Intracranial ependymomas: analysis of prognostic factors in a population-based series

Conformal Radiation Therapy for Ependymoma at Age ≤3 Years: A 25-Year Experience

PURPOSE

Adjuvant radiation therapy (RT) affects survival after surgery for young children (age <3 years) diagnosed with intracranial ependymoma. Conformal photon RT promised to spare normal tissue and was introduced more than 25 years ago to improve outcomes for these vulnerable patients. Long-term results for those first treated with conformal methods provide valuable information and serve as a comparison against newer methods.

METHODS AND MATERIALS

Between 1997 and 2018, 101 patients <3.1-years-old were treated with conformal and intensity modulated photon therapy after definitive surgery for intracranial ependymoma. The median age at RT was 2.1 years and the time from diagnosis to the start of RT was 10 weeks. The extent of resection was gross-total in 82%, and 38% underwent more than 1 attempt at resection. The total prescribed dose was 54 to 59.4 Gy at 1.8 Gy per fraction.

RESULTS

The 10-year event-free and overall survivals were 58.5% ± 5.0% and 72.6% ± 4.5%, respectively, with a median follow-up of 18.4 years (range, 4.2-23.3 years). Tumor progression occurred in 34 patients with a median time of 1.6 years. Death occurred in 34 patients from ependymoma (n = 24), secondary malignancy (n = 6), necrosis (n = 2), shunt failure (n = 1), and anaphylactic reaction (n = 1). Twenty-three patients developed a secondary tumor including 6 cases of fatal high-grade glioma. Of the surviving cohort and those ≥18 years old, 98% obtained a high school diploma, 64% had a current driver's license, 89% were students or employed full or part time, 32% were living independently, and 70% received higher education or training.

CONCLUSIONS

Long-term results of children treated using photon conformal RT after surgery demonstrate that adjuvant RT resulted in long-term disease control and functional independence. These results point to the need for new treatment strategies to improve tumor control and provide investigators hope that newer RT methods will further reduce complications.

Why haven't we solved intracranial pediatric ependymoma? Current questions and barriers to treatment advances

Pediatric intracranial ependymoma has seen a recent exponential expansion of biological findings, rapidly dividing the diagnosis into several subgroups, each with specific molecular and clinical characteristics. While such subdivision may complicate clinical conclusions from historical trials, this knowledge also provides an opportunity for interrogating the major clinical and biological questions preventing near-term translation into effective therapy for children with ependymoma. In this article, we briefly review some of the most critical clinical questions facing both patient management and the construct of future trials in childhood ependymoma, as well as explore some of the current barriers to efficient translation of preclinical discovery to the clinic.

Canadian Pediatric Neuro-Oncology Standards of Practice

Primary CNS tumors are the leading cause of cancer-related death in pediatrics. It is essential to understand treatment trends to interpret national survival data. In Canada, children with CNS tumors are treated at one of 16 tertiary care centers. We surveyed pediatric neuro-oncologists to create a national standard of practice to be used in the absence of a clinical trial for seven of the most prevalent brain tumors in children. This allowed description of practice across the country, along with a consensus. This had a multitude of benefits, including understanding practice patterns, allowing for a basis to compare in future research and informing Health Canada of the current management of patients. This also allows all children in Canada to receive equivalent care, regardless of location.

World Health Organization Grade III Supratentorial Extraventricular Ependymomas in Adults: Case Series and Review of Treatment Modalities

Context:

Supratentorial ependymomas and their anaplastic variants are relatively uncommon central nervous system neoplasms that afflict both adults and children.

Aims:

Discuss the clinical and pathological features of patients with anaplastic ependymomas involving an extraventricular supratentorial location and review modalities and options of treatment for those rare tumors.

Settings and Design:

Whereas the treatment algorithm in the pediatric population is well established, however, treatment in the adult population is less defined. Treatment options are exposed through the author's cases and review of the literature.

Subjects and Methods:

In our case series of two adult patients with supratentorial ependymomas World Health Organization (WHO) Grade III (anaplastic variant), patients presented in both cases in the emergency room after having a generalized tonic–clonic seizure at home the first case, and mild hemiparesis the second case.

Results:

Patients underwent surgical treatment, and a gross total resection was achieved in both cases. The histopathological examination revealed a diagnosis of anaplastic ependymoma (WHO Grade III). Both patients had additional radiotherapy, and in the first case, adjuvant platinum-based chemotherapy was administered due to leptomeningeal gliomatosis.

Conclusion:

In our experience, gross total resection was achieved in all patients with supratentorial extraventricular ependymomas WHO Grade III with additional radiotherapy and platinum-based chemotherapy. Patients require initial close serial imaging follow-up. The role of chemotherapy is still uncertain but may be necessary in younger patients and in tumors that behave more like the pediatric ependymomas.

Incidence of metastatic disease and survival among patients with newly diagnosed primary CNS tumors in the United States from 2004-2013

Background: Population-based estimates of the incidence and prognosis of metastatic disease at the initial diagnosis of primary central nervous system (CNS) tumors are currently lacking.

Methods: A total of 43,455 patients diagnosed with a primary CNS tumor were enrolled to evaluate metastatic rates utilizing the data from the Surveillance, Epidemiology, and End Results (SEER) program. We used multivariate logistic regression to analyze the risk factors associated with the presence of metastasis at the first visit of patients with metastatic medulloblastoma (MB), atypical teratoid/rhabdoid tumor (ATRT), glioblastoma multiforme (GBM), or pilocytic astrocytoma (PA). Hazard ratios (HRs) and 95% confidence intervals (CIs) for cancer-specific death (CSD) of patients with these four CNS tumors were analyzed using multivariate Cox regression.

Results: In patients with primary CNS embryonal tumors, the metastatic rates of patients with MB and ATRT were 14.51% and 19.25%, respectively. The metastatic rate for MB patients aged 0 to 18 years was 16.69%. In the patients with glioma, the metastatic rates of patients with PA and GBM were 1.55% and 1.39%, respectively. On multivariate logistic regression among patients with glioma, GBM (vs PA; OR, 2.12; 95% CI, 1.37 to 3.30; P=0.001) was associated with greater odds of having metastatic disease at diagnosis. On multivariate logistic regression among patients with GBM, MB, or ATRT, MB (vs GBM; OR, 4.66; 95% CI, 2.81 to 7.72; P<0.001) and ATRT (vs GBM; OR, 5.65; 95% CI, 3.27 to 9.75; P<0.001) were associated with greater odds of having metastatic disease at diagnosis. In the multivariate Cox proportional hazards model for CSD among patients with metastatic GBM or MB at diagnosis, gross total resection/total lobectomy (vs partial resection/partial lobectomy) was not related to a decreased or an increased risk of CSD. In patients with metastatic ATRT, compared to no surgery, gross total resection/total lobectomy or partial resection/partial lobectomy was not associated with a decreased risk of CSD.

