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

Neuropsychological assessment, intervention, and best practices for women with non-Central nervous system cancer: A scoping review of current standards

Objective: Existing literature has sought to characterize the broad cognitive impact of non-central nervous system cancer and its treatment, including chemotherapy, radiation, surgery, and hormonal regulation. However, despite the frequency of women that are diagnosed with breast and gynecological cancer, there is limited research on the specific cognitive experiences of women undergoing cancer treatment. Presently, the current literature lacks concise guidance for neuropsychologists to support the cognitive health of women facing cancer, despite the acknowledged impact of cancer interventions and chronic illness on cognitive outcomes. Method: Applying scoping review criteria outlined by Peters et al. (2015) and adhering to Preferred Reporting Items for Systemic Reviews and Meta-Analysis (PRISMA) guidelines, we conducted a comprehensive examination of literature spanning multiple databases (Google Scholar, PubMed, PsychINFO) with a focus on the cognitive impact of cancer treatment on women. Conclusions: Women are subject to unique treatment-related outcomes due to the impact of hormonal alterations, differences in metabolization of certain chemotherapies, and psychosocial risk factors. Despite the known impact of cancer intervention, chronic illness, and cancer-related sequelae on cognitive outcomes, the current literature does not parsimoniously outline best practices for neuropsychologists to promote the health of women experiencing cancer. The current paper (1) provides an overview of the cognitive implications of cancer treatment with an intentional focus on cancers that are more prevalent in women versus men, (2) addresses the characteristics of this impact for women undergoing cancer intervention(s), and (3) provides possible intervention and treatment strategies for mental health providers and neuropsychologists.

Irradiation and Alterations in Hippocampal DNA Methylation

The response of the brain to radiation is important for cancer patients receiving whole or partial brain irradiation or total body irradiation, those exposed to irradiation as part of a nuclear accident or a nuclear war or terrorism event, and for astronauts during and following space missions. The mechanisms mediating the effects of irradiation on the hippocampus might be associated with alterations in hippocampal DNA methylation. Changes in cytosine methylation involving the addition of a methyl group to cytosine (5 mC) and especially those involving the addition of a hydroxy group to 5 mC (hydroxymethylcytosine or 5 hmC) play a key role in regulating the expression of genes required for hippocampal function. In this review article, we will discuss the effects of radiation on hippocampal DNA methylation and whether these effects are associated with hippocampus-dependent cognitive measures and molecular measures in the hippocampus involved in cognitive measures. We will also discuss whether the radiation-induced changes in hippocampal DNA methylation show an overlap across different doses of heavy ion irradiation and across irradiation with different ions. We will also discuss whether the DNA methylation changes show a tissue-dependent response.

Treatment of Pediatric Acute Lymphoblastic Leukemia: A Historical Perspective

Acute lymphoblastic leukemia (ALL) is the most common disease in pediatric oncology. The history of developmental therapeutics for ALL began in the 1960s with the repetition of "unreliable" medical interventions against this lethal disease. By the 1990s, the development of multi-agent chemotherapy and various types of supportive care rendered ALL treatable. Highly sophisticated, molecular, diagnostic techniques have enabled highly accurate prediction of the relapse risk, and the application of risk-adapted treatments has increased the survival rate in the standard-risk group to nearly 100% in most European nations and North America. Incorporation of state-of-the-art, molecularly targeted agents and novel treatments, including cell and immunotherapy, is further improving outcomes even in the high-risk group. On the other hand, the financial burden of treating children with ALL has increased, imperiling the availability of these diagnostic and treatment strategies to patients in low- and middle-income countries (LMICs). The fundamental treatment strategy, consisting of corticosteroid and classical cytotoxic therapy, has achieved fairly good outcomes and should be feasible in LMICs as well. The present review will discuss the history of developmental therapeutics for childhood ALL in various countries through an extensive literature review with the aim of proposing a model for a treatment backbone for pediatric ALL. The discussion will hopefully benefit LMICs and be useful as a base for future clinical trials of novel treatments.

Integrating Systemic Therapies into the Multimodality Therapy of Patients with Craniopharyngioma

OPINION STATEMENT

The integration of targeted therapy into the multimodal management of craniopharyngiomas represents a significant advancement in the field of neuro-oncology. Historically, the management of these tumors has been challenging due to their proximity to vital brain structures, necessitating a delicate balance between tumor control and the preservation of neurological function. Traditional treatment modalities, such as surgical resection and radiation, while effective, carry their own set of risks, including potential damage to surrounding healthy tissues and the potential for long-term side effects. Recent insights into the molecular biology of craniopharyngiomas, particularly the discovery of the BRAF V600E mutation in nearly all papillary craniopharyngiomas, have paved the way for a targeted systemic treatment approach. However, advances have been limited for adamantinomatous craniopharyngiomas. The success of BRAF/MEK inhibitors in clinical trials underscores the potential of these targeted therapies not only to control tumor growth but also to reduce the need for more invasive treatments, potentially minimizing treatment-related complications. However, the introduction of these novel therapies also brings forth new challenges, such as determining the optimal timing, sequencing, and duration of targeted treatments. Furthermore, there are open questions regarding which specific BRAF/MEK inhibitors to use, the potential need for combination therapy, and the strategies for managing intolerable adverse events. Finally, ensuring equitable access to these therapies, especially in healthcare systems with limited resources, is crucial to prevent widening healthcare disparities. In conclusion, targeted therapy with BRAF/MEK inhibitors holds great promise for improving outcomes and quality of life for patients with BRAF-mutated craniopharyngiomas. However, additional research is needed to address the questions that remain about its optimal use and integration into comprehensive treatment plans.

Educational attainment in survivors of childhood cancer in Denmark, Finland, and Sweden

BACKGROUND

Survivors of childhood cancer may face difficulties at school. We investigated whether childhood cancer affects attainment of upper secondary education, in a register-based cohort study from Denmark, Finland, and Sweden, where we limit bias from selection and participation.

METHODS

From the national cancer registers, we identified all long-term survivors of childhood cancer diagnosed aged 0-14 years in 1971-2005 (n = 7629), compared them to matched population comparisons (n = 35,411) and siblings (n = 6114), using odds ratios (OR) and 95% confidence intervals (CI).

RESULTS

Overall, 6127 survivors (80%) had attained upper secondary education by age 25, compared to 84% among comparison groups. Elevated OR for not attaining this level were mainly confined to survivors of central nervous system (CNS) tumours (ORSurv_PopComp2.05, 95%CI: 1.83-2.29). Other risk groups were survivors who had spent more time in hospital around cancer diagnosis and those who had hospital contacts in early adulthood, particularly psychiatric. Survivors of all cancer types were less likely to have attained upper secondary education without delay.

CONCLUSIONS

Although survivors of childhood cancer experienced delays in their education, many had caught up by age 25. Except for survivors of CNS tumours, survivors attained upper secondary education to almost the same extent as their peers.

Metabolic/endocrine disorders in survivors of childhood-onset and cranial radiotherapy- treated ALL/NHL: a meta-analysis

BACKGROUND

Cranial radiotherapy (CRT) is recommended to high-risk pediatric patients with acute lymphoblastic leukemia or aggressive non-Hodgkin's lymphoma (ALL/NHL). However, effects of CRT treatment on the development of metabolic/endocrine disorders remain unclear. This meta-analysis aimed to identify metabolic and endocrine disturbances in survivors of childhood-onset and CRT-treated ALL/NHL.

