Neuroanatomical abnormalities related to dexamethasone exposure in survivors of childhood acute lymphoblastic leukemia

Attention and executive functioning in children and adolescents treated for high-risk acute lymphoblastic leukemia: A report from the Children's Oncology Group (COG)

OBJECTIVES

Survivors of childhood B-acute lymphoblastic leukemia (B-ALL) are at risk for difficulties with attention and executive functioning (EF) as a late effect of treatment. The present study aimed to identify treatment and demographic factors associated with risk for difficulties with EF in youth treated for high-risk B-ALL.

METHOD

Children and adolescents with B-ALL treated on Children's Oncology Group (COG) protocol AALL0232 were randomized to high-dose or escalating-dose methotrexate (MTX), and either dexamethasone or prednisone during the induction phase. Neuropsychological functioning was evaluated via protocol AALL06N1, including performance-based and parent-report measures, for 177 participants (57% female, 81% white; mean age at diagnosis = 8.4 years; SD = 5.0) 8-24 months following treatment completion.

RESULTS

Mean scores for all attention and EF measures were within the average range, with no significant differences as a function of MTX delivery or steroid treatment (all p > 0.05). In multivariable models, participants with US public insurance exhibited significantly greater parent-reported EF difficulties than those with US private or non-US insurance (p ≤ 0.05). Additionally, participants diagnosed under 10 years of age performed significantly more poorly on measures of attention (i.e., continuous performance task, p ≤ 0.05) and EF (i.e., verbal fluency and tower planning task, p ≤ 0.05).

CONCLUSIONS

For survivors of pediatric B-ALL, treatment-related factors were not associated with attention or EF outcomes. In contrast, outcomes varied by demographic characteristics, including age and insurance type, an indicator of economic hardship. Future research is needed to more directly assess the contribution of socioeconomic status on cognitive outcomes in survivors.

The gut microbiome: an important factor influencing therapy for pediatric acute lymphoblastic leukemia

Acute lymphoblastic leukemia (ALL) is the most prevalent form of pediatric leukemia. The gut microbiome (GM) is crucial for proper nutrition, immunity, and biological conflict. Since the relationship between ALL and GM is bidirectional, ALL occurrence and treatment are closely related to GM destruction and the development of impaired immunity. Studies have discovered significant GM alterations in patients with ALL, including decreased diversity, that are likely directly caused by the development of ALL. Chemotherapy, antibiotic therapy, and hematopoietic stem cell transplantation (HSCT) are the mainstays of treatment for pediatric ALL. These approaches affect the composition, diversity, and abundance of intestinal microorganisms, which in turn affects therapeutic efficiency and can cause a variety of complications. Modulating the GM can aid the recovery of patients with ALL. This article discusses the various treatment modalities for pediatric ALL and their corresponding effects on the GM, as well as the changes in the GM that occur in children with ALL from diagnosis to treatment. Gaining a greater understanding of the link between ALL and the GM is expected to help improve treatment for pediatric ALL in the future.

Progression of brain injuries associated with methotrexate chemotherapy in childhood acute lymphoblastic leukemia

BACKGROUND

Brain bases and progression of methotrexate-associated neurotoxicity and cognitive disturbances remain unknown. We tested whether brain abnormalities worsen in proportion to intrathecal methotrexate(IT-MTX) doses.

METHODS

In this prospective, longitudinal study, we recruited 19 patients with newly diagnosed acute lymphoblastic leukemia 4-to-20 years of age and 20 matched controls. We collected MRI and neuropsychological assessments at a pre-methotrexate baseline and at week 9, week 22, and year 1 during treatment.

RESULTS

Patients had baseline abnormalities in cortical and subcortical gray matter(GM), white matter(WM) volumes and microstructure, regional cerebral blood flow, and neuronal density. Abnormalities of GM, blood flow, and metabolites worsened in direct proportions to IT-MTX doses. WM abnormalities persisted until week 22 but normalized by year 1. Brain injuries were localized to dorsal and ventral attentional and frontoparietal cognitive networks. Patients had cognitive deficits at baseline that persisted at 1-year follow-up.

CONCLUSIONS

Baseline abnormalities are likely a consequence of neuroinflammation and oxidative stress. Baseline abnormalities in WM microstructure and volumes, and blood flow persisted until week 22 but normalized by year 1, likely due to treatment and its effects on reducing inflammation. The cytotoxic effects of IT-MTX, however, likely contributed to continued, progressive cortical thinning and reductions in neuronal density, thereby contributing to enduring cognitive deficits.