Conclusions: The findings in this study provide a population-based estimate of the incidence and prognosis of metastatic disease at the initial diagnosis of primary CNS tumors. These survival outcomes are relevant because they will help to prioritize future research directions to improve the treatment strategies of these metastatic CNS tumors.

Integrating RNA sequencing into neuro-oncology practice

Malignant tumors of the central nervous system (CNS) cause substantial morbidity and mortality, yet efforts to optimize chemo- and radiotherapy have largely failed to improve dismal prognoses. Over the past decade, RNA sequencing (RNA-seq) has emerged as a powerful tool to comprehensively characterize the transcriptome of CNS tumor cells in one high-throughput step, leading to improved understanding of CNS tumor biology and suggesting new routes for targeted therapies. RNA-seq has been instrumental in improving the diagnostic classification of brain tumors, characterizing oncogenic fusion genes, and shedding light on intratumor heterogeneity. Currently, RNA-seq is beginning to be incorporated into regular neuro-oncology practice in the form of precision neuro-oncology programs, which use information from tumor sequencing to guide implementation of personalized targeted therapies. These programs show great promise in improving patient outcomes for tumors where single agent trials have been ineffective. As RNA-seq is a relatively new technique, many further applications yielding new advances in CNS tumor research and management are expected in the coming years.

Clinical, radiological, and histological features and treatment outcomes of supratentorial extraventricular ependymoma: 14 cases from a single center

OBJECTIVE Reports on supratentorial extraventricular ependymoma (STE) are relatively rare. The object of this study was to analyze the clinical, radiological, and histological features and treatment outcomes of 14 patients with STE. METHODS Overall, 227 patients with ependymoma underwent surgical treatment in the authors' department between January 2010 and June 2015; 14 of these patients had STE. Data on clinical presentation, radiological studies, histopathological findings, surgical strategies, and treatment outcomes in these 14 cases were retrospectively analyzed. RESULTS The patients consisted of 6 women and 8 men (sex ratio 0.75). Mean age at diagnosis was 24.5 ± 13.5 years (range 3-48 years). Tumors were predominantly located in the frontal and temporal lobes (5 and 4 cases, respectively). Typical radiological features were mild to moderate heterogeneous tumor enhancements on contrast-enhanced MRI. Other radiological features included well-circumscribed, "popcorn" enhancement and no distinct adjoining brain edema. Gross-total resection was achieved in 12 patients, while subtotal removal was performed in 2. Radiotherapy was administered in 7 patients after surgery. Seven tumors were classified as WHO Grade II and the other 7 were verified as WHO Grade III. The mean follow-up period was 22.6 months (range 8-39 months). There were 3 patients with recurrence, and 2 of these patients died. CONCLUSIONS Supratentorial extraventricular ependymoma has atypical clinical presentations, various radiological features, and heterogeneous histological forms; therefore, definitive diagnosis can be difficult. Anaplastic STE shows malignant biological behavior, a higher recurrence rate, and a relatively poor prognosis. Gross-total resection with or without postoperative radiotherapy is currently the optimal treatment for STE.

Progression-free survival of children with localized ependymoma treated with intensity-modulated radiation therapy or proton-beam radiation therapy

BACKGROUND

The treatment for childhood intracranial ependymoma includes maximal surgical resection followed by involved-field radiotherapy, commonly in the form of intensity-modulated radiation therapy (IMRT). Proton-beam radiation therapy (PRT) is used at some centers in an effort to decrease long-term toxicity. Although protons have the theoretical advantage of a minimal exit dose to the surrounding uninvolved brain tissue, it is unknown whether they have the same efficacy as photons in preventing local recurrence.

METHODS

A retrospective review of medical records from September 2000 to April 2013 was performed. Seventy-nine children with newly diagnosed localized intracranial ependymomas treated with either IMRT (n = 38) or PRT (n = 41) were identified, and progression-free survival (PFS) was analyzed with Kaplan-Meier and Cox multivariate analyses.

RESULTS

The median age at diagnosis was 3.7 years for all patients (range, 0.4-18.7 years). There were 54 patients with infratentorial tumors (68% of the total population). Patients treated with PRT were younger (median age, 2.5 vs 5.7 years; P = .001) and had a shorter median follow-up (2.6 vs 4.9 years; P < .0001). Gross total resection (GTR) was achieved in 67 patients (85%) and was more frequent in the PRT group versus the IMRT group (93% vs 76%; P = .043). The 3-year PFS rates were 60% and 82% with IMRT and PRT, respectively (P = .031).

CONCLUSIONS

Children with localized ependymomas treated with PRT have a 3-year PFS rate comparable to that of children treated with IMRT. This analysis suggests that local control is not compromised by the use of PRT. The data also support GTR as the only prognostic factor for PFS. Cancer 2017;123:2570-78. © 2017 American Cancer Society.

Pediatric Ependymoma

Over the past 150 years since Virchow's initial characterization of ependymoma, incredible efforts have been made in the classification of these tumors and in the care of pediatric patients with this disease. While the advent of modern neurosurgery and the optimization of radiation have provided significant gains, a more complex but incomplete picture of pediatric ependymomas has begun to form through a combination of international collaborations and detailed genetic and histologic characterizations. This review includes and synthesizes the clinical understanding of pediatric ependymoma and their developing molecular insight into what is truly a family of malignancies in which distinct members require different surgical approaches, radiation plans, and targeted therapies.