METHODS

Different online databases were searched using restricted search fields. Follow-up data and outcome measurements, including the prevalence of growth hormone (GH) deficiency, hypothyroidism, vitamin D deficiency, overweight/obesity, and hypogonadism were recorded. The height data was indicated by height-standard deviation score (height-SDS). Statistical estimates such as odds ratio (OR) and weighted standard mean difference (SMD) were compared between additional CRT treatment group and non-CRT treatment group. Study-to-study heterogeneity was calculated by calculating I-squared statistic, and fixed/random effect was applied to synthesize and analyze extracted data.

RESULTS

Fifteen studies were included (4269 patients in total). Adult height SDS was lower in CRT-treated patients (pooled SMD = -0.581, 95% CI: -0.649--0.512), and CRT-treated patients were likely to develop short stature (pooled OR = 2.289, 95% CI:1.674-3.130). Regardless of the study year, which potentially reflects the state-of-the-art CRT technique, the prevalence of short stature and GH deficiency was time-independent. Additionally, previous CRT can increase the risk of precocious puberty (pooled OR = 2.937, 95% CI: 1.281-6.736), hypothyroidism (pooled OR = 2.057, 95% CI:1.510-2.801), and hypogonadism (pooled OR = 3.098, 95% CI:2.521-3.807). However, the risk of being overweight/obese was similar between the patients with and without CRT (pooled OR = 1.278, 95% CI: 0.675-2.421).

CONCLUSION

Childhood-onset and CRT-treated ALL/NHL survivors are likely to have shorter height, precocious puberty, hypothyroidism, and hypogonadism.

Radiotherapy for Primary Pediatric Central Nervous System Malignancies: Current Treatment Paradigms and Future Directions

BACKGROUND

Central nervous system tumors are the most common solid tumors in childhood. Treatment paradigms for pediatric central nervous system malignancies depend on elements including tumor histology, age of patient, and stage of disease. Radiotherapy is an important modality of treatment for many pediatric central nervous system malignancies.

SUMMARY

While radiation contributes to excellent overall survival rates for many patients, radiation also carries significant risks of long-term side effects including neurocognitive decline, hearing loss, growth impairment, neuroendocrine dysfunction, strokes, and secondary malignancies. In recent decades, clinical trials have demonstrated that with better imaging and staging along with more sophisticated radiation planning and treatment set-up verification, smaller treatment volumes can be utilized without decrement in survival. Furthermore, the development of intensity-modulated radiotherapy and proton-beam radiotherapy has greatly improved conformality of radiation.

KEY MESSAGES

Recent changes in radiation treatment paradigms have decreased risks of short- and long-term toxicity for common histologies and in different age groups. Future studies will continue to develop novel radiation regimens to improve outcomes in aggressive central nervous system tumors, integrate molecular subtypes to tailor radiation treatment, and decrease radiation-associated toxicity for long-term survivors.

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

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

[Medulloblastoma: The latest major advances]

Medulloblastoma (MB) is a malignant brain tumor that mainly affects children. It is rarely found in adults. Among the four groups of MB defined today according to molecular characteristics, group 3 is the least favorable with an overall survival rate of 50 %. Current treatments, based on surgery, radiotherapy, and chemotherapy, are not sufficiently adapted to the different characteristics of the four MB groups. However, the use of new cellular and animal models has opened new doors to interesting therapeutic avenues. In this review, we detail recent advances in MB research, with a focus on the genes and pathways that drive tumorigenesis, with particular emphasis on the animal models that have been developed to study tumor biology, as well as advances in new targeted therapies.

Quality of Life in Craniopharyngioma: A Systematic Review

BACKGROUND

Craniopharyngiomas are morbid tumors that significantly reduce patients' quality of life (QoL). The lifelong burden of endocrine, visual, hypothalamic, and limbic dysfunction can have disastrous consequences for the physical and psychosocial health of patients. Elucidating the factors that influence QoL could guide therapeutic interventions to improve patient well-being.

METHODS

A systematic review was performed in accordance with the PRISMA (preferred reporting items for systematic reviews and meta-analyses) statement using the PubMed and Medline databases. Studies that had reported patient QoL using validated metrics in both adult and pediatric populations were included. Bias and methodological rigor were assessed using the MINORS (methodological index for nonrandomized studies) criteria.

RESULTS

A total of 25 studies, including 2025 patients, were available for review. Most studies were small, retrospective, cohort studies with a high risk of bias. The QoL of the patients with craniopharyngioma was lower than that of the general population. Hypothalamic involvement was consistently the strongest predictor of QoL. Endocrinopathy contributed to morbidity but could be ameliorated by hormone replacement therapy. Social and emotional dysregulation and a poor memory are common complaints after surgery, and iatrogenic damage to the infundibulum, hypothalamus, limbic system, and frontal lobes might underlie these concerns. Sleep-wake cycle dysfunction and hypothalamic obesity are serious consequences of hypothalamic damage.

CONCLUSIONS

An experienced multidisciplinary team is necessary to optimally manage the complex cases of these patients. The poor QoL of patients with craniopharyngioma is multifactorial. However, the contribution of iatrogenesis is not insubstantial. Improved surgical techniques, focusing on hypothalamic preservation, and adjuvant treatment options are required to improve the well-being of these patients.

School academic performance of children hospitalised with a chronic condition

OBJECTIVE

To examine academic outcomes among children hospitalised with a chronic health condition.

DESIGN

Population-level birth cohort.

SETTING

New South Wales, Australia.

PARTICIPANTS

397 169 children born 2000-2006 followed up to 2014.

INTERVENTION/EXPOSURE

Hospitalisations with a chronic condition.

MAIN OUTCOME MEASURES

Academic underperformance was identified as 'below the national minimum standard' (BNMS) in five literacy/numeracy domains using the national assessment (National Assessment Program-Literacy and Numeracy) data. Multivariable logistic regression assessed the adjusted ORs (aORs) of children performing BNMS in each domain at each grade (grades 3, 5 and 7, respectively).

RESULTS

Of children hospitalised with a chronic condition prior to National Assessment Program-Literacy and Numeracy (NAPLAN) (16%-18%), 9%-12% missed ≥1 test, with a maximum of 37% of those hospitalised ≥7 times, compared with 4%-5% of children not hospitalised. Excluding children who missed a NAPLAN test, more children hospitalised with a chronic condition performed BNMS across all domains and grades, compared with children not hospitalised (eg, for BNMS in reading at grade 3: n=2588, aOR 1.35 (95% CI 1.28 to 1.42); for BNMS in numeracy at grade 3: n=2619, aOR 1.51 (95% CI 1.43 to 1.59)). Increasing frequency and bed-days of hospitalisation were associated with 2-3 fold increased odds of performing BNMS across all domains and grades. Children hospitalised with mental health/behavioural conditions had the highest odds of performing BNMS across all domains at each grade.

CONCLUSIONS

Children hospitalised with a chronic condition underperform academically across literacy/numeracy domains at each school grade. Health and educational supports are needed to improve these children's academic outcomes.

Macrohistory of Moyamoya Disease Analyzed Using Artificial Intelligence

INTRODUCTION

Moyamoya disease is characterized by progressive stenotic changes in the terminal segment of the internal carotid artery and the development of abnormal vascular networks called moyamoya vessels. The objective of this review was to provide a holistic view of the epidemiology, etiology, clinical findings, treatment, and pathogenesis of moyamoya disease. A literature search was performed in PubMed using the term "moyamoya disease," for articles published until 2021.

