EANO guidelines for the diagnosis and treatment of ependymal tumors

Long-Term Outcomes and Quality of Life of Children With Intracranial Ependymoma Treated With Pencil Beam Scanning Proton Therapy

BACKGROUND

Ependymoma is a common brain tumor in children and adolescents. Adjuvant radiation therapy improves prognosis but carries potential toxicity risks, particularly for young patients. Proton therapy (PT) offers better conformal treatments and reduces dose exposure compared to traditional photon radiotherapy.

PROCEDURE

This study retrospectively analyzed long-term outcomes of children treated with pencil beam scanning (PBS) PT for intracranial ependymomas (EPs) at the Paul Scherrer Institute (PSI) between 2004 and 2022.

RESULTS

We identified 119 children, with most having infra-tentorial tumors (70.6%) and anaplastic ependymomas (82.4%). The median PT dose was 59.4 GyRBE delivered in 1.8 GyRBE/fraction. Follow-up at 5 years showed 70.4% local control, 63.5% progression-free survival (PFS), and 82.2% overall survival (OS). OS was better with upfront than relapse treatment (83% vs. 69.8%; p = 0.024), and complete resection improved both LC (74% vs. 65.1%; p = 0.033) and PFS (67.5% vs. 57.1%; p = 0.049) compared to subtotal resection. No hearing loss was observed with cochlea Dmax not exceeding 48 GyRBE (10.5% vs. 0%; p = 0.0097), whereas the risk of hormone deficiency was significantly increased with pituitary Dmean above 38 GyRBE (33.3% vs. 6.0%; p = 0.00007). Most patients (72.3%) had no late toxicity. Four secondary brain malignancies (3.4%) occurred within a median of 9.3 years after PT (range: 3.7-15). Quality of life 5 years after PT was good in older (>4 years) patients, though proxy-rated social functioning was poorer than the norm group.

CONCLUSION

Intracranial PBS-PT offers excellent tumor control and low late toxicity, and revealed good overall quality of life in children with ependymoma, both by proxy- and self-assessment.

Individualized therapeutic approaches for relapsed and refractory pediatric ependymomas: a single institution experience

PURPOSE

This retrospective study aims to show a real-life single-center experience with clinical management of relapsed pediatric ependymomas using results from comprehensive molecular profiling.

METHODS

Eight relapsed ependymomas were tested by whole exome sequencing, RNA sequencing, phosphoproteomic arrays, array comparative genome hybridization, and immunohistochemistry staining for PD-L1 expression and treated with an individualized approach implementing targeted inhibitors, immunotherapy, antiangiogenic metronomic treatment, or other agents. Treatment efficacy was evaluated using progression-free survival (PFS), overall survival (OS), survival after relapse (SAR), and PFS ratios.

RESULTS

Genomic analyses did not reveal any therapeutically actionable alterations. Surgery remained the cornerstone of patient treatment, supplemented by adjuvant radiotherapy. Empiric agents were chosen quite frequently, often involving drug repurposing. In six patients, prolonged PFS after relapse was seen because of immunotherapy, MEMMAT, or empiric agents and is reflected in the PFS ratio ≥ 1. The 5-year OS was 88%, the 10-year OS was 73%, the 2-year SAR was 88%, and the 5-year SAR was 66%.

CONCLUSION

We demonstrated the feasibility and good safety profile. Promising was the effect of immunotherapy on ZFTA-positive ependymomas. However, further research is required to establish the most effective approach for achieving sustained remission in these patients.

Radiosurgery for central nervous system ependymomas: a systematic review and meta-analysis

BACKGROUND

Ependymomas, rare malignant central nervous system (CNS) lesions (2-6% of primary CNS tumors), are typically treated with maximal safe resection followed by fractionated radiation therapy. Stereotactic radiosurgery (SRS) has emerged as an alternative, particularly in recurrent or residual cases. This study evaluates the safety and efficacy of SRS for CNS ependymomas, while also identifying key prognostic factors.

METHOD

A systematic search was conducted to identify studies that evaluated the efficacy and safety of SRS in WHO Grade 2/3 CNS ependymoma patients. Random-effect meta-analysis was employed.

RESULTS

Fourteen studies with 298 patients and 496 lesions were included. Our meta-analysis demonstrated an overall local tumor control (LTC) rate of 72% (95% CI: 65-79%). LTC rates at 1, 3, and 5 years were 83% (95% CI: 76-88%), 72% (95% CI: 64-78%), and 69% (95% CI: 61-76%), respectively. Progression-free survival (PFS) rates at 1, 3, and 5 years were estimated at 67% (95% CI: 50-80%), 56% (95% CI: 48-64%), and 51% (95% CI: 39-63%), respectively. Additionally, the 5-year overall survival (OS) rate was 58% (95% CI: 48-67%). The incidence of adverse radiation events (ARE) was 20% (95% CI: 12-31%). Meta-regression showed older age correlated with improved tumor control (P = 0.02) and lower ARE (P = 0.06) and radionecrosis rates (P < 0.01), while larger tumor volumes (P = 0.03) and anaplastic histology (P = 0.01) were associated with poorer PFS.

CONCLUSIONS

SRS is a reasonably valuable therapeutic option in the multimodal management of WHO Grade 2/3 CNS ependymomas, especially for individuals with inoperable, recurrent, or residual lesions. Key patient and tumor characteristics have been analyzed to determine factors potentially impacting treatment outcomes.

The association between postoperative photon radiotherapy dose and disease control and salvage treatment in pediatric and adolescent ependymoma: a multi-institutional investigation

PURPOSE

We characterized the association between photon radiation dose (< 59.4 versus ≥ 59.4 Gy) and outcomes in intracranial ependymoma. We also examined factors associated with survival after relapse.

METHODS

This multi-institutional retrospective study included patients age ≤ 21 years who received postoperative definitive-intent photon radiotherapy for posterior fossa ependymoma between 1997 and 2021. Clinical characteristics were obtained from medical records. Five-year overall (OS) and progression-free (PFS) survival were estimated using the Kaplan-Meier method. Factors associated with progression after radiotherapy, including dose < 59.4 versus ≥ 59.4 Gy, were analyzed using Fine and Gray's proportional subhazards model. Factors associated with post-relapse survival were explored using the Cox proportional-hazards model.

RESULTS

We identified 45 patients meeting inclusion criteria; 48.9% received ≥ 59.4 Gy. There was no difference in 5-year OS or PFS between those who received < 59.4 Gy versus ≥ 59.4 (OS 49.0% vs. 82.9%, p = 0.11; PFS 36.4% vs. 63.9%, p = 0.08); however, there was a trend towards worse 5-year OS and PFS among patients with grade 2 ependymoma who received < 59.4 Gy (OS 48.8% vs. 88.9%, p = 0.06, PFS 40.0% vs. 83.1%, p = 0.08). Only age > 4 years at diagnosis (subdistribution hazard ratio [SHR]: 0.40, p = 0.03) was associated lower risk of progression. Following radiotherapy, 24 patients relapsed. Receipt of salvage systemic therapy was associated with worse post-relapse OS on multivariable analysis (HR = 2.84, p = 0.04).

CONCLUSION

Underlying biological factors such as age and molecular subtype may hold greater prognostic significance than radiation dose in pediatric ependymoma. Regardless, recurrences are common and outcomes remain poor. Further research into optimal management of relapsed disease is critical.

Strong nuclear expression of HOXB13 is a reliable surrogate marker for DNA methylome profiling to distinguish myxopapillary ependymoma from spinal ependymoma

Spinal ependymoma and myxopapillary ependymoma are the two most common spinal ependymal tumor types that feature distinct histological characteristics, genetic alterations and DNA methylation profiles. Their histological distinction may be difficult in individual cases and molecular diagnostic assessment, in particular DNA methylome profiling, may then be required to assign the correct diagnosis. Expression of the homeobox gene HOXB13 at the mRNA and protein levels has been reported as a frequent finding in myxopapillary ependymoma that may serve as a diagnostic marker for these tumors. Here, we evaluated the diagnostic role of HOXB13 immunostaining in 143 spinal neoplasms, comprising 54 histologically classified myxopapillary ependymomas, 46 histologically classified spinal ependymomas, and various other tumor types. Immunohistochemical results for HOXB13 protein were compared to molecular findings obtained by bead array-based DNA methylation and DNA copy number profiling, as well as next generation gene panel sequencing-based mutational analysis. Our findings indicate strong nuclear HOXB13 expression as a reliable diagnostic marker for molecularly confirmed myxopapillary ependymoma. Moreover, we provide evidence that differential HOXB13 protein expression is related to differential HOXB13-associated CpG site methylation in myxopapillary vs. spinal ependymomas, which can be assessed by targeted DNA methylation analysis. Taken together, immunohistochemistry for HOXB13 protein expression and targeted DNA methylation analysis of HOXB13 represent useful surrogate approaches that may substitute for DNA methylome profiling in routine diagnostics and facilitate precise classification of spinal ependymal tumors. In particular, strong nuclear HOXB13 immunoreactivity may serve as a novel diagnostic criterion for the classification of myxopapillary ependymoma.