IMPACT

Brain abnormalities at a pre-methotrexate baseline likely are due to acute illness. The cytotoxic effects of intrathecal MTX contribute to progressive cortical thinning, reductions in neuronal density, and enduring cognitive deficits. Baseline white matter abnormalities may have normalized via methotrexate treatment and decreasing neuroinflammation. Corticosteroid and leucovorin conferred neuroprotective effects. Our findings suggest that the administration of neuroprotective and anti-inflammatory agents should be considered even earlier than they are currently administered. The neuroprotective effects of leucovorin suggest that strategies may be developed that extend the duration of this intervention or adapt it for use in standard risk patients.

Cognitive and behavioural rehabilitation interventions for survivors of childhood cancer with neurocognitive sequelae: A systematic review

There is considerable interest in cognitive and behavioural interventions to manage and improve neurocognitive (dys)functions in childhood cancer survivors and the literature is rapidly growing. This systematic review aimed to examine the literature of such interventions and their impact on executive functions (EFs) and attention. A search of relevant manuscripts was performed in PubMed, PsycINFO, and Web of Science in March 2023 in accordance with the PRISMA statement. After screening 3737 records, 17 unique studies published between 2002 and 2022 were charted and summarized. Participants (N = 718) were mostly children (M = 12.2 years), who were long-term survivors (M = 5.0 years post treatment) of brain or CNS tumours (48%). Identified interventions included computerized cognitive training, physical activity, and cognitive interventions with compensatory strategy training. The highest quality RCT studies included computerized training (i.e., Cogmed), neurofeedback, and exergaming. Evidence suggests that Cogmed may improve the performance of certain working memory tasks (near transfer) and possibly improve visual attention tasks for individuals with working memory impairments. However, the evidence did not support far transfer of effects to real life. No significant effects (near or far-transfer) were found following neurofeedback and exergaming interventions. Finally, a knowledge gap was identified for interventions directed at long-term survivors in adulthood.

Changed cortical thickness and sulcal depth in pediatric acute lymphoblastic leukemia survivors treated with chemotherapy only

The purpose of this study is to observe the changes of cortical morphological characteristics and their potential contribution to cognitive function in ALL survivors by using surface-based morphometry (SBM). Using SBM analysis, we calculated and compared group differences in cortical thickness, sulcal depth, gyrification, and fractal dimension of the cerebral cortex between 18 pediatric ALL survivors treated on chemotherapy-only protocols and off treatment within 2 years, and 18 healthy controls (HCs) with two-sample t-tests [P < 0.05, family-wise error (FWE) corrected]. Relationships between abnormal cortical characteristic values and cognitive function parameters were investigated with partial correlation analysis, taking age as a covariate. We found decreased cortical thickness mainly located in the prefrontal and temporal region, and increased sulcal depth in left rostral middle frontal cortex and left pars orbitalis in the ALL survivors compared to HCs. There were no statistically significant differences in the gyrification and fractal dimension between the two groups. In ALL survivors, cortical thickness and sulcal depth of above areas values revealed no significant correlation with the cognitive function parameters. In conclusion, pediatric ALL survivors show decreased cortical thickness in prefrontal and temporal regions, and increased sulcal depth in prefrontal region. These results suggest that SBM-based approach can be used to assess changes of cortical morphological characteristics in pediatric ALL survivors.

Late-onset Cognitive Impairment and Modifiable Risk Factors in Adult Childhood Cancer Survivors

Importance

Long-term survivors of childhood cancer may be at elevated risk for new neurocognitive impairment and decline as they age into adulthood.

Objective

To determine whether aging adult childhood cancer survivors report more new-onset neurocognitive impairments compared with their siblings and to identify risk factors associated with such impairments.

Design, Setting, and Participants

Participants of this cohort study included adult survivors of childhood cancer from the Childhood Cancer Survivor Study and their siblings as a control group. The original cohort included survivors who received a diagnosis between January 1, 1970, and December 31, 1986, for whom longitudinal neurocognitive assessment was available. This study examined the prevalence of new-onset neurocognitive impairment between baseline (23.4 years after diagnosis) and follow-up (35.0 years after diagnosis). The analysis was performed from January 2021 to May 2022.

