas the interobserver agreement was only 50% for MRI (P < 0.01). Quantitative MRI and ¹¹C-methionine PET evaluation using receiver-operating characteristics demonstrated higher specificity (80%) than did qualitative evaluations (40%–60%). Postcontrast enhancement volume, metabolic tumor volume, tumor-to-brain ratio, and presence of tumor as determined by consensus MRI assessment were inversely associated with OS. Conclusion:¹¹C-methionine PET has slightly higher sensitivity and accuracy for correctly predicting tumor recurrence, with excellent interobserver agreement, than does MRI. Quantitative ¹¹C-methionine PET can also predict OS. These findings suggest that ¹¹C-methionine PET can be useful for further evaluation of MRI changes during surveillance of previously treated PHGGs.

Surveillance for subsequent neoplasms of the CNS for childhood, adolescent, and young adult cancer survivors: a systematic review and recommendations from the International Late Effects of Childhood Cancer Guideline Harmonization Group

Exposure to cranial radiotherapy is associated with an increased risk of subsequent CNS neoplasms among childhood, adolescent, and young adult (CAYA) cancer survivors. Surveillance for subsequent neoplasms can translate into early diagnoses and interventions that could improve cancer survivors' health and quality of life. The practice guideline presented here by the International Late Effects of Childhood Cancer Guideline Harmonization Group was developed with an evidence-based method that entailed the gathering and appraisal of published evidence associated with subsequent CNS neoplasms among CAYA cancer survivors. The preparation of these guidelines showed a paucity of high-quality evidence and highlighted the need for additional research to inform survivorship care. The recommendations are based on careful consideration of the evidence supporting the benefits, risks, and harms of the surveillance interventions, clinical judgment regarding individual patient circumstances, and the need to maintain flexibility of application across different health-care systems. Currently, there is insufficient evidence to establish whether early detection of subsequent CNS neoplasms reduces morbidity and mortality, and therefore no recommendation can be formulated for or against routine MRI surveillance. The decision to start surveillance should be made by the CAYA cancer survivor and health-care provider after careful consideration of the potential harms and benefits of surveillance for CNS neoplasms, including meningioma.

Characterization of Leukoencephalopathy and Association With Later Neurocognitive Performance in Pediatric Acute Lymphoblastic Leukemia

OBJECTIVES

The most common form of pediatric cancer is acute lymphoblastic leukemia (ALL). Magnetic resonance (MR) neuroimaging studies have revealed leukoencephalopathy (LE) in pediatric ALL, but the impact of LE on long-term neurocognitive performance remains unknown. This study aims to objectively characterize the prevalence, extent, and intensity of LE, and their association with later neurocognitive performance.

MATERIALS AND METHODS

Pediatric patients (N = 377) treated for ALL without irradiation underwent MR neuroimaging at 4 time points throughout therapy (end of remission induction [MR1], end of consolidation [MR2], and week 31 [MR3] and week 120 [end therapy, MR4] of continuation treatment) and neurocognitive evaluations at the end of therapy and 2 years later. Generalized estimation equation models with logit link were developed to explore the association between LE prevalence and extent with time points throughout therapy, age at diagnosis (≤5 years or >5 years), treatment risk arm (low risk or standard/high risk), and sex. General linear models were also developed to investigate the association between neuroimaging metrics during treatment and neurocognitive performance at 2-year follow-up.

RESULTS

The prevalence of LE was greatest (22.8%, 74/324) after consolidation therapy. The prevalence of LE increased at MR2 relative to MR1 regardless of treatment risk arm (both P's < 0.001), age group (both P's < 0.001), or sex (male, P < 0.001; female, P = 0.013). The extent of white matter affected also increased at MR2 relative to MR1 regardless of treatment risk arm (standard/high risk, P < 0.001; low risk, P = 0.004), age group (both P's < 0.001), or sex (male, P < 0.001; female, P = 0.001). Quantitative relaxation rates were significantly longer in LE compared with that in normal-appearing white matter in the same examination (T1, P < 0.001; T2, P < 0.001). The LE prevalence early in therapy was associated with increased parent ratings of conduct problems (P = 0.039) and learning difficulties (P = 0.036) at 2-year follow-up compared with that at the end of therapy. A greater extent of LE early in therapy was associated with decreasing performance on a measure of processing speed (P = 0.003) from the end of therapy to 2-year follow-up. A larger extent of LE at the end of therapy was associated with decreased performance in reading (P = 0.004), spelling (P = 0.003), and mathematics (P = 0.019) at 2-year follow-up and increasing problems with attention (omissions, P = 0.045; β, P = 0.015) and memory (list A total recall, P = 0.010) at 2-year follow-up compared with that at the end of therapy.

CONCLUSIONS

In this large cohort of pediatric patients treated for ALL without irradiation, asymptomatic LE during therapy can be seen in almost a quarter of patients, involves as much as 10% of the white matter volume, and is associated with decreasing neurocognitive performance, increasing parent reports of conduct problems, and learning difficulties in survivors.

Diffusion Tensor Imaging-Based Analysis of Baseline Neurocognitive Function and Posttreatment White Matter Changes in Pediatric Patients With Craniopharyngioma Treated With Surgery and Proton Therapy

PURPOSE

To determine the preirradiation baseline association of white matter integrity with neurocognitive function and to assess posttreatment changes in pediatric patients with craniopharyngioma treated with proton therapy.

METHODS AND MATERIALS

Ninety children and adolescents (2-20 years old) with craniopharyngioma were treated with proton therapy (54 Gy[RBE]) in a prospective therapeutic trial. Neurocognitive performance at the postoperative baseline before proton therapy and diffusion tensor imaging (DTI) data acquired at baseline and at annual follow-up were analyzed. Tract-based spatial statistics and structural connectomics were used to derive global and local white matter features from DTI. Baseline DTI features were compared for patients with average and below-average neurocognitive performance. Longitudinal DTI data were analyzed to determine the proton dose effect on white matter structures in relation to the irradiated brain volume and baseline age.

RESULTS

Before proton therapy, patients with below-average working memory, processing speed, verbal fluency, verbal learning, or fine motor dexterity exhibited more globally degraded white matter structures compared with their counterparts with average performance, as indicated by lower mean fractional anisotropy, decreased global efficiency, or higher modularity. Surgery, obstructive hydrocephalus, and preoperative hypothalamic involvement appeared to be related to this degradation. In local analyses, tract-based spatial statistics revealed left-lateralized associations with verbal and motor functions, which supported surgical approaches to midline tumors via the right hemisphere. The mean fractional anisotropy of the brain and the global efficiency derived from DTI increased over the 5 years after proton therapy. The rate of increase was lower with larger irradiated brain volumes and in older children.