Geriatric patients undergo surgery less and have worse survival outcomes with intramedullary ependymoma: A surveillance, epidemiology, and end results database analysis

OBJECTIVE

Intramedullary ependymomas account for ∼50 % of all primary tumors in the spinal cord. Though gross total resection has become mainstay, other predictors of survival remain poorly characterized. The present study aims to perform a survival analysis and compare prognostic factors across pediatric, adult and geriatric cohorts.

METHODS

The Surveillance, Epidemiology, and End Results database was employed to isolate cases of intramedullary ependymomas from 2000 to 2021. Cases were grouped based on age: 0-19 years=pediatric, 20-64 years=adult, 65 + years=geriatric. Kaplan Meier followed by multivariate cox regression analyses were used to identify survival trends. Univariate comparison analyses compared age cohorts.

RESULTS

2045 cases were included. Geriatric patients demonstrate increased risk of mortality (pediatric vs geriatric: HR=0.23, CI [0.13-0.39], p < 0.001; adult vs geriatric: HR=0.18, CI [0.15-0.23], p < 0.001). Compared to adult patients (92.7 %), geriatric patients (85.2 %) underwent significantly less surgery (p < 0.001). Sex did not influence pediatric or geriatric survival nor did surgery statistically impact pediatric survival, but otherwise surgery not performed, male patients and grade III tumors significantly worsened overall and age-specific survival. Surgery performed in a pediatric patient led to a longer mean survival of 19.8 months, which is clinically relevant despite not meeting statistical significance. Year of diagnosis did not impact overall (p = 0.79) nor age-specific survival (pediatric: p = 0.98, adult: p = 0.91, geriatric: p = 0.11).

CONCLUSIONS

Geriatric patients suffer from worse survival than those of younger age. Surgery decreases mortality, yet less geriatric patients are receiving surgical resection. No significant survival gains have been made over the last two decades among any age. Further study is needed to optimize medical management to compliment surgical resection and surgery should be considered more often in geriatric patients to improve survival.

Transcriptomics and epigenomics datasets of primary brain cancers in formalin-fixed paraffin embedded format

The access of public omics-based datasets is of paramount importance in brain cancer research as allows the proposal and validation of both biomarkers and therapeutic targets in gliomas, especially in the most prevalent and aggressive glioblastomas. Taking profit of current advances in next generation sequencing and DNA methylation profiling, we have created datasets from approximately 150 formalin-fixed paraffin embedded (FFPE) tumours. These datasets enable for the first time integrative transcriptional and epigenetics studies in a context that consider the degradation and fixation-derived chemical alterations of the most extended archiving format in hospitals, and provide an independent cohort from current public databases for further validation of putative novel biomarkers. Alongside with the most profusely known glioblastomas, astrocytomas and oligodendrogliomas, we have also included for comparison purposes few examples of rare tumours that are often neglected in brain cancer research. Taken together, we provide a valuable tool to explore combined gene expression and DNA methylation patterns in the study of gliomas and glioneuronal tumours.

Addressing the role of surgery in brain tumour trials: A report from the neurosurgery committee of the EORTC brain tumour group

The Brain Tumor Group (BTG) of the European Organization for Research and Treatment of Cancer (EORTC) conducts academic clinical trials and translational research to improve clinical management of patients with primary and secondary brain tumors. The EORTC BTG has traditionally played an important role in providing evidence and thus advancing the field, albeit with a main focus on radiotherapy and pharmacotherapy in gliomas. Although examples of well-designed neuro-oncological surgical trials can be found, evidence in surgical neuro-oncology predominantly includes data from uncontrolled prospective series or retrospective cohorts. By means of a thorough literature and EORTC database review, we demonstrate, firstly, that while the pathway of the neuro-oncology patient most often starts with neurosurgery, its several aspects have traditionally been poorly acknowledged in clinical trials in neuro-oncology. We also show that the definitions and methods of assessment vary greatly between studies, limiting generalizability. The newly established Neurosurgery Committee of the EORTC BTG aims to address this gap by increasing the number of prospective surgical trials, but also the involvement of neurosurgeons in clinical trial design, promoting standardized terminology for description of the surgical aspects, including extent of resection. We will also explore alternative trial designs when randomization is deemed difficult, as well as focus on defining surgical quality indicators that influence outcome. By addressing these challenges, the committee aims to enhance the quality of neurosurgical evidence in neuro-oncology and define optimal surgical methods and standards of care. This should ultimately improve outcomes and quality of life for patients with brain tumors through evidence-based surgical interventions.

Characteristics and therapeutic profile of the patients with upper cervical spinal cord ependymoma from the medulla oblongata to C4: A cohort of 108 cases

BACKGROUND

Upper cervical spinal ependymomas (uCSE) is routinely identified as intramedullary ependymomas located from the oblongata medulla to C4 level. Our study aimed to report the outcomes and treatment profiles of uCSE from our cohort of uCSE patients.

METHODS

This retrospective observational study included 108 patients with upper cervical spinal ependymomas (uCSE) who underwent surgery at Huashan Hospital from 2008 to 2022. Demographic and clinical data were collected to identify risk factors may associated with post-operative spinal cord function, quality of life and respiratory function.

RESULTS

The mean age of included patients was 44.30 ± 12.71 years old. The most common uCSE was ependymoma (103 of 108, 95.37 %), followed by subependymoma (3 of 108, 2.78 %) and anaplastic Ependymoma (2 of 108, 1.85 %). Age (P = 0.003), sex (P = 0.004), duration of symptoms (P = 0.010), pre-operative bladder functions (P = 0.012), post-operative pneumonia (P = 0.013) and Carbon Dioxide Retention (CDR) (P = 0.004) could independently correlate with Iiving quality of uCSE patients. Post-operative spinal cord function was associated with pneumonia immediately after operation (P = 0.017). In addition, post-operative pneumonia correlated with tumor location (P = 0.048), pre-operative McCormick scores (P = 0.008)/ motor functions (P = 0.022)/ NRS scores (P = 0.020), and tracheotomy immediately after operation (P < 0.001). Tracheotomy immediately after operation was associated with tumor location (P = 0.023), unsteady walking (P = 0.033), pre-operative NRS scores (P = 0.029), post-operative pneumonia (P < 0.001) and CDR (P < 0.001).

CONCLUSION

Within uCSE patients, post-operative quality of life is associated with pre-operative spinal cord function and symptom duration, which emphasizing the importance of early intervention. Their post-operative respiratory dysfunctions also correlated with post-operative spinal cord function and quality of life.

Central nervous system tumors in adolescents and young adults: A Society for Neuro-Oncology Consensus Review on diagnosis, management, and future directions

Adolescents and young adults (AYAs; ages 15-39 years) are a vulnerable population facing challenges in oncological care, including access to specialized care, transition of care, unique tumor biology, and poor representation in clinical trials. Brain tumors are the second most common tumor type in AYA, with malignant brain tumors being the most common cause of cancer-related death. The 2021 WHO Classification for central nervous system (CNS) Tumors highlights the importance of integrated molecular characterization with histologic diagnosis in several tumors relevant to the AYA population. In this position paper from the Society for Neuro-Oncology (SNO), the diagnosis and management of CNS tumors in AYA is reviewed, focusing on the most common tumor types in this population, namely glioma, medulloblastoma, ependymoma, and CNS germ cell tumor. Current challenges and future directions specific to AYA are also highlighted. Finally, possible solutions to address barriers in the care of AYA patients are discussed, emphasizing the need for multidisciplinary and collaborative approaches that span the pediatric and adult paradigms of care, and incorporating advanced molecular testing, targeted therapy, and AYA-centered care.

Glial transformation of a DNET: About a case

Dysembryoplastic neuroepithelial tumors (DNETs) are benign cortical tumors frequently associated with medically incurable focal epilepsy. These tumors occur most commonly in children. Given the fact that they rarely become malignant, the long-term prognosis in terms of mortality is excellent, however its similar appearance with other tumors of the central nervous system increases the potential for misdiagnosis and the risk of a pejorative clinical evolution. Our patient underwent partial resection of the lesion with a pathology study revealing a WHO grade 2 cortical ependymoma, reflecting the malignant transformation of the tumor.

Prognostic Factors and Nomogram for Malignant Brainstem Ependymoma: A Population-Based Retrospective Surveillance, Epidemiology, and End Results Database Analysis

PURPOSE

This study aimed to identify prognostic factors and develop a nomogram for survival in patients with brainstem ependymoma.

METHODS

Data of 652 patients diagnosed with brainstem ependymoma extracted from the Surveillance, Epidemiology, and End Results (SEER) registry from 2000 to 2020 were analyzed. Univariate and multivariable Cox regression analyses were performed to examine factors influencing overall survival (OS). Receiver operating characteristic curve (ROC) and calibration curves were used to verify the nomogram. The Kaplan-Meier method was used to analyze OS based on treatment methods stratification or different age patterns.

RESULTS

Six independent prognostic factors of patients with brainstem ependymoma were identified, including age, race, marital status, radiation, gross total resection (GTR), and histology. A comprehensive nomogram model was developed utilizing these predictors identified through multivariable Cox regression analysis. Furthermore, we found that patients with GTR have improved overall survival than patient with no surgery and biopsy only or with partial resection (GTR vs. no: p = 0.0004, GTR vs. partial resection: p = 0.022). Patients with radiation have improved overall survival than patient without radiation (p = 0.00013). Patients with GTR combined radiation therapy have improved overall survival than patient without or with GTR or radiation therapy only (p < 0.0001). Different treatment methods have no significant difference in the overall survival probability of the elderly group.

