Radiation-induced moyamoya syndrome

Case report: Pediatric low-grade gliomas: a fine balance between treatment options, timing of therapy, symptom management and quality of life

Introduction

Pediatric low-grade gliomas (pLGG) are the most common brain tumor in children and encompass a wide range of histologies. Treatment may pose challenges, especially in those incompletely resected or those with multiple recurrence or progression.

Case description

We report the clinical course of a girl diagnosed with pilocytic astrocytoma and profound hydrocephalus at age 12 years treated with subtotal resection, vinblastine chemotherapy, and focal proton radiotherapy. After radiotherapy the tumor increased in enhancement temporarily with subsequent resolution consistent with pseudoprogression. Despite improvement in imaging and radiographic local control, the patient continues to have challenges with headaches, visual and auditory concerns, stroke-like symptoms, and poor quality of life.

Conclusion

pLGG have excellent long-term survival; thus, treatments should focus on maintaining disease control and limiting long-term toxicities. Various treatment options exist including surgery, chemotherapy, targeted agents, and radiation therapy. Given the morbidity associated with pLGG, individualized treatment approaches are necessary, with a multi-disciplinary approach to care focused on minimizing treatment side effects, and promoting optimal quality of life for patients.

Cancer Predisposition Syndromes in Neuro-oncology

Although most primary central and peripheral nervous system (NS) tumors occur sporadically, there are a subset that may arise in the context of a cancer predisposition syndrome. These syndromes occur due to a pathogenic mutation in a gene that normally functions as a tumor suppressor. With increased understanding of the molecular pathogenesis of these tumors, more people have been identified with a cancer predisposition syndrome. Identification is crucial, as this informs surveillance, diagnosis, and treatment options. Moreover, relatives can also be identified through genetic testing. Although there are many cancer predisposition syndromes that increase the risk of NS tumors, in this review, we focus on three of the most common cancer predisposition syndromes, neurofibromatosis type 1, neurofibromatosis type 2, and tuberous sclerosis complex type 1 and type 2, emphasizing the clinical manifestations, surveillance guidelines, and treatment options.

Neurologic Complications in Adult Cancer Survivorship

Over the past decade, the improvement in cancer diagnostics and therapeutics has extended the overall survival of patients diagnosed with cancer including brain cancer. However, despite these unprecedented medical successes, patients continue to experience numerous neurologic complications after treatment that interfere with their independence, functionality, and overall quality of life. These include, among others, cognitive impairment, endocrinopathies, peripheral and cranial neuropathies, and vasculopathy. This article describes the long-term neurologic complications cancer survivors commonly experience to increase awareness of these complications and discuss treatments when available. Further research is necessary to understanding of mechanisms of neurologic injury and advance diagnosis and treatment. Effective patient education, monitoring, and managing neurologic issues after cancer treatment may improve independence, functionality, and quality of life during survivorship.

Characteristics and therapeutic strategies of brain and cranial radiation-induced sarcoma: analysis of 165 cases from our case experience and comprehensive review

BACKGROUND

Radiation-induced sarcoma (RIS) is among the neoplasms potentially caused by radiation therapy (RT) for brain tumors. However, the clinical characteristics of and ideal treatment for RIS are unclear. We analysed our case experience and conducted a comprehensive literature review to reveal the characteristics of brain and cranial RIS.

METHODS

We analysed 165 cases of RIS from the literature together with the RIS case treated at our institution. In each case, the latency period from irradiation to the development of each RIS and the median overall survival (OS) of the patients was analysed by Kaplan-Meier analysis. Spearman's correlation test was used to determine the relationship between the latency period and radiation dose or age at irradiation.

RESULTS

The mean age at the development of RIS was 39.63 ± 17.84 years. The mean latency period was 11.79 ± 8.09 years. No factors associated with early development of RIS were detected. The median OS was 11 months, with fibrosarcoma showing significantly shorter OS compared with osteosarcoma and other sarcomas (p = 0.0021), and intracranial RIS showing a worse prognosis than extracranial RIS (p < 0.0001). Patients treated with surgery (p < 0.0001) and postoperative chemotherapy (p = 0.0157) for RIS presented significantly longer OS, whereas RT for RIS was not associated with a survival benefit.

CONCLUSIONS

Although prognosis for RIS is universally poor, pathological characteristics and locations are associated with worse prognosis. Surgery and chemotherapy may be the ideal treatment strategies for RIS.

Review of Cerebral Radiotherapy-Induced Vasculopathy in Pediatric and Adult Patients

Radiation therapy (RT) causes radiation-induced vasculopathy, which requires clinicians to identify and manage this side effect in pediatric and adult patients. This article reviews previous findings about the pathophysiology of RT-induced vascular injury, including endothelial cell injury, oxidative stress, inflammatory cytokines, angiogenic pathways, and remodeling. The vasculopathy is categorized into ischemic vasculopathy, hemorrhagic vasculopathy, carotid artery injury, and other malformations (cavernous malformations and aneurysms) in populations of pediatric and adult patients separately. The prevention and management of this RT-induced side effect are also discussed. The article summarizes the distribution and risk factors of different types of RT-induced vasculopathy. This will help clinicians identify high-risk patients with corresponding vasculopathy subtypes to deduce prevention and treatment strategies accordingly.

Complications after proton radiotherapy in children, focusing on severe late complications. A complete Swedish cohort 2008-2019

BACKGROUND

Proton radiotherapy (RT) is an attractive tool to deliver local therapy with minimal dose to uninvolved tissue, however, not suitable for all patients. The aim was to explore complications, especially severe late complications (grades 3-4), following proton RT delivered to a complete Swedish cohort of paediatric patients aged <18 years treated 2008-2019.

MATERIAL AND METHODS

Data was downloaded from a national registry. Complications with a possible causation with RT are reported. Proton treatments until July 2015 was performed with a fixed horizontal 172 MeV beam (The Svedberg Laboratory (TSL), Uppsala) in a sitting position and thereafter with gantry-based pencil-beam scanning technique (Skandion Clinic, Uppsala) in a supine position.

RESULTS

219 courses of proton RT (77 at TSL and 142 at Skandion) were delivered to 212 patients (mean age 9.2 years) with various tumour types (CNS tumours 58%, sarcomas 26%, germ cell tumours 7%). Twenty-five patients had severe acute complications (skin, mucous membrane, pharynx/oesophagus, larynx, upper gastrointestinal canal, lower gastrointestinal canal, eyes, ears). Fifteen patients had severe late complications; with increased proportion over time: 4% at 1-year follow-up (FU), 5% at 3-year, 11% at 5-year. Organs affected were skin (1 patient), subcutaneous tissue (4), salivary glands (1), upper GI (1), bone (7), joints (2), CNS (2), PNS (1), eyes (1) and ears (5). Twenty-one of the 28 patients with 10-year FU had at least one late complication grades 1-4 and fourteen of them had more than one (2-5 each).

CONCLUSION

The most important result of our study is the relatively low proportion of severe late complications, comparable with other proton studies on various tumours. Furthermore, the numbers of late complications are lower than our own data set on a mixed population of photon and proton treated paediatric patients, assuring the safety of using proton therapy also in the clinical practice.

Neurotoxicity from Old and New Radiation Treatments for Brain Tumors

Research regarding the mechanisms of brain damage following radiation treatments for brain tumors has increased over the years, thus providing a deeper insight into the pathobiological mechanisms and suggesting new approaches to minimize this damage. This review has discussed the different factors that are known to influence the risk of damage to the brain (mainly cognitive disturbances) from radiation. These include patient and tumor characteristics, the use of whole-brain radiotherapy versus particle therapy (protons, carbon ions), and stereotactic radiotherapy in various modalities. Additionally, biological mechanisms behind neuroprotection have been elucidated.