CONCLUSIONS

Below-average baseline neurocognitive performance in patients with craniopharyngioma before proton therapy appeared to be related to structural degradation of white matter tracts. Posttherapy longitudinal DTI showed improving trends in global integrity and efficiency measures, particularly in children in whom a smaller brain volume was irradiated.

Molecular grouping and outcomes of young children with newly diagnosed ependymoma treated on the multi-institutional SJYC07 trial

BACKGROUND

This report documents the clinical characteristics, molecular grouping, and outcome of young children with ependymoma treated prospectively on a clinical trial.

METHODS

Fifty-four children (aged ≤3 y) with newly diagnosed ependymoma were treated on the St Jude Young Children 07 (SJYC07) trial with maximal safe surgical resection, 4 cycles of systemic chemotherapy, consolidation therapy using focal conformal radiation therapy (RT) (5-mm clinical target volume), and 6 months of oral maintenance chemotherapy. Molecular groups were determined by tumor DNA methylation using Infinium Methylation EPIC BeadChip and profiled on the German Cancer Research Center/Molecular Neuropathology 2.0 classifier.

RESULTS

One of the 54 study patients had metastases (cerebrospinal fluid positive) at diagnosis. Gross or near-total resection was achieved in 48 (89%) patients prior to RT. At a median follow-up of 4.4 years (range, 0.2-10.3 y), 4-year progression-free survival (PFS) was 75.1% ± 7.2%, and overall survival was 92.6% ± 4.4%. The molecular groups showed no significant difference in PFS (4-year estimates: posterior fossa ependymoma group A [PF-EPN-A; 42/54], 71.2% ± 8.3%; supratentorial ependymoma positive for v-rel avian reticuloendotheliosis viral oncogene homolog A [ST-EPN-RELA; 8/54], 83.3% ± 17.0%; and supratentorial ependymoma positive for Yes-associated protein [4/54], 100%, P = 0.22). Subtotal resection prior to RT was associated with an inferior PFS compared with gross or near-total resection (4-year PFS: 41.7% ± 22.5% vs 79.0% ± 7.1%, P = 0.024), as was PF-EPN-A group with 1q gain (P = 0.05). Histopathologic grading was not associated with outcomes (classic vs anaplastic; P = 0.89).

CONCLUSIONS

In this prospectively treated cohort of young children with ependymoma, ST-EPN-RELA tumors had a more favorable outcome than reported from retrospective data. Histologic grade did not impact outcome. PF-EPN-A with 1q gain and subtotal resection were associated with inferior outcomes.

Brain Activity Associated With Attention Deficits Following Chemotherapy for Childhood Acute Lymphoblastic Leukemia

BACKGROUND

The impact of contemporary chemotherapy treatment for childhood acute lymphoblastic leukemia on central nervous system activity is not fully appreciated.

METHODS

Neurocognitive testing and functional magnetic resonance imaging (fMRI) were obtained in 165 survivors five or more years postdiagnosis (average age = 14.4 years, 7.7 years from diagnosis, 51.5% males). Chemotherapy exposure was measured as serum concentration of methotrexate following high-dose intravenous injection. Neurocognitive testing included measures of attention and executive function. fMRI was obtained during completion of two tasks, the continuous performance task (CPT) and the attention network task (ANT). Image analysis was performed using Statistical Parametric Mapping software, with contrasts targeting sustained attention, alerting, orienting, and conflict. All statistical tests were two-sided.

RESULTS

Compared with population norms, survivors demonstrated impairment on number-letter switching (P < .001, a measure of cognitive flexibility), which was associated with treatment intensity (P = .048). Task performance during fMRI was associated with neurocognitive dysfunction across multiple tasks. Regional brain activation was lower in survivors diagnosed at younger ages for the CPT (bilateral parietal and temporal lobes) and the ANT (left parietal and right hippocampus). With higher serum methotrexate exposure, CPT activation decreased in the right temporal and bilateral frontal and parietal lobes, but ANT alerting activation increased in the ventral frontal, insula, caudate, and anterior cingulate.

CONCLUSIONS

Brain activation during attention and executive function tasks was associated with serum methotrexate exposure and age at diagnosis. These findings provide evidence for compromised and compensatory changes in regional brain function that may help clarify the neural substrates of cognitive deficits in acute lymphoblastic leukemia survivors.

Association Between Anesthesia Exposure and Neurocognitive and Neuroimaging Outcomes in Long-term Survivors of Childhood Acute Lymphoblastic Leukemia

IMPORTANCE

Limited studies have reported associations between anesthesia and neurocognitive and neuroimaging outcomes, particularly in pediatric patients who undergo multiple exposures to anesthesia as part of chronic disease management.

OBJECTIVE

To investigate whether general anesthesia is associated with neurocognitive impairment and neuroimaging abnormalities in long-term survivors of childhood acute lymphoblastic leukemia.

DESIGN, SETTING, AND PARTICIPANTS

A cohort study of 212 survivors of childhood acute lymphoblastic leukemia who received treatment between July 7, 2000, and November 3, 2010, and follow-up at a mean (SD) of 7.7 (1.7) years post diagnosis, was conducted at an academic medical center. Of 301 survivors who were alive and eligible for participation, 217 individuals (72.1%) agreed to participate in long-term follow-up. Data analysis was performed from August 23, 2017, to May 3, 2018.

EXPOSURES

For 5699 anesthesia procedures, data on duration and cumulative doses of all anesthetics, sedatives, analgesics, anxiolytics, and neuromuscular blockers were abstracted, along with cumulative doses of high-dose intravenous methotrexate and number of triple intrathecal chemotherapy treatments.

MAIN OUTCOMES AND MEASURES

Neurocognitive measures of attention, processing speed, executive function, and intelligence were examined. Brain volumes, cortical thickness, and diffusion tensor imaging of the whole brain, corpus callosum, frontal lobes, and parietal lobes were evaluated.