CONCLUSIONS

Individuals who are Black and anaplastic ependymomas were negative risk factors for brainstem ependymoma associated with an increased risk of mortality. Patients aged < 50 years with GTR and radiation always had better survival.

Evaluation of pediatric spinal ependymomas: A 25-year retrospective observational study

This study aims to evaluate the clinical and radiological features, histopathological characteristics, treatment modalities, and their effectiveness, as well as long-term follow-up results of pediatric spinal ependymomas treated at a single institution. In this retrospective study, medical records of 14 pediatric patients (3 females and 11 males) who were surgically treated for spinal ependymoma in our institution between 1995 and 2020 were reviewed. Data regarding age, gender, presenting symptoms and signs, radiological findings, postoperative status, extent of resection, histopathological grading, recurrence, tumor growth, seeding, and adjuvant treatment were collected and analyzed. Six patients had myxopapillary ependymoma, 7 patients had grade II ependymoma, and 1 had grade III ependymoma. Median age at diagnosis was 10.5 (range, 1-15) years. The most common presenting symptoms and signs were axial and radicular pain, paresis, and first motor neuron involvement. In 10 patients, gross total tumor resection was achieved. Five patients underwent additional surgeries for disease progression (recurrence or residual tumor growth). Most of the patients who had no disease progression were treated with gross total resection. Two patients experienced seeding. One patient who had a grade III tumor and did not achieve gross total resection died during follow-up. Pediatric spinal ependymomas are uncommon tumors with relatively benign course. Gross total resection should be the primary goal of surgery since it may prevent disease progression, and in case it fails, progression occurs later than those that were treated with subtotal resection.

Spinal Intramedullary Tumors

BACKGROUND

Intramedullary tumors are a subgroup of spinal tumors and are associated with high morbidity and mortality. The estimated incidence of spinal tumors in general is 0.74 to 1.6 per 100 000 persons per year, with intramedullary tumors making up 10% to 30% of the total. The diagnosis is often delayed because of the insidious onset of symptoms, which are often nonspecific at first.

METHODS

This review is based on pertinent publications about intramedullary tumors that were retrieved by a selective search in the PubMed database.

RESULTS

Intramedullary tumors often cause diffuse neurologic symptoms of gradually increasing severity, progressing, in advanced cases, to a complete spinal cord transection syndrome. Magnetic resonance imaging of the spine without and with intravenous contrast is the standard diagnostic technique. The histopathological origin of most intramedullary tumors is from glial cells, but other types of intramedullary tumor exist as well. The primary treatment of all intramedullary tumors is surgical resection. 9% to 34% of patients may experience a worse neurological deficit after surgery than before, but such problems resolve completely in 25% to 41% of cases. The extent of resection is the main factor affecting the risk of tumor recurrence and progression. The extent of resection also determines the possible indication for adjuvant treatment, which is needed, in particular, for high-grade and subtotally resected tumors, and for those that display progression. The treatment of intramedullary tumors is based on case series, retrospective analyses, and case reports, as randomized trials are lacking.

CONCLUSION

Patients with intramedullary tumors should be cared for, as much as possible, in the setting of prospective, uniform studies of their spontaneous course and the outcomes after treatment. This will yield better evidence on the treatment of these tumors in the future.

Spontaneous ependymoma in a free-ranging juvenile black-horned capuchin (Sapajus nigritus)

A young free-ranging black-horned capuchin (Sapajus nigritus) with a history of ataxia, anisocoria, diminished threat and pupil reflexes and increased cranial circumference was referred for evaluation to the Medicine and Wildlife Conservation Section, Federal University of Paraná, Paraná, Brazil. Due to the clinical presentation and radiographic findings of hydrocephalus, euthanasia was performed. Necropsy revealed a dark red mass (1.5 × 1.8 cm) in the region of the third ventricle and marked dilation of the lateral ventricles. Histopathological findings were characterized by proliferation of ciliated round cells with eosinophilic cytoplasm, as well as the formation of ependymal rosettes and pseudorosettes. In some areas the cells contained brown cytoplasmic pigment, which stained with Fontana-Masson. The neoplastic cells were immunoreactive for glial fibrillary acidic protein and negative for pancytokeratin. Considering the anatomopathological and immunohistochemical findings, the diagnosis was ependymoma grade II with melanocytic features, which is the first report of this neoplasm in any member of the genus Sapajus.

Measuring the diagnostic management and follow-up imaging for glioma patients across Belgian hospitals between 2016 and 2019

OBJECTIVES

This study aimed to assess the diagnostic management and follow-up imaging for glioma patients across Belgian hospitals by calculating process indicators.

METHODS

Patients with newly diagnosed glioma in Belgium (2016-2019) were selected from the Belgian Cancer Registry. The National Social Security Number served as unique patient identifier, linking the Registry to vital status and reimbursement data. Nine measurable process related to diagnosis and follow-up imaging were identified, with reformulations for 7 due to data limitations. For each indicator, technical documentation sheets, containing all required details (rationale, numerator and denominator, target, limitations, benchmarking, subgroup analyses) were developed, reviewed by a multidisciplinary expert panel, and validated in six pilot hospitals. Per indicator, patients were assigned to the most relevant hospital per indicator using allocation algorithms.

RESULTS

Results for process indicators assessing MRI use in glioma diagnosis and follow-up aligned with predefined targets (90%), except for early postoperative MRI (48.5% vs. target 90%). Mandatory reporting of the WHO performance status (89.3% vs. target 100%) and performance of full-spine (43.6% vs. target 90%) and follow-up MRI (73.5% vs. target 90%) in ependymoma were suboptimal. The largest variability across centers was noted for the indicator on early postoperative MRI.

CONCLUSION

This calculation of process indicators identified opportunities for improvement in diagnosis and follow-up imaging for glioma patients in Belgium. Monitoring indicator results and providing individual feedback reports to the Belgian hospitals invites neuro-oncology care teams and hospital managements to reflect on their results and to take measures to continuously improve care for glioma.

Clinical, magnetic resonance imaging, histopathological features, treatment options and outcome of spinal ependymoma in dogs: 8 cases (2011-2022)

OBJECTIVES

This study aims to report on the clinical magnetic resonance imaging, histological features, treatment options and outcomes of spinal ependymomas in dogs.

MATERIALS AND METHODS

Retrospective evaluation of medical records from dogs histologically confirmed spinal ependymomas with clinical presentations, magnetic resonance imaging findings, histological aspects, treatment options and outcomes.

RESULTS

Eight dogs presented with acute to subacute onset of para- or tetraparesis. Magnetic resonance imaging findings included intramedullary oval-shaped space-occupying lesions that appeared hyperintense on T2-weighted images isointense on T1-weighted images and exhibited marked homogeneous or ring contrast enhancement. A peculiar feature, previously described only in human ependymomas, was observed in three patients - a T2-weighted hypointense rim, termed hemosiderin cap sign. Haematomyelia with necrotic foci was observed in one dog. Surgery, when performed, enabling a definitive intra-vitam diagnosis. Histological examination revealed that rosettes and pseudo-rosettes as disposition of neoplastic cells were the most common features reported. Furthermore, cerebrospinal fluid metastases were identified in one case.

CLINICAL SIGNIFICANCE

Clinical and histopathological findings in our case series were consistent with those previously reported in the literature. Magnetic resonance imaging features were fairly typical and highly suggestive of spinal ependymomas. The hemosiderin cap sign may aid in the presumptive intra-vitam diagnosis of these rare spinal tumours. Additionally, we described cerebrospinal fluid spread of neoplastic cells and subsequent multifocal or metastasis presentations. Surgery offered a dual benefit by facilitating intra-vitam diagnosis and, in some cases, extending survival time.

Survival Factors in 1580 Adults with Spinal Ependymoma: Insights from a Multicenter Oncology Database

BACKGROUND

Using a multi-institutional oncology database, we investigate the survival rates and the impacts of demographic, clinical, and management characteristics on overall survival among adult patients diagnosed with spinal ependymoma.

METHODS

Utilizing the SEER registry, patients with histologically or radiologically confirmed ependymomas were included. Factors impacting overall survival were analyzed using Kaplan-Meier survival curves and log-rank statistical analyses.

RESULTS

A total of 1,580 patients were included. Their mean ± standard deviation age was 46.68 ± 15.96 years, and 51.1% were women. Gross total resection (GTR) was achieved in 66.4% of patients. The 5- and 10-year survival rates were 96.7% and 95.4%, respectively. A multivariable backward Cox regression showed that age ≥65 years was a significant predictor for mortality (hazard ratio [HR]: 3.93; 95% confidence interval [CI]: 2.21-7.00; P < 0.001). Likewise, tumor grade 3 (HR: 6.36; 95% CI: 1.95-20.76; P = 0.002), tumor grade 4 (HR: 7.74; 95% CI: 3.97-15.11; P < 0.001), presence of extra-neural metastasis (HR: 13.81; 95% CI: 3.67-51.96; P < 0.001), and receiving radiotherapy (HR: 2.50; 95% CI: 1.50-4.19; P < 0.001) were significant risk factors for mortality, while GTR was significantly associated with improved overall survival compared with subtotal resection or nonsurgical management (HR: 0.42; 95% CI: 0.25-0.73; P = 0.002). There were no significant effects for gender, race, marital status, income, residential area, chemotherapy, tumor size, and the presence of other benign or malignant tumors on the survival hazards (P > 0.05 for each).