Exposures

Cancer treatment exposures were abstracted from medical records. Chronic health conditions were graded using Common Terminology Criteria for Adverse Events version 4.03.

Main Outcomes and Measures

The primary outcome was new-onset (present at follow-up, but not present at baseline) neurocognitive impairment (defined as a score in the worst 10% of the sibling cohort). Impairment was assessed using the Childhood Cancer Survivor Study Neurocognitive questionnaire. Relative risks (RRs) and 95% CIs were used to estimate associations of neurocognitive impairment with treatment and health behaviors and conditions using generalized linear models.

Results

The cohort comprised 2375 survivors (mean [SD] age at evaluation, 31.8 [7.5] years; 1298 women [54.6%]) of childhood cancer, including acute lymphoblastic leukemia (ALL; 1316 participants), central nervous system (CNS) tumors (488 participants), and Hodgkin lymphoma (HL; 571 participants). A total of 232 siblings (mean [SD] age at evaluation, 34.2 [8.4] years; 134 women [57.8%]) were included. Compared with siblings, a higher proportion of survivors with no impairment in memory at baseline had new-onset memory impairment at follow-up: siblings proportion, 7.8% (95% CI, 4.3%-11.4%); ALL survivors treated with chemotherapy only, 14.0% (95% CI, 10.7%-17.4%); ALL survivors treated with cranial radiation (CRT), 25.8% (95% CI, 22.6%-29.0%); CNS tumor survivors, 34.7% (95% CI, 30.0%-39.5%); and HL survivors, 16.6% (95% CI, 13.4%-19.8%). New-onset memory impairment was associated with CRT in CNS tumor survivors (RR, 1.97; 95% CI, 1.33-2.90) and alkylator chemotherapy greater than or equal to 8000 mg/m2 in ALL survivors treated without CRT (RR, 2.80; 95% CI, 1.28-6.12). Neurologic conditions mediated the impact of CRT on new-onset memory impairment in CNS survivors. Smoking, low educational attainment, and low physical activity were associated with elevated risk for new-onset memory impairment.

Conclusions and Relevance

These findings suggest that adult survivors of childhood cancer are at elevated risk for late-onset memory impairment related to modifiable risk factors identified early in survivorship.

[Recent research on cognitive impairment in children with acute lymphoblastic leukemia]

Acute lymphoblastic leukemia (ALL) is the most common malignant neoplastic disease in children. With the continuous improvement in diagnosis and treatment, there has been an increasing number of ALL children who achieve long-term survival after complete remission; however, a considerable proportion of these children have cognitive impairment, which has a serious adverse impact on their learning, employment, and social life. This article reviews the latest research on cognitive impairment in children with ALL from the aspects of the influencing factors, detection techniques, and prevention/treatment methods for cognitive impairment.

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

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

Dexamethasone: Insights into Pharmacological Aspects, Therapeutic Mechanisms, and Delivery Systems

Dexamethasone (DEX) has been widely used to treat a variety of diseases, including autoimmune diseases, allergies, ocular disorders, cancer, and, more recently, COVID-19. However, DEX usage is often restricted in the clinic due to its poor water solubility. When administered through a systemic route, it can elicit severe side effects, such as hypertension, peptic ulcers, hyperglycemia, and hydro-electrolytic disorders. There is currently much interest in developing efficient DEX-loaded nanoformulations that ameliorate adverse disease effects inhibiting advancements in scientific research. Various nanoparticles have been developed to selectively deliver drugs without destroying healthy cells or organs in recent years. In the present review, we have summarized some of the most attractive applications of DEX-loaded delivery systems, including liposomes, polymers, hydrogels, nanofibers, silica, calcium phosphate, and hydroxyapatite. This review provides our readers with a broad spectrum of nanomedicine approaches to deliver DEX safely.

Sex-Based Differences in Functional Brain Activity during Working Memory in Survivors of Pediatric Acute Lymphoblastic Leukemia

Background

Long-term survivors of pediatric acute lymphoblastic leukemia are at elevated risk for neurocognitive deficits and corresponding brain dysfunction. This study examined sex-based differences in functional neuroimaging outcomes in acute lymphoblastic leukemia survivors treated with chemotherapy alone.