RESULTS

Artificial intelligence (AI) clustering was used to classify the articles into 5 clusters: (1) pathophysiology (23.5%); (2) clinical background (37.3%); (3) imaging (13.2%); (4) treatment (17.3%); and (5) genetics (8.7%). Many articles in the "clinical background" cluster were published from the 1970s. However, in the "treatment" and "genetics" clusters, the articles were published from the 2010s through 2021. In 2011, it was confirmed that a gene called Ringin protein 213 (RNF213) is a susceptibility gene for moyamoya disease. Since then, tremendous progress in genomic, transcriptomic, and epigenetic profiling (e.g., methylation profiling) has resulted in new concepts for classifying moyamoya disease. Our literature survey revealed that the pathogenesis involves aberrations of multiple signaling pathways through genetic mutations and altered gene expression.

CONCLUSION

We analyzed the content vectors in abstracts using AI, and reviewed the pathophysiology, clinical background, radiological features, treatments, and genetic peculiarity of moyamoya disease.

Comparison of Absolute Dose Achievable Between Helical Tomotherapy and RapidArc in Total Dura Mater Irradiation for Child Cancer

Background and Purpose: In this study, the absolute dose achievable between helical tomotherapy (HT) plans and RapidArc (RA) plans for total dura mater irradiation (TDMI) was compared. Materials and methods: A planning study was conducted on nine children's case datasets with dura mater metastasis of neuroblastoma. The target included the entire calvarium and skull base and formed a closed volume with a certain thickness around the brain. HT and RA plans with four coplanar full arcs (RA4) with half-field technique were generated for the comparison of absolute dose achievable. In total, 30.6 Gy was prescribed as D_95% (ie, dose to 95% of PTV volume). Results: In the dosimetric comparison between the two modalities, HT provided more homogenous dose distribution than RA4 (mean HI_5−95%: 1.046 vs 1.088, P < .001). The V_107% and D_2Gy of PTV in HT versus RA4 were 3.06% versus 30.47% and 32.59 Gy versus 33.45 Gy, respectively. HT reduced the D_mean and V_5Gy of the brain, brainstem, and hippocampus by 25%–48% and 27%–56% compared with RA4, respectively. Conclusion: Both techniques could provide sufficient coverage for targets, but HT offered more homogenous dose to PTV and lower dose to the central region of the brain involving the brainstem and hippocampus. RA4 could be completed in a shorter time with lower MUs, but with relatively higher dose to the brain or hippocampus. In terms of dosimetry, HT may improve long-term cognitive decline in these young pediatric patients with TDMI.

Immunotherapy and Radioimmunotherapy for Desmoplastic Small Round Cell Tumor

Desmoplastic small round cell tumor (DRSCT) is a highly aggressive primitive sarcoma that primarily affects adolescent and young adult males. The 5-year survival rate is 15-30% and few curative treatment options exist. Although there is no standard treatment for DSRCT, patients are most often treated with a combination of aggressive chemotherapy, radiation, and surgery. Targeted therapy inhibitors of PDGFA and IGF-1R, which are almost uniformly overexpressed in DSRCT, have largely failed in clinical trials. As in cancer in general, interest in immunotherapy to treat DSRCT has increased in recent years. To that end, several types of immunotherapy are now being tested clinically, including monoclonal antibodies, radionuclide-conjugated antibodies, chimeric antigen receptor T cells, checkpoint inhibitors, and bispecific antibodies (BsAbs). These types of therapies may be particularly useful in DSRCT, which is frequently characterized by widespread intraperitoneal implants, which are difficult to completely remove surgically and are the frequent cause of relapse. Successful treatment with immunotherapy or radioimmunotherapy following debulking surgery could eradiate these micrometasteses and prevent relapse. Although there has been limited success to date for immunotherapy in pediatric solid tumors, the significant improvements in survival seen in the treatment of other pediatric solid tumors, such as metastatic neuroblastoma and its CNS spread, suggest a potential of immunotherapy and specifically compartmental immunotherapy in DSRCT.

Bridging the treatment gap in infant medulloblastoma: molecularly informed outcomes of a globally feasible regimen

BACKGROUND

Infant medulloblastoma represents an enormous challenge in neuro-oncology, due to their simultaneous high-risk of recurrence and high risk of severe neurodevelopmental sequelae with craniospinal irradiation. Currently infant medulloblastoma are treated with intensified protocols, either comprising intraventricular methotrexate or autologous transplant, both of which carry significant morbidity and are not feasible in the majority of the world. We sought to evaluate the molecular predictors of outcome in a cohort of infants homogeneously treated with induction chemotherapy, focal radiation and maintenance chemotherapy.

METHODS

In a retrospective analysis, 29 young children treated with a craniospinal irradiation sparing strategy from Hospital Garrahan in Buenos Aires were profiled using Illumina HumanMethylationEPIC arrays, and correlated with survival.

RESULTS

Twenty-nine children (range, 0.3-4.6 y) were identified, comprising 17 sonic hedgehog (SHH), 10 Group 3/4, and 2 non-medulloblastomas. Progression-free survival (PFS) across the entire cohort was 0.704 (95% CI: 0.551-0.899). Analysis by t-distributed stochastic neighbor embedding revealed 3 predominant groups, SHHβ, SHHγ, and Group 3. Survival by subtype was highly prognostic with SHHγ having an excellent 5-year PFS of 100% (95% CI: 0.633-1) and SHHβ having a PFS of 0.56 (95% CI: 0.42-1). Group 3 had a PFS of 0.50 (95% CI: 0.25-1). Assessment of neurocognitive outcome was performed in 11 patients; the majority of survivors fell within the low average to mild intellectual disability, with a median IQ of 73.5.

CONCLUSIONS

We report a globally feasible and effective strategy avoiding craniospinal radiation in the treatment of infant medulloblastoma, including a robust molecular correlation along with neurocognitive outcomes.

Pediatric CNS imaging and long-term effects of irradiation in pediatric oncology patients

BACKGROUND

The aim of this study was to evaluate post-irradiation changes in the central nervous system (CNS) detected using magnetic resonance (MR) imaging.

METHODS

Magnetic resonance images of 15 children with CNS tumors treated through whole-brain irradiation over 10 years were reviewed retrospectively. Variables such as age at the time of irradiation, total radiation dose, treatment length, and time interval between irradiation and MR changes, were evaluated.

RESULTS

All patients included in the study had imaging abnormalities of the CNS. Eight patients (53%) developed CNS abnormalities within a short period of time - only a few months after irradiation (mean 4.8 months). Seven patients (47%) developed CNS abnormalities within a long time interval after treatment (mean 4.6 years). In almost all patients, a T2 increase in supra- and infratentorial white matter was observed. Follow-up examinations showed nine patients (60%) with cerebellar atrophy.

CONCLUSIONS

In this sample of pediatric patients who underwent whole-brain irradiation, the time receiving irradiation was not related to the severity of the MR changes. A correlation between the age of the child or the length of the radiotherapy and the extent of the changes could not be confirmed. However, we observed a trend towards stronger brain parenchymal degeneration with cystic changes in the younger age group of children in our sample. Older children who received irradiation seem to be more susceptible to vascular dysplasia with cavernous hemangiomas and microbleeding.

Cognitive functions of children with brain tumor in the treatment process

Introduction

This study assesses the cognitive functions of children with brain tumor, including orientation, spatial perception, praxis, visuomotor constructions and thinking operations. The aim of the study was to assess the cognitive functions of children with brain tumor in the treatment process and the effects of different treatments on cognitive functionality.

Method

Cognitive functions of children with brain tumor ( n = 102) and children with typical development ( n = 90) were assessed with the Dynamic Occupational Therapy Assessment for Children. Children with brain tumor were divided into four subgroups according to the treatment they received. Multiple comparisons were analyzed using the Kruskal–Wallis test and binary comparisons were analyzed using the Mann–Whitney U test.