CONCLUSION

Early diagnosis and surgical management of spinal ependymomas, such as GTR, were associated with remarkable survival benefits. Old age, high-grade spinal ependymoma, and extra-neural metastasis were associated with worse overall survival, whereas radiotherapy's role remains unclear.

Spinal ependymal tumors

Spinal ependymomas are strictly to be subdivided into intramedullary lesions and extramedullary lesions as they are histologically and genetically distinct. Whereas the intramedullary lesions (SPE) are assigned to the WHO grade 2 and very rarely grade 3, the extramedullary lesions or myxopapilary tumors (MPE) are only as recently also assigned to WHO grade 2. The major difference is that in general, an intramedullary lesion of grade 2 remains confined to the local site of origin, even when rarely recurring after complete resection. In contrast, the MPEs have the capacity to spread throughout the cerebrospinal fluid compartment but can also be controlled by cautious complete resection. We here review the clinical features of spinal ependymomas, contrasting the entities, and describe the treatment found best from the literature to manage these lesions including interdisciplinary approaches.

Fractionated radiotherapy for spinal tumors: A literature review regarding spinal glioma, ependymoma, and meningioma

Radiation therapy plays a vital role in the management of primary spinal tumors in adults. However, due to the rarity of these tumor types, the literature on optimal treatment indications and radiation doses is limited. Many treatment recommendations are extrapolated from their cranial counterparts, where more data are available. Despite the absence of prospective data, numerous retrospective studies have provided valuable insights to guide treatment decisions until more comprehensive data become available. This review provides an overview of the most relevant literature, with a specific focus on spinal gliomas, ependymomas, and meningiomas, in the context of the role of radiation therapy.

Conditional survival estimates for ependymomas reveal the dynamic nature of prognostication

BACKGROUND

Traditional survival analysis is frequently used to assess the prognosis of ependymomas (EPNs); however, it may not provide additional survival insights for patients who have survived for several years. Thus, the conditional survival (CS) pattern of this disease is yet to be further investigated. This study aimed to evaluate the improvement of survival over time using CS analysis and develop a CS-based nomogram model for real-time dynamic survival estimation for EPN patients.

METHODS

Data on patients with EPN were collected from the Surveillance, Epidemiology, and End Results (SEER) database. In order to construct and validate the model effectively, the selected patients were randomly divided at 7:3 ratio. CS is defined as the probability of surviving for a specified time period (y years) after initial diagnosis, given that the patient has survived x years. The CS pattern of EPN patients were explored. Then, the least absolute shrinkage and selection operator (LASSO) regression method with tenfold cross-validation was employed to identify prognostic predictors. Multivariate Cox regression was employed to develop a CS-based nomogram model, and we used this model to quantify EPN patient risk. Finally, the performance of the prediction model was also evaluated and verified.

RESULTS

In total, 1829 patients diagnosed with EPN were included in the study, with 1280 and 549 patients in the training and validation cohorts, respectively. The CS analysis demonstrated that patients' OS saw gradual improvements over time. With each additional year of survival post-diagnosis, the 10-year survival rate of EPN patients saw an increase, updating from 74% initially to 79%, 82%, 85%, 87%, 89%, 91%, 93%, 96%, and 98% (after surviving for 1-9 years, respectively). The LASSO regression model, which implements tenfold cross-validation, identified 7 significant predictors (age, tumor grade, tumor site, tumor extension, tumor size, surgery and radiotherapy) to develop a CS-based nomogram model. And further risk stratification was conducted based on nomogram model for these patients. Furthermore, this survival prediction model was successfully validated.

CONCLUSION

This study described the CS pattern of EPN patients and highlighted the gradual improvement of survival observed over time for long-term survivors. We also developed the first novel CS-nomogram model that enabled individualized and real-time prognosis prediction. But patients must be counselled that individual circumstances may not always accurately reflect the findings of the nomogram.

Machine learning-based nomogram for distinguishing between supratentorial extraventricular ependymoma and supratentorial glioblastoma

Objective

To develop a machine learning-based nomogram for distinguishing between supratentorial extraventricular ependymoma (STEE) and supratentorial glioblastoma (GBM).

Methods

We conducted a retrospective analysis on MRI datasets obtained from 140 patients who were diagnosed with STEE (n=48) and GBM (n=92) from two institutions. Initially, we compared seven different machine learning algorithms to determine the most suitable signature (rad-score). Subsequently, univariate and multivariate logistic regression analyses were performed to identify significant clinical predictors that can differentiate between STEE and GBM. Finally, we developed a nomogram by visualizing the rad-score and clinical features for clinical evaluation.

Results

The TreeBagger (TB) outperformed the other six algorithms, yielding the best diagnostic efficacy in differentiating STEE from GBM, with area under the curve (AUC) values of 0.735 (95% CI: 0.625-0.845) and 0.796 (95% CI: 0.644-0.949) in the training set and test set. Furthermore, the nomogram incorporating both the rad-score and clinical variables demonstrated a robust predictive performance with an accuracy of 0.787 in the training set and 0.832 in the test set.

Conclusion

The nomogram could serve as a valuable tool for non-invasively discriminating between STEE and GBM.

Impact of Molecular Subgroups on Prognosis and Survival Outcomes in Posterior Fossa Ependymomas: A Retrospective Study of 412 Cases

BACKGROUND AND OBJECTIVES

Posterior fossa ependymomas (PFEs) are rare brain tumors classified as PF-EPN-A (PFA) and PF-EPN-B (PFB) subgroups. The study aimed to evaluate the prognosis and survival outcomes in PFEs, with a focus on the impact of molecular subgroups.

METHODS

A retrospective study was conducted on 412 patients with PFEs. Kaplan-Meier survival analyses were conducted to evaluate the overall survival (OS) and progression-free survival. Cox regression analyses were conducted to assess the prognostic factors. A nomogram was developed to predict the OS rates of PFEs.

RESULTS

The study revealed significant differences between PFA and PFB in patient and tumor characteristics. PFAs were associated with poorer OS (hazard ratios [HR] 3.252, 95% CI 1.777-5.950, P < .001) and progression-free survival (HR 4.144, 95% CI 2.869-5.985, P < .001). World Health Organization grade 3 was associated with poorer OS (HR 2.389, 95% CI 1.236-4.617, P = .010). As for treatment patterns, gross total resection followed by radiotherapy or the combination of radiotherapy and chemotherapy yielded the most favorable OS for PFA ( P = .025 for both), whereas gross total resection followed by radiotherapy rather than observation showed improved OS for PFB ( P = .046). The nomogram demonstrated a high degree of accuracy and discrimination capacity for the prediction of OS rates for up to 10 years. In addition, 6 cases of PFA (3.51%) with H3K27M mutations were identified.

CONCLUSION

PFAs demonstrate worse prognosis and survival outcomes compared with PFBs. Both PFAs and PFBs necessitate maximal resection followed by intensive adjuvant therapies in long-term effects.

Navigated intraoperative ultrasound in pediatric brain tumors

PURPOSE

The aim of this study was to evaluate the diagnostic value and accuracy of navigated intraoperative ultrasound (iUS) in pediatric oncological neurosurgery as compared to intraoperative magnetic resonance imaging (iMRI).

METHODS

A total of 24 pediatric patients undergoing tumor debulking surgery with iUS, iMRI, and neuronavigation were included in this study. Prospective acquisition of iUS images was done at two time points during the surgical procedure: (1) before resection for tumor visualization and (2) after resection for residual tumor assessment. Dice similarity coefficients (DSC), Hausdorff distances 95th percentiles (HD95) and volume differences, sensitivity, and specificity were calculated for iUS segmentations as compared to iMRI.

RESULTS

A high correlation (R = 0.99) was found for volume estimation as measured on iUS and iMRI before resection. A good spatial accuracy was demonstrated with a median DSC of 0.72 (IQR 0.14) and a median HD95 percentile of 4.98 mm (IQR 2.22 mm). The assessment after resection demonstrated a sensitivity of 100% and a specificity of 84.6% for residual tumor detection with navigated iUS. A moderate accuracy was observed with a median DSC of 0.58 (IQR 0.27) and a median HD95 of 5.84 mm (IQR 4.04 mm) for residual tumor volumes.

CONCLUSION

We found that iUS measurements of tumor volume before resection correlate well with those obtained from preoperative MRI. The accuracy of residual tumor detection was reliable as compared to iMRI, indicating the suitability of iUS for directing the surgeon's attention to areas suspect for residual tumor. Therefore, iUS is considered as a valuable addition to the neurosurgical armamentarium.

TRIAL REGISTRATION NUMBER AND DATE

PMCLAB2023.476, February 12th 2024.