Advances in Radiation Therapy in Pediatric Neuro-oncology

Radiation therapy remains a highly effective therapy for many pediatric central nervous system tumors. With more children achieving long-term survival after treatment for brain tumors, late-effects of radiation have become an important concern. In response to this problem, treatment protocols for a variety of pediatric central nervous system tumors have evolved to reduce radiation fields and doses when possible. Recent advances in radiation technology such as image guidance and proton therapy have led to a new era of precision treatment with significantly less exposure to healthy tissues. These developments along with the promise of molecular classification of tumors and targeted therapies point to an optimistic future for pediatric neuro-oncology.

Advances in the biology and treatment of pediatric central nervous system tumors

PURPOSE OF REVIEW

Central nervous system tumors represent the most common solid tumors in children and are a leading cause of cancer-related fatalities in this age group. Here, we provide an update on insights gained through molecular profiling of the most common malignant childhood brain tumors.

RECENT FINDINGS

Genomic profiling studies of medulloblastoma, ependymoma, and diffuse intrinsic pontine glioma (diffuse midline glioma, with H3-K27M mutation), have refined, if not redefined, the diagnostic classification and therapeutic stratification of patients with these tumors. They detail the substantial genetic heterogeneity across each disease type and, importantly, link genotypic information to clinical course. The most aggressive, treatment-resistant (and also treatment-sensitive) forms within each disease entity are identified, and their potentially actionable targets.

SUMMARY

Molecularly based classification of pediatric brain tumors provides a critical framework for the more precise stratification and treatment of children with brain tumors.

Ependymoma: a heterogeneous tumor of uncertain origin and limited therapeutic options

Ependymomas are tumors that typically occur with an age-based site preference, with adults harboring supratentorial and spinal tumors and pediatric tumors being mainly in the posterior fossa. Despite their similar histologic appearance, the prognosis varies significantly by age and tumor location, with a better prognosis in increasing age. The mainstay of treatment remains surgical excision with or without radiation therapy as the tumor biology is poorly understood and chemotherapy is generally considered to be ineffective. More recently, molecular biology data have increased our understanding of the genetic and epigenetic changes that drive these tumors, but still it will take a lot of effort to find effective chemotherapeutic regimens. Currently, we are trying to define a subset of tumors, for which radiation therapy can be avoided.

Malignant Transformation of Grade II Ependymoma in a 2-Year-Old Child: Case Report

Ependymomas are central nervous system neoplasms that account for a third of all posterior fossa tumors in children. The most common location for infratentorial ependymoma is within the fourth ventricle. We present a case report of malignant transformation of an infratentorial grade II ependymoma in a 2-year-old child who presented with vomiting and visual disturbance. An infratentorial brain tumor in the left cerebellar area was totally removed, and the initial pathologic diagnosis was grade II ependymoma. The tumor recurred aggressively 1 year later; subtotal removal and adjuvant chemotherapy were performed. After a second operation, a histopathologic study was performed. The second specimen was defined as a grade III anaplastic ependymoma. Transformation to grade III anaplastic ependymoma is possible for a grade II ependymoma but very rare. The diagnosis of the anaplastic variant of intracranial ependymomas is difficult. Surgical treatment remains the mainstay of the treatment for all cases. Ependymomas in young infants have a worse prognosis than older children, so we need individual clinical evaluation and close follow-up of such cases. This article highlights the requirement of a close follow-up for grade II ependymomas for anaplastic transformation.

Does the real-time thermal damage estimate allow for estimation of tumor control after MRI-guided laser-induced thermal therapy? Initial experience with recurrent intracranial ependymomas

OBJECT Although control of intracranial ependymomas is highly correlated with degree of resection, it is unknown if the same is true for MRI-guided laser-induced thermal therapy (MRgLITT). The authors report their experience with MRgLITT for ependymoma and examine the utility of the real-time thermal damage estimate (TDE), a recent software advance, with respect to completeness of ablation and impact on tumor control. To the authors' knowledge, this is the largest single-center experience utilizing MRgLITT for recurrent ependymomas. METHODS Five tumors in 4 patients were treated with the Visualase Thermal Therapy System. Two tumors were treated similarly on recurrence. Ablation was performed using a 980-nm diode laser with a real-time image acquisition system. Single-plane TDEs were calculated and compared with the original lesion area to compute percentage area ablated (PAA). Volumetric analysis was performed, and percentage volume ablated (PVA) was estimated and correlated with the TDE. Tumor control was correlated with the TDE and volumetric data during treatment. RESULTS Nine ablations were performed on 5 tumors, 2 of which had multiple recurrences. The average pretreatment lesion volume was 8.4 ± 6.3 cm(3), and the average largest 2D area was 5.3 ± 2.7 cm(2). The averaged TDE was 3.9 ± 2.1 cm(2), average PAA was 80.1% ± 34.3%, and average PVA was 64.4% ± 23.5%. For subtotal ablations, average recurrence time was 4.4 ± 5.3 months; 1 adult case remains recurrence-free at 40 months. Using TDEs, the correlation between recurrence time and PAA was r = 0.93 (p = 0.01), and for PVA was r = 0.88 (p = 0.02). Furthermore, PVA and PAA were strongly correlated (r = 0.88, p = 0.02). CONCLUSIONS Through using the PAA, the real-time TDE correlated with the volume of ablation in this initial investigation. Furthermore, the TDE and volumetric data corresponded to the level of tumor control, with time to recurrence dependent on ablation completeness. MRgLITT may have a role in the management of recurrent ependymomas, especially with recent software advances.

Molecular sub-group-specific immunophenotypic changes are associated with outcome in recurrent posterior fossa ependymoma

Better understanding of ependymoma (EPN) biology at relapse is needed to improve therapy at this critical event. Convincing data exist defining transcriptionally distinct posterior fossa (PF) sub-groups A and B at diagnosis. The clinical and biological consequence of these sub-groups at recurrence has not yet been defined. Genome and transcriptome microarray profiles and clinical variables of matched primary and first recurrent PF EPN pairs were used to identify biologically distinct patterns of progression between EPN sub-groups at recurrence. Key findings were validated by histology and immune function assays. Transcriptomic profiles were partially conserved at recurrence. However, 4 of 14 paired samples changed sub-groups at recurrence, and significant sub-group-specific transcriptomic changes between primary and recurrent tumors were identified, which were predominantly immune-related. Further examination revealed that Group A primary tumors harbor an immune gene signature and cellular functionality consistent with an immunosuppressive phenotype associated with tissue remodeling and wound healing. Conversely, Group B tumors develop an adaptive, antigen-specific immune response signature and increased T-cell infiltration at recurrence. Clinical distinctions between sub-groups become more apparent after first recurrence. Group A tumors were more often sub-totally resected and had a significantly shorter time to subsequent progression and worse overall survival. Minimal tumor-specific genomic changes were observed for either PF Groups A or B at recurrence. Molecular sub-groups of PF EPN convey distinct immunobiologic signatures at diagnosis and recurrence, providing potential biologic rationale to their disparate clinical outcomes. Immunotherapeutic approaches may be warranted, particularly in Group A PF EPN.