The incidence of radiation-induced moyamoya among pediatric brain tumor patients who received photon radiation versus those who received proton beam therapy: a systematic review

Cranial irradiation is associated with several adverse events such as endocrinopathy, growth retardation, neurocognitive impairment, secondary malignancies, cerebral vasculopathy, and potential stroke. The better side effects profile of proton beam therapy compared with that of photon radiation therapy is due to its physical properties, mainly the sharp dose fall-off after energy deposition in the Bragg peak. Despite the better toxicity profile of proton beam therapy, the risk of  moyamoya syndrome still exists. We conducted a systematic review of the existing literature on moyamoya syndrome after receiving cranial radiation therapy for pediatric brain tumors to investigate the incidence of moyamoya syndrome after receiving photon versus proton radiation therapy. In this review, we report that the incidence of moyamoya syndrome after receiving proton beam therapy is almost double that of photon-induced moyamoya syndrome. Patients who received proton beam therapy for the management of pediatric brain tumors are more likely to develop moyamoya syndrome at the age of less than 5 years. Meanwhile, most patients with proton-induced moyamoya are more likely to be diagnosed within the first 2 years after the completion of their proton beam therapy.

Secondary meningioma after cranial irradiation: case series and comprehensive literature review

BACKGROUND

Secondary meningioma after cranial irradiation, so-called radiation-induced meningioma, is one of the important late effects after cranial radiation therapy. In this report, we analyzed our case series of secondary meningioma after cranial irradiation and conducted a critical review of literature to reveal the characteristics of secondary meningioma.

MATERIALS AND METHODS

We performed a comprehensive literature review by using Pubmed, MEDLINE and Google scholar databases and investigated pathologically confirmed individual cases. In our institute, we found pathologically diagnosed seven cases with secondary meningioma between 2000 and 2018. Totally, 364 cases were analyzed based on gender, WHO grade, radiation dose, chemotherapy. The latency years from irradiation to development of secondary meningioma were analyzed with Kaplan-Meier analysis. Spearman's correlation test was used to determine the relationship between age at irradiation and the latency years.

RESULTS

The mean age at secondary meningioma development was 35.6 ± 15.7 years and the mean latency periods were 22.6 ± 12.1 years. The latency periods from irradiation to the development of secondary meningioma are significantly shorter in higher WHO grade group (P = 0.0026, generalized Wilcoxon test), higher radiation dose group (P < 0.0001) and concomitant systemic chemotherapy group (P = 0.0003). Age at irradiation was negatively associated with the latency periods (r = -0.23231, P < 0.0001, Spearman's correlation test).

CONCLUSION

Cranial irradiation at older ages, at higher doses and concomitant chemotherapy was associated with a shorter latency period to develop secondary meningiomas. However, even low-dose irradiation can cause secondary meningiomas after a long latency period. Long-term follow-up is necessary to minimize the morbidity and mortality caused by secondary meningioma after cranial irradiation.

Case report of intracranial large vessel occlusion in glioblastoma multiforme patient after radiation therapy

INTRODUCTION

Vasculopathy of the large arteries is a prominent complication of radiotherapy. Radiation-induced cerebral vasculopathy can cause arterial stenosis/occlusion, cerebral hemorrhage, and aneurysm formation. We report a cases of glioblastoma multiforme (GBM) with occlusive radiation vasculopathy (ORV).

CASE PRESENTATION

This 28-year-old patient who suffered from GBM had surgery for cytoreduction and received postoperative CCRT. We adopted the radiotherapy and oncology group radiation guideline. This patient had cerebrovascular accident episodes without any known risk. Therefore, ORV was highly suspected and vascular stenosis was confirmed using magnetic resonance angiography (MRA) or digital subtraction angiography. Extracranial-intracranial bypass was performed and patency was confirmed. The patient had not suffered from recurrent symptoms of transient ischemic attack or ischemic stroke for 1.5 years.

DISCUSSION

This is the first article to report bypass surgery for GBM patients. Although the median survival rate of GBM is approximately 15 months, the short survival time may be sufficient for occlusive vasculopathy to occur. Regular follow-up magnetic resonance imaging assessments are recommended, as is MRA as a screening tool for the early diagnosis of ORV.The Stenting versus Aggressive Medical Management for Preventing Recurrent Stroke in Intracranial Stenosis (SAMMPRIS) trial focused on atherosclerotic intracranial arterial stenosis, revealing that aggressive medical management was superior to stenting for secondary stroke prevention; however, it did not mention radiation-induced vasculopathy. Bypass surgery has yielded some positive outcomes. In the absence of contraindications, antiplatelet or anticoagulation agents could be added, and bypass surgery could be performed because there was no stent in the distal intracranial arteries.

CONCLUSION

MRA is a potential screening tool for ORV in GBM patients and bypass surgery could be performed to improve brain perfusion. Bypass surgery could help patient with occlusive radiation vasculopathy.

A new era for optic pathway glioma: A developmental brain tumor with life-long health consequences

Optic pathway and hypothalamic glioma (OPHG) are low-grade brain tumors that arise from any part of the visual pathways frequently involving the hypothalamus. The tumors grow slowly and present with features driven by their precise anatomical site, their age at presentation and the stage of growth and development of the host neural and orbital bony tissues. Up to 50% of optic pathway glioma arise in association with Neurofibromatosis type 1 (NF1), which affects 1 in 3,000 births and is a cancer predisposition syndrome. As low-grade tumors, they almost never transform to malignant glioma yet they can threaten life when they present under two years of age. The main risks are to threaten vision loss by progressive tumor damage to optic pathways; furthermore, invasion of the hypothalamus can lead to diencephalic syndrome in infancy and hypopituitarism later in life. Progressive cognitive and behavioural dysfunction can occur, as part of NF1 syndromic features and in sporadic cases where large bulky tumors compress adjacent structures and disrupt neuro-hypothalamic pathways. Persistently progressive tumors require repeated treatments to attempt to control vision loss, other focal brain injury or endocrine dysfunction. In contrast tumors presenting later in childhood can be seen to spontaneously arrest in growth and subsequently progress after periods of stability. These patterns are influenced by NF status as well as stages of growth and development of host tissues. The past two decades has seen an expansion in our understanding and knowledge of the clinical and scientific features of these tumors, their modes of presentation, the need for careful visual and endocrine assessment. This influences the decision-making surrounding clinical management with surgery, radiotherapy, chemotherapy and most recently, the potential benefit of molecularly targeted drug therapy. This article, based upon the authors' clinical and research experience and the published literature will highlight advances in approach to diagnosis, the established role of vision loss as justification of treatments and the emerging evidence of endocrine and neurological consequences that need to be incorporated into judgements for case selection for therapy or observation. Consideration is given to the current state of biological evidence justifying current trials of new therapies, the genetic studies of the NF1 gene and the potential for new approaches to OPHG detection and treatment. The outstanding health system priorities from the perspective of children, their parents and health system commissioners or insurers are discussed.