Comprehensive genetic profiling and molecularly guided treatment for patients with primary CNS tumors

Despite major advances in molecular profiling and classification of primary brain tumors, personalized treatment remains limited for most patients. Here, we explored the feasibility of individual molecular profiling and the efficacy of biomarker-guided therapy for adult patients with primary brain cancers in the real-world setting within the molecular tumor board Freiburg, Germany. We analyzed genetic profiles, personalized treatment recommendations, and clinical outcomes of 102 patients with 21 brain tumor types. Alterations in the cell cycle, BRAF, and mTOR pathways most frequently led to personalized treatment recommendations. Molecularly informed therapies were recommended in 71% and implemented in 32% of patients with completed molecular diagnostics. The disease control rate following targeted treatment was 50% and the overall response rate was 30%, with a progression-free survival 2/1 ratio of at least 1.3 in 31% of patients. This study highlights the efficacy of molecularly guided treatment and the need for biomarker-stratified trials in brain cancers.

The Role of Radiotherapy, Chemotherapy, and Targeted Therapies in Adult Intramedullary Spinal Cord Tumors

Intramedullary primary spinal cord tumors are rare in adults and their classification has recently evolved. Their treatment most frequently relies on maximal safe surgical resection. Herein, we review, in light of the WHO 2021 classification of central nervous system tumors, the knowledge regarding the role of radiotherapy and systemic treatments in spinal ependymomas, spinal astrocytomas (pilocytic astrocytoma, diffuse astrocytoma, spinal glioblastoma IDH wildtype, diffuse midline glioma H3-K27M altered, and high-grade astrocytoma with piloid features), neuro-glial tumors (ganglioglioma and diffuse leptomeningeal glioneuronal tumor), and hemangioblastomas. In spinal ependymomas, radiotherapy is recommended for incompletely resected grade 2 tumors, grade 3 tumors, and recurrent tumors not amenable to re-surgery. Chemotherapy is used in recurrent cases. In spinal astrocytomas, radiotherapy is recommended for incompletely resected grade 2 astrocytomas and grade 3 or 4 tumors as well as recurrent tumors. Chemotherapy is indicated for newly diagnosed high-grade astrocytomas and recurrent cases. In hemangioblastomas not amenable to surgery, radiotherapy is an effective alternative option. Targeted therapies are playing an increasingly important role in the management of some intramedullary primary spinal cord tumor subtypes. BRAF and/or MEK inhibitors have demonstrated efficacy in pilocytic astrocytomas and glioneuronal tumors, belzutifan in von Hippel-Lindau-related hemangioblastomas, and promising results have been reported with ONC201 in diffuse midline glioma H3-K27M altered.

Stereotactic Radiosurgery for Ependymoma in Pediatric and Adult Patients: A Single-Institution Experience

BACKGROUND AND OBJECTIVES

Ependymoma is commonly classified as World Health Organization grade 2 with the anaplastic variant categorized as grade 3. Incomplete resection or anaplastic features can result in unfavorable outcomes. Stereotactic radiosurgery (SRS) provides a minimally invasive approach for recurrent ependymomas. Our study investigates the efficacy and safety of SRS for grade 2 and 3 ependymomas in pediatric and adult populations.

METHODS

We conducted a retrospective analysis on 34 patients with 75 ependymomas after CyberKnife SRS between 1998 and 2023. Fourteen were pediatric (3-18 years), and 20 were adult (19-75 years) patients. The median age was 21 years, and the median tumor volume was 0.64 cc. The median single-fraction equivalent dose was 16.6 Gy, with SRS administered at 77% of the median isodose line.

RESULTS

After a median follow-up of 42.7 months (range: 3.8-438.3), 22.7% of ependymomas progressed. The 5-year local tumor control rate was 78.1%, varying between 59.6% and 90.2% for children and adults, with grade 2 at 85.9% compared with 58.5% for grade 3 tumors. The 5-year overall survival rate was 73.6%, notably higher in adults (94.7%) than in children (41%), and 100% for grade 2 but decreased to 35.9% for grade 3 patients. The 5-year progression-free survival rate was 68.5%, with 78.3% and 49.2% for adults and children, respectively, and a favorable 88.8% for grade 2, contrasting with 32.6% for grade 3 patients. Symptom improvement was observed in 85.3% of patients. Adverse radiation effects occurred in 21.4% of pediatric patients.

CONCLUSION

Our study supports SRS as a viable modality for pediatric and adult patients with grade 2 and 3 ependymomas. Despite lower local tumor control in pediatric and grade 3 cases, integrating SRS holds promise for improved outcomes. Emphasizing careful patient selection, personalized treatment planning, and long-term follow-up is crucial for optimal neurosurgical outcomes.

Posterior Fossa Ependymoma in a Child with Extensive Chondro-Osseous Metaplasia Occurring at Cerebellopontine Angle and Masquerading as a Vestibular Schwannoma: An Exceptionally Rare Clinicopathological Manifestation with Review of Literature

Ependymoma occurring at the cerebellopontine (CP) angle is an extremely uncommon sight and poses diagnostic and management dilemmas to neurosurgeons, radiologists, and neuropathologists alike. Moreover, the presence of extensive chondro-osseous metaplastic elements in ependymomas is an exceptionally infrequent histopathological manifestation. However, due to the seldom-seen nature of this histomorphological feature, there is no definite consensus regarding its etiopathogenesis and clinical consequences, and there is an extreme scarcity of literature elucidating its clinicopathological spectrum and prognostic significance. Herein, we illustrate an intriguing clinical tale of a 7-year-old male child with posterior fossa ependymoma, central nervous system (CNS) World Health Organization (WHO) grade 3, arising at the right CP angle and masquerading as a vestibular schwannoma, which in itself is a rare presentation, and additionally, exhibiting extensive chondro-osseous metaplasia, which is a very uncommon histomorphological observation. To the best of the authors' knowledge and after a comprehensive literature search, the coexistence of these two rare observations has merely been described once in international literature. This case sheds light on and highlights the importance of keeping ependymoma as a possible differential while coming across CP angle space-occupying lesions. They should be diligently distinguished from schwannomas and other masqueraders that typically occur at this site, as they have diverse management and follow-up protocols, with varying prognostic outcomes for the patients. Moreover, this case also unravels and details the clinicopathological characteristics of a scarcely described feature of chondro-osseous metaplasia in ependymomas.

Ependymomas of the spinal region in adults: Clinical and pathological features and MYCN expression levels in spinal ependymomas and myxopapillary ependymomas

BACKGROUND

Ependymomas (EPNs) of the spinal region are a heterogeneous group of tumors that account for 17.6 % in adults. Four types have been recognized: subependymoma, spinal ependymoma (Sp-EPN), myxopapillary ependymoma (MPE), and Sp-EPN-MYCN amplified, each with distinct histopathological and molecular features.

METHODS

This study investigated the clinical and pathological characteristics and MYCN expression levels of 35 Sp-EPN and MPE cases diagnosed at a tertiary university hospital over a decade-long period.

RESULTS

Twenty-five cases were Sp-EPN and 10 cases were MPE, and were graded as WHO grade 2, except for 1 Sp-EPN case with grade 3 features. The most common symptoms were lower back pain and difficulty in walking. Radiology showed different tumor sizes and locations along the spinal cord, with MPEs exclusively in the lumbosacral region. Surgery was the main treatment, and gross total resection was achieved in all cases except for one. Immunohistochemistry showed low Ki-67 proliferation indices in all cases, and no MYCN expression. During follow-up, 3 (8.6 %) cases recurred and/or metastasized and 5 cases (14.3 %) died. No significant difference was found in disease-free survival or overall survival between Sp-EPN and MPE cases. However, 3 cases with grade 2 histology demonstrated recurrence and/or metastasis, despite the lack of MYCN expression.

CONCLUSION

Our results underscore the multifactorial nature of tumor aggressiveness in EPNs of the spinal region. This study enhances our knowledge of the clinical and pathological features of Sp-EPNs and MPEs and highlights the need for better diagnostic and prognostic markers in these rare tumors.

Brainstem toxicity after proton or photon therapy in children and young adults with localized intracranial ependymoma: A French retrospective study

BACKGROUND AND PURPOSE

Ependymoma is the third most frequent childhood braintumor. Standard treatment is surgery followed by radiation therapy including proton therapy (PBT). Retrospective studies have reported higher rates of brainstem injury after PBT than after photon therapy (XRT). We report a national multicenter study of the incidence of brainstem injury after XRT versus PBT, and their correlations with dosimetric data.

MATERIAL AND METHODS

We included all patients aged < 25 years who were treated with PBT or XRT for intracranial ependymoma at five French pediatric oncology reference centers between 2007 and 2020. We reviewed pre-irradiation MRI, follow-up MRIs over the 12 months post-treatment and clinical data.

RESULTS

Of the 83 patients, 42 were treated with PBT, 37 with XRT, and 4 with both (median dose: 59.4 Gy, range: 53‑60). No new or progressive symptomatic brainstem injury was found. Four patients presented asymptomatic radiographic changes (punctiform brainstem enhancement and FLAIR hypersignal), with median onset at 3.5 months (range: 3.0‑9.4) after radiation therapy, and median offset at 7.6 months (range: 3.7‑7.9). Two had been treated with PBT, one with XRT, and one with mixed XRT-PBT. Prescribed doses were 59.4, 55.8, 59.4 and 54 Gy.