Role of stereotactic radiosurgery and fractionated stereotactic radiotherapy in the management of intracranial ependymoma

Ependymoma accounts for 5-10% of all childhood CNS tumors and less than 5% of intracranial tumors in adults. Ependymomas typically have a sharp tumor-brain parenchyma interface and this characteristic lends itself well to stereotactic radiation delivery. Data on the use of stereotactic radiosurgery (SRS) and fractionated stereotactic radiotherapy (FSRT) for ependymoma in various settings have emerged over the past 10 years. SRS has been used in recurrent disease and as a boost after external beam radiation therapy. FSRT has been used in pediatric brain tumors and can potentially limit the long-term toxicities associated with radiation therapy by reducing the amount of normal brain parenchyma treated. Long-term follow-up is needed to determine the long-term efficacy and toxicities associated with these treatment modalities.

Cortical anaplastic ependymoma with significant desmoplasia: a case report and literature review

Ectopic brain anaplastic ependymomas with no connection to the ventricles are rare. We present a rare case of a 25-year-old male who presented with generalized convulsions. Computed tomography (CT), Magnetic Resonance Imaging (MRI), and magnetic resonance spectroscopy (MRS) showed characters of an intra- and extra-axial lesion. Intraoperatively, the lesion was a cortical solid mass that had no connections to the dura or to the ventricle. The histological diagnosis showed an anaplastic ependymoma with WHO grade III with distinctive desmoplasia. A literature review of ectopic anaplastic ependymomas regarding their clinical presentations, management, and prognostic factors was performed. There is a need to establish a clinically based histopathological grading system for anaplastic ependymomas. Ectopic anaplastic ependymomas should be included in the preoperative differential diagnosis.

A systematic review of treatment outcomes in pediatric patients with intracranial ependymomas

OBJECT

Ependymoma is the third most common primary brain tumor in children. Tumors are classified according to the WHO pathological grading system. Prior studies have shown high levels of variability in patient outcomes within and across pathological grades. The authors reviewed the results from the published literature on intracranial ependymomas in children to describe clinical outcomes as they relate to treatment modality, associated mortality, and associated progression-free survival (PFS).

METHODS

A search of English language peer-reviewed articles describing patients 18 years of age or younger with intracranial ependymomas yielded data on 182 patients. These patients had undergone treatment for ependymoma with 1 of 5 modalities: 1) gross-total resection (GTR), 2) GTR as well as external beam radiation therapy (EBRT), 3) subtotal resection (STR), 4) STR as well as EBRT, or 5) radiosurgery. Mortality and outcome data were analyzed for time to tumor progression in patients treated with 1 of these 5 treatment modalities.

RESULTS

Of these 182 patients, 69% had supratentorial ependymomas and 31% presented with infratentorial lesions. Regardless of tumor location or pathological grade, STR was associated with the highest rates of mortality. In contrast, GTR was associated with the lowest rates of mortality, the best overall survival, and the longest PFS. Children with WHO Grade II ependymomas had lower mortality rates when treated more aggressively with GTR. However, patients with WHO Grade III tumors had slightly better survival outcomes after a less aggressive surgical debulking (STR+EBRT) when compared with GTR.

CONCLUSIONS

Mortality, PFS, and overall survival vary in pediatric patients with intracranial ependymomas. Pathological classification, tumor location, and method of treatment play a role in outcomes. In this study, GTR was associated with the best overall and PFS rates. Patients with WHO Grade II tumors had better overall survival after GTR+EBRT and better PFS after GTR alone. Patients with WHO Grade III tumors had better overall survival after STR+EBRT. Patients with infratentorial tumors had improved overall survival compared with those with supratentorial tumors. Progression-free survival was best in those patients with infratentorial tumors following STR+EBRT. Consideration of all of these factors is important when counseling families on treatment options.

Current treatment options for pediatric and adult patients with ependymoma

OPINION STATEMENT

Survival rates for patients with ependymoma, a glial tumor arising from the ependymal cells lining the ventricles of the brain and spinal cord canal, have changed little during the past decade. Contemporary "standard" therapy for children and adults with ependymoma consists of maximal surgical resection followed by focal irradiation except in cases of disseminated disease. Despite refinements in radiotherapy techniques and improvements in survival for patients with gross totally resected, nonanaplastic disease, many therapeutic challenges remain, especially for patients with unresectable, macroscopic, metastatic, or anaplastic disease. Moreover, radiotherapy to the developing central nervous system, especially in patients younger than age 5 years, can have potential long-term neurocognitive and neuroendocrine sequelae. Chemotherapy has not played a role in most treatment regimens for ependymoma to date, but due to the ongoing therapeutic challenges for a subset of patients, this modality is being reinvestigated in a few ongoing studies. Early recognition of patients who will not respond to primary therapy is imperative to modify treatment regimens, such as intensification with the addition of adjuvant chemotherapy, the use of novel experimental therapies, or their combination. Refinements in patient stratification schemes that are based on a combination of clinical variables and molecular profiles also require improved knowledge of tumor biology. Several molecular alterations have been identified already, some of which may be of prognostic significance. Furthermore, disruption of molecular alterations in signaling pathways involved in the development and maintenance of ependymoma by using novel molecularly targeted therapies may improve outcomes and reduce toxicity for patients with ependymoma.

Patient-derived tumour xenografts as models for oncology drug development

Progress in oncology drug development has been hampered by a lack of preclinical models that reliably predict clinical activity of novel compounds in cancer patients. In an effort to address these shortcomings, there has been a recent increase in the use of patient-derived tumour xenografts (PDTX) engrafted into immune-compromised rodents such as athymic nude or NOD/SCID mice for preclinical modelling. Numerous tumour-specific PDTX models have been established and, importantly, they are biologically stable when passaged in mice in terms of global gene-expression patterns, mutational status, metastatic potential, drug responsiveness and tumour architecture. These characteristics might provide significant improvements over standard cell-line xenograft models. This Review will discuss specific PDTX disease examples illustrating an overview of the opportunities and limitations of these models in cancer drug development, and describe concepts regarding predictive biomarker development and future applications.