Cerebral hemodynamic and metabolic dysregulation in the postradiation brain

Technological advances in the delivery of radiation and other novel cancer therapies have significantly improved the 5-year survival rates over the last few decades. Although recent developments have helped to better manage the acute effects of radiation, the late effects such as impairment in cognition continue to remain of concern. Accruing data in the literature have implicated derangements in hemodynamic parameters and metabolic activity of the irradiated normal brain as predictive of cognitive impairment. Multiparametric imaging modalities have allowed us to precisely quantify functional and metabolic information, enhancing the anatomic and morphologic data provided by conventional MRI sequences, thereby contributing as noninvasive imaging-based biomarkers of radiation-induced brain injury. In this review, we have elaborated on the mechanisms of radiation-induced brain injury and discussed several novel imaging modalities, including MR spectroscopy, MR perfusion imaging, functional MR, SPECT, and PET that provide pathophysiological and functional insights into the postradiation brain, and its correlation with radiation dose as well as clinical neurocognitive outcomes. Additionally, we explored some innovative imaging modalities, such as quantitative blood oxygenation level-dependent imaging, susceptibility-based oxygenation measurement, and T2-based oxygenation measurement, that hold promise in delineating the potential mechanisms underlying deleterious neurocognitive changes seen in the postradiation setting. We aim that this comprehensive review of a range of imaging modalities will help elucidate the hemodynamic and metabolic injury mechanisms underlying cognitive impairment in the irradiated normal brain in order to optimize treatment regimens and improve the quality of life for these patients.

Characteristics and therapeutic strategies of radiation-induced glioma: case series and comprehensive literature review

INTRODUCTION

The so-called radiation-induced glioma (RIG, a secondary glioma after cranial irradiation), is a serious late effect after cranial radiation therapy. The clinical characteristics of and ideal treatment for these tumors are unclear. We analyzed our case series and conducted a comprehensive literature review to reveal the precise characteristics of RIGs.

METHODS

We analyzed the cases of six patients with RIGs treated at our institution and 354 patients with RIGs from the literature. The latency period from irradiation to the development of each RIG and the median overall survival of the patients were subjected to Kaplan-Meier analyses. Spearman's correlation test was used to determine the relationship between age at irradiation and the latency period.

RESULTS

The mean age of the 360 patients at the development of RIG was 27.42 ± 17.87 years. The mean latency period was 11.35 ± 8.58 years. Multiple gliomas were observed in 28.4%. WHO grade 3 and 4 RIGs accounted for 93.3%. The latency periods were significant shorter in the higher WHO grade group (p = 0.0366) and the concomitant systemic chemotherapy group (p < 0.0001). Age at irradiation was negatively associated with the latency period (r =- 0.2287, p = 0.0219). The patients treated with radiotherapy achieved significantly longer survival compared to those treated without radiotherapy (p = 0.0011).

CONCLUSIONS

Development in younger age, multiplicity, and high incidence of grade 3 and 4 are the clinical characteristics of RIGs. Cranial irradiation at older ages and concomitant chemotherapy were associated with shorter latency for the development of RIG. Radiation therapy may be the feasible treatment option despite radiation-induced gliomas.

Acute ischemic stroke secondary to ventriculoperitoneal shunt dysfunction in a child with Moyamoya syndrome

Background:

Patients with brain vascular disease and hydrocephalus may be predisposed to acute ischemic stroke in case of shunt dysfunction and subsequent increased intracranial pression. Patients with brain tumor may develop hydrocephalus as a consequence of obstruction of cerebrospinal fluid pathways and radiation-induced moyamoya syndrome secondary (RIMS) to radiotherapy (RT).

Case Description:

A 15-year-old male patient, affected by hydrocephalus and RIMS, presented acute cerebral ischemia after an episode of shunt malfunction. The shunt was promptly revised and the areas of ischemia visible at magnetic resonance imaging significantly decreased.

Conclusion:

Children who receive RT for brain tumor, particularly if the circle of Willis region is involved, require close surveillance for the development of vasculopathy and consequent stroke. This surveillance must be even tighter if the patient has been treated with ventricular shunt for the possible synergistic interaction between the two causes on reducing cerebral perfusion and increasing the risk of acute ischemic events.

Western Moyamoya Phenotype: A Scoping Review

Moyamoya, a rare angiographic finding, is characterized by chronic and progressive stenosis at the terminal end of the internal carotid artery, followed by collateralization of the cerebral vasculature at the base of the skull. Coined by Suzuki and Takaku in 1969, the term "moyamoya" means a "puff of smoke" in Japanese, a reference to the angiographic appearance of moyamoya collateralization. Moyamoya is most commonly found in East Asian countries, where much governmental and civilian effort has been expended to characterize this unique disease process. However, despite its rarity, the occurrence of moyamoya in Western countries is associated with significant divergence regarding incidence, gender, sex, age at diagnosis, clinical presentation, and outcomes. Here, we attempted to review the Western literature on moyamoya presentation using the PubMed database to characterize the Western phenotype of moyamoya. We were guided by the Preferred Reporting Items for Systematic Reviews and Meta-Analyses extension for scoping reviews (PRISMA-ScR). We reviewed papers generated from a search with keywords "moyamoya case report," those reported from a Western institution, and those reported on a relevant association. Our scoping review demonstrated various clinical associations with moyamoya. Moreover, we summarized the demographic profile and clinical symptomatology, as well as reported disease associations to better elucidate the Western phenotype of moyamoya.

The mechanobiological theory: a unifying hypothesis on the pathogenesis of moyamoya disease based on a systematic review

OBJECTIVE

Moyamoya angiopathy (MMA) affects the distal internal carotid artery and is designated as moyamoya disease (MMD) when predisposing conditions are absent, or moyamoya syndrome (MMS) when it occurs secondary to other causes. The authors aimed to investigate the reason for this anatomical site predilection of MMA. There is compelling evidence to suggest that MMA is a phenomenon that occurs due to stereotyped mechanobiological processes. Literature regarding MMD and MMS was systematically reviewed to decipher a common pattern relating to the development of MMA.

METHODS

A systematic review was conducted to understand the pathogenesis of MMA in accordance with PRISMA guidelines. PubMed MEDLINE and Scopus were searched using "moyamoya" and "pathogenesis" as common keywords and specific keywords related to six identified key factors. Additionally, a literature search was performed for MMS using "moyamoya" and "pathogenesis" combined with reported associations. A progressive search of the literature was also performed using the keywords "matrix metalloprotease," "tissue inhibitor of matrix metalloprotease," "endothelial cell," "smooth muscle cell," "cytokines," "endothelin," and "transforming growth factor" to infer the missing links in molecular pathogenesis of MMA. Studies conforming to the inclusion criteria were reviewed.

RESULTS

The literature search yielded 44 published articles on MMD by using keywords classified under the six key factors, namely arterial tortuosity, vascular angles, wall shear stress, molecular factors, blood rheology/viscosity, and blood vessel wall strength, and 477 published articles on MMS associations. Information obtained from 51 articles that matched the inclusion criteria and additional information derived from the progressive search mentioned above were used to connect the key factors to derive a network pattern of pathogenesis.

CONCLUSIONS

Based on the available literature, the authors have proposed a unifying theory for the pathogenesis of MMA. The moyamoya phenomenon appears to be the culmination of an interplay of vascular anatomy, hemodynamics, rheology, blood vessel wall strength, and a plethora of intricately linked mechanobiological molecular mediators that ultimately results in the mechanical process of occlusion of the blood vessel, stimulating angiogenesis and collateral blood supply in an attempt to perfuse the compromised brain.

Spectrum of neuroimaging findings post-proton beam therapy in a large pediatric cohort

PURPOSE

Proton beam therapy (PBT) is now well established for the treatment of certain pediatric brain tumors. The intrinsic properties of PBT are known to reduce long-term negative effects of photon radiotherapy (PRT). To better understand the intracranial effects of PBT, we analyzed the longitudinal imaging changes in a cohort of children with brain tumors treated by PBT with clinical and radiotherapy dose correlations.