Results

Cognitive functions of children with brain tumor were weaker than children with typical development. Children who received chemotherapy, radiotherapy, surgery and both chemotherapy and radiotherapy had weaker cognitive functions.

Conclusions

Children with brain tumor whose treatment process is continuing are cognitively affected and their occupational performance in daily living tasks is weakened. In these children, cognitive- and occupation-based early intervention approaches should be developed and implemented. Especially when children start receiving radiotherapy, it may also be useful to start cognitive occupational therapy programs simultaneously for preserving children’s cognitive functionality.

Pituitary germinomas: a multi-institutional study analyzing patient demographics and management patterns

PURPOSE

Intracranial germinomas are exceedingly rare tumors found in the pineal and suprasellar regions. The extremely low incidence of pituitary germinoma has resulted in a significant gap in knowledge regarding its demographics, management, and treatment outcomes. We present the largest multicenter analysis of pituitary germinomas to date, focused on analyzing demographic and management patterns.

METHODS

This study utilizes the National Cancer Institute's Surveillance, Epidemiology, and End Results (SEER) program (2004-2016) to study patients with a primary intracranial germinoma of the pituitary gland. We analyzed demographic information and management strategies among adult and pediatric populations and conducted a 20-year overall survival analysis using Kaplan-Meier curve for a descriptive evaluation of survival outcomes between age groups and treatment groups.

RESULTS

92 patients were included in the study, consisting of 58% pediatric patients and 42% adults, with overall 60% males. 82% patients received radiation as part of the treatment, with no significant difference between pediatric and adult groups. Chemotherapy was used significantly more in pediatrics (p = 0.0002) while surgery was significantly more common in adults (p = 0.0117). The most common treatment in pediatrics was radiation + chemotherapy (47%), while the most common treatment in adults was radiation + gross total resection + chemotherapy (23%) followed by radiation + gross total resection (19%). Younger age, radiotherapy, and chemotherapy were associated with increased 20-year survival on Kaplan-Meier curves.

CONCLUSIONS

There exist significant differences in the management of pediatric and adult populations with pituitary germinomas. The low incidence of these tumors makes them challenging to study, but also highlights the importance of national cancer registries in amassing sufficient patient data from which to draw evidence-based conclusions.

Assessing changes in microstructural integrity of white matter tracts in children with leukaemia following exposure to chemotherapy

BACKGROUND

Intrathecal and intravenous chemotherapy, specifically methotrexate, might contribute to neural microstructural damage.

OBJECTIVE

To assess, by diffusion tensor imaging, microstructural integrity of white matter in paediatric patients with acute lymphoblastic leukaemia (ALL) following intrathecal and intravenous chemotherapy.

MATERIALS AND METHODS

Eleven children diagnosed with de novo ALL underwent MRI scans of the brain with diffusion tensor imaging (DTI) prior to commencement of chemotherapy and at 12 months after diagnosis, using a 3-tesla (T) MRI scanner. We investigated the changes in DTI parameters in white matter tracts before and after chemotherapy using tract-based spatial statistics overlaid on the International Consortium of Brain Mapping DTI-81 atlas. All of the children underwent formal neurodevelopmental assessment at the two study time points.

RESULTS

Whole-brain DTI analysis showed significant changes between the two time points, affecting several white matter tracts. The tracts demonstrated longitudinal changes of decreasing mean and radial diffusivity. The neurodevelopment of the children was near compatible for age at the end of ALL treatment.

CONCLUSION

The quantification of white matter tracts changes in children undergoing chemotherapy showed improving longitudinal values in DTI metrics (stable fractional anisotropy, decreasing mean and radial diffusivity), which are incompatible with deterioration of microstructural integrity in these children.

Neuroprotection of Radiosensitive Juvenile Mice by Ultra-High Dose Rate FLASH Irradiation

Major advances in high precision treatment delivery and imaging have greatly improved the tolerance of radiotherapy (RT); however, the selective sparing of normal tissue and the reduction of neurocognitive side effects from radiation-induced toxicities remain significant problems for pediatric patients with brain tumors. While the overall survival of pediatric patients afflicted with medulloblastoma (MB), the most common type primary brain cancer in children, remains high (≥80%), lifelong neurotoxic side-effects are commonplace and adversely impact patients’ quality of life. To circumvent these clinical complications, we have investigated the capability of ultra-high dose rate FLASH-radiotherapy (FLASH-RT) to protect the radiosensitive juvenile mouse brain from normal tissue toxicities. Compared to conventional dose rate (CONV) irradiation, FLASH-RT was found to ameliorate radiation-induced cognitive dysfunction in multiple independent behavioral paradigms, preserve developing and mature neurons, minimize microgliosis and limit the reduction of the plasmatic level of growth hormone. The protective “FLASH effect” was pronounced, especially since a similar whole brain dose of 8 Gy delivered with CONV-RT caused marked reductions in multiple indices of behavioral performance (objects in updated location, novel object recognition, fear extinction, light-dark box, social interaction), reductions in the number of immature (doublecortin⁺) and mature (NeuN⁺) neurons and increased neuroinflammation, adverse effects that were not found with FLASH-RT. Our data point to a potentially innovative treatment modality that is able to spare, if not prevent, many of the side effects associated with long-term treatment that disrupt the long-term cognitive and emotional well-being of medulloblastoma survivors.

Functional equivalence of stem cell and stem cell-derived extracellular vesicle transplantation to repair the irradiated brain

Cranial radiotherapy, although beneficial for the treatment of brain tumors, inevitably leads to normal tissue damage that can induce unintended neurocognitive complications that are progressive and debilitating. Ionizing radiation exposure has also been shown to compromise the structural integrity of mature neurons throughout the brain, an effect believed to be at least in part responsible for the deterioration of cognitive health. Past work has shown that cranially transplanted human neural stem cells (hNSCs) or their extracellular vesicles (EVs) afforded long-term beneficial effects on many of these cognitive decrements. To provide additional insight into the potential neuroprotective mechanisms of cell-based regenerative strategies, we have analyzed hippocampal neurons for changes in structural integrity and synaptic remodeling after unilateral and bilateral transplantation of hNSCs or EVs derived from those same cells. Interestingly, hNSCs and EVs similarly afforded protection to host neurons, ameliorating the impact of irradiation on dendritic complexity and spine density for neurons present in both the ipsilateral and contralateral hippocampi 1 month following irradiation and transplantation. These morphometric improvements were accompanied by increased levels of glial cell-derived growth factor and significant attenuation of radiation-induced increases in postsynaptic density protein 95 and activated microglia were found ipsi- and contra-lateral to the transplantation sites of the irradiated hippocampus treated with hNSCs or hNSC-derived EVs. These findings document potent far-reaching neuroprotective effects mediated by grafted stem cells or EVs adjacent and distal to the site of transplantation and support their potential as therapeutic agents to counteract the adverse effects of cranial irradiation.

Nystagmus in the Diagnosis of Russell Diencephalic Syndrome

Russell diencephalic syndrome is a condition in which infants become emaciated in the setting of a decreased or normal caloric intake as the result of a hypothalamic astrocytoma. The diagnosis may be delayed if providers initially attribute the symptoms to a behavioral disorder. The detection of nystagmus, which is present in many patients, may be a critical diagnostic clue. The authors describe two patients in whom the discovery of nystagmus months after the onset of emaciation led to the diagnosis of Russell diencephalic syndrome. [J Pediatr Ophthalmol Strabismus. 2019;56:e79-e83.].