Intensity modulated radiation therapy or stereotactic fractionated radiotherapy for infratentorial ependymoma in children: a multicentric study

This study was to evaluate the treatment dosimetry, efficacy and toxicity of intensity modulated radiation therapy (IMRT) and fractionated stereotactic radiotherapy (FSRT) in the management of infratentorial ependymoma. Between 1999 and 2007, seven children (median age, 3.1 years) with infratentorial ependymoma were planned with either IMRT (3 patients) or SFRT (4 patients), the latter after conventional posterior fossa irradiation. Two children underwent gross total resection. Median prescribed dose was 59.4 Gy (range, 55.8-60). The median follow-up for surviving patients was 4.8 years (range, 1.3-8). IMRT (median dose, 59.4 Gy) and FSRT (median dose, 55.8 Gy) achieved similar optimal target coverage. Percentages of maximum doses delivered to the cochleae (59.5 vs 85.0% Gy; P = 0.05) were significantly inferior with IMRT, when compared to FSRT planning. Percentages of maximum doses administered to the pituitary gland (38.2 vs 20.1%; P = 0.05) and optic chiasm (38.1 vs 14.1%; P = 0.001) were, however, significantly higher with IMRT, when compared to FSRT planning. No recurrences were observed at the last follow-up. The estimated 3-year progression-free survival and overall survival were 87.5 and 100%, respectively. No grade >1 acute toxicity was observed. Two patients presented late adverse events (grade 2 hypoacousia) during follow-up, without cognitive impairment. IMRT or FSRT for infratentorial ependymomas is effective and associated with a tolerable toxicity level. Both treatment techniques were able to capitalize their intrinsic conformal ability to deliver high-dose radiation. Larger series of patients treated with these two modalities will be necessary to more fully evaluate these delivery techniques.

Proton beam therapy following resection for childhood ependymoma

INTRODUCTION

Proton radiation therapy is a form of radiation with physical properties that can provide an advantage in normal tissue sparing compared to the more commonly used photon therapy.

DISCUSSION

The greatest benefit may be for young patients with tumors requiring relatively high doses of radiation and adjacent to critical structures. Children with central nervous system ependymomas meet these criteria and have a very high likelihood of benefit from proton radiation. At present, proton radiation is limited to select centers. However, knowledge of many of the physical advantages of proton therapy has spread rapidly over the past several years, and its availability is becoming more widespread.

A clinically relevant orthotopic xenograft model of ependymoma that maintains the genomic signature of the primary tumor and preserves cancer stem cells in vivo

Limited availability of in vitro and in vivo model systems has hampered efforts to understand tumor biology and test novel therapies for ependymoma, the third most common malignant brain tumor that occurs in children. To develop clinically relevant animal models of ependymoma, we directly injected a fresh surgical specimen from a 9-year-old patient into the right cerebrum of RAG2/severe complex immune deficiency (SCID) mice. All five mice receiving the initial transplantation of the patient tumor developed intracerebral xenografts, which have since been serially subtransplanted in vivo in mouse brains for 4 generations and can be cryopreserved for long-term maintenance of tumorigenicity. The xenograft tumors shared nearly identical histopathological features with the original tumors, harbored 8 structural chromosomal abnormalities as detected with spectral karyotyping, maintained gene expression profiles resembling that of the original patient tumor with the preservation of multiple key genetic abnormalities commonly found in human ependymomas, and contained a small population (<2.2%) of CD133(+) stem cells that can form neurospheres and display multipotent capabilities in vitro. The permanent cell line (BXD-1425EPN), which was derived from a passage II xenograft tumor and has been passaged in vitro more than 70 times, expressed similar differentiation markers of the xenograft tumors, maintained identical chromosomal abnormalities, and formed tumors in the brains of SCID mice. In conclusion, direct injection of primary ependymoma tumor cells played an important role in the generation of a clinically relevant mouse model IC-1425EPN and a novel cell line, BXD-1425EPN. This cell line and model will facilitate the biological studies and preclinical drug screenings for pediatric ependymomas.

Survival following treatment for intracranial ependymoma: a review

The actual definition of survival rates following treatment for intracranial ependymomas is substantially influenced by the strict interaction among different factors. Age, location, and grading, for example, act together, negatively influencing the prognosis of younger children also invariably influenced by the more demanding role of surgery and the still limited use, up to recently, of radiotherapy under 3 years of age. In the same direction, the worse prognosis in most series of infratentorial ependymomas if compared with their supratentorial counterpart should be cautiously considered, midline posterior fossa tumors having completely different implications from those originating or predominantly extending to the cerebellopontine angle, where the extent of surgery has more invariably to compare with patients' quality of life. New radiotherapic regimens and their applications in infancy are promisingly demonstrating an improvement of present prognostic criteria, with the limit of still insufficient information on their long-term secondary effects. Similarly, molecular biology research studies, though still in their preclinical stage, are prompting to change the concept of a substantially chemoresistant tumor helping to stratify these lesions with the final aim of targeted pharmacological therapies. In the present review paper, we investigated singularly the role that the more commonly considered prognostic factors have had in the literature on survival of children affected by intracranial ependymomas, trying to elucidate their cumulative effect on the actual knowledge of this issue.

New chemotherapy strategies and biological agents in the treatment of childhood ependymoma

INTRODUCTION

With the limited role of current treatment regimens and potential associated side effects of radiation in young children with ependymoma, considerable effort is being focused on new chemotherapeutic strategies and biologic agents.

DISCUSSION AND CONCLUSION

Identification of those molecular changes underlying the development of ependymoma may, in time, lead to the development of not only novel therapeutic agents, but also specific patient-tailored therapies directed against known cell-signaling pathways.

Advances in surgical techniques for resection of childhood cerebellopontine angle ependymomas are key to survival

BACKGROUND

Childhood cerebellopontine angle (CPA) ependymoma is an uncommon anatomical variant of posterior fossa ependymoma. In infants and young children, the tumor often goes undetected until it causes hydrocephalus. As CPA ependymomas grow, they distort the anatomy and encase cranial nerves and vessels, thereby making resection a formidable surgical challenge.