MATERIALS AND METHODS

Retrospective imaging review of 46 patients from our hospital with brain tumors treated by PBT. The imaging findings were correlated with clinical and dose parameters.

RESULTS

Imaging changes were assessed by reviewing serial magnetic resonance imaging (MRI) scans following PBT over a follow-up period ranging from 1 month to 7 years. Imaging changes were observed in 23 patients undergoing PBT and categorized as pseudoprogression (10 patients, 43%), white matter changes (6 patients, 23%), parenchymal atrophy (6 patients, 23%), and cerebral large vessel arteriopathy (5 patients, 25%). Three patients had more than one type of imaging change. Clinical symptoms attributable to PBT were observed in 13 (28%) patients.

CONCLUSION

In accordance with published literature, we found evidence of varied intracranial imaging changes in pediatric brain tumor patients treated with PBT. There was a higher incidence (10%) of large vessel cerebral arteriopathy in our cohort than previously described in the literature. Twenty-eight percent of patients had clinical sequelae as a result of these changes, particularly in the large vessel arteriopathy subgroup, arguing the need for angiographic and perfusion surveillance to pre-empt any morbidities and offer potential neuro-protection.

Intracranial long-term complications of radiation therapy: an image-based review

BACKGROUND AND PURPOSE

Radiation therapy is commonly utilized in the majority of solid cancers and many hematologic malignancies and other disorders. While it has an undeniably major role in improving cancer survival, radiation therapy has long been recognized to have various negative effects, ranging from mild to severe. In this manuscript, we review several intracranial manifestations of therapeutic radiation, with particular attention to those that may be encountered by radiologists.

METHODS

We conducted an extensive literature review of known complications of intracranial radiation therapy. Based on this review, we selected complications that had salient, recognizable imaging findings. We searched our imaging database for illustrative examples of these complications, focusing only on patients who had a history of intracranial radiation therapy. We then selected cases that best exemplified expected imaging findings in these entities.

RESULTS

Based on our initial literature search and imaging database review, we selected cases of radiation-induced meningioma, radiation-induced glioma, cavernous malformation, enlarging perivascular spaces, leukoencephalopathy, stroke-like migraine after radiation therapy, Moyamoya syndrome, radiation necrosis, radiation-induced labyrinthitis, optic neuropathy, and retinopathy. Although retinopathy is not typically apparent on imaging, it has been included given its clinical overlap with optic neuropathy.

CONCLUSIONS

We describe the clinical and imaging features of selected sequelae of intracranial radiation therapy, with a focus on those most relevant to practicing radiologists. Knowledge of these complications and their imaging findings is important, because radiologists play a key role in early detection of these entities.

Co-occurrence of Moyamoya syndrome and Kartagener syndrome caused by the mutation of DNAH5 and DNAH11: a case report

BACKGROUND

Kartagener syndrome is an autosomal recessive inherited disorder of primary ciliary dyskinesia. Moyamoya syndrome refers to a moyamoya angiopathy associated with other neurological and/or extra-neurological symptoms, or due to a well identified acquired or inherited cause. We herein reported a case of a 48-year-old woman who was favored the diagnosis of Kartagener syndrome and moyamoya syndrome. The whole genome sequencing and bioinformatics analysis showed a homozygotic nonsense mutation in the dynein, axonemal, heavy chain (DNAH) 5 gene, and heterozygotic missense mutation in the DNAH11 gene. This is the first report of the co-occurrence of the two rare diseases.

CASE PRESENTATION

A case of a 48-year-old woman was presented with hemiplegia and slurred speech. The magnetic resonance imaging of the brain confirmed acute cerebral infarction in the right basal ganglia region, semi-oval center, insular lobe, and frontal parietal lobe. The electrocardiogram showed inverted "P" waves in L1 and AVL on left-sided chest leads and computed tomography scan of the chest showed bronchiectasis changes, cardiac shadow and apex on the right side, and situs inversus of aortic arch position. The digital subtraction angiography showed inversion of the aortic arch, and bilateral internal carotid arteries are occluded from the ophthalmic segment. The clinical, radiological, and laboratory findings made the diagnosis of Kartagener syndrome and moyamoya syndrome. The whole genome sequencing and bioinformatics analysis showed a homozygotic nonsense mutation in DNAH5 gene, and heterozygotic missense mutation in the DNAH11 gene.

CONCLUSION

The combined mutation of DNAH5 and DNAH11 may lead to the overlapping dysfunction of motile and nonmotile cilia, which contribute to the co-occurrence of Kartagener syndrome and moyamoya syndrome. Our report deserves further confirm by more case reports.

Late effects of cancer treatment: consequences for long-term brain cancer survivors

Late adverse effects of cancer treatments represent a significant source of morbidity and also financial hardship among brain tumor patients. These effects can be produced by direct neurologic damage of the tumor and its removal, and/or by complementary treatments such as chemotherapy and radiotherapy, either alone or combined. Notably, young adults are the critical population that faces major consequences because the early onset of the disease may affect their development and socioeconomic status. The spectrum of these late adverse effects is large and involves multiple domains. In this review we classify the main long-term adverse effects into 4 sections: CNS complications, peripheral nervous system complications, secondary neoplasms, and Economic impact. In addition, CNS main complications are divided into nonfocal and focal symptoms. Owing to all the secondary effects mentioned, it is essential for physicians to have a high level of clinical suspicion to prevent and provide early intervention to minimize their impact.

Pencil beam scanning proton therapy for the treatment of craniopharyngioma complicated with radiation-induced cerebral vasculopathies: A dosimetric and linear energy transfer (LET) evaluation

BACKGROUND AND PURPOSE

This study analyses the dosimetric and dose averaged Linear Energy transfer (LETd) correlation in paediatric craniopharyngioma (CP) patients with and without radiation-induced cerebral vasculopathies (RICVs) treated with pencil beam scanning (PBS) proton therapy (PT).

MATERIAL AND METHODS

We reviewed a series of 16 CP patients treated with PT to a median dose of 54 Gy(RBE). Two (12.5%) index patients presented RICVs 14 and 24 months (median, 19) after PT. Organs at risks (OARs) as bilateral internal carotid arteries (ICAs) and circle of Willis were contoured based on CTs and MRIs pre- and post-PT. Dosimetry was reviewed and LETd distributions were calculated; LETd metric for PTVs and OARs were analysed. For a sub-cohort, dosimetric and LETd values robustness due to range uncertainties were computed.

RESULTS

For the two index patients, no correlation was observed between RICVs and OARs doses. However for those patients mean(maximum) LETd values in the affected OARs were up to 4.0 ± 0.4 (7.8 ± 0.1)keV/μm; those LETd values were significantly higher (p = 0.02) than the mean(maximum) LETd values for the rest of the cohort (mean: 3.1 ± 0.3, maximum: 4.8 ± 1.0 keV/μm). This was due to asymmetric field arrangement, thus resulting in marked asymmetric LETd distributions. For such arrangement, maximum LETd values variations in vascular structures due to range uncertainties were up to 1.2 keV/μm, whilst for the symmetric one they were up to 0.7 keV/μm.

CONCLUSIONS

For children with and without RICVs, quantitative analysis showed a significant correlation with LETd average/maximum values in vascular structures, whilst no correlation was found on dosimetric parameters.