Tumor bed proton irradiation in young children with localized medulloblastoma

BACKGROUND

Radiotherapy is often deferred in very young children with medulloblastoma, in favor of more intense chemotherapy and stem cell rescue; however, posterior fossa radiation has been shown to improve overall survival (OS) and event-free survival compared with adjuvant chemotherapy alone. This study was performed to assess the OS, recurrence-free survival (RFS), patterns of failure, and clinical toxicity for children aged five and under who received focal proton radiation to the tumor bed alone.

PROCEDURE

From 2010 to 2017, 14 patients with newly diagnosed medulloblastoma at one institution received tumor bed irradiation following surgery and chemotherapy. The median age of the patients was 40 months (range, 10.9-62.9 months).

RESULTS

With a median follow-up of 54 months, four patients relapsed: three within the central nervous system (CNS) outside of the posterior fossa, and one within the tumor bed after subtotal resection. All relapses occurred within 28 months after the completion of radiation therapy. Five-year OS and RFS for this cohort of patients were 84% (95% CI, 48%-96%) and 70% (95% CI, 38%-88%), respectively. One patient experienced significant tumor regrowth soon after completion of radiation, autopsy showed viable tumor and necrosis near and within the brainstem, with relation to radiation unknown; however, no other acute clinical toxicities greater than grade 2 were observed in this group of patients. In the nine patients with available performance status follow-up, no significant changes in Lansky performance status were observed.

CONCLUSIONS

Five-year OS and RFS following tumor bed irradiation in young children with medulloblastoma appear to be improved compared with other studies that forego the use of radiation therapy in this patient population. This approach should be further investigated in young children with medulloblastoma.

Hyperthermia Treatment Planning Including Convective Flow in Cerebrospinal Fluid for Brain Tumour Hyperthermia Treatment Using a Novel Dedicated Paediatric Brain Applicator

Hyperthermia therapy (40-44 °C) is a promising option to increase efficacy of radiotherapy/chemotherapy for brain tumours, in particular paediatric brain tumours. The Chalmers Hyperthermia Helmet is developed for this purpose. Hyperthermia treatment planning is required for treatment optimisation, but current planning systems do not involve a physically correct model of cerebrospinal fluid (CSF). This study investigates the necessity of fluid modelling for treatment planning. We made treatments plans using the Helmet for both pre-operative and post-operative cases, comparing temperature distributions predicted with three CSF models: a convective "fluid" model, a non-convective "solid" CSF model, and CSF models with increased effective thermal conductivity ("high-k"). Treatment plans were evaluated by T90, T50 and T10 target temperatures and treatment-limiting hot spots. Adequate heating is possible with the helmet. In the pre-operative case, treatment plan quality was comparable for all three models. In the post-operative case, the high-k models were more accurate than the solid model. Predictions to within ±1 °C were obtained by a 10-20-fold increased effective thermal conductivity. Accurate modelling of the temperature in CSF requires fluid dynamics, but modelling CSF as a solid with enhanced effective thermal conductivity might be a practical alternative for a convective fluid model for many applications.

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

Background

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

Methods

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

Results

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

Conclusions

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

Neuroimaging of the component white matter connections and structures within the cerebellar-frontal pathway in posterior fossa tumor survivors

Introduction

In posterior fossa tumor survivors, lower white matter integrity (WMI) in the right cerebellar-left frontal pathway has been well documented and appears to be related to proximity to the cerebellum, radiation treatment, as well as time since treatment in both cranial radiation and surgery-only treatment groups. The current study investigated theories of transneural degeneration following cerebellar tumor resection that may underlie or relate to reductions in WMI and regional brain volumes using correlations. We hypothesized a positive relationship between the volume of the right cerebellum and known white matter output pathways, as well as with the volume of structures that receive cerebellar projections along the pathway.

Methods

Adult survivors of childhood brain tumors were recruited (n = 29; age, M = 22 years, SD = 5; 45% female). Age- and gender-matched controls were also included (n = 29). Participants completed 3 T diffusion-weighted and T1 MPRAGE MRI scans. Brain structure volume relative to intracranial vault served as regional volumetric measures. Fractional anisotropy (FA) and radial diffusivity (RD) served as WMI measures. In the survivor group, partial correlations between WMI and regional volume included controlling for disease severity.

Results

In posterior fossa tumor survivors, the volumes of the cerebellum, thalamus, and frontal lobe were correlated with WMI of the thalamic-frontal segment of the cerebellar-frontal pathway (r = 0.41–0.49, p < .05). Cerebellar atrophy was correlated with reduced WMI in the cerebellar-rubral segment (FA, r = −0.32 p > .05; RD, r = 0.53, p < .01). In the no-radiation survivor group, the regional volume of each structure along the pathway was associated with WMI in the cerebellar-rubral segment. In the radiation survivor group, significant correlations were found between the regional brain volume of each structure and the thalamic-frontal segment of the pathway.

Discussion

The results of this multimodal neuroimaging study provide correlational evidence that the mechanism of injury subsequent to brain tumor treatment may be different depending on type of treatment(s). Without radiation, the primary mechanism of injury is cerebellar tumor growth, resection, and hydrocephalus. Therefore, the most proximal connection to that injury (cerebellar-rubral pathway) was correlated with reductions in volume along the pathway. In contrast, the survivor group treated with radiation may have had possible radiation-induced demyelination of the thalamic-frontal portion of the pathway, based on a strong correlation with volume loss in the cerebellum, red nucleus, thalamus, and frontal lobe.

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Cerebellar atrophy predicted lower white matter integrity (WMI) in the cerebellar-rubral segment.

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The no-radiation group showed a correlational pattern that is consistent with possible transneural degeneration.

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The radiation group showed a correlational pattern consistent with theories of neurodevelopmental vulnerability to radiation-induced demyelination.

Management for Different Glioma Subtypes: Are All Low-Grade Gliomas Created Equal?

Following the identification of key molecular alterations that provided superior prognostication and led to the updated 2016 World Health Organization (WHO) Central Nervous System (CNS) Tumor Classification, the understanding of glioma behavior has rapidly evolved. Mutations in isocitrate dehydrogenase (IDH) 1 and 2 are present in the majority of adult grade 2 and 3 gliomas, and when used in conjunction with 1p/19q codeletion for classification, the prognostic distinction between grade 2 versus grade 3 is diminished. As such, the previously often used term of "low-grade glioma," which referred to grade 2 gliomas, has now been replaced by the phrase "lower-grade glioma" to encompass both grade 2 and 3 tumors. Additional molecular characterization is ongoing to even further classify this heterogeneous group of tumors. With such a colossal shift in the understanding of lower-grade gliomas, management of disease is being redefined in the setting of emerging molecular-genetic biomarkers. In this article, we review recent progress and future directions regarding the surgical, radiotherapeutic, chemotherapeutic, and long-term management of adult lower-grade gliomas.

Outcomes After Gamma Knife Stereotactic Radiosurgery in Pediatric Patients with Cushing Disease or Acromegaly: A Multi-Institutional Study

OBJECTIVE

Pituitary adenomas comprise about 3% of all intracranial tumors in pediatric patients. This study examines the role of stereotactic radiosurgery in the management of pediatric acromegaly or patients with Cushing disease (CD).

METHODS

From an international consortium, we retrospectively collected treatment and outcome data on pediatric adrenocorticotrophic hormone and growth hormone-secreting pituitary adenomas treated with Gamma Knife radiosurgery (GKRS). There were a total of 36 patients including 24 with CD and 12 with acromegaly. The data were analyzed to assess outcomes including tumor control, endocrine remission, and adverse effects. Statistical analysis was performed to determine correlation between clinical/treatment parameters and outcomes.