Methods

Functional magnetic resonance imaging (fMRI) and neurocognitive testing were obtained in 123 survivors (46% male; median [min-max] age = 14.2 years [8.3-26.5 years]; time since diagnosis = 7.7 years [5.1-12.5 years]) treated on the St. Jude Total XV treatment protocol. Participants performed the n-back working memory task in a 3 T scanner. Functional neuroimaging data were processed (realigned, slice time corrected, normalized, smoothed) and analyzed using statistical parametric mapping with contrasts for 1-back and 2-back conditions, which reflect varying degrees of working memory and task load. Group-level fMRI contrasts were stratified by sex and adjusted for age and methotrexate exposure. Statistical tests were 2-sided (P < .05 statistical significance threshold).

Results

Relative to males, female survivors exhibited less activation (ie, reduced blood oxygen dependent–level signals) in the right parietal operculum, supramarginal gyrus and inferior occipital gyrus, and bilateral superior frontal medial gyrus during increased working memory load (family-wise error–corrected P = .004 to .008, adjusting for age and methotrexate dose). Female survivors were slower to correctly respond to the 2-back condition than males (P < .05), though there were no differences in overall accuracy. Performance accuracy was negatively correlated with fMRI activity in female survivors (Pearson’s r = −0.39 to −0.29, P = .001 to .02), but not in males.

Conclusions

These results suggest the working memory network is more impaired in female survivors than male survivors, which may contribute to ongoing functional deficits.

Default-Mode Network Connectivity Changes Correlate with Attention Deficits in ALL Long-Term Survivors Treated with Radio- and/or Chemotherapy

Simple Summary

Both chemotherapy and radiotherapy play a role in the neurocognitive impairment of long-term survivors from acute lymphoblastic leukemia, but it is unknown if similar mechanisms are involved. We assessed neurocognitive alterations, brain tissue volumes, and functional connectivity of the main hubs of the default-mode network, in 13 patients treated with chemotherapy and radiotherapy (Group A) and in 13 treated with chemotherapy only (Group B). Correlations with neuropsychological scores, independent of group, were assessed for regions that showed significant differences between the two groups at neuroimaging. Compared to Group B, Group A performed significantly worse at the digit span and digit symbol tests and showed increased functional connectivity between the medial prefrontal cortex and the rolandic operculi, along with the absence of differences in regional brain tissue volumes. Functional connectivity in these regions correlated inversely with speed of processing in both groups, suggesting that similar mechanisms may be involved in the neurocognitive deficits in both groups.

Abstract

Whether chemotherapy (ChT) and radiotherapy (RT) determine neurocognitive impairment in acute lymphoblastic leukemia long-term survivors (ALL LTSs) through similar mechanisms affecting the same brain regions is still unknown. We compared neurocognitive alterations, regional brain tissue volumes (by voxel-based morphometry), and functional connectivity of the main default-mode network hubs (by seed-based analysis of resting state functional MRI data), in 13 ALL LTSs treated with RT and ChT (Group A) and 13 treated with ChT only (Group B). Group A performed significantly worse than Group B at the digit span and digit symbol tests (p = 0.023 and 0.013, respectively). Increased connectivity between the medial prefrontal cortex (the main anterior hub of the default-mode network) and the rolandic operculi was present in Group A compared to Group B, along with the absence of significant differences in regional brain tissue volumes. In these regions, the functional connectivity correlated inversely with the speed of processing scores, independent of treatment group. These results suggest that similar mechanisms may be involved in the neurocognitive deficits in ALL LTS patients, regardless of the treatment group. Further studies are needed to clarify whether these changes represent a direct expression of the mechanisms underlying the cognitive deficits or ineffective compensatory phenomena.

Social adjustment in survivors of acute lymphoblastic leukemia without cranial radiation therapy

OBJECTIVE

To evaluate group differences in social adjustment in survivors of pediatric acute lymphoblastic leukemia (ALL) compared to survivor siblings and controls; identify disease-related predictors of social adjustment in survivors; and explore whether executive functioning explained differences in social adjustment across groups and between disease-related predictors.

METHODS

Survivors of pediatric ALL (n = 38, average age at diagnosis = 4.27 years [SD = 1.97]; average time off treatment = 4.83 years [SD = 1.52]), one sibling (if available, n = 20), and one parent from each family were recruited from a long-term survivor clinic. Healthy age- and sex-matched controls (n = 38) and one parent from each family were recruited from the community. Parents completed the Behavioral Assessment System for Children, Parent Rating Scale (BASC-3) Social Withdrawal subscale as a measure of social adjustment, and the Behavior Rating Inventory of Executive Functions (BRIEF-2) as a measure of executive function for each of their children. Multilevel modeling and mediation analysis were used to achieve the study aims.