Radiation-induced accelerated aging of the brain vasculature in young adult survivors of childhood brain tumors

Background

Cranial radiotherapy may damage the cerebral vasculature. The aim of this study was to understand the prevalence and risk factors of cerebrovascular disease (CVD) and white matter hyperintensities (WMHs) in childhood brain tumors (CBT) survivors treated with radiotherapy.

Methods

Seventy CBT survivors who received radiotherapy were enrolled in a cross-sectional study at a median 20 years after radiotherapy cessation. The prevalence of and risk factors for CVD were investigated using MRI, MRA, and laboratory testing. Tumors, their treatment, and stroke-related data were retrieved from patients’ files.

Results

Forty-four individuals (63%) had CVD at a median age of 27 years (range, 16-43 years). The prevalence rates at 20 years for CVD, small-vessel disease, and large-vessel disease were 52%, 38%, and 16%, respectively. Ischemic infarcts were diagnosed in 6 survivors, and cerebral hemorrhage in 2. Lacunar infarcts were present in 7, periventricular or deep WMHs in 34 (49%), and mineralizing microangiopathy in 21 (30%) survivors. Multiple pathologies were detected in 44% of the participants, and most lesions were located in a high-dose radiation area. Higher blood pressure was associated with CVD and a presence of WMHs. Higher cholesterol levels increased the risk of ischemic infarcts and WMHs, and lower levels of high-density lipoprotein and higher waist circumference increased the risk of lacunar infarcts.

Conclusions

Treating CBTs with radiotherapy increases the risk of early CVD and WMHs in young adult survivors. These results suggest an urgent need for investigating CVD prevention in CBT patients.

Evaluation and treatment of children with radiation-induced cerebral vasculopathy

OBJECTIVE

Stenoocclusive cerebral vasculopathy is an infrequent delayed complication of ionizing radiation. It has been well described with photon-based radiation therapy but less so following proton-beam radiotherapy. The authors report their recent institutional experience in evaluating and treating children with radiation-induced cerebral vasculopathy.

METHODS

Eligible patients were age 21 years or younger who had a history of cranial radiation and subsequently developed vascular narrowing detected by MR arteriography that was significant enough to warrant cerebral angiography, with or without ischemic symptoms. The study period was January 2011 to March 2019.

RESULTS

Thirty-one patients met the study inclusion criteria. Their median age was 12 years, and 18 (58%) were male. Proton-beam radiation therapy was used in 20 patients (64.5%) and photon-based radiation therapy was used in 11 patients (35.5%). Patients were most commonly referred for workup as a result of incidental findings on surveillance tumor imaging (n = 23; 74.2%). Proton-beam patients had a shorter median time from radiotherapy to catheter angiography (24.1 months [IQR 16.8-35.4 months]) than patients who underwent photon-based radiation therapy (48.2 months [IQR 26.6-61.1 months]; p = 0.04). Eighteen hemispheres were revascularized in 15 patients. One surgical patient suffered a contralateral hemispheric infarct 2 weeks after revascularization; no child treated medically (aspirin) has had a stroke to date. The median follow-up duration was 29.2 months (IQR 21.8-54.0 months) from the date of the first catheter angiogram to last clinic visit.

CONCLUSIONS

All children who receive cranial radiation therapy from any source, particularly if the parasellar region was involved and the child was young at the time of treatment, require close surveillance for the development of vasculopathy. A structured and detailed evaluation is necessary to determine optimal treatment.

Efficacy of Direct Revascularization Surgery for Hemorrhagic Moyamoya Syndrome As a Late Complication of Cranial Irradiation for Childhood Craniopharyngioma

Moyamoya syndrome (MMS) is an uncommon late complication after cranial irradiation. Its hemorrhagic presentation from the associated pseudo-aneurysm is extremely rare, and the optimal management strategy is undetermined. We herein report a 36-year-old man who developed intraventricular hemorrhage from a pseudo-aneurysm at the extended left anterior choroidal artery as an abnormal collateral of MMS 30 years after surgical removal and cranial irradiation for childhood craniopharyngioma. Catheter angiography confirmed the diagnosis of MMS, and multiple pseudo-aneurysms were evident at the ipsilateral abnormal choroidal collateral, one of which was considered to be a source of bleeding. The patient underwent left superficial temporal artery (STA)-middle cerebral artery (MCA) anastomosis with indirect pial synangiosis based on the observation that the development of choroidal collateral may be associated with a high rebleeding risk in hemorrhagic moyamoya disease. The patient was discharged without neurological deficit, and postoperative magnetic resonance angiography confirmed the STA-MCA bypass to be patent. Catheter angiography 1 year after revascularization surgery revealed the complete disappearance of the pseudoaneurysms with the apparently patent STA-MCA bypass. The patient did not exhibit any cerebrovascular events during the follow-up period of 16 months. In conclusion, hemorrhagic MMS with choroidal collateral as a dangerous anastomosis was effectively managed by STA-MCA anastomosis. Although long-term follow-up is necessary to evaluate our strategy, the favorable disappearance of pseudoaneurysms after revascularization surgery in the present case strongly suggests that STA-MCA anastomosis has a potential role for preventing rebleeding in MMS after cranial irradiation.

Adult moyamoya angiopathy in Bourgogne-Franche-Comté: Epidemiology, diagnosis and management

INTRODUCTION

Moyamoya angiopathy (MMA) is a progressive steno-occlusive disease of the distal internal carotid arteries mainly described in Asia. It induces the development of collateral vascular networks to reduce chronic cerebral hypoperfusion. Symptoms depend on the patient's age in Asia: children are at greater risk of transient or constituted ischemic events, whereas adults are more exposed to hemorrhagic stroke. Data from the literature seem to show that the pattern of MMA in western countries differs from that in Asia.

MATERIAL AND METHODS

A retrospective study of patients with MMA was conducted in Bourgogne-Franche-Comté (mid-eastern France). Clinical data (symptoms, risk factors, age at diagnosis, number and timing of recurrences, type of treatment) as well as radiological data (angiographic findings, Suzuki's grade) were analyzed.

RESULTS

Seventeen adult patients (9 men, 53%) were followed at the university hospitals of Besançon and Dijon from 2009 to 2016. Fourteen patients (83%) had bilateral disease. The mean age at diagnosis was 49 years (±16), 83% of the patients were Caucasian and 17% originated from Maghreb. Only 17% of the hemispheres had a hemorrhagic form. Ischemic form was more frequent before diagnosis with transient ischemic attack (24% of patients) and stroke (83% of patients). With medical treatment, 9 patients suffered from stroke recurrence (53% of patients) with an average delay of 22.7±34 months. Three patients (18%) had combined surgical management by encephelo-synangiosis and superficial temporal artery-to-middle cerebral artery (STA-MCA) anastomosis, without symptom recurrence after treatment with an average follow up of 14 months.

CONCLUSION

MMA remains a rare cerebrovascular disease in Europe and requires multidisciplinary care. Epidemiological analysis showed differences with the Asian population, especially the predominance of ischemic forms in adults.

Evaluation of late cerebral vascular complications in cranially irradiated pediatric cancer patients with magnetic resonance angiography

BACKGROUND:

We aimed to establish the early diagnosis of cerebral vascular complications by using cerebral magnetic resonance angiography (MRA) in patients who were treated with cranial RT in childhood as part of their cancer treatment.

PROCEDURE:

Patients who had received cranial RT before the age of 18 and had been in remission for at least 1 year were enrolled in the study. A data form including demographic and clinical characteristics and findings of cerebral MRA was filled in for each patient.