CONCLUSION

Asymptomatic radiographic changes occurred in 4.8% of patients with ependymoma in a large national series. There was no correlation with dose or technique. No symptomatic brainstem injury was identified.

MYCN immunohistochemistry as surrogate marker for MYCN-amplified spinal ependymomas

MYCN (master regulator of cell cycle entry and proliferative metabolism) gene amplification defines a molecular subgroup of spinal cord ependymomas that show high-grade morphology and aggressive behavior. Demonstration of MYCN amplification by DNA methylation or fluorescence-in situ hybridization (FISH) is required for diagnosis. We aimed to (i) assess prevalence and clinicopathological features of MYCN-amplified spinal ependymomas and (ii) evaluate utility of immunohistochemistry (IHC) for MYCN protein as a surrogate for molecular testing. A combined retrospective-prospective study spanning 8 years was designed during which all spinal cord ependymomas with adequate tissue were subjected to MYCN FISH and MYCN IHC. Among 77 spinal cord ependymomas included, MYCN amplification was identified in 4 samples from 3 patients (3/74, 4%) including two (1st and 2nd recurrences) from the same patient. All patients were adults (median age at diagnosis of 32 years) including two females and one male. The index tumors were located in thoracic (n = 2) and lumbar (n = 1) spinal cord. One of the female patients had neurofibromatosis type 2 (NF2). All four tumors showed anaplastic histology. Diffuse expression of MYCN protein was seen in all four MYCN-amplified samples but in none of the non-amplified cases, thus showing 100% concordance with FISH results. On follow-up, the NF2 patient developed widespread spinal dissemination while another developed recurrence proximal to the site of previous excision. To conclude, MYCN-amplified spinal ependymomas are rare tumors, accounting for ~ 4% of spinal cord ependymomas. Within the limitation of small sample size, MYCN IHC showed excellent concordance with MYCN gene amplification.

Helical tomotherapy craniospinal irradiation in primary brain tumours: Toxicities and outcomes in a peadiatric and adult population

Objective

As craniospinal irradiation (CSI) is delivered more frequently by helical tomotherapy (HT) with few reports about late effects, we analysed all patients treated in our centre over an 11-year period.

Methods and materials

Our study included all patients that underwent CSI by HT, between September 2009 and January 2020, in the Department of Radiation Oncology of the Toulouse Cancer Institute. Acute radiotherapy toxicities were reported and medium- to long-term outcomes analysed.

Results

Among the 79 patients included, 70.9 % were younger than 18 years at diagnosis, the median age was 13 (range: 1-52) at the time of radiation therapy, 67.1 % of patients had medulloblastoma. Half of them (49.4 %) had a metastatic disease at diagnosis. The median dose of CSI was 36 Gy (range, 18-36). Seventy-seven patients received a radiation boost to the original location of the primary tumour (97.5 %), 32 patients also received a boost to their metastatic sites (40.5 %). Median follow-up was 55.5 months (95 %CI = [41.2; 71.8]). The 3-year event-free survival rate was 66.3 % (95 %CI = [54.2; 75.9]). Most patients presented with acute haematological toxicities during CSI (85.9 %), predominantly severe thrombocytopenia (39.7 %). Among the 64 patients assessed for medium- and long-term outcomes, 52 survived and 47 were alive and disease-free at the latest follow-up visit on record. There were 3.8 % secondary tumours: two meningiomas and one diffuse intrinsic pontine glioma. Adult and paediatric patients respectively presented with secondary cataract (4.3 % vs 22.0 %), persistent hearing disorders (26.1 % vs 29.3 %), pulmonary or cardiac late effects (4.3 % vs 2.4 %), hormonal pituitary gland deficiencies (30.0 % vs 56.8 %) and psycho-cognitive disorders (56.5 % vs 53.7 %).

Conclusion

CSI dispensed by HT, did not result in any additional acute or late toxicities when compared to 3D-CSI. There was no increase in the secondary tumour rate compared to that reported in the literature.

Cauda equina neuroendocrine tumor: a report of three cases and review of the literature with focus on differential diagnosis and postoperative management

INTRODUCTION

Cauda equina neuroendocrine tumors (CENETs), previously described as cauda equina paragangliomas (PGLs) are rare and well-vascularized benign entities which can be often misdiagnosed with other intradural tumors more common in this anatomical site, such as ependymomas and neurinomas. We describe three cases of CENETs observed at our institution with particular focus on differential diagnosis and postoperative management. Since the lack of guidelines, we performed a literature review to identify factors that can predict recurrence and influence postoperative decision making.

CASE REPORT AND LITERATURE REVIEW

We report on three patients, two of them presenting with a clinical history of lower back pain and sciatica. In all cases magnetic resonance imaging (MRI) of the lumbosacral spine with and without Gd-DTPA revealed an intradural lesion with strong contrast enhancement, first described as atypical ependymoma or schwannoma. A complete tumor resection was achieved in all cases, the histopathological diagnosis classified the tumors as CENETs. In our literature review, a total of 688 articles were screened and 162 patients were included. Patients demographic data, clinical symptoms, resection and recurrence were recorded.

DISCUSSION

Differential diagnosis between CENETs and other more common tumors affecting cauda equina region, such as ependymomas or schwannomas (neurinomas), is still very challenging. Due to the lack of specific clinical or radiological characteristics, a correct preoperative diagnosis is almost impossible. With this paper we want to point out that CENETs must be considered in the differential diagnosis, most of all in case of entities with atypical radiological features. According to the literature, tumor recurrence after gross total resection is unlikely, while a long-term follow-up is recommended in case of subtotal resection or local aggressive behavior.

Unusual location of myxopapillary ependymoma in the sacrum: Case report and review of the literature

Myxopapillary ependymoma, a rare variant of ependymoma, commonly occurs in the conus medullaris or filum terminale. The rarity of these tumors can make their diagnosis and treatment challenging. This case report presents an atypical occurrence of myxopapillary ependymoma within the sacrum in a 68-year-old patient presented with a 3-month history of persistent left-sided low back pain radiating to the legs and fecal dysfunction. The patient underwent a sacral laminectomy and subtotal excision of the tumor, followed by adjuvant radiotherapy with favorable outcomes. This report highlights the significance of tailored approaches for unconventional tumor locations emphasizes the potential benefits of multimodal treatment strategies and provides insights from a comprehensive literature review on similar cases.

Is proton beam therapy always better than photon irradiation? Lessons from two cases

Proton beam therapy (PBT) is increasingly used to treat cancers, especially in the paediatric and adolescent and young adult (AYA) population. As PBT becomes more accessible, determining when PBT should be used instead of photon irradiation can be difficult. There is a need to balance patient, tumour and treatment factors when making this decision. Comparing the dosimetry between these two modalities plays an important role in this process. PBT can reduce low to intermediate doses to organs at risk (OAR), but photon irradiation has its dosimetric advantages. We present two cases with brain tumours, one paediatric and one AYA, in which treatment plan comparison between photons and protons showed dosimetric advantages of photon irradiation. The first case was an 18-month-old child diagnosed with posterior fossa ependymoma requiring adjuvant radiotherapy. Photon irradiation using volumetric modulated arc therapy (VMAT) had lower doses to the hippocampi but higher doses to the pituitary gland. The second case was a 21-year-old with an optic pathway glioma. There was better sparing of the critical optic structures and pituitary gland using fractionated stereotactic radiation therapy over PBT. The dosimetric advantages of photon irradiation over PBT have been demonstrated in these cases. This highlights the role of proton-to-photon comparative treatment planning to better understand which patients might benefit from photon irradiation versus PBT.

Whole-tumor histogram analysis of postcontrast T1-weighted and apparent diffusion coefficient in predicting the grade and proliferative activity of adult intracranial ependymomas

PURPOSE

To investigate the value of histogram analysis of postcontrast T1-weighted (T1C) and apparent diffusion coefficient (ADC) images in predicting the grade and proliferative activity of adult intracranial ependymomas.

METHODS

Forty-seven adult intracranial ependymomas were enrolled and underwent histogram parameters extraction (including minimum, maximum, mean, 1st percentile (Perc.01), Perc.05, Perc.10, Perc.25, Perc.50, Perc.75, Perc.90, Perc.95, Perc.99, standard deviation (SD), variance, coefficient of variation (CV), skewness, kurtosis, and entropy of T1C and ADC) using FireVoxel software. Differences in histogram parameters between grade 2 and grade 3 adult intracranial ependymomas were compared. Receiver operating characteristic curves and logistic regression analyses were conducted to evaluate the diagnostic performance. Spearman's correlation analysis was used to evaluate the relationship between histogram parameters and Ki-67 proliferation index.

RESULTS

Grade 3 intracranial ependymomas group showed significantly higher Perc.95, Perc.99, SD, variance, CV, and entropy of T1C; lower minimum, mean, Perc.01, Perc.05, Perc.10, Perc.25, Perc.50 of ADC; and higher CV and entropy of ADC than grade 2 intracranial ependymomas group (all p < 0.05). Entropy (T1C) and Perc.10 (ADC) had a higher diagnostic performance with AUCs of 0.805 and 0.827 among the histogram parameters of T1C and ADC, respectively. The diagnostic performance was improved by combining entropy (T1C) and Perc.10 (ADC), with an AUC of 0.857. Significant correlations were observed between significant histogram parameters of T1C (r = 0.296-0.417, p = 0.001-0.044) and ADC (r = -0.428-0.395, p = 0.003-0.038).