RESULTS

Of the 217 study participants, 212 were included in both neurocognitive and brain imaging analysis. Of these, 105 were female (49.5%); mean (SD) age at diagnosis was 14.36 (4.79) years; time since diagnosis was 7.7 (1.7) years. Adjusting for chemotherapy doses and age at diagnosis, neurocognitive impairment was associated with higher propofol cumulative dose (relative risk [RR], 1.40 per 100 mg/kg; 95% CI, 1.11-1.75), flurane exposure (RR, 1.10 per exposure; 95% CI, 1.01-1.21), and longer anesthesia duration (RR, 1.03 per cumulative hour; 95% CI, 1.00-1.06). Slower processing speed was associated with higher propofol dose (estimate [est], -0.30; P = .04), greater number of exposures to fluranes (est, -0.14; P = .01), and longer anesthesia duration (est, -0.04; P = .003). Higher corpus callosum white matter diffusivity was associated with dose of propofol (est, 2.55; P = .01) and duration of anesthesia (est, 2.40; P = .02). Processing speed was significantly correlated with corpus callosum diffusivity (r = -0.26, P < .001).

CONCLUSIONS AND RELEVANCE

Higher cumulative anesthesia exposure and duration may be associated with neurocognitive impairment and neuroimaging abnormalities in long-term survivors of childhood acute lymphoblastic leukemia, beyond the known outcomes associated with neurotoxic chemotherapies. Anesthesia exposures should be limited in pediatric populations with chronic health conditions who undergo multiple medical procedures.

Conformal Radiation Therapy for Pediatric Ependymoma, Chemotherapy for Incompletely Resected Ependymoma, and Observation for Completely Resected, Supratentorial Ependymoma

PURPOSE

The Children's Oncology Group trial ACNS0121 estimated event-free survival (EFS) and overall survival for children with intracranial ependymoma treated with surgery, radiation therapy, and-selectively-with chemotherapy. Treatment was administered according to tumor location, histologic grade, and extent of resection. The impacts of histologic grade, focal copy number gain on chromosome 1q, and DNA methylation profiles were studied for those undergoing surgery and immediate postoperative conformal radiation therapy (CRT).

METHODS

ACNS0121 included 356 newly diagnosed patients (ages 1 to 21 years). Patients with classic supratentorial ependymoma were observed after gross total resection (GTR). Those undergoing subtotal resection received chemotherapy, second surgery, and CRT. The remaining patients received immediate postoperative CRT after near-total resection or GTR. CRT was administered with a 1.0-cm clinical target volume margin. The cumulative total dose was 59.4 Gy, except for patients who underwent GTR and were younger than age 18 months (who received 54 Gy). Patients were enrolled between October 2003 and September 2007 and were observed for 5 years. Supratentorial tumors were evaluated for RELA fusion; infratentorial tumors, for chromosome 1q gain. Classification of posterior fossa groups A and B was made by methylation profiles.

RESULTS

The 5-year EFS rates were 61.4% (95% CI, 34.5% to 89.6%), 37.2% (95% CI, 24.8% to 49.6%), and 68.5% (95% CI, 62.8% to 74.2%) for observation, subtotal resection, and near-total resection/GTR groups given immediate postoperative CRT, respectively. The 5-year EFS rates differed significantly by tumor grade (P = .0044) but not by age, location, RELA fusion status, or posterior fossa A/posterior fossa B grouping. EFS was higher for patients with infratentorial tumors without 1q gain than with 1q gain (82.8% [95% CI, 74.4% to 91.2%] v 47.4% [95% CI, 26.0% to 68.8%]; P = .0013).

CONCLUSION

The EFS for patients with ependymoma younger than 3 years of age who received immediate postoperative CRT and for older patients is similar. Irradiation should remain the mainstay of care for most subtypes.

Growth hormone deficiency and neurocognitive function in adult survivors of childhood acute lymphoblastic leukemia

BACKGROUND

The impact of growth hormone deficiency (GHD) on neurocognitive function is poorly understood in survivors of childhood acute lymphoblastic leukemia (ALL). This study examined the contribution of GHD to functional outcomes while adjusting for cranial radiation therapy (CRT).

METHODS

Adult survivors of ALL (N = 571; 49% female; mean age, 37.4 years; age range, 19.4-62.2 years) completed neurocognitive tests and self-reported neurocognitive symptoms, emotional distress, and quality of life. GHD was defined as a previous diagnosis of GHD or a plasma insulin-like growth factor1 level less than -2.0 standard deviations for sex and age at the time of neurocognitive testing. Hypothyroidism, hypogonadism, sex, age at diagnosis, CRT dose, and intrathecal and high-dose intravenous methotrexate were included as covariates in multivariable linear regression models.

RESULTS

Of the 571 survivors, 298 (52%) had GHD, and those with GHD received higher doses of CRT (P = .002). Survivors who had GHD, irrespective of prior growth hormone treatment, demonstrated poorer vocabulary (z-score, -0.84 vs -0.61; P = .02), processing speed (z-score, -0.49 vs -0.30; P = .04), cognitive flexibility (z-score, -1.37 vs -0.94; P = .01), and verbal fluency (z-score, -0.74 vs -0.44; P = .001), and they self-reported more neurocognitive problems and poorer quality of life compared with survivors who did not have GHD. Multivariable and mediation models revealed that GHD was associated with small effects on quality of life (general health, P = .01; vitality, P = .01; mental health, P = .01); and CRT dose accounted for the lower neurocognitive outcomes.

CONCLUSIONS

Adult survivors of childhood ALL who receive CRT are at risk for GHD, although poor neurocognitive outcomes are determined by CRT dose and not by the presence of GHD.

The Impact of Persistent Leukoencephalopathy on Brain White Matter Microstructure in Long-Term Survivors of Acute Lymphoblastic Leukemia Treated with Chemotherapy Only

BACKGROUND AND PURPOSE

Survivors of acute lymphoblastic leukemia are at risk for neurocognitive deficits and leukoencephalopathy. We performed a longitudinal assessment of leukoencephalopathy and its associations with long-term brain microstructural white matter integrity and neurocognitive outcomes in survivors of childhood acute lymphoblastic leukemia treated on a modern chemotherapy-only protocol.

MATERIALS AND METHODS

One hundred seventy-three survivors of acute lymphoblastic leukemia (49% female), treated on a chemotherapy-only protocol, underwent brain MR imaging during active therapy and repeat imaging and neurocognitive testing at follow-up (median, 13.5 years of age; interquartile range, 10.7-17.6 years; median time since diagnosis, 7.5 years; interquartile range, 6.3-9.1 years). Persistence of leukoencephalopathy was examined in relation to demographic and treatment data and to brain DTI in major fiber tracts and neurocognitive testing at follow-up.