RESULTS:

Cerebral MRA examination was performed between November 2013 and October 2015 in 53 patients who met the inclusion criteria. Abnormalities were found in 7 patients (13.2%). All patients were asymptomatic at the time of examination. There was a significant difference between patients in the abnormality-positive and abnormality-negative groups related to cranial radiation dose (p = 0.013) and age at the time of examination (p = 0.015) in univariate analysis. In multivariate analysis, cranial radiation dose was found to have an impact on developing cerebral vascular abnormalities (p = 0.045).

CONCLUSIONS:

Cerebral MRA is a noninvasive method of follow-up for late cerebral vascular complications in surviving pediatric oncology patients who were treated with cranial RT as part of their cancer treatment.

Neurological Complications of the Treatment of Pediatric Neoplastic Disorders

Neurological complications resulting from childhood cancer treatments are common. Treatment for childhood neoplastic disorders is often multimodal and may include procedures, cranial irradiation, chemotherapy, transplant, and immunotherapy, each of which carries distinct neurological risks. Procedures, such as lumbar punctures, are commonly used in this population for diagnostic purposes as well as intrathecal medication administration. Surgery is associated with an array of potential neurological complications, with posterior fossa syndrome being a common cause of morbidity in pediatric brain tumor patients after neurosurgical resection. Cranial irradiation can cause late neurological sequelae such as stroke, cerebral vasculopathy, secondary malignancy, and cognitive dysfunction. Neurotoxic effects of chemotherapeutic agents are common and include neuropathy, coagulopathy causing stroke or cerebral sinovenous thrombosis, encephalopathy, seizures, cerebellar dysfunction, myelopathy, and neuropsychologic difficulties. Hematopoietic stem cell transplant has a high risk of neurological complications including central nervous system infection, seizures, and stroke. Immunotherapies, including chimeric antigen receptor-modified T-cells (CAR T-cells) and immune checkpoint inhibitors, are emerging as potentially effective strategies to treat some types of childhood cancer, but may carry with them substantial neurotoxicity which is just beginning to be recognized and studied. With evolving treatment protocols, childhood cancer survivorship is increasing, and the role of the neurologist in managing both the acute and chronic neurological consequences of treatment is becoming more important. Prevention, early recognition, and treatment of therapy-associated neurotoxicity are imperative to ensuring children can remain on the most effective therapeutic regimens and to improve the neurological function and quality of life of childhood cancer survivors.

Imaging findings in radiation therapy complications of the central nervous system

Radiation therapy is a useful treatment for tumors and vascular malformations of the central nervous system. Radiation therapy is associated with complications, including leukoencephalopathy, radiation necrosis, vasculopathy, and optic neuropathy. Secondary tumors are also often seen long after radiation therapy. Secondary tumors are often benign tumors, such as hemangiomas and meningiomas, but sometimes malignant gliomas and soft tissue sarcomas emerge. We review the imaging findings of complications that may occur after brain radiation therapy.

Pediatric Glioma at the Optic Pathway and Thalamus

Gliomas are the most common pediatric tumors of the central nervous system. In this review, we discuss the clinical features, treatment paradigms, and evolving concepts related to two types of pediatric gliomas affecting two main locations: the optic pathway and thalamus. In particular, we discuss recently revised pathologic classification, which adopting molecular parameter. We believe that our review contribute to the readers' better understanding of pediatric glioma because pediatric glioma differs in many ways from adult glioma according to the newest advances in molecular characterization of this tumor. A better understanding of current and evolving issues in pediatric glioma is needed to ensure effective management decision.

Longitudinal brain structural alterations in patients with nasopharyngeal carcinoma early after radiotherapy

Background and purpose

To investigate effects of radiotherapy on normal brain tissue using in vivo neuroimaging in patients with nasopharyngeal carcinoma (NPC).

Methods and materials

We used longitudinal MRI to monitor structural brain changes during standard radiotherapy in patients newly diagnosed with NPC. We assessed volumetric measures in 63 patients at 2–3 time points before and after radiotherapy, with 20 NPC-free participants as normal controls. Images were processed using validated software (FreeSurfer). Automated results were inspected visually for accuracy. We examined changes in volume of the whole brain, gray matter, white matter, and ventricles, as well as in cerebral volumes partitioned into temporal, frontal, parietal, and occipital lobes. A linear mixed model was used to evaluate longitudinal changes in these measurements. Statistical significance was evaluated at p < 0.05, which was corrected for multiple comparisons.

Results

Volumes of the gray matter, and bilateral temporal lobes decreased in a time-dependent manner, whereas ventricle volume showed a time-dependent increase after radiotherapy. No volume changes were detected in NPC patients before radiotherapy when compared normal controls. No volume changes were detected in the subcohort of patients after completion of induction chemotherapy but prior to initiation of radiotherapy. Changes of bilateral temporal lobe volume correlated with irradiation dose in this region. Expansion of the ventricles correlated with a reduction in cognition assessment.

Conclusions

We detected significant and progressive radiotherapy-associated structural changes in the brains of patients with NPC who were treated with standard radiotherapy, especially in the bilateral temporal lobe in which the effect was dose-dependent. Expansion of the ventricles can serve as an imaging marker for treatment-related reduction in cognitive function. Future studies with longer follow-ups are needed to evaluate morphometric changes long-term after radiotherapy.

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Time-dependent ventricle expansion in NPC patients post radiotherapy (RT)

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Time-dependent total gray matter and bilateral temporal lobe atrophy in NPC post-RT

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The bilateral temporal lobe had a pattern of dose-dependent atrophy.

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Longitudinal dilation of the ventricles correlated with reduction of cognition.

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Moreover, these findings cannot be explained by chemotherapy.

Large Vessel Arteriopathy After Cranial Radiation Therapy in Pediatric Brain Tumor Survivors

Among childhood cancer survivors, increased stroke risk after cranial radiation therapy may be caused by radiation-induced arteriopathy, but limited data exist to support this hypothesis. Herein, we assess the timing and presence of cerebral arteriopathy identified by magnetic resonance angiography (MRA) after cranial radiation therapy in childhood brain tumor survivors. In a cohort of 115 pediatric brain tumor survivors, we performed chart abstraction and prospective annual follow-up to assess the presence of large vessel cerebral arteriopathy by MRA. We identified 10 patients with cerebral arteriopathy. The cumulative incidence of arteriopathy 5 years post-cranial radiation therapy was 5.4% (CI 0.6%-10%) and 10 years was 16% (CI 4.6%-26%). One patient had an arterial ischemic stroke 2.4 years post-cranial radiation therapy in the distribution of a radiation-induced stenotic artery. We conclude that large vessel arteriopathies can occur within a few years of cranial radiation therapy and can become apparent on MRA in under a year.

Moya-Moya syndrome after cranial radiation for optic glioma with NF1. Case report and literature review of syndromic cases

INTRODUCTION

Moya-Moya angiopathy is a neurovascular disease that predisposes to ischemic or hemorrhagic strokes. It is generated by a steno-occlusion of the terminal portion of the internal carotid arteries, which induces the development of abnormal neovessels in the deep regions of the brain. Some pathologies such as sickle cell disease, Down syndrome or Graves' disease may be associated with Moya-Moya angiopathy. These syndromic forms harbor several differences compared with idiopathic Moya-Moya disease.

CASE REPORT

We report the case of a young patient who presented with a syndromic form of Moya-Moya angiopathy after cranial radiation therapy for an optic glioma associated with type 1 neurofibromatosis treated by combined revascularization. We discuss the particularities of syndromic forms, in their presentation and management based on a review of the literature.