CONCLUSION

Whole-tumor histogram analysis of T1C and ADC may be a promising approach for predicting the grade and proliferative activity of adult intracranial ependymomas.

Treatment Outcomes of Patients with Ependymoma Receiving Radiotherapy: A Single Institution Experience

INTRODUCTION

This study explored the failure pattern and clinical outcomes in patients with ependymoma undergoing radiotherapy.

METHODS

Between January 2004 and June 2022, we included 32 patients with ependymoma who underwent radiotherapy as part of the multimodality treatment at our institution. Of these, 27 (84.4%) underwent adjuvant radiotherapy, four received radiotherapy after local recurrence, and one received definitive CyberKnife radiotherapy (21 Gy in three fractions). The median prescribed dose was 54 Gy in patients who received conventional radiotherapy. We analyzed the local progression-free survival (LPFS), distant metastasis-free survival (DMFS), progression-free survival (PFS), overall survival (OS), and potential prognostic factors.

RESULTS

The median age was 29.8 years. Approximately 28.1% were pediatric patients. Fifteen tumors (46.9%) were World Health Organization (WHO) grade II, 10 (31.3%) were WHO grade III, and seven (22.8%) were WHO grade I. Among them, 15 patients (46.9%) had posterior fossa tumors, 10 (31.3%) had supratentorial tumors, and seven (22.8%) had spinal tumors. Of the 31 patients who underwent upfront surgical resection, 19 (61.3%) underwent gross total resection or near-total resection. Seventeen of 19 patients with first failures (89.5%) had isolated local recurrences. Of the 19 patients with disease progression, 11 (57.9%) were disease free or had stable disease after salvage therapy, and five (26.3%) had disease-related mortality. Most of the first local recurrences after radiotherapy occurred infield (13 of 16, 81.3%). The 5-year LPFS, DMFS, PFS, and OS rates were 48.5%, 89.6%, 45.1%, and 88.4%, respectively, at a median follow-up of 6.25 years. Subtotal resection was associated with poorer LPFS and PFS in patients with intracranial ependymoma (hazard ratio = 3.69, p = 0.018, for LPFS; hazard ratio = 3.20, p = 0.029, for PFS).

CONCLUSION

Incorporating radiotherapy into multimodal treatment has led to favorable outcomes in patients with ependymoma, and the extent of resection is a prognostic factor for the local control of intracranial ependymoma.

Imaging features to distinguish posterior fossa ependymoma subgroups

OBJECTIVES

Posterior fossa ependymoma group A (EPN_PFA) and group B (EPN_PFB) can be distinguished by their DNA methylation and give rise to different prognoses. We compared the MRI characteristics of EPN_PFA and EPN_PFB at presentation.

METHODS

Preoperative imaging of 68 patients with posterior fossa ependymoma from two centers was reviewed by three independent readers, blinded for histomolecular grouping. Location, tumor extension, tumor volume, hydrocephalus, calcifications, tissue component, enhancement or diffusion signal, and histopathological data (cellular density, calcifications, necrosis, mitoses, vascularization, and microvascular proliferation) were compared between the groups. Categorical data were compared between groups using Fisher's exact tests, and quantitative data using Mann-Whitney tests. We performed a Benjamini-Hochberg correction of the p values to account for multiple tests.

RESULTS

Fifty-six patients were categorized as EPN_PFA and 12 as EPN_PFB, with median ages of 2 and 20 years, respectively (p = 0.0008). The median EPN_PFA tumoral volume was larger (57 vs 29 cm3, p = 0.003), with more pronounced hydrocephalus (p = 0.002). EPN_PFA showed an exclusive central position within the 4th ventricle in 61% of patients vs 92% for EPN_PFB (p = 0.01). Intratumor calcifications were found in 93% of EPN_PFA vs 40% of EPN_PFB (p = 0.001). Invasion of the posterior fossa foramina was mostly found for EPN_PFA, particularly the foramina of Luschka (p = 0.0008). EPN_PFA showed whole and homogeneous tumor enhancement in 5% vs 75% of EPN_PFB (p = 0.0008). All mainly cystic tumors were EPN_PFB (p = 0.002). The minimal and maximal relative ADC was slightly lower in EPN_PFA (p = 0.02 and p = 0.01, respectively).

CONCLUSION

Morphological characteristics from imaging differ between posterior fossa ependymoma subtypes and may help to distinguish them preoperatively.

CLINICAL RELEVANCE STATEMENT

This study provides a tool to differentiate between group A and group B ependymomas, which will ultimately allow the therapeutic strategy to be adapted in the early stages of patient management.

KEY POINTS

• Posterior fossa ependymoma subtypes often have different imaging characteristics. • Posterior fossa ependymomas group A are commonly median or lateral tissular calcified masses, with incomplete enhancement, affecting young children and responsible for pronounced hydrocephalus and invasion of the posterior fossa foramina. • Posterior fossa ependymomas group B are commonly median non-calcified masses of adolescents and adults, predominantly cystic, and minimally invasive, with total and homogeneous enhancement.

Lateral-type posterior fossa ependymomas in pediatric population

BACKGROUND

Lateral-type posterior fossa ependymomas are a well-defined subtype of tumours both clinically and pathologically, with a poor prognosis. Their incidence is low and surgical management is challenging. The objective of the present work is to review our series of lateral-tye posterior fossa ependymomas and compare our results with those of previous series.

METHODS

Among 30 cases of ependymoma operated in our paediatric department in the last ten years, we identified seven cases of lateral-type posterior fossa ependymomas. We then performed a retrospective, descriptive study.

RESULTS

Mean age of our patients was 3.75 years. 6 cases presented with hydrocephalus. Mean tumour volume at diagnosis was 61 cc. A complete resection was achieved in six cases and a near-total resection in one patient. 5 patients transiently required a gastrostomy and a tracheostomy. Mean follow-up was 58 months. One case progressed along this period and eventually died. 4 cases of hydrocephalus required a ventriculoperitoneal CSF shunt and two were managed with a third ventriculostomy. At last follow-up 4 patients carried a normal life and two displayed a mild restriction according to Lansky´s scale.

CONCLUSIONS

The aim of surgical treatment in lateral-type posterior fossa ependymomas is complete resection. Neurological deficits associated to lower cranial nerve dysfunction are common but transient. Deeper genetic characterization of these tumours may identify risk factors that guide stratification of adjuvant therapies.

In vitro and in vivo modeling systems of supratentorial ependymomas

Ependymomas are rare brain tumors that can occur in both children and adults. Subdivided by the tumors' initial location, ependymomas develop in the central nervous system in the supratentorial or infratentorial/posterior fossa region, or the spinal cord. Supratentorial ependymomas (ST-EPNs) are predominantly characterized by common driver gene fusions such as ZFTA and YAP1 fusions. Some variants of ST-EPNs carry a high overall survival rate. In poorly responding ST-EPN variants, high levels of inter- and intratumoral heterogeneity, limited therapeutic strategies, and tumor recurrence are among the reasons for poor patient outcomes with other ST-EPN subtypes. Thus, modeling these molecular profiles is key in further studying tumorigenesis. Due to the scarcity of patient samples, the development of preclinical in vitro and in vivo models that recapitulate patient tumors is imperative when testing therapeutic approaches for this rare cancer. In this review, we will survey ST-EPN modeling systems, addressing the strengths and limitations, application for therapeutic targeting, and current literature findings.

Lateral-type posterior fossa ependymomas in pediatric patients: a national collaborative study

PURPOSE

To review a multicentric series of lateral-type posterior fossa ependymomas operated in the last ten years and to analyze the factors related to clinical evolution and tumor survival.

METHODS

Descriptive, retrospective study. Active members of the Spanish Society of Pediatric Neurosurgery were invited to participate in this multicentric study. Clinical and radiological data were incorporated to an open database. The role of histologic grade, grade of resection, postoperative morbidities, and clinical follow-up was evaluated through bivariate associations (chi-square), Kaplan-Meier's curves (log-rank test), and multivariate analysis (binary logistic regression).

RESULTS

Fourteen centers entered the study, and 25 cases with a minimum follow-up of 6 months were included. There were 13 boys and 12 girls with a mean age close to 3 years. Mean tumor volume at diagnosis was over 60 cc. A complete resection was achieved in 8 patients and a near-total resection in 5 cases. Fifteen tumors were diagnosed as ependymoma grade 2 and ten as ependymoma grade 3. Major morbidity occurred postoperatively in 14 patients but was resolved in twelve within 6 months. There were six cases of death and 11 cases of tumor progression along the observation period. Mean follow-up was 44.8 months. Major morbidity was significantly associated with histologic grade but not with the degree of resection. Overall and progression-free survival were significantly associated with complete surgical resection. At the last follow-up, 16 patients carried a normal life, and three displayed a mild restriction according to Lansky's scale.