RESULTS

At the last follow-up after GKRS, endocrine remission rates for CD and acromegaly were 80% and 42%, respectively. Tumor control was achieved in 87.5% of patients with CD and in 42% of patients with acromegaly. New pituitary hormone deficiency occurred in 7 of the 36 patients at a median time of 18 months after GKRS (range, 12-81 months). The predictive factors for endocrine remission were age <15 years (P = 0.015) and margin dose (P = 0.042). The median endocrine follow-up was 63.7 months (range, 7-246 months).

CONCLUSIONS

GKRS affords reasonable rates of endocrine remission and tumor control in most pediatric patients with functioning adenomas. The most common post-GKRS complication was hypopituitarism, although this occurred in only a few patients. Given the larger at-risk period for pediatric patients, further study is required to evaluate for delayed recurrences and hypopituitarism.

Radiation resistance of normal human astrocytes: the role of non-homologous end joining DNA repair activity

Radiotherapy is a common modality for treatment of brain cancers, but it can induce long-term physiological and cognitive deficits. The responses of normal human brain cells to radiation is not well understood. Astrocytes have been shown to have a variety of protective mechanisms against oxidative stress and have been shown to protect neurons. We investigated the response of cultured normal human astrocytes (NHAs) to X-ray irradiation. Following exposure to 10 Gy X-irradiation, NHAs exhibited DNA damage as indicated by the formation of γ-H2AX foci. Western blotting showed that NHAs displayed a robust increase in expression of non-homologous end joining DNA repair enzymes within 15 min post-irradiation and increased expression of homologous recombination DNA repair enzymes ~2 h post-irradiation. The cell cycle checkpoint protein p21/waf1 was upregulated from 6-24 h, and then returned to baseline. Levels of DNA repair enzymes returned to basal ~48 h post-irradiation. NHAs re-entered the cell cycle and proliferation was observed at 6 days. In contrast, normal human mesenchymal stem cells (MSCs) failed to upregulate DNA repair enzymes and instead displayed sustained upregulation of p21/waf1, a cell cycle checkpoint marker for senescence. Ectopic overexpression of Ku70 was sufficient to protect MSCs from sustained upregulation of p21/waf1 induced by 10 Gy X-rays. These findings suggest that increased expression of Ku70 may be a key mechanism for the radioresistance of NHAs, preventing their accelerated senescence from high-dose radiation. These results may have implications for the development of novel targets for radiation countermeasure development.

Osteogenic sarcoma of the skull: long-term outcome of a rare tumor

BACKGROUND

Osteogenic sarcoma of the skull is uncommon and long-term outcome is not well defined. We review the literature and present a pediatric case of calvarial osteogenic sarcoma with good long-term oncological and cosmetic outcome and excellent quality of life. This case presented major surgical challenges, which are detailed.

CASE DESCRIPTION

A 6-year-old boy presented with a painless 5 cm × 5 cm lump over the vertex region. He was neurologically normal. Imaging showed an extensive bony lesion with intradural extension. After incisional biopsy showed probable low grade osteosarcoma, a complete en bloc resection with margins was attempted via a concentric craniotomy around the lesion after embolization to reduce blood loss. Invasion of the brain by the tumor precluded the complete en bloc resection, but gross total resection was achieved. The final pathology was consistent with a low-grade osteosarcoma and adjuvant chemotherapy was provided. Follow-up for 8 years has shown no recurrence with good cosmetic and functional outcome.

The effect of brain-derived neurotrophic factor on radiation-induced neuron architecture impairment is associated with the NFATc4/3 pathway

Irradiation to developing brains results in progressive cognitive dysfunction. Changes in the morphology of mature neurons are thought to be related to impairments of cognitive function. However, little is known about the effects of radiation on neurite outgrowth of immature neurons. Therefore, we sought to evaluate the structural alterations of immature neurons following X-ray irradiation and determine potential strategies to reverse it. Our data revealed damage to the neurite outgrowths of cultured neurons after 2 Gy and 8 Gy irradiation at 1 d and 3 d, respectively. De-phosphorylation of nuclear factor of activated T-cells c4/3 (NFATc4/3) was inhibited post-irradiation. Extraneous brain-derived neurotrophic factor (BDNF) ameliorated impairment of neurite growth and activated the NFATc4/3 signaling pathway. These data indicate that BDNF confers neuroprotective effects against irradiation by modulating the NFATc4/3 pathway.

Stem Cell Therapies for the Resolution of Radiation Injury to the Brain

Purpose of review

To encapsulate past and current research efforts focused on stem cell transplantation strategies to resolve radiation-induced cognitive dysfunction.

Recent Findings

Transplantation of human stem cells in the irradiated brain was first shown to resolve radiation-induced cognitive dysfunction in a landmark paper by Acharya et al., appearing in PNAS in 2009. Since that time, work from the same laboratory as well as other groups have reported on the beneficial (as well as detrimental) effects of stem cell grafting after cranial radiation exposure. Improved learning and memory found many months after engraftment has since been associated with a preservation of host neuronal morphology, a suppression of neuroinflammation, improved myelination and increased cerebral blood flow. Interestingly, many (if not all) of these beneficial effects can be demonstrated by substituting stem cells with microvesicles derived from human stem cells during transplantation, thereby eliminating many of the more long-standing concerns related to immunorejection and teratoma formation.

Summary

Stem cell and microvesicle transplantation into the irradiated brain of rodents has uncovered some unexpected benefits that hold promise for ameliorating many of adverse neurocognitive complications associated with major cancer treatments. Properly developed, such approaches may provide much needed clinical recourse to millions of cancer survivors suffering from the unintended side effects of their cancer therapies.

Treatment of pediatric average-risk medulloblastoma using craniospinal irradiation less than 2500 cGy and chemotherapy: single center experience in Korea

BACKGROUND

Although craniospinal irradiation (CSI) of 2340 cGy plus tumor booster with chemotherapy have been established as a standard treatment of childhood average-risk (AvR) medulloblastoma (MBL) in Western counties, there are a few recent reports in outcomes of AvR MBL using this strategy in Korean and other Asian children. We investigated the outcome of the Korean children with AvR MBL who were treated with CSI <2500 cGy and chemotherapy.

METHODS

Between January 2001 and December 2010, clinical characteristics and outcomes of 42 patients who were diagnosed with AvR MBL postoperatively and treated with radiation including CSI <2500 cGy and chemotherapy in Seoul National University Children's Hospital were analyzed.

RESULTS

Their median age was 9 years (range: 3-18.8), and 29 were male. Histological subtypes were classic type in 28 patients, nodular/desmoplastic in 7, and large cell/anaplastic (LCA) in 7. All the patients received adjuvant radiotherapy (CSI with median 2340 cGy and booster) and multiagent chemotherapy as the first-line treatment. With a median follow-up of 54 months, 12 patients experienced relapse or progression of the tumor. The 3- and 5-year disease-free survival (DFS) rates were 78.0%±6.5% and 75.0%±6.9%, respectively, and overall survival (OS) rates were 85.3%±5.6% and 76.8%±6.9%, respectively. The LCA subtype was associated with poorer DFS (P=0.023) and OS (P=0.008), compared with non-LCA subtypes.

CONCLUSIONS

The outcomes of children and adolescents with AvR MBL treated with radiation including CSI <2500 cGy and chemotherapy, are compatible to those in Western countries; however, the LCA subtype has a poor outcome with this strategy.