CONCLUSION

Many diseases can be associated with Moya-Moya syndrome. Symptomatic patients should undergo surgery, but the risk of postoperative complications appears to be greater than that encountered in patients with non-syndromic Moya-Moya angiopathy.

Pediatric Optic Pathway/Hypothalamic Glioma

Optic pathway/hypothalamic gliomas (OP/HGs) are rare astrocytic tumors that appear more commonly among young children and often are unresectable. They comprise approximately 2% of all central nervous system tumors and account for 3–5% of pediatric intracranial tumors. Initial manifestations are often visual disturbances, endocrinopathies and hypothalamic dysfunction such as the diencephalic syndrome, and sometimes hydrocephalus due to cerebrospinal fluid (CSF) outflow obstruction. In many cases, the tumors are diagnosed late in the clinical course because they silently enlarge. These tumors consist mostly of histologically benign, World Health Organization (WHO) grade I tumors represented by pilocytic astrocytomas (PA), the rest being pilomyxoid astrocytomas (PXA) – WHO grade II tumors. In young pediatric patients, however, can be seen PXA that show aggressive clinical course such as CSF dissemination. Our small series of 14 non-Neurofibromatosis type 1 (NF-1) OP/HGs PA patients underwent extended resection without any adjuvant treatments. The median age at initial treatment was 11.5 ± 6.90 years (range, 1–25 years) and median follow up 85.5 ± 25.0 months. Surgical resection for OP/HGs results in acceptable middle-term survival, tumor control and functional outcome equivalent to chemotherapy. There is, however, no longer doubt that chemotherapy with or without biopsy and as-needed debulking surgery remains the golden standard in management of OP/H. Clinical conditions and treatment plans for OP/HGs vary depending on their structure of origin.

Coexistence of Radiation-Induced Meningioma and Moyamoya Syndrome 10 Years after Irradiation against Medulloblastoma: a Case Report

Radiotherapy is one of the standard treatments for medulloblastoma. However, therapeutic central nervous system irradiation in children may carry delayed side effects, such as radiation-induced tumor and vasculopathy. Here, we report the first case of coexisting meningioma and moyamoya syndrome, presenting 10 years after radiotherapy for medulloblastoma. A 13-year-old boy presented with an enhancing mass at the cerebral falx on magnetic resonance imaging (MRI) after surgery, radiotherapy (30.6 Gy craniospinal axis, 19.8 Gy posterior fossa) and chemotherapy against medulloblastoma 10 years ago, previously. The second tumor was meningioma. On postoperative day 5, he complained of right-sided motor weakness, motor dysphasia, dysarthria, and dysphagia. MRI revealed acute cerebral infarction in the left frontal lobe and both basal ganglia. MR and cerebral angiography confirmed underlying moyamoya syndrome. Four months after the meningioma surgery, the patient presented with headaches, dysarthria, and dizziness. Indirect bypass surgery was performed. He has been free from headaches since one month after the surgery. For patients who received radiotherapy for medulloblastoma at a young age, clinicians should consider the possibility of the coexistence of several complications. Careful follow up for development of secondary tumor and delayed vasculopathy is required.

Moyamoya Disease Associated with Tuberculum Sellae Meningioma and Cavernous Sinus Hemangioma

BACKGROUND

Primary moyamoya disease associated with skull base tumors has been reported only rarely in the literature. Surgical treatment can be complicated due to the compensatory collateral circulation through meningeal and leptomeningeal anastomosis. A standard frontotemporal craniotomy may interrupt critical transdural anastomoses.

CASE DESCRIPTION

We report a case of primary moyamoya disease coexisting with tuberculum sellae meningioma and left cavernous sinus hemangioma. Simultaneous management of tuberculum sellae meningioma and moyamoya disease was performed using a left modified pterional incision. Two separate bone windows were opened to protect the transdural anastomosis via the middle meningeal artery. The tuberculum sellae meningioma was successfully removed through a small frontal craniotomy, and encephaloduromyosynangiosis was used to treat moyamoya disease through a temporoparietal craniotomy. Finally, CyberKnife radiotherapy was used to treat the left cavernous sinus hemangioma at 6 weeks after the initial operation. The patient recovered well without complications. This is the first report of moyamoya disease associated with tuberculum sellae meningioma and cavernous sinus hemangioma.

CONCLUSIONS

With careful bone flap design, moyamoya disease and skull base tumors can be treated simultaneously. Care should be taken to avoid interruption of critical dural-pial collaterals and injury to fragile moyamoya vessels.

[Radiotherapy and radiosurgery in treatment of craniopharyngiomas]

Craniopharyngiomas are benign epithelial tumors having a dysembryogenetic origin, which are usually located in the sellar/parasellar and/or third ventricle regions. Gross total resection is the modern standard of treatment for these tumors because of a low recurrence rate. However, this surgery in some patients with craniopharyngioma often leads to the development or worsening of diencephalic disorders poorly responding to treatment. Perhaps, in these cases, subtotal or partial tumor resection or implantation of an Ommaya reservoir into the tumor cyst followed by stereotactic radiotherapy/radiosurgery may provide better functional outcomes and higher life quality in patients, with tumor growth control being reasonable (according to the published data, the mean 10-year disease-free survival is 66.9% after total tumor resection and 79.6% after combined treatment). The paper presents a review of the literature on radiological treatment of craniopharyngiomas. We discuss the issues of indications, optimal timing of radiotherapy/radiosurgery, its efficacy, and treatment outcomes in terms of complications and quality of life. Particular attention is paid to enlargement of craniopharyngioma cysts during and after radiological treatment.

Mechanisms of radiotherapy-associated cognitive disability in patients with brain tumours

Standard treatment of primary and metastatic brain tumours includes high-dose megavoltage-range radiation to the cranial vault. About half of patients survive >6 months, and many attain long-term control or cure. However, 50-90% of survivors exhibit disabling cognitive dysfunction. The radiation-associated cognitive syndrome is poorly understood and has no effective prevention or long-term treatment. Attention has primarily focused on mechanisms of disability that appear at 6 months to 1 year after radiotherapy. However, recent studies show that CNS alterations and dysfunction develop much earlier following radiation exposure. This finding has prompted the hypothesis that subtle early forms of radiation-induced CNS damage could drive chronic pathophysiological processes that lead to permanent cognitive decline. This Review presents evidence of acute radiation-triggered CNS inflammation, injury to neuronal lineages, accessory cells and their progenitors, and loss of supporting structure integrity. Moreover, injury-related processes initiated soon after irradiation could synergistically alter the signalling microenvironment in progenitor cell niches in the brain and the hippocampus, which is a structure critical to memory and cognition. Progenitor cell niche degradation could cause progressive neuronal loss and cognitive disability. The concluding discussion addresses future directions and potential early treatments that might reverse degenerative processes before they can cause permanent cognitive disability.

Outcomes for pediatric patients with central nervous system germ cell tumors treated with proton therapy

Purpose

We assessed outcomes after proton therapy (PT) for central nervous system germinomas or non-germinomatous germ cell tumors (NGGCTs) in children.

Patients and methods

We identified children with germ cell tumors of the central nervous system who received proton therapy in 2006–2009 and extracted information on tumor response, treatment failures, and toxicity.