CONCLUSIONS

Lateral-type posterior fossa ependymomas constitute a specific pathologic and clinical tumor subtype with bad prognosis. Gross total resection is the goal of surgical treatment, for it significantly improves prognosis with no additional morbidity. Neurological deficits associated to lower cranial nerve dysfunction are common, but most are transient. Deeper genetic characterization of these tumors may identify risk factors that guide new treatments and stratification of adjuvant therapies.

Transcriptomic and epigenetic dissection of spinal ependymoma (SP-EPN) identifies clinically relevant subtypes enriched for tumors with and without NF2 mutation

Ependymomas encompass multiple clinically relevant tumor types based on localization and molecular profiles. Tumors of the methylation class "spinal ependymoma" (SP-EPN) represent the most common intramedullary neoplasms in children and adults. However, their developmental origin is ill-defined, molecular data are scarce, and the potential heterogeneity within SP-EPN remains unexplored. The only known recurrent genetic events in SP-EPN are loss of chromosome 22q and NF2 mutations, but neither types and frequency of these alterations nor their clinical relevance have been described in a large, epigenetically defined series. Transcriptomic (n = 72), epigenetic (n = 225), genetic (n = 134), and clinical data (n = 112) were integrated for a detailed molecular overview on SP-EPN. Additionally, we mapped SP-EPN transcriptomes to developmental atlases of the developing and adult spinal cord to uncover potential developmental origins of these tumors. The integration of transcriptomic ependymoma data with single-cell atlases of the spinal cord revealed that SP-EPN display the highest similarities to mature adult ependymal cells. Unsupervised hierarchical clustering of transcriptomic data together with integrated analysis of methylation profiles identified two molecular SP-EPN subtypes. Subtype A tumors primarily carried previously known germline or sporadic NF2 mutations together with 22q loss (bi-allelic NF2 loss), resulting in decreased NF2 expression. Furthermore, they more often presented as multilocular disease and demonstrated a significantly reduced progression-free survival as compared to SP-EP subtype B. In contrast, subtype B predominantly contained samples without NF2 mutation detected in sequencing together with 22q loss (monoallelic NF2 loss). These tumors showed regular NF2 expression but more extensive global copy number alterations. Based on integrated molecular profiling of a large multi-center cohort, we identified two distinct SP-EPN subtypes with important implications for genetic counseling, patient surveillance, and drug development priorities.

A Fully Automated Deep-Learning Model for Predicting the Molecular Subtypes of Posterior Fossa Ependymomas Using T2-Weighted Images

PURPOSE

We aimed to develop and validate a deep learning (DL) model to automatically segment posterior fossa ependymoma (PF-EPN) and predict its molecular subtypes [Group A (PFA) and Group B (PFB)] from preoperative MR images.

EXPERIMENTAL DESIGN

We retrospectively identified 227 PF-EPNs (development and internal test sets) with available preoperative T2-weighted (T2w) MR images and molecular status to develop and test a 3D nnU-Net (referred to as T2-nnU-Net) for tumor segmentation and molecular subtype prediction. The network was externally tested using an external independent set [n = 40; subset-1 (n = 31) and subset-2 (n =9)] and prospectively enrolled cases [prospective validation set (n = 27)]. The Dice similarity coefficient was used to evaluate the segmentation performance. Receiver operating characteristic analysis for molecular subtype prediction was performed.

RESULTS

For tumor segmentation, the T2-nnU-Net achieved a Dice score of 0.94 ± 0.02 in the internal test set. For molecular subtype prediction, the T2-nnU-Net achieved an AUC of 0.93 and accuracy of 0.89 in the internal test set, an AUC of 0.99 and accuracy of 0.93 in the external test set. In the prospective validation set, the model achieved an AUC of 0.93 and an accuracy of 0.89. The predictive performance of T2-nnU-Net was superior or comparable to that of demographic and multiple radiologic features (AUCs ranging from 0.87 to 0.95).

CONCLUSIONS

A fully automated DL model was developed and validated to accurately segment PF-EPNs and predict molecular subtypes using only T2w MR images, which could help in clinical decision-making.

Clinical Characteristics, Treatment, and Survival Outcome of Ependymoma in Infants

BACKGROUND

Treatment modalities of ependymoma in infants remain controversial. Postoperative adjuvant radiotherapy could prolong overall survival but has the potential to affect nervous system development in infants. The role of adjuvant chemotherapy in prolonging overall survival for infants with ependymoma is still unclear. Therefore we designed this study to explore the effect of treatment modalities on survival time of infants with ependymoma.

METHODS

We studied 72 infants with ependymoma from the Surveillance, Epidemiology, and End Results database in this retrospective analysis. Univariate and multivariate Cox proportional hazard models were adopted to determine hazard ratios and compare overall survival.

RESULTS

Among 72 infants with ependymoma, 35 were male (48.6%) and 37 were female (51.4%). The 5-year overall survival of all patients was 67%. Forty-six infants (63.9%) received gross total resection, 20 (27.8%) received subtotal resection, and 6 (8.3%) did not receive surgical resection or only autopsy. Twenty-one infants (29.2%) received radiotherapy, and 45 (62.5%) received chemotherapy. Multivariate analysis revealed that patients accepted surgical resection (No vs. gross total resection, P < 0.001; No vs. subtotal resection, P = 0.026) and chemotherapy (No vs. Yes, P = 0.024) are the independent prognostic factors for overall survival.

CONCLUSIONS

Treatment modality is associated with survival time in infants with ependymoma. The extent of resection and chemotherapy were independent prognostic factors for infants with ependymoma.

Pediatric-Like Brain Tumors in Adults

Pediatric brain tumors are different to those found in adults in pathological type, anatomical site, molecular signature, and probable tumor drivers. Although these tumors usually occur in childhood, they also rarely present in adult patients, either as a de novo diagnosis or as a delayed recurrence of a pediatric tumor in the setting of a patient that has transitioned into adult services.Due to the rarity of pediatric-like tumors in adults, the literature on these tumor types in adults is often limited to small case series, and treatment decisions are often based on the management plans taken from pediatric studies. However, the biology of these tumors is often different from the same tumors found in children. Likewise, adult patients are often unable to tolerate the side effects of the aggressive treatments used in children-for which there is little or no evidence of efficacy in adults. In this chapter, we review the literature and summarize the clinical, pathological, molecular profile, and response to treatment for the following pediatric tumor types-medulloblastoma, ependymoma, craniopharyngioma, pilocytic astrocytoma, subependymal giant cell astrocytoma, germ cell tumors, choroid plexus tumors, midline glioma, and pleomorphic xanthoastrocytoma-with emphasis on the differences to the adult population.

Supratentorial and Infratentorial Ependymoma

Ependymomas are the third most common intracranial tumor in children, presenting in both the supratentorial and infratentorial compartments. They may present in infants, young children, and adolescents with symptoms depending on size, location, and the age of the patient. The ideal imaging for evaluation and treatment is MRI. This is crucial for preoperative evaluation and planning, as well as postoperative assessment and evaluating the efficacy of treatment. Essentially without exception, aggressive surgery aimed at complete resection is the initial and most important factor in the long-term outcome of all these children. Histopathologic diagnosis for intracranial pediatric ependymoma has been narrowed to grade II and grade III, no longer characterized as classic and anaplastic. Subsequent conformal photon or proton beam irradiation is an established post-surgical therapy, with solid evidence that it benefits survival and offers lower toxicity to the normal brain of the young child. Although chemotherapeutic treatment has not been generally impactful, immunotherapeutic interventions may be on the horizon. Updated molecular subgrouping of ependymoma is changing the post-resection approach of these tumors with regard to both treatment and outcome. Excluding spinal ependymoma and subependymoma, there are four subtypes that are defined by genetic characteristics, two found in the supratentorial compartment, ST-EPN-YAP1 and ST-EPN-ZFTA, and two in the posterior fossa, PF-EPN-A and PF-EPN-B. Younger children harboring ZFTA fusion-positive supratentorial and type A posterior fossa tumors, regardless of histology, tend toward the poorest outcomes. On the contrary, older children with supratentorial YAP1 fusion-positive ependymomas and type B posterior fossa tumors may survive with surgery alone. The paradigm shift regarding the behavior of the various childhood ependymoma subtypes will hopefully lead to targeted, individualized therapies and improved outcomes.

Ependymoma from Benign to Highly Aggressive Diseases: A Review

Ependymomas comprise biologically distinct tumor types with respect to age distribution, (epi)genetics, localization, and prognosis. Multimodal risk-stratification, including histopathological and molecular features, is essential in these biologically defined tumor types. Gross total resection (GTR), achieved with intraoperative monitoring and neuronavigation, and if necessary, second-look surgery, is the most effective treatment. Adjuvant radiation therapy is mandatory in high-risk tumors and in case of residual tumor. There is yet growing evidence that some ependymal tumors may be cured by surgery alone. To date, the role of chemotherapy is unclear and subject of current studies.Even though standard therapy can achieve reasonable survival rates for the majority of ependymoma patients, long-term follow-up still reveals a high probability of relapse in certain biological entities.With increasing knowledge of biologically distinct tumor types, risk-adapted adjuvant therapy gains importance. Beyond initial tumor control, and avoidance of therapy-induced morbidity for low-risk patients, intensified treatment for high-risk patients comprises another challenge. With identification of specific risk features regarding molecular alterations, targeted therapy may represent an option for individualized treatment modalities in the future.