Lithium protects hippocampal progenitors, cognitive performance and hypothalamus-pituitary function after irradiation to the juvenile rat brain

Cranial radiotherapy in children typically causes delayed and progressive cognitive dysfunction and there is no effective preventive strategy for radiation-induced cognitive impairments. Here we show that lithium treatment reduced irradiation-induced progenitor cell death in the subgranular zone of the hippocampus, and subsequently ameliorated irradiation-reduced neurogenesis and astrogenesis in the juvenile rat brain. Irradiation-induced memory impairment, motor hyperactivity and anxiety-like behaviour were normalized by lithium treatment. Late-onset irradiation-induced hypopituitarism was prevented by lithium treatment. Additionally, lithium appeared relatively toxic to multiple cultured tumour cell lines, and did not improve viability of radiated DAOY cells in vitro. In summary, our findings demonstrate that lithium can be safely administered to prevent both short- and long-term injury to the juvenile brain caused by ionizing radiation.

Serum concentrations of the axonal injury marker neurofilament light protein are not influenced by blood-brain barrier permeability

A blood biomarker to monitor individual susceptibility to neuronal injury from cranial radiotherapy could potentially help to individualize radiation treatment and thereby reduce the incidence and severity of late effects. An important feature of such a blood biomarker is that its concentration is not confounded by varying degrees of release from the brain into the blood across the blood-brain barrier (BBB). In this study, we investigated serum neurofilament light protein (NFL) concentrations in 21-day old mice following a single dose of cranial irradiation (8Gy). Cranial irradiation resulted in acute cell injury measured as a 12.9-fold increase in caspase activity 6h after irradiation; activation of inflammation measured by levels of CCL2 and increased BBB permeability measured by ¹⁴C-sucrose concentration ratios in brain and cerebrospinal fluid (CSF). Serum levels of NFL peaked at 6h after both anesthesia and cranial irradiation, but no timely correlation of serum NFL concentration with BBB permeability was found. Further, three groups of patients with different degrees of BBB impairment (measured as the CSF/serum albumin ratio) were investigated. There was no correlation between serum NFL concentration and CSF/serum albumin ratio (r=0.139, p=0.3513), however a strong correlation was found for NFL concentration in serum and NFL concentration in CSF (r=0.6303, p<0.0001). In conclusion, serum NFL appears to be a reliable blood biomarker for neuronal injury, and its concentration is not confounded by BBB permeability.

Ionizing Radiation-Induced Immune and Inflammatory Reactions in the Brain

Radiation-induced late brain injury consisting of vascular abnormalities, demyelination, white matter necrosis, and cognitive impairment has been described in patients subjected to cranial radiotherapy for brain tumors. Accumulating evidence suggests that various degrees of cognitive deficit can develop after much lower doses of ionizing radiation, as well. The pathophysiological mechanisms underlying these alterations are not elucidated so far. A permanent deficit in neurogenesis, chronic microvascular alterations, and blood–brain barrier dysfunctionality are considered among the main causative factors. Chronic neuroinflammation and altered immune reactions in the brain, which are inherent complications of brain irradiation, have also been directly implicated in the development of cognitive decline after radiation. This review aims to give a comprehensive overview on radiation-induced immune alterations and inflammatory reactions in the brain and summarizes how these processes can influence cognitive performance. The available data on the risk of low-dose radiation exposure in the development of cognitive impairment and the underlying mechanisms are also discussed.

Osteoblastic differentiation and cell calcification of adamantinomatous craniopharyngioma induced by bone morphogenetic protein-2

BACKGROUND

The calcification of adamantinomatous craniopharyngioma (ACP) often creates difficulties for surgical therapy. Nevertheless, the mechanism of ACP calcification is unclear. Our previous studies demonstrated that osteoblastic factors might play important roles in ACP calcification.

OBJECTIVE

We examined the effects of recombinant human Bmp2 on ACP cell differentiation by testing osteoblastic proteins and calcium deposition.

METHODS

The expression of osteoblastic factors including osteopontin (OPN), Runx2, and osterix in Bmp2-treated ACP cells was examined by western blot and/or real time PCR. ALP activity and calcium deposition after Bmp2 induction were also tested.

RESULTS

Bmp2 significantly amplified the expression of Runx2, Osterix and OPN, as well as ALP activity. Both of these effects could be repressed by noggin treatment. Bmp2 also significantly induced the calcification of ACP, and noggin inhibited this calcium deposition.

CONCLUSION

Our study demonstrated for the first time that ACP cells could differentiate into an osteoblastic lineage via induction by Bmp2. The mechanism of ACP calcification likely involves osteoblastic differentiation modulated by Bmp2. Further studies targeting Bmp2 cascades could result in novel therapeutic interventions for recurrent ACP.

Impact of chronic disease on emotional distress in adult survivors of childhood cancer: A report from the Childhood Cancer Survivor Study

BACKGROUND

The current study was performed to examine associations between childhood cancer therapies, chronic health conditions, and symptoms of emotional distress in adult survivors of childhood cancer.

METHODS

Participants included 5021 adult survivors of childhood cancer (mean age, 32.0 years [standard deviation, 7.6 years] with a time since diagnosis of 23.2 years [standard deviation, 4.5 years]) who completed measures assessing symptoms of anxiety, depression, and posttraumatic stress. Cardiac, pulmonary, and endocrine conditions were graded using the National Cancer Institute Common Terminology Criteria for Adverse Events (version 4.03; grades 1-4). Structural equation modeling was used to examine hypothesized pathways between cancer treatment exposures, chronic health conditions, and symptoms of emotional distress. Multivariable models were used to estimate relative risks (RRs) for associations between chronic health conditions and distress.

RESULTS

Survivors with cardiovascular, endocrine, or pulmonary conditions were found to have a significantly higher prevalence of emotional distress symptoms. In path analyses and multivariable models, significant effects were observed between endocrine (β = .12 [P = .002] and RR, 1.3 [95% confidence interval (95% CI), 1.1-1.6]) and pulmonary (β = .13 [P<.001] and RR, 1.4 [95% CI, 1.1-1.7]) conditions and depression, and between cardiac (β = .13 [P = .001] and RR, 1.5 [95% CI, 1.2-1.8]) and pulmonary (β = .15 [P<.001] and RR, 1.6 [95% CI, 1.3-2.0]) conditions and anxiety. All treatment-related chronic health conditions were found to be associated with posttraumatic stress symptoms (cardiac: β = .09 [P = .004] and RR, 1.3 [95% CI, 1.2-1.5]; endocrine: β = .12 [P<.001] and RR, 1.3 [95% CI, 1.2-1.5]; and pulmonary: β = .13 [P<.001] and RR, 1.4 [95% CI, 1.2-1.6]).

CONCLUSIONS

Chronic health conditions resulting from childhood cancer therapies contribute to emotional distress in adult survivors. Targeted mental health screening efforts in this at-risk population appear warranted. Therapeutic approaches should consider the complex interplay between chronic health conditions and symptoms of emotional distress. Cancer 2017;123:521-528. © 2016 American Cancer Society.

Valproic acid enhances the efficacy of radiation therapy by protecting normal hippocampal neurons and sensitizing malignant glioblastoma cells

Neurocognitive deficits are serious sequelae that follow cranial irradiation used to treat patients with medulloblastoma and other brain neoplasms. Cranial irradiation causes apoptosis in the subgranular zone of the hippocampus leading to cognitive deficits. Valproic acid (VPA) treatment protected hippocampal neurons from radiation-induced damage in both cell culture and animal models. Radioprotection was observed in VPA-treated neuronal cells compared to cells treated with radiation alone. This protection is specific to normal neuronal cells and did not extend to cancer cells. In fact, VPA acted as a radiosensitizer in brain cancer cells. VPA treatment induced cell cycle arrest in cancer cells but not in normal neuronal cells. The level of anti-apoptotic protein Bcl-2 was increased and the pro-apoptotic protein Bax was reduced in VPA treated normal cells. VPA inhibited the activities of histone deacetylase (HDAC) and glycogen synthase kinase-3β (GSK3β), the latter of which is only inhibited in normal cells. The combination of VPA and radiation was most effective in inhibiting tumor growth in heterotopic brain tumor models. An intracranial orthotopic glioma tumor model was used to evaluate tumor growth by using dynamic contrast-enhanced magnetic resonance (DCE MRI) and mouse survival following treatment with VPA and radiation. VPA, in combination with radiation, significantly delayed tumor growth and improved mouse survival. Overall, VPA protects normal hippocampal neurons and not cancer cells from radiation-induced cytotoxicity both in vitro and in vivo. VPA treatment has the potential for attenuating neurocognitive deficits associated with cranial irradiation while enhancing the efficiency of glioma radiotherapy.