PURPOSE

The purpose of this paper is to describe the surgical technique used to achieve gross total resection (GTR) of CPA ependymomas and demonstrate improved survival in these patients.

MATERIALS AND METHODS

Surgical techniques used for GTR in 45 patients with CPA ependymoma treated from 1997 to 2008 are described. Results of those procedures are compared with data from 11 patients who previously underwent surgical resection (1985-1995).

RESULTS

We achieved GTR in 43 (95.6%) patients and near-total resection in two (4.4%); the probability of progression-free survival was 53.8%, and that of overall survival was 64%.

CONCLUSION

Our novel surgical techniques greatly improve central nervous system function and survival among pediatric patients with CPA ependymoma.

The role of stereotactic radiotherapy in the management of ependymomas

INTRODUCTION

Intracranial ependymomas in children have high rates of recurrence. Salvage therapy typically includes repeat resection, possibly chemotherapy, and re-irradiation. Stereotactic radiosurgery has been used for re-irradiation. It offers the theoretical advantages of delivering a high dose of radiation to a small target, providing a maximum dose to the tumor while avoiding surrounding critical brain structures and previously irradiated tissue.

DISCUSSION

Few reports in the literature describe this technique, with mixed, but not often successful, outcomes.

The history of ependymoma management

INTRODUCTION

The ependymomas are relatively not a common tumor. However, most clinicians agree that the radical removal of the tumor is the most important prognostic factor.

MORBIDITY OF TREATMENT

Tumor removal was not sufficient before the era of magnetic resonance imaging (MRI) and resulted in a considerable operative morbidity and mortality. As the microneurosurgical techniques and microsurgical anatomy become popular and the MRI provide more detailed anatomical information preoperatively, radical removal of this complex and complicated tumor can be more feasible. In childhood ependymoma, the treatment-related morbidity and mortality can be the special issues, which can modify the policy of management safe tumor removal and minimal adjuvant treatment, which are extremely important.

RADIATION THERAPY

Radiation treatment has been the option for disseminated disease and residual tumor. With the advancement of detailed MR anatomical information, safer and more delicate radiation becomes possible with newer radiation modalities, three-dimensional conformal radiotherapy, intensity modulating radiotherapy, and tomotherapy.

PROGNOSTIC FACTORS

Although many clinicians believe that the ependymomas are inheritably chemoresistant, the new targets for the treatment are under investigation or clinically tried. Also, the genetic alterations of ependymoma are developing and might be a promising target.

CONCLUSION

The surgical techniques and assistant modalities for tumor removal are still advancing. So, the outcome of ependymoma is still improving. Unfortunately, newer treatment modalities, such as new chemotherapeutic agent and gene modification agent, are still not promising. The history of ependymoma management is still in progress.

Maximally safe resection followed by hypofractionated re-irradiation for locally recurrent ependymoma in children

BACKGROUND

Treatment failure in children with ependymoma is relatively common, with the majority of events consisting of local failure. Salvage therapy for these children historically had poor results, with repeated local recurrences. To improve these outcomes, we began to offer hypofractionated re-irradiation after resection at first local recurrence. To minimize the duration of therapy, we chose a hypofractionated regimen that has been shown to be well tolerated in adult patients.

PROCEDURE

We performed a review of the experience at the Children's Hospital in Denver and at the Department of Radiation Oncology at the University of Colorado Denver from 1995 to 2008 with hypofractionated re-irradiation after maximally safe resection in children with locally recurrent ependymoma.

RESULTS

Six children with locally recurrent ependymoma were seen in that time period. After maximally safe resection, all six received hypofractionated radiation therapy of 24-30 Gy delivered in three fractions. With a median follow-up of 28 months from the time of re-irradiation, all six children are alive with no evidence of disease. Three children had evidence of radiation necrosis, either clinically or based on imaging, but none required significant intervention.

CONCLUSIONS

Hypofractionated re-irradiation after resection for locally recurrent ependymoma is well tolerated. This approach also appears to provide good local control. Additional follow-up is required to determine the efficacy and potential late effects of hypofractionated re-irradiation in this patient population.

Ependymal tumors

Ependymomas represent a heterogeneous group of glial tumors whose biological behavior depends on various histological, molecular, and clinical variables. The scope of this chapter is to review the clinical and histo-logical features as well as the molecular genetics of ependymomas with special emphasis on their influence on tumor recurrence and prognosis. Furthermore, potential molecular targets for therapy are outlined.

Outcomes of malignant CNS ependymomas: an examination of 2408 cases through the Surveillance, Epidemiology, and End Results (SEER) database (1973-2005)

BACKGROUND

Determine the role of surgery and radiation therapy for patients with malignant CNS ependymomas.

METHODS

The Surveillance, Epidemiology, and End Results (SEER) database (1973-2005) was queried.

RESULTS

Overall, a total of 2408 cases of malignant ependymomas were identified. Of these, 2132 cases (88.5%) were identified as WHO grade II ependymomas and 276 cases (11.5%) as WHO grade III (anaplastic) ependymomas. The annual incidence of ependymomas was approximately 1.97 cases per million in 2005. Overall median survival for all patients was 230 mo, with a significant difference between women and men (262 mo versus196 mo, respectively) (P=0.004). Median age at diagnosis was 37 y among females and 34 y in males. Patients who successfully underwent surgical resection had a considerably longer median survival (237 mo versus 215 mo, P<0.001) as well as a significantly improved five-year survival (72.4% versus 52.6%, P<0.001). Univariate analysis demonstrated that age, gender, ethnicity, primary tumor site, WHO grade and surgical resection were significant predictors of improved survival for ependymoma patients. Multivariate analysis identified that a WHO grade III tumor, male gender, patient age, intracranial tumor locations and failure to undergo surgical resection were independent predictors of poorer outcomes. Multivariate analysis of partially resection cases revealed that lack of radiation was a sign of poor prognosis (HR 1.748, P=0.024).

CONCLUSION

Surgical extirpation of ependymomas is associated with significantly improved patient survival. For partially resected tumors, radiation therapy provides significant survival benefit.