RESULTS

Parents reported that survivors had significantly worse social adjustment compared to controls (b = 6.34, p = .004), but not survivor siblings. Among survivors, greater time off treatment (b = 2.06, p = .058) and poorer executive functioning (b = 0.42, p = .006) were associated with worse social adjustment. Executive function did not mediate differences in social withdrawal between survivors and controls or the relationship between time off treatment and social withdrawal among survivors.

CONCLUSIONS

Survivors of pediatric ALL presenting to follow-up programs should be screened for difficulties with social adjustment. Future research should examine treatment- and nontreatment-related factors contributing to poorer social outcomes.

Cognitive Rehabilitation for Neurocognitive Late Effects in Adult Survivors of Childhood Acute Lymphoblastic Leukemia: A Feasibility and Case-Series Study

Neurocognitive late effects following the diagnosis and treatment of childhood acute lymphoblastic leukemia (ALL) commonly include impaired executive functions (EFs), with negative consequences for one's health-related quality of life and mental health. However, interventions for EF impairments are scarce. Thus, the aims of this study were to (1) explore the feasibility and acceptability of the cognitive rehabilitation program Goal Management Training (GMT) and (2) examine whether GMT is associated with positive outcomes across cases of ALL survivors with EF complaints. Four participants (median age 31.5 years) underwent nine GMT modules in a total of five group sessions. Rehabilitation was focused on compensatory strategies to improve real-life EFs. Participants were evaluated at 2-week and 6-month follow-ups. Evaluation of feasibility and acceptability included adherence, a semi structured interview, self-reports, and safety. Additionally, therapists' experience with implementation was evaluated. Outcome measures included self-reports and neurocognitive tests of attention, EF, and processing speed. All participants completed GMT and rated the intervention as useful, suitable, and satisfactory. The reliable change index showed improved daily life EFs (two participants) and neurocognitive performance (three participants) at 6-month follow-up. Additionally, all participants improved on a "real-life" task involving EF. A future randomized controlled trial is recommended.

Structural and Functional Brain Imaging in Long-Term Survivors of Childhood Acute Lymphoblastic Leukemia Treated With Chemotherapy: A Systematic Review

Background

The effect of chemotherapy on brain development in long-term survivors of pediatric acute lymphoblastic leukemia (ALL) was systematically reviewed.

Methods

A systematic search of Pubmed, Scopus, and PsycINFO databases was conducted to identify articles published between January 2000 and February 2020 that implemented magnetic resonance imaging to assess brain structure and function in pediatric ALL survivors (diagnosed younger than 21 years of age). The review included articles that were published on children diagnosed with ALL between 0 and 21 years of age and treated with chemotherapy-only protocols. Articles meeting the inclusion criteria described survivors on average of 5 years or more from diagnosis and were peer-reviewed articles and original studies.

Results

The search yielded 1975 articles with 23 articles meeting inclusion criteria. The review revealed that survivors had statistically significant alterations in brain anatomy, most commonly a smaller hippocampus and impaired microstructural white matter integrity in frontal brain regions. Survivors also had impaired brain function including lower brain network efficiency and altered resting state connectivity. Survivors also displayed widespread reductions in brain activation (ie, frontal, temporal, parietal brain regions) during cognitive tasks.

Conclusion

Although the neurotoxic effects of cancer treatment are reduced in the absence of cranial radiation, survivors treated on chemotherapy-only protocols still display long-term alterations in brain structure and function, which contribute to lifelong neurocognitive late effects.

Small nucleolar RNA host genes promoting epithelial-mesenchymal transition lead cancer progression and metastasis

The small nucleolar RNA host genes (SNHGs) belong to the long non-coding RNAs and are reported to be able to influence all three levels of cellular information-bearing molecules, that is, DNA, RNA, and proteins, resulting in the generation of complex phenomena. As the host genes of the small nucleolar RNAs (snoRNAs), they are commonly localized in the nucleolus, where they exert multiple regulatory functions orchestrating cellular homeostasis and differentiation as well as metastasis and chemoresistance. Indeed, worldwide literature has reported their involvement in the epithelial-mesenchymal transition (EMT) of different histotypes of cancer, being able to exploit peculiar features, for example, the possibility to act both in the nucleus and the cytoplasm. Moreover, SNHGs regulation is a fundamental topic to better understand their role in tumor progression albeit such mechanism is still debated. Here, we reviewed the biological functions of SNHGs in particular in the EMT process and discussed the perspectives for new cancer therapies.