Intellectual development of childhood ALL patients: a multicenter longitudinal study

BACKGROUND

In childhood acute lymphoblastic leukemia (ALL), radiotherapy for CNS prophylaxis is not used in frontline therapy anymore. Standard treatment for ALL nowadays consists of polychemotherapy. Therefore, assessment of potential chemotherapy-induced cognitive side effects becomes important. Although neurotoxicity was demonstrated in cross-sectional studies, longitudinal studies remain scarce.

PROCEDURE

We evaluated intellectual development of 94 pediatric ALL patients between 1990 and 1997, diagnosed before the age of 12 years, treated according to the European Organisation for Research and Treatment of Cancer Children's Leukemia Group 58881 protocol. Three assessments of the Wechsler Intelligence Scale for Children Revised were performed since diagnosis, according to age. Using repeated measures regression analysis, we investigated the effect of gender (low versus increased) risk group, parents' education, age at diagnosis, intelligence quotient (IQ) subscale (verbal (VIQ) versus performance (PIQ) intelligence), and test session.

RESULTS

PIQ scores were lower than VIQ at baseline (-5.3 points on average, p = 0.0032), yet PIQ increased more strongly (PIQ: +3.9 points per test session; VIQ: +0.8, p = 0.0079), so this baseline difference disappeared (p = 0.0079). There were no clear effects of gender (girls: +0.6 points; p = 0.78) or risk group (low risk: +1.5 points; p = 0.49), but IQ scores were higher when one parent had followed higher education (+9.5 points, p < 0.0001). Finally, diagnosis at younger age predicted lower IQ scores (-1.3 points per year, p = 0.0009).

CONCLUSION

Given that IQ scores did not decline, our findings demonstrate a stable pattern. However, the lower PIQ scores at baseline may indicate that performance functioning is vulnerable to acute neurotoxicity. Also, lower scores for younger patients highlight the stronger impact of the disease and/or treatment at younger age.Copyright © 2016 John Wiley & Sons, Ltd.

Chemotherapy-induced neurotoxicity in pediatric solid non-CNS tumor patients: An update on current state of research and recommended future directions

Neurocognitive sequelae are known to be induced by cranial radiotherapy and central-nervous-system-directed chemotherapy in childhood Acute Lymphoblastic Leukemia (ALL) and brain tumor patients. However, less evidence exists for solid non-CNS-tumor patients. To get a better understanding of the potential neurotoxic mechanisms of non-CNS-directed chemotherapy during childhood, we performed a comprehensive literature review of this topic. Here, we provide an overview of preclinical and clinical studies investigating neurotoxicity associated with chemotherapy in the treatment of pediatric solid non-CNS tumors. Research to date suggests that chemotherapy has deleterious biological and psychological effects, with animal studies demonstrating histological evidence for neurotoxic effects of specific agents and human studies demonstrating acute neurotoxicity. Although the existing literature suggests potential neurotoxicity throughout neurodevelopment, research into the long-term neurocognitive sequelae in survivors of non-CNS cancers remains limited. Therefore, we stress the critical need for neurodevelopmental focused research in children who are treated for solid non-CNS tumors, since they are at risk for potential neurocognitive impairment.

Unique epigenetic influence of H2AX phosphorylation and H3K56 acetylation on normal stem cell radioresponses

Normal stem cells from tissues often exhibiting radiation injury are highly radiosensitive and exhibit a muted DNA damage response, in contrast to differentiated progeny. These radioresponses can be attributed to unique epigenetic regulation in stem cells, identifying potential therapeutic targets for radioprotection.

Normal tissue injury resulting from cancer radiotherapy is often associated with diminished regenerative capacity. We examined the relative radiosensitivity of normal stem cell populations compared with non–stem cells within several radiosensitive tissue niches and culture models. We found that these stem cells are highly radiosensitive, in contrast to their isogenic differentiated progeny. Of interest, they also exhibited a uniquely attenuated DNA damage response (DDR) and muted DNA repair. Whereas stem cells exhibit reduced ATM activation and ionizing radiation–induced foci, they display apoptotic pannuclear H2AX-S139 phosphorylation (γH2AX), indicating unique radioresponses. We also observed persistent phosphorylation of H2AX-Y142 along the DNA breaks in stem cells, which promotes apoptosis while inhibiting DDR signaling. In addition, down-regulation of constitutively elevated histone-3 lysine-56 acetylation (H3K56ac) in stem cells significantly decreased their radiosensitivity, restored DDR function, and increased survival, signifying its role as a key contributor to stem cell radiosensitivity. These results establish that unique epigenetic landscapes affect cellular heterogeneity in radiosensitivity and demonstrate the nonubiquitous nature of radiation responses. We thus elucidate novel epigenetic rheostats that promote ionizing radiation hypersensitivity in various normal stem cell populations, identifying potential molecular targets for pharmacological radioprotection of stem cells and hopefully improving the efficacy of future cancer treatment.

Late Effects of Treatment of Pediatric Central Nervous System Tumors

Central nervous system tumors represent the most common solid malignancy in childhood. Improvement in treatment approaches have led to a significant increase in survival rates, with over 70% of children now surviving beyond 5 years. As more and more children with CNS tumors have longer survival times, it is important to be aware of the long-term morbidities caused not only by the tumor itself but also by tumor treatment. The most common side effects including poor neurocognition, endocrine dysfunction, neurological and vascular late effects, as well as secondary malignancies, are discussed within this article.

Cognitive dysfunction in children with brain tumors at diagnosis

BACKGROUND

Survivors of brain tumors have a high risk for a wide range of cognitive problems. These dysfunctions are caused by the lesion itself and its surgical removal, as well as subsequent treatments (chemo- and/or radiation therapy). Multiple recent studies have indicated that children with brain tumors (BT) might already exhibit cognitive problems at diagnosis, i.e., before the start of any medical treatment. The aim of the present study was to investigate the baseline neuropsychological profile in children with BT compared to children with an oncological diagnosis not involving the central nervous system (CNS).

METHODS

Twenty children with BT and 27 children with an oncological disease without involvement of the CNS (age range: 6.1-16.9 years) were evaluated with an extensive battery of neuropsychological tests tailored to the patient's age. Furthermore, the child and his/her parent(s) completed self-report questionnaires about emotional functioning and quality of life. In both groups, tests were administered before any therapeutic intervention such as surgery, chemotherapy, or irradiation. Groups were comparable with regard to age, gender, and socioeconomic status.

RESULTS

Compared to the control group, patients with BTs performed significantly worse in tests of working memory, verbal memory, and attention (effect sizes between 0.28 and 0.47). In contrast, the areas of perceptual reasoning, processing speed, and verbal comprehension were preserved at the time of measurement.

CONCLUSION

Our results highlight the need for cognitive interventions early in the treatment process in order to minimize or prevent academic difficulties as patients return to school.