RESULTS

Leukoencephalopathy was found in 52 of 173 long-term survivors (30.0%) and persisted in 41 of 52 (78.8%) who developed it during therapy. DTI parameters were associated with leukoencephalopathy in multiple brain regions, including the corona radiata (fractional anisotropy, P = .001; mean diffusivity, P < .001), superior longitudinal fasciculi (fractional anisotropy, P = .02; mean diffusivity, P < .001), and superior fronto-occipital fasciculi (fractional anisotropy, P = .006; mean diffusivity, P < .001). Mean diffusivity was associated with neurocognitive impairment including in the genu of the corpus callosum (P = .04), corona radiata (P = .02), and superior fronto-occipital fasciculi (P = .02).

CONCLUSIONS

Leukoencephalopathy during active therapy and neurocognitive impairment at long-term follow-up are associated with microstructural white matter integrity. DTI may be more sensitive than standard MR imaging for detection of clinically consequential white matter abnormalities in childhood acute lymphoblastic leukemia survivors treated with chemotherapy and in children undergoing treatment.

Molecular heterogeneity and CXorf67 alterations in posterior fossa group A (PFA) ependymomas

Of nine ependymoma molecular groups detected by DNA methylation profiling, the posterior fossa type A (PFA) is most prevalent. We used DNA methylation profiling to look for further molecular heterogeneity among 675 PFA ependymomas. Two major subgroups, PFA-1 and PFA-2, and nine minor subtypes were discovered. Transcriptome profiling suggested a distinct histogenesis for PFA-1 and PFA-2, but their clinical parameters were similar. In contrast, PFA subtypes differed with respect to age at diagnosis, gender ratio, outcome, and frequencies of genetic alterations. One subtype, PFA-1c, was enriched for 1q gain and had a relatively poor outcome, while patients with PFA-2c ependymomas showed an overall survival at 5 years of > 90%. Unlike other ependymomas, PFA-2c tumors express high levels of OTX2, a potential biomarker for this ependymoma subtype with a good prognosis. We also discovered recurrent mutations among PFA ependymomas. H3 K27M mutations were present in 4.2%, occurring only in PFA-1 tumors, and missense mutations in an uncharacterized gene, CXorf67, were found in 9.4% of PFA ependymomas, but not in other groups. We detected high levels of wildtype or mutant CXorf67 expression in all PFA subtypes except PFA-1f, which is enriched for H3 K27M mutations. PFA ependymomas are characterized by lack of H3 K27 trimethylation (H3 K27-me3), and we tested the hypothesis that CXorf67 binds to PRC2 and can modulate levels of H3 K27-me3. Immunoprecipitation/mass spectrometry detected EZH2, SUZ12, and EED, core components of the PRC2 complex, bound to CXorf67 in the Daoy cell line, which shows high levels of CXorf67 and no expression of H3 K27-me3. Enforced reduction of CXorf67 in Daoy cells restored H3 K27-me3 levels, while enforced expression of CXorf67 in HEK293T and neural stem cells reduced H3 K27-me3 levels. Our data suggest that heterogeneity among PFA ependymomas could have clinicopathologic utility and that CXorf67 may have a functional role in these tumors.

Risk-adapted therapy for young children with medulloblastoma (SJYC07): therapeutic and molecular outcomes from a multicentre, phase 2 trial

BACKGROUND

Young children with medulloblastoma have a poor overall survival compared with older children, due to use of radiation-sparing therapy in young children. Radiotherapy is omitted or reduced in these young patients to spare them from debilitating long-term side-effects. We aimed to estimate event-free survival and define the molecular characteristics associated with progression-free survival in young patients with medulloblastoma using a risk-stratified treatment strategy designed to defer, reduce, or delay radiation exposure.

METHODS

In this multicentre, phase 2 trial, we enrolled children younger than 3 years with newly diagnosed medulloblastoma at six centres in the USA and Australia. Children aged 3-5 years with newly diagnosed, non-metastatic medulloblastoma without any high-risk features were also eligible. Eligible patients were required to start therapy within 31 days from definitive surgery, had a Lansky performance score of at least 30, and did not receive previous radiotherapy or chemotherapy. Patients were stratified postoperatively by clinical and histological criteria into low-risk, intermediate-risk, and high-risk treatment groups. All patients received identical induction chemotherapy (methotrexate, vincristine, cisplatin, and cyclophosphamide), with high-risk patients also receiving an additional five doses of vinblastine. Induction was followed by risk-adapted consolidation therapy: low-risk patients received cyclophosphamide (1500 mg/m2 on day 1), etoposide (100 mg/m2 on days 1 and 2), and carboplatin (area under the curve 5 mg/mL per min on day 2) for two 4-week cycles; intermediate-risk patients received focal radiation therapy (54 Gy with a clinical target volume of 5 mm over 6 weeks) to the tumour bed; and high-risk patients received chemotherapy with targeted intravenous topotecan (area under the curve 120-160 ng-h/mL intravenously on days 1-5) and cyclophosphamide (600 mg/m2 intravenously on days 1-5). After consolidation, all patients received maintenance chemotherapy with cyclophosphamide, topotecan, and erlotinib. The coprimary endpoints were event-free survival and patterns of methylation profiling associated with progression-free survival. Outcome and safety analyses were per protocol (all patients who received at least one dose of induction chemotherapy); biological analyses included all patients with tissue available for methylation profiling. This trial is registered with ClinicalTrials.gov, number NCT00602667, and was closed to accrual on April 19, 2017.