Immunohistochemical prognostic markers in intracranial ependymomas: systematic review and meta-analysis

Distinction between grade II ependymomas and anaplastic ependymomas based on histopathological examination solely is problematic and, therefore, the management of intracranial ependymomas remains controversial. The aim of this study was to conduct a systematic review (SR) and meta-analysis (MA) of data published on immunohistochemical prognostic markers (IPM) in intracranial ependymomas (IE), and to establish an evidence-based perspective on their clinical value. Following the extensive search based on a strictly defined group of key words, 30 studies reporting results on IPM in IE were identified. Due to a pronounced inter-study heterogeneity, only 14 publications fulfilled the criteria for inclusion into SR. From the total of 67 immunohistochemical markers, 18 were found to correlate with prognosis. However, owing to inadequate data publishing, MA could be performed only with data on proliferation marker MIB-1 (Ki-67) from 5 publications, including 337 patients: The pooled hazard ratio for overall survival was 3.16 (95% confidence interval = 1.96-5.09; p < 0.001) implicating that patients suffering from tumors with higher immunohistochemical expression of MIB-1 had a significantly worse outcome. Marked inter-study heterogeneity and incomplete data publishing in primary studies significantly limited extent of the SR, and the possibility of performing MA. Although the prognostic impact of MIB-1 immunoexpression in IE could be confirmed, there remains lack of further reliable IPM that could be used in routine diagnosis. We encourage to search for new, useful markers, as well as to standardize lab-techniques and data interpretation algorithms across laboratories in order to increase data compatibility.

OUTCOME PREDICTORS FOR INTRACRANIAL EPENDYMOMA RADIOSURGERY

OBJECTIVE

To develop outcome predictors after stereotactic radiosurgery (SRS) in patients with intracranial ependymomas who had received previous fractionated radiation therapy, we compared tumor control, survival, and complications with tumor grade, volume, age of patients, and imaging characteristics.

METHODS

We retrospectively reviewed records of 39 consecutive ependymoma patients who underwent SRS for 56 tumors. The median patient age was 22.8 years (range, 2.9–71.1 years). All patients had previous surgical resection of their ependymomas followed by radiotherapy, and 14 patients underwent previous chemotherapy. Twenty-five patients had low-grade ependymomas (34 tumors), and 14 patients had anaplastic ependymomas (22 tumors). The median radiosurgery target volume was 3.6 cm3 (range, 0.1–36.8 cm3), and the median margin dose was 15.0 Gy (range, 10–22 Gy).

RESULTS

At a median of 23.5 months after SRS (range, 6.1–155.2 months), 25 patients died as a result of metastases (12 patients) or disease progression (13 patients). The overall survival rates after SRS were 60.1, 36.1, and 32.1% at 1, 3, and 5 years, respectively. The progression-free survival rates after SRS at 1, 3, and 5 years were 81.6, 45.8, and 45.8%, respectively, for all grades of ependymomas. Lower histological tumor grade was not significantly associated with better progression-free survival (P = 0.725). Factors associated with an improved progression-free survival included smaller tumor volume and homogeneous tumor contrast enhancement in low-grade ependymomas.

CONCLUSION

SRS provides another management option for patients with residual or recurrent ependymomas that have failed surgery and radiation therapy. Predictors of response include smaller volume and homogeneous contrast enhancement.

WHO Grade II and III supratentorial hemispheric ependymomas in adults: case series and review of treatment options

Supratentorial ependymomas and their anaplastic variants are relatively uncommon central nervous system neoplasms that afflict both adults and children. Whereas the treatment algorithm in the pediatric population is well established, however, treatment in the adult population is less defined. In our case series of three adult patients with supratentorial ependymomas, two patients had tumors of WHO Grade III (anaplastic variant) and one had tumor of WHO Grade II. In all patients, gross total resection was achieved. Additional radiation therapy was administered in the Grade III patients. Twenty-four-month follow-up in case 1 yielded no tumor recurrence and no requirement of adjuvant chemotherapy. In case 2, tumor recurred with leptomeningeal gliomatosis by 6 months. Addition of platinum-based chemotherapy did not improve long-term survival; the patient succumbed to the disease after 14 months. In case 3 (WHO Grade II), no radiation therapy was required. Tumor did not recur during the 42-month follow-up. In our experience, gross total resection was achieved in all patients with hemispheric supratentorial WHO Grade II or Grade III ependymomas with additional radiation therapy for Grade III variants. All patients require initial close serial imaging and follow-up. The role of chemotherapy is still uncertain but may be necessary in younger patients who may have tumors that behave more like the pediatric ependymomas.

Ki67 index in intracranial ependymoma: a promising histopathological candidate biomarker

AIMS

The Ki67 tumour cell proliferation index is an independent prognostic factor in ependymoma patients. Essential prerequisites for validation of the Ki67 index as a histopathological biomarker are the reproducibility of this factor and its prognostic influence by different observers (proof of objective clinical and analytical performance). To this end, the aim was to analyse systematically inter- and intraobserver agreement and reproducibility of the prognostic impact of the Ki67 index in intracranial ependymoma.

METHODS AND RESULTS

The study cohort contained 78 cases of intracranial ependymoma. In all cases, the Ki67 index was assessed by four experienced observers (EOs) and by four inexperienced observers (IOs) using the manual hot-spot method. There was considerable agreement on Ki67 index assessment. There was higher observer agreement among EOs compared with IOs. For each observer, survival analysis showed significant association of low Ki67 index with favourable patient outcome.

CONCLUSIONS

Our data show that the Ki67 index in intracranial ependymoma is a reproducible and robust prognostic factor and can be considered a promising histopathological candidate biomarker. Attainment of biomarker status requires further translational studies in the context of prospective therapeutic trials.

Surgical management of pediatric brain tumors

Brain tumors are the most common cause of cancer-related death and the second most common form of cancer in pediatric patients. Many of these tumors are treated primarily with surgery, either alone or in combination with radiation or chemotherapy. Recent advances have lead to greater survival and decreased morbidities in childhood brain tumor patients. A full understanding of the biology and primary treatment modalities for the particular tumor are essential for any professional treating these patients, including the neurosurgeon. Each tumor type has features in common with, and unique from, other tumors that need to be understood prior to undertaking a rational treatment plan. This article summarizes some of these features.