Neurocognitive and Behavioral Outcomes of Chinese Survivors of Childhood Lymphoblastic Leukemia

Background

Increasing attention has been dedicated to investigate modifiable risk factors of late effects in survivors of childhood cancer. This study aims to evaluate neurocognitive and behavioral functioning in a relatively young cohort of survivors of childhood acute lymphoblastic leukemia (ALL) in Hong Kong, and to identify clinical and socio-environmental factors associated with these outcomes.

Methods

This analysis included 152 survivors of childhood ALL who were ≥5 years post-diagnosis (52% male, mean [SD] age 23.5[7.2] years at evaluation, 17.2[7.6] years post-diagnosis). Survivors completed performance-based neurocognitive tests, and reported their emotional and behavioral symptoms using the Child/Adult Behavior Checklist. Socio-environmental variables (living space, fatigue, physical activity, family functioning, and academic stress) were self-reported using validated questionnaires. Clinical variables and chronic health conditions were extracted from medical charts. Multivariable linear modeling was conducted to test identify factors associated with neurocognitive/behavioral outcomes, adjusting for current age, sex, age at diagnosis and cranial radiation. An exploratory mediation analysis was performed to examine the mediating effects of risk factors on neurocognitive and behavioral outcomes.

Results

As compared to population norms, a minority of survivors developed mild-moderate impairment in motor processing speed (36.2%), memory (9.2%) and attention measures (4.0%-10.5%). Survivors also reported attention problems (12.5%), sluggish cognitive tempo (23.7%) and internalizing (depressive, anxiety and somatic symptoms) problems (17.1%). A minority of survivors developed mild-moderate treatment-related chronic conditions (n=37, 24.3%). As compared to survivors without chronic conditions, survivors with chronic conditions had more executive dysfunction (B=5.09, standard error [SE]=2.05; P=0.014) and reported more attention problems (B=5.73, SE=1.43; P<0.0001). Fatigue and poor family functioning was associated with multiple measures of behavior problems (all P<0.001). A lower level of physical activity was correlated with more self-reported symptoms of inattention (B= -1.12, SE=0.38, P=0.004) and sluggish cognitive tempo (B=-1.22, SE=0.41, P=0.003). Exploratory analysis showed that chronic health conditions were associated with behavioral measures through fatigue as the mediator.

Conclusion

The majority of young Chinese survivors of ALL had normal cognitive and behavioral function. Regular monitoring of behavioral function should be performed on survivors who develop treatment-related chronic conditions. Health behavior and socio-environment factors may be potentially modifiable risk factors associated with health outcomes in survivors.

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

Simple Summary

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

Abstract

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

FreeSurfer ‐based segmentation of hippocampal subfields: A review of methods and applications, with a novel quality control procedure for ENIGMA studies and other collaborative efforts

Structural hippocampal abnormalities are common in many neurological and psychiatric disorders, and variation in hippocampal measures is related to cognitive performance and other complex phenotypes such as stress sensitivity. Hippocampal subregions are increasingly studied, as automated algorithms have become available for mapping and volume quantification. In the context of the Enhancing Neuro Imaging Genetics through Meta Analysis Consortium, several Disease Working Groups are using the FreeSurfer software to analyze hippocampal subregion (subfield) volumes in patients with neurological and psychiatric conditions along with data from matched controls. In this overview, we explain the algorithm's principles, summarize measurement reliability studies, and demonstrate two additional aspects (subfield autocorrelation and volume/reliability correlation) with illustrative data. We then explain the rationale for a standardized hippocampal subfield segmentation quality control (QC) procedure for improved pipeline harmonization. To guide researchers to make optimal use of the algorithm, we discuss how global size and age effects can be modeled, how QC steps can be incorporated and how subfields may be aggregated into composite volumes. This discussion is based on a synopsis of 162 published neuroimaging studies (01/2013–12/2019) that applied the FreeSurfer hippocampal subfield segmentation in a broad range of domains including cognition and healthy aging, brain development and neurodegeneration, affective disorders, psychosis, stress regulation, neurotoxicity, epilepsy, inflammatory disease, childhood adversity and posttraumatic stress disorder, and candidate and whole genome (epi‐)genetics. Finally, we highlight points where FreeSurfer‐based hippocampal subfield studies may be optimized.