FINDINGS

Between Nov 27, 2007, and April 19, 2017, we enrolled 81 patients with histologically confirmed medulloblastoma. Accrual to the low-risk group was suspended after an interim analysis on Dec 2, 2015, when the 1-year event-free survival was estimated to be below the stopping rule boundary. After a median follow-up of 5·5 years (IQR 2·7-7·3), 5-year event-free survival was 31·3% (95% CI 19·3-43·3) for the whole cohort, 55·3% (95% CI 33·3-77·3) in the low-risk cohort (n=23) versus 24·6% (3·6-45·6) in the intermediate-risk cohort (n=32; hazard ratio 2·50, 95% CI 1·19-5·27; p=0·016) and 16·7% (3·4-30·0) in the high-risk cohort (n=26; 3·55, 1·66-7·59; p=0·0011; overall p=0·0021). 5-year progression-free survival by methylation subgroup was 51·1% (95% CI 34·6-67·6) in the sonic hedgehog (SHH) subgroup (n=42), 8·3% (95% CI 0·0-24·0%) in the group 3 subgroup (n=24), and 13·3% (95% CI 0·0-37·6%) in the group 4 subgroup (n=10). Within the SHH subgroup, two distinct methylation subtypes were identified and named iSHH-I and iSHH-II. 5-year progression-free survival was 27·8% (95% CI 9·0-46·6; n=21) for iSHH-I and 75·4% (55·0-95·8; n=21) for iSHH-II. The most common adverse events were grade 3-4 febrile neutropenia (48 patients [59%]), neutropenia (21 [26%]), infection with neutropenia (20 [25%]), leucopenia (15 [19%]), vomiting (15 [19%]), and anorexia (13 [16%]). No treatment-related deaths occurred.

INTERPRETATION

The risk-adapted approach did not improve event-free survival in young children with medulloblastoma. However, the methylation subgroup analyses showed that the SHH subgroup had improved progression-free survival compared with the group 3 subgroup. Moreover, within the SHH subgroup, the iSHH-II subtype had improved progression-free survival in the absence of radiation, intraventricular chemotherapy, or high-dose chemotherapy compared with the iSHH-I subtype. These findings support the development of a molecularly driven, risk-adapted, treatment approach in future trials in young children with medulloblastoma.

FUNDING

American Lebanese Syrian Associated Charities, St Jude Children's Research Hospital, NCI Cancer Center, Alexander and Margaret Stewart Trust, Sontag Foundation, and American Association for Cancer Research.

Approach for Classification and Severity Grading of Long-term and Late-Onset Health Events among Childhood Cancer Survivors in the St. Jude Lifetime Cohort

Characterization of toxicity associated with cancer and its treatment is essential to quantify risk, inform optimization of therapeutic approaches for newly diagnosed patients, and guide health surveillance recommendations for long-term survivors. The NCI Common Terminology Criteria for Adverse Events (CTCAE) provides a common rubric for grading severity of adverse outcomes in cancer patients that is widely used in clinical trials. The CTCAE has also been used to assess late cancer treatment-related morbidity but is not fully representative of the spectrum of events experienced by pediatric and aging adult survivors of childhood cancer. Also, CTCAE characterization does not routinely integrate detailed patient-reported and medical outcomes data available from clinically assessed cohorts. To address these deficiencies, we standardized the severity grading of long-term and late-onset health events applicable to childhood cancer survivors across their lifespan by modifying the existing CTCAE v4.03 criteria and aligning grading rubrics from other sources for chronic conditions not included or optimally addressed in the CTCAE v4.03. This article describes the methods of late toxicity assessment used in the St. Jude Lifetime Cohort Study, a clinically assessed cohort in which data from multiple diagnostic modalities and patient-reported outcomes are ascertained. Cancer Epidemiol Biomarkers Prev; 26(5); 666-74. ©2016 AACR.

Diagnostic Clues to Human Herpesvirus 6 Encephalitis and Wernicke Encephalopathy After Pediatric Hematopoietic Cell Transplantation

Human herpesvirus 6 (HHV6) encephalitis and Wernicke encephalopathy are treatable yet frequently undiagnosed causes of encephalopathy in pediatric recipients of allogeneic and autologous hematopoietic cell transplantation. Here we review representative cases of both conditions to highlight specific and relevant neurologic features that prompted effective diagnosis and treatment. Two patients with confusion accompanied by seizures, memory changes, or specific visual hallucinations and HHV6 detectable by polymerase chain reaction (PCR) in cerebrospinal fluid had improvement in viral load with ganciclovir or foscarnet treatment. Two patients had confusion, ataxia, or ocular changes and low serum thiamine levels, which resolved with parenteral thiamine. In all cases, definitive diagnosis and treatment were facilitated by a high index of suspicion and search for specific pathognomonic neurologic deficits accompanying the confusional state. It is critical to clinically differentiate these 2 conditions from other common neurologic syndromes occurring after transplant, allowing potentially improved patient outcomes by prompt diagnosis and effective treatment.

Clinical, radiological, histological and molecular characteristics of paediatric epithelioid glioblastoma

AIMS

A few case series in adults have described the characteristics of epithelioid glioblastoma (e-GB), one of the rarest variants of this cancer. We evaluated clinical, radiological, histological and molecular characteristics in the largest series to date of paediatric e-GB.

METHODS

Review of clinical characteristics and therapy, imaging studies and histology was performed in patients younger than 22 years with e-GB seen at our institution over 15 years. Sequencing of hotspot mutations and fluorescence in situ hybridization of relevant genes were undertaken.

RESULTS

Median age at diagnosis of six patients was 7.6 years. Tumours originated in the cerebral cortex (n = 2) or diencephalon (n = 4). Three patients presented with acute, massive haemorrhage and three had leptomeningeal dissemination at diagnosis. Paediatric e-GB had the typical histological characteristics seen in adult tumours. Universal immunoreactivity for INI1 and lack of diverse protein expression were seen in all cases. One tumour had a chromosome 22q loss. Three tumours (50%) harboured a BRAF: p.V600E. One thalamic tumour had an H3F3A p.K27M. All patients received radiation therapy with (n = 3) or without chemotherapy (n = 3). All patients experienced tumour progression with a median survival of 169 days. One patient with nonmetastatic disease had early leptomeningeal progression. Two patients had symptomatic tumour spread outside the central nervous system (CNS) through a ventriculoperitoneal shunt. One additional patient had widespread metastases outside the CNS identified at autopsy.

CONCLUSIONS

Paediatric e-GBs are rare cancers with an aggressive behaviour that share histological and genetic characteristics with their adult counterparts. BRAF inhibition is a potential treatment for these tumours.