Results

Of the 20 identified patients (median age 12 years [range 3–16]), 9 had germinoma and 11 NGGCTs; 19 patients received three-dimensional conformal PT and 1 scanning-beam PT. Fourteen patients had craniospinal irradiation (CSI), 4 had ventricular irradiation that excluded the 4th ventricle, and 2 had whole-ventricle irradiation. All received involved-field boosts. At a median follow-up interval of 5.6 years (range, 0.3–8.2 years), 1 patient with germinoma had an out-of-field failure in the 4th ventricle and 2 with NGGCT died from disease progression after CSI. Rates of local control, progression-free survival, and overall survival at 5 years were 89%, 89%, and 100% for patients with germinoma; corresponding rates for NGGCTs were 82%, 82%, and 82%. The most common late toxicity (9 patients [45%]) was endocrinopathy.

Conclusions

PT for CNS germ cell tumors is associated with acceptable disease control rates and toxicity profiles.

Association between the rs112735431 polymorphism of the RNF213 gene and moyamoya disease: A case-control study and meta-analysis

Ring finger protein 213 (RNF213) gene polymorphisms are thought to be significant in the etiology and pathogenesis of moyamoya disease (MMD). Due to the rarity of MMD patients, their ethnic diversity, and the use of varying methodologies, studies of the association between these polymorphisms and MMD have not been repeatable. This lack of reproducibility affects the strength of the conclusions drawn from their results. We conducted the present case-control study and meta-analysis to provide more precise estimates of the association between the rs112735431 (c.14576G>A) polymorphism and the risk of MMD. A total of 81 MMD patients and 100 healthy controls were enrolled in our case-control study. The RNF213 rs112735431 (c.14576G>A) polymorphism was genotyped using Sanger sequencing after amplification with polymerase chain reaction (PCR). The genetic algorithm (GA) genotype and A allele frequencies of RNF213 rs112735431 (c.14576G>A) (odds ratio, OR=7.10, 95% confidence interval, CI=1.51-33.43, p=0.006; OR=9.37, 95% CI=2.10-41.84, p<0.001, respectively) were significantly higher in the MMD group than those in the control group. In our meta-analysis, we assessed a total of eight case-control studies, including 985 patients and 2335 controls. Pooled ORs indicated a significant association between the presence of the rs112735431 (c.14576G>A) polymorphism and MMD risk (dominant model: OR=74.55, 95% CI=35.86-154.98, p<0.00001). Subgroup analysis based on country and sensitivity analysis verified these results. Our case-control study and meta-analysis both provide evidence of an association between the rs112735431(c.14576G>A) polymorphism in the RNF213 gene and MMD risk.

Incidence and long-term outcome of postradiotherapy moyamoya syndrome in pediatric patients with primary brain tumors: a single institute experience in Taiwan

We aimed to investigate the incidence and long‐term outcome of moyamoya syndrome in pediatric patients with primary brain tumors after receiving cranial radiotherapy (RT) in a single institute in Taiwan. The complete medical records, medical images, and RT notes of 391 pediatric patients with primary brain tumors treated with cranial RT between January 1975 and December 2005 in Taipei Veterans General Hospital (TVGH), Taiwan, were entered into an electronic registry and reviewed. Eight (2%) cases of post‐RT moyamoya syndrome were identified in the sample of 391 patients. The median latency was 3 years post‐RT. Among the eight patients, three had craniopharyngioma, two had optic glioma, two had medulloblastoma, and one had a suprasellar astrocytoma. The prescribed physical doses of RT were in the range of 40–54 Gy. The incidence was highest in those with optic glioma (0.039/person‐year), followed by craniopharyngioma (0.013/person‐year), astrocytoma (0.003/person‐year), and medulloblastoma (0.002/person‐year). No patients died of vasculopathy. No difference in crude incidence was found between our results and those of other series. The incidence of moyamoya syndrome was diagnosis dependent, with the highest incidence among patients with optic glioma. No regional difference in incidence was found. Long‐term, stable neurological function may be achieved following timely surgical intervention.

Cardiovascular Complications of Cranial and Neck Radiation

OPINION STATEMENT

Cancer survivors who receive head and neck radiation are at increased risk for cerebrovascular events. This is mediated via damage to the hypothalamus-pituitary axis leading to the metabolic syndrome and extracranial arterial injury leading to carotid artery stenosis. Head and neck radiation can also lead to intracranial injury that can present as moyamoya, especially in children. Survivors require lifelong periodic follow-up for the development of pan-hypopituitarism or its individual components as well as for dyslipidemia and obesity. Aggressive control of traditional cardiovascular risk factors is recommended to reduce cardiovascular morbidity and mortality. There are no specific guidelines for the surveillance and management of asymptomatic carotid artery disease in cancer survivors. However, regular detailed examination for carotid bruits and neurological symptoms is recommended. Treatment of significant radiation-induced carotid artery disease has not been specifically studied and is based upon recommendations for patients with atherosclerotic carotid stenosis. Carotid endarterectomy can be difficult in radiation patients due to anatomic concerns and the risk of post-operative cranial nerve injury and wound complications but should be considered in patients with suitable anatomy and neck architecture. Carotid artery stenting, while successful, may be associated with greater long-term mortality and neurologic complications. Regardless of the strategy employed, radiation patients are at increased risk for restenosis and should undergo routine surveillance even after revascularization.

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.

Radiation-Induced Moyamoya Syndrome after Proton Beam Therapy in the Pediatric Patient: A Case Series

Minimizing normal-tissue radiation exposure is especially important in the pediatric population as children appear to be particularly sensitive to postradiation vasculopathies after conventional photon radiotherapy. Given the limited scattering effect and low-dose radiation delivery to the surrounding tissues with proton beam radiotherapy, this modality is considered to be an effective treatment for pediatric skull-base tumors compared to conventional radiotherapy, and to have fewer adverse side effects. We report 2 cases of radiation-induced moyamoya syndrome following proton beam therapy in pediatric patients. To our knowledge, only a few other reported cases of radiation-induced moyamoya syndrome following proton beam therapy exist in the current literature. While rare, radiation-induced moyamoya syndrome can occur in the pediatric population with newer techniques like proton beam radiotherapy. Accordingly, patients and their families should be informed about this potential complication prior to all forms of radiation treatment.

Strategies to improve the quality of survival for childhood brain tumour survivors

BACKGROUND

Tumours of the central nervous system (CNS) are the most frequent solid tumours and the second most frequent type of cancer in children and adolescents. Overall survival has continuously improved in Germany, since an increasing number of patients have been treated according to standardised, multicentre, multimodal treatment recommendations, trials of the German Paediatric Brain Tumour Consortium (HIT-Network) or the International Society of Paediatric Oncology-Europe (SIOP-E) during the last decades. Today, two out of three patients survive. At least 8000 long-term childhood brain tumour survivors (CBTS) are currently living in Germany. They face lifelong disease- and treatment-related late effects (LE) and associated socioeconomic problems more than many other childhood cancer survivors (CCS).

METHOD

We review the LE and resulting special needs of this particular group of CCS.

RESULTS

Despite their increasing relevance for future treatment optimisation, neither the diversity of chronic and cumulative LE nor their pertinent risk factors and subsequent impact on quality of survival have yet been comprehensively addressed for CBTS treated according to HIT- or SIOP-E-protocols. Evidence-based information to empower survivors and stakeholders, as well as medical expertise to manage their individual health care, psychosocial and educational/vocational needs must still be generated and established.

CONCLUSION

The establishment of a long-term research- and care network in Germany shall contribute to a European platform, that aims at optimising CBTSs' transition into adulthood as resilient individuals with high quality of survival including optimal levels of activity, participation and acceptance by society.