Connectivity of the Cerebello-Thalamo-Cortical Pathway in Survivors of Childhood Leukemia Treated With Chemotherapy Only

IMPORTANCE

Treatment with contemporary chemotherapy-only protocols is associated with risk for neurocognitive impairment among survivors of childhood acute lymphoblastic leukemia (ALL).

OBJECTIVE

To determine whether concurrent use of methotrexate and glucocorticoids is associated with interference with the antioxidant system of the brain and damage and disruption of glucocorticoid-sensitive regions of the cerebello-thalamo-cortical network.

DESIGN, SETTING, AND PARTICIPANTS

This cross-sectional study was conducted from December 2016 to July 2019 in a single pediatric cancer tertiary care center. Participants included survivors of childhood ALL who were more than 5 years from cancer diagnosis, age 8 years or older, and treated on an institutional chemotherapy-only protocol. Age-matched community members were recruited as a control group. Data were analyzed from August 2017 to August 2020.

EXPOSURE

ALL treatment using chemotherapy-only protocols.

MAIN OUTCOMES AND MEASURES

This study compared brain volumes between survivors and individuals in a community control group and examined associations among survivors of methotrexate and dexamethasone exposure with neurocognitive outcomes. Functional and effective connectivity measures were compared between survivors with and without cognitive impairment. The Rey-Osterrieth complex figure test, a neurocognitive evaluation in which individuals are asked to copy a figure and then draw the figure from memory, was scored according to published guidelines and transformed into age-adjusted z scores based on nationally representative reference data and used to measure organization and planning deficits. β values for neurocognitive tests represented the amount of change in cerebellar volume or chemotherapy exposure associated with 1 SD change in neurocognitive outcome by z score (mm3/1 SD in z score for cerebellum, mm3/[g×hr/L] for dexamethasone and methotrexate AUC, and mm3/intrathecal count for total intrathecal count).

RESULTS

Among 302 eligible individuals, 218 (72%) participated in the study and 176 (58%) had usable magnetic resonance imaging (MRI) results. Among these, 89 (51%) were female participants and the mean (range) age was 6.8 (1-18) years at diagnosis and 14.5 (8-27) years at evaluation. Of 100 community individuals recruited as the control group, 82 had usable MRI results; among these, 35 (43%) were female individuals and the mean (range) age was 13.8 (8-26) years at evaluation. There was no significant difference in total brain volume between survivors and individuals in the control group. Survivors of both sexes showed decreased mean (SD) cerebellar volumes compared with the control population (female: 70 568 [6465] mm3 vs 75 134 [6780] mm3; P < .001; male: 77 335 [6210] mm3 vs 79 020 [7420] mm3; P < .001). In female survivors, decreased cerebellar volume was associated with worse performance in Rey-Osterrieth complex figure test (left cerebellum: β = 55.54; SE = 25.55; P = .03; right cerebellum: β = 52.57; SE = 25.50; P = .04) and poorer dominant-hand motor processing speed (ie, grooved pegboard performance) (left cerebellum: β = 82.71; SE = 31.04; P = .009; right cerebellum: β = 91.06; SE = 30.72; P = .004). In female survivors, increased number of intrathecal treatments (ie, number of separate injections) was also associated with Worse Rey-Osterrieth test performance (β = -0.154; SE = 0.063; P = .02), as was increased dexamethasone exposure (β = -0.0014; SE = 0.0005; P = .01). Executive dysfunction was correlated with increased global efficiency between smaller brain regions (Pearson r = -0.24; P = .01) compared with individuals without dysfunction. Anatomical connectivity showed differences between impaired and nonimpaired survivors. Analysis of variance of effective-connectivity weights identified a significant interaction association (F = 3.99; P = .02) among the direction and strength of connectivity between the cerebellum and DLPFC, female sex, and executive dysfunction. Finally, no effective connectivity was found between the precuneus and DLPFC in female survivors with executive dysfunction.

CONCLUSIONS AND RELEVANCE

These findings suggest that dexamethasone exposure was associated with smaller cerebello-thalamo-cortical regions in survivors of ALL and that disruption of effective connectivity was associated with impairment of executive function in female survivors.