Diffusion tensor imaging and neurocognition in survivors of childhood acute lymphoblastic leukaemia

Survivors of childhood acute lymphoblastic leukaemia are at risk for neurocognitive impairment, though little information is available on its association with brain integrity, particularly for survivors treated without cranial radiation therapy. This study compares neurocognitive function and brain morphology in long-term adult survivors of childhood acute lymphoblastic leukaemia treated with chemotherapy alone (n = 36) to those treated with cranial radiation therapy (n = 39) and to healthy control subjects (n = 23). Mean (standard deviation) age at evaluation was 24.9 (3.6) years for the chemotherapy group and 26.7 (3.4) years for the cranial radiation therapy group, while time since diagnosis was 15.0 (1.7) and 23.9 (3.1) years, respectively. Brain grey and white matter volume and diffusion tensor imaging was compared between survivor groups and to 23 healthy controls with a mean (standard deviation) age of 23.1 (2.6) years. Survivors treated with chemotherapy alone had higher fractional anisotropy in fibre tracts within the left (P < 0.05), but not in the right, hemisphere when compared to controls. Survivors of acute lymphoblastic leukaemia, regardless of treatment, had a lower ratio of white matter to intracranial volume in frontal and temporal lobes (P < 0.05) compared with control subjects. Survivors of acute lymphoblastic leukaemia treated with chemotherapy alone performed worse in processing speed (P < 0.001), verbal selective reminding (P = 0.01), and academics (P < 0.05) compared to population norms and performed better than survivors treated with cranial radiation therapy on verbal selective reminding (P = 0.02), processing speed (P = 0.05) and memory span (P = 0.009). There were significant associations between neurocognitive performance and brain imaging, particularly for frontal and temporal white and grey matter volume. Survivors of acute lymphoblastic leukaemia treated with chemotherapy alone demonstrated significant long-term differences in neurocognitive function and altered neuroanatomical integrity. These results suggest substantial region-specific white matter alterations in survivors of acute lymphoblastic leukaemia possibly resulting in restricted radial diffusion due to the compaction of neuronal fibres.

Regional brain glucose metabolism and neurocognitive function in adult survivors of childhood cancer treated with cranial radiation

The objective of this study was to examine associations between regional brain metabolism, as measured by (18)F-FDG PET, and neurocognitive outcomes in adult survivors of childhood acute lymphoblastic leukemia (ALL) treated with cranial radiation.

METHOD

Thirty-eight adult survivors of ALL were randomly selected from a large cohort treated with cranial radiation therapy (19 with 18 Gy and 19 with 24 Gy of exposure). At a mean age of 26.4 (range, 22.3-37.4) years, and 23.5 (range, 20.4-32.8) years since diagnosis, patients underwent comprehensive neurocognitive evaluations and brain (18)F-FDG PET imaging during a resting condition. (18)F-FDG PET images were analyzed stereotactically, and pixel values were normalized to global activity. Predefined region-of-interest and voxel-based correlation analyses were performed.

RESULTS

Compared with national norms, survivors demonstrated lower vocabulary (P < 0.001), reading (P < 0.001), mathematics (P < 0.001), working memory (P < 0.001), oral naming speed (P < 0.001), and cognitive flexibility (P < 0.001). Metabolic activity was higher in basal gangliar structures for those treated with 24 Gy of cranial radiation therapy (P = 0.04). Metabolic activity was positively correlated with oral naming speed in both lateral frontal lobes (ρ = 0.48 and 0.47 for right and left frontal regions, respectively, P < 0.01) and negatively correlated with cognitive flexibility in the sections of the basal ganglia (P < 0.01 for both caudate and putamen).

CONCLUSION

Neurocognitive impairment in long-term survivors of ALL treated with cranial radiation appears to be associated with increased metabolic activity in frontal cerebral cortical and subcortical regions in the basal ganglia, suggesting decreased efficiency of the frontostriatal brain circuit.

Incidental detection of late subsequent intracranial neoplasms with magnetic resonance imaging among adult survivors of childhood cancer

PURPOSE

Survivors of childhood cancer are at an increased risk of developing subsequent neoplasms. In long-term survivors of childhood malignancies treated with and without cranial radiation therapy (CRT), undergoing unenhanced magnetic resonance imaging (MRI) of the brain, we estimated detection of intracranial neoplasms.

METHODS

To investigate neurocognitive outcomes, 219 survivors of childhood cancer underwent unenhanced screening MRI of the brain. Of the survivors, 164 had been treated for acute lymphoblastic leukemia (ALL) (125 received CRT) and 55 for Hodgkin lymphoma (HL) (none received CRT). MRI examinations were reviewed and systematically coded by a single neuroradiologist. Demographic and treatment characteristics were compared for survivors with and without subsequent neoplasms.

RESULTS

Nineteen of the 219 survivors (8.7 %) had a total of 31 subsequent intracranial neoplasms identified by neuroimaging at a median time of 25 years (range 12-46 years) from diagnosis. All neoplasms occurred after CRT, except for a single vestibular schwannoma within the cervical radiation field in a HL survivor. The prevalence of subsequent neoplasms after CRT exposure was 14.4 % (18 of 125). By noncontrast MRI, intracranial neoplasms were most suggestive of meningiomas. Most patients presented with no specific, localizing neurological complaints. In addition to the schwannoma, six tumors were resected based on results of MRI screening, all of which were meningiomas on histologic review.

CONCLUSION

Unenhanced brain MRI of long-term survivors of childhood cancer detected a substantial number of intracranial neoplasms. Screening for early detection of intracranial neoplasms among aging survivors of childhood cancer who received CRT should be evaluated.

IMPLICATIONS FOR CANCER SURVIVORS

The high prevalence of incidentally detected subsequent intracranial neoplasms after CRT in long-term survivors of childhood cancer and the minimal symptoms reported by those with intracranial tumors in our study indicate that brain MRI screening of long-term survivors who received CRT may be warranted. Prospective studies of such screening are needed.

Elevated cerebral blood volume contributes to increased FLAIR signal in the cerebral sulci of propofol-sedated children

BACKGROUND AND PURPOSE

Hyperintense FLAIR signal in the cerebral sulci of anesthetized children is attributed to supplemental oxygen (fraction of inspired oxygen) but resembles FLAIR hypersignal associated with perfusion abnormalities in Moyamoya disease and carotid stenosis. We investigated whether cerebral perfusion, known to be altered by anesthesia, contributes to diffuse signal intensity in sulci in children and explored the relative contributions of supplemental oxygen, cerebral perfusion, and anesthesia to signal intensity in sulci.

MATERIALS AND METHODS

Supraventricular signal intensity in sulci on pre- and postcontrast T2 FLAIR images of 24 propofol-sedated children (6.20 ± 3.28 years) breathing supplemental oxygen and 18 nonsedated children (14.28 ± 2.08 years) breathing room air was graded from 0 to 3. The Spearman correlation of signal intensity in sulci with the fraction of inspired oxygen and age in 42 subjects, and with dynamic susceptibility contrast measures of cortical CBF, CBV, and MTT available in 25 subjects, were evaluated overall and compared between subgroups. Factors most influential on signal intensity in sulci were identified by stepwise logistic regression.

RESULTS

CBV was more influential on noncontrast FLAIR signal intensity in sulci than the fraction of inspired oxygen or age in propofol-sedated children (CBV: r = 0.612, P = .026; fraction of inspired oxygen: r = -0.418, P = .042; age: r = 0.523, P = .009) and overall (CBV: r = 0.671, P = .0002; fraction of inspired oxygen: r = 0.442, P = .003; age: r = -0.374, P = .015). MTT (CBV/CBF) was influential in the overall cohort (r = 0.461, P = .020). Signal intensity in sulci increased with contrast in 45% of subjects, decreased in none, and was greater (P < .0001) in younger propofol-sedated subjects, in whom the signal intensity in sulci increased with age postcontrast (r = .600, P = .002).

CONCLUSIONS

Elevated cortical CBV appears to contribute to increased signal intensity in sulci on noncontrast FLAIR in propofol-sedated children. The effects of propofol on age-related cerebral perfusion and vascular permeability may play a role.

Methotrexate-induced neurotoxicity and leukoencephalopathy in childhood acute lymphoblastic leukemia

PURPOSE

Methotrexate (MTX) can cause significant clinical neurotoxicity and asymptomatic leukoencephalopathy. We sought to identify clinical, pharmacokinetic, and genetic risk factors for these MTX-related toxicities during childhood acute lymphoblastic leukemia (ALL) therapy and provide data on safety of intrathecal and high-dose MTX rechallenge in patients with neurotoxicity.

PATIENTS AND METHODS

Prospective brain magnetic resonance imaging was performed at four time points for 369 children with ALL treated in a contemporary study that included five courses of high-dose MTX and 13 to 25 doses of triple intrathecal therapy. Logistic regression modeling was used to evaluate clinical and pharmacokinetic factors, and a genome-wide association study (GWAS) was performed to identify germline polymorphisms for their association with neurotoxicities.

RESULTS

Fourteen patients (3.8%) developed MTX-related clinical neurotoxicity. Of 13 patients rechallenged with intrathecal and/or high-dose MTX, 12 did not experience recurrence of neurotoxicity. Leukoencephalopathy was found in 73 (20.6%) of 355 asymptomatic patients and in all symptomatic patients and persisted in 74% of asymptomatic and 58% of symptomatic patients at the end of therapy. A high 42-hour plasma MTX to leucovorin ratio (measure of MTX exposure) was associated with increased risk of leukoencephalopathy in multivariable analysis (P = .038). GWAS revealed polymorphisms in genes enriched for neurodevelopmental pathways with plausible mechanistic roles in neurotoxicity.

CONCLUSION

MTX-related clinical neurotoxicity is transient, and most patients can receive subsequent MTX without recurrence of acute or subacute symptoms. All symptomatic patients and one in five asymptomatic patients develop leukoencephalopathy that can persist until the end of therapy. Polymorphisms in genes related to neurogenesis may contribute to susceptibility to MTX-related neurotoxicity.

Dexamethasone exposure and memory function in adult survivors of childhood acute lymphoblastic leukemia: A report from the SJLIFE cohort

BACKGROUND

Dexamethasone is used in acute lymphoblastic leukemia (ALL) treatment, though long-term impact on central nervous system (CNS) function is unclear. As glucocorticoids influence hippocampal function, we investigated memory networks in survivors of childhood ALL treated with dexamethasone or prednisone.

PROCEDURE

Neurocognitive assessment and functional magnetic resonance imaging (fMRI) were conducted in 38 adult survivors randomly recruited from cohorts treated on one of two standard treatment protocols, which differed primarily in the glucocorticoid administered during continuation therapy (dexamethasone [n = 18] vs. prednisone [n = 20]). Groups did not differ in age at diagnosis, age at evaluation, or cumulative intravenous or intrathecal methotrexate exposure.

RESULTS

Survivors treated with dexamethasone demonstrated lower performance on multiple memory-dependent measures, including story memory (P = 0.01) and word recognition (P = 0.04), compared to survivors treated with only prednisone. Dexamethasone treatment was associated with decreased fMRI activity in the left retrosplenial brain region (effect size = 1.3), though the small sample size limited statistical significance (P = 0.08). Story memory was associated with altered activation in left inferior frontal-temporal brain regions (P = 0.007).

CONCLUSIONS

Results from this pilot study suggest that adult survivors of ALL treated with dexamethasone are at increased risk for memory deficits and altered neural activity in specific brain regions and networks associated with memory function.

Neurocognitive function and CNS integrity in adult survivors of childhood hodgkin lymphoma

PURPOSE

Long-term survivors of childhood Hodgkin lymphoma (HL) are at risk for cardiopulmonary complications and CNS stroke, although neurocognitive function has not been previously examined. The aim of this study was to examine neurocognitive and brain imaging outcomes in adult survivors of childhood HL.

PATIENTS AND METHODS

In all, 62 adult survivors (mean age, 42.2 years; standard deviation [SD], 4.77; mean age at diagnosis, 15.1 years; SD, 3.30) were identified by stratified random selection from a large cohort treated with either high-dose (≥ 30 Gy) thoracic radiation (n = 38) or lower-dose (< 30 Gy) thoracic radiation combined with anthracycline (n = 24). Patients underwent neurocognitive evaluations, brain magnetic resonance imaging (MRI), echocardiograms, pulmonary function tests, and physical examinations.

RESULTS

Compared with national age-adjusted norms, HL survivors demonstrated lower performance on sustained attention (P = .004), short-term memory (P = .001), long-term memory (P = .006), working memory (P < .001), naming speed (P < .001), and cognitive fluency (P = .007). MRI revealed leukoencephalopathy in 53% of survivors, and 37% had evidence of cerebrovascular injury. Higher thoracic radiation dose was associated with impaired cardiac diastolic function (E/E'; ratio of peak mitral flow velocity of early rapid filling [E] to early diastolic velocity of the mitral annulus [E']; P = .003), impaired pulmonary function (diffusing capacity of lungs for carbon monoxide [DL(co)(corr); P = .04), and leukoencephalopathy (P = .02). Survivors with leukoencephalopathy demonstrated reduced cognitive fluency (P = .001). Working memory impairment was associated with E/E', although impaired sustained attention and naming speed were associated with DL(co)(corr). Neurocognitive performance was associated with academic and vocational functioning.

CONCLUSION

These results suggest that adult long-term survivors of childhood HL are at risk for neurocognitive impairment, which is associated with radiologic indices suggestive of reduced brain integrity and which occurs in the presence of symptoms of cardiopulmonary dysfunction.

Cerebral white matter integrity and executive function in adult survivors of childhood medulloblastoma

Survivors of pediatric medulloblastoma are at risk for neurocognitive dysfunction. Reduced white matter integrity has been correlated with lower intelligence in child survivors, yet associations between specific cognitive processes and white matter have not been examined in long-term adult survivors. Twenty adult survivors of medulloblastoma were randomly recruited from a larger institutional cohort of adult survivors of childhood cancer. Survivors underwent comprehensive neurocognitive evaluations and MRI. Data on brain volume and cortical thickness and diffusion tensor imaging were acquired, including measures of fractional anisotropy, apparent diffusion coefficient, and axial and radial diffusivity. Observed neurocognitive scores were compared with population norms and correlated to MRI indices. Survivors were, on average, 29 years of age and 18 years postdiagnosis. Mean full-scale intelligence quotient was nearly 1 SD below the normative mean (86.3 vs 100, P = .004). Seventy-five percent of survivors were impaired on at least one measure of executive function. Radial diffusivity in the frontal lobe of both hemispheres was correlated with shifting attention (left: r(s) = -0.67, P = .001; right: r(s) = -0.64, P = .002) and cognitive flexibility (left: r(s) = -0.56, P = .01; right: r(s) = -0.54, P = .01). Volume and cortical thickness were not correlated with neurocognitive function. Neurocognitive impairment was common and involved many domains. Reduced white matter integrity in multiple brain regions correlated with poorer performance on tasks of executive function. Future research integrating diffusion tensor imaging should be a priority to more rigorously evaluate long-term consequences of cancer treatment and to inform cognitive intervention trials in this high-risk population.

Imaging changes in very young children with brain tumors treated with proton therapy and chemotherapy

SUMMARY

PT promises to reduce side effects in children with brain tumors by sparing normal tissue compared with 3D conformal or intensity-modulated radiation therapy. Information is lacking about the combined effects of PT and chemotherapy in young children. We describe imaging changes in 8 very young children with localized brain tumors who received PT after chemotherapy. Mostly transient signal abnormalities and enhancement in brain parenchyma were observed by serial MR imaging, which were consistent with radiation-induced effects on normal-appearing tissue. Correlation with PT planning data revealed that the areas of imaging abnormality were located within or adjacent to the volume that received the highest radiation dose. Radiologists should be aware of these findings in children who receive PT after chemotherapy. In this report, we describe the time course of these PT-related imaging findings and correlate them with treatment and clinical outcomes.

Symptoms of attention-deficit/hyperactivity disorder in long-term survivors of childhood leukemia

BACKGROUND

Survivors of childhood acute lymphoblastic leukemia (ALL) sometimes have clinical features that suggest attention-deficit/hyperactivity disorder (ADHD), though few studies have examined specific symptoms in survivors.

PROCEDURE

Long-term survivors of childhood ALL (n = 161) received a neurological examination, while parents completed rating scales to establish formal criteria for ADHD. Symptom profiles were generated and compared across demographic and treatment characteristics, as well as medical tests associated with brain pathology.

RESULTS

Prevalence rates of ADHD were similar in survivors (10.5%) compared to those reported in the general population (7-10%). However, 25.5% of survivors reported symptoms that impair functioning in multiple settings, with attention problems being most common. These symptoms were associated with cranial radiation therapy (CRT) (mean inattentive symptoms [SD] = 3.6 [3.19] for group treated with CRT vs. 1.6 [2.40] for non-CRT group, P = 0.0006), and survivors who demonstrated impaired anti-saccades during the neurologic exam (mean inattentive symptoms [SD] = 3.4 [3.29] for those with impaired anti-saccades vs. 1.4 [2.41] for those with normal anti-saccades; P = 0.0004).

CONCLUSIONS

The presence of a neurologically-based phenotype of attention problems in survivors of leukemia that is not fully captured by the syndrome of ADHD suggests that treatments specific to childhood ALL should be explored.

Three-dimensional susceptibility-weighted imaging and two-dimensional T2*-weighted gradient-echo imaging of intratumoral hemorrhages in pediatric diffuse intrinsic pontine glioma

INTRODUCTION

We compared the sensitivity and specificity of T2*-weighted gradient-echo imaging (T2*-GRE) and susceptibility-weighted imaging (SWI) in determining prevalence and cumulative incidence of intratumoral hemorrhages in children with diffuse intrinsic pontine glioma (DIPG) undergoing antiangiogenic and radiation therapy.

METHODS

Patients were recruited from an institutional review board-approved prospective phase I trial of vandetanib administered in combination with radiation therapy. Patient consent was obtained before enrollment. Consecutive T2*-GRE and SWI exams of 17 patients (F/M: 9/8; age 3-17 years) were evaluated. Two reviewers (R1 and R2) determined the number and size of hemorrhages at baseline and multiple follow-ups (92 scans, mean 5.4/patient). Statistical analyses were performed using descriptive statistics, graphical tools, and mixed-effects Poisson regression models.

RESULTS

Prevalence of hemorrhages at diagnosis was 41% and 47%; the cumulative incidences of hemorrhages at 6 months by T2*-GRE and SWI were 82% and 88%, respectively. Hemorrhages were mostly petechial; 9.7% of lesions on T2*-GRE and 5.2% on SWI were hematomas (>5 mm). SWI identified significantly more hemorrhages than T2*-GRE did. Lesions were missed or misinterpreted in 36/39 (R1/R2) scans by T2*-GRE and 9/3 scans (R1/R2) by SWI. Hemorrhages had no clinically significant neurological correlates in patients.

CONCLUSIONS

SWI is more sensitive than T2*-GRE in detecting hemorrhages and differentiating them from calcification, necrosis, and artifacts. Also, petechial hemorrhages are more common in DIPG at diagnosis than previously believed and their number increases during the course of treatment; hematomas are rare.