The prognostic value of histological grading of posterior fossa ependymomas in children: a Children's Oncology Group study and a review of prognostic factors

We performed a retrospective analysis of 96 pediatric posterior fossa ependymomas in order to determine the prognostic value of histological grade based on the current WHO grading scheme. The patients were selected among Children's Oncology Group (previously Pediatric Oncology Group-POG) patients enrolled in clinical trials, and on the basis of central pathology review, location, and age. We excluded entities such as sub-ependymoma, myxopapillary, or clear-cell ependymoma, after a consensus diagnosis by three neuropathologists. A total of 66 males and 30 females with a median age of 48 months were identified. The group was analyzed to determine the effects of histological grade, age, gender, and extent of resection on event-free and overall survival. Our results showed that extent of resection, age, and histological grade were independent prognostic variables for event-free survival. The relative risk for extent of resection and histological grade was calculated as 3.59 (P<0.001) and 3.58 (P<0.001), respectively. Overall survival significantly correlated with extent of resection and age, but not with histological grade. We compared our results with peer-reviewed publications on pediatric intracranial ependymomas in the English language between 1990 and 2005. Selection criteria identified 32 manuscripts involving 1444 patients. Extent of resection was a significant factor in 21, age in 12, and histological grading in nine of these studies. Other factors reported to be significant by more than one study included tumor location and radiation treatment. Our findings suggest that histological grade (WHO Grade II vs III) is an independent prognostic indicator for event-free survival, but may not be so for overall survival in pediatric posterior fossa ependymomas. We believe that an accurate assessment of the prognostic value of histological grade depends on the selection of a well-characterized clinical cohort of sufficient size, and the inclusion of relevant histological criteria as outlined in the WHO classification scheme.

Metastatic ependymoma: a multi-institutional retrospective analysis of prognostic factors

PURPOSE

Metastatic ependymoma is exceedingly rare at diagnosis with variable prognosis reported in the literature. The purpose of this study was to identify prognostic factors in children with metastatic ependymoma.

PROCEDURE

Data regarding diagnosis, treatment and follow-up for 40 patients from eight institutional cohorts were collected.

RESULTS

Twenty-nine (72%) patients were less than 36 months of age at the time of diagnosis, 28% were females, and 90% of the patients had posterior fossa tumors. Gross total resection (GTR) of the primary tumor was achieved in 16 patients (40%). Adjuvant therapy was variable and included craniospinal irradiation (CSRT), chemotherapy, and chemotherapy with focal irradiation. The 5-year event free survival (EFS) and overall survival (OS) from the time of diagnosis were 29% (+/-7%) and 43% (+/-8%), respectively. Age at diagnosis was associated significantly with both EFS and OS (P < 0.001 for EFS, and P = 0.01 for OS). Patients who were 24-35 months of age at diagnosis had a 5-year EFS of 66% and a 5-year OS of 73%; both survival rates were superior to those of patients younger than 24 months of age or older than 36 months. Patients with GTR achieved a 5-year EFS of 35% and OS of 59%, compared to a 5-year EFS of 25% and OS of 32% for patients who did not achieve GTR (P = 0.12 for EFS, P = 0.03 for OS).

CONCLUSIONS

GTR should be attempted in patients with metastatic ependymoma. A subgroup of patients between 24 and 35 months might have a favorable outcome.

Outcome for young children newly diagnosed with ependymoma, treated with intensive induction chemotherapy followed by myeloablative chemotherapy and autologous stem cell rescue

BACKGROUND

The purpose of this study is to investigate the efficacy of an intensive chemotherapy induction regimen followed by myeloablative chemotherapy and autologous hematopoietic stem cell rescue (AHSCR) in children with newly diagnosed ependymoma.

PATIENTS AND METHODS

Twenty-nine children less than 10 years of age at diagnosis of ependymoma were enrolled on the "Head Start" studies. Twenty-four patients with localized disease received an induction regimen including five cycles of chemotherapy (cisplatin, vincristine, etoposide cyclophosphamide, and high dose methotrexate for patients with metastatic disease). Following induction, individuals without evidence of disease proceeded to marrow-ablative chemotherapy (thiotepa, carboplatin, and etoposide) with AHSCR.

RESULTS

The estimated 5-year event free survival (EFS) and overall survival (OS) from diagnosis were 12% (+/-6%) and 38% (+/-10%), respectively. The toxic mortality amongst this group of 29 patients was 10.3%. Younger age (less than 18 months at diagnosis) was the only statistically significant prognostic factor. The estimated 5-year OS rate for the five patients with metastatic disease at presentation was 80% (+/-18%). Overall, radiation-free survival at 5 years from diagnosis was 8% (+/-5%).

CONCLUSIONS

The use of an intensive induction chemotherapy regimen including myeloablative chemotherapy followed by AHSCR in newly diagnosed young children with ependymoma is not superior to other previously reported chemotherapeutic strategies.

Three-dimensional computer reconstruction of a fourth ventricle ependymoma

It is very important to establish the surgical strategy for fourth ventricle ependymoma with the aim of total tumor resection because improving the degree of surgical removal is the most promising means of improving outcome. We present our experience in reconstructing a three-dimensional (3-D) image of a fourth ventricle ependymoma perioperation. We used computer-assisted 3-D reconstruction to visualize a fourth ventricle ependymoma. Tumor outlines were manually traced out and imported to a 3-D visualization tool for 3-D reconstruction. The patient was operated through a median infratentorial approach. Perioperation by rotating the 3-D image and observing from various angles, we acquired abundant information such as 3-D tumor contour, the relation between the tumor and the wall of the fourth ventricle, the origin and invasion of the tumor, which were very useful to monitor tumor resection, adjust the approach to the ependymoma, and avoid inadvertent injury of important anatomic structures. Computer-assisted 3-D reconstruction may not only provide useful information before and during surgery, but also simplify the surgical procedure. It may be a useful aid to surgery making neurosurgery less invasive and more effective.

Recurrence in supratentorial anaplastic ependymoma

AIM

To study the outcome and recurrence in supratentorial anaplastic ependymoma.

METHODS

Sixteen cases of supratentorial anaplastic ependymoma were reviewed. The average age of presentation was 8.2 years ranging from 1 to 16 years of age. The mean duration between the onset of first symptoms to time of presentation was 4.2 months. Follow-up ranged from 5 to 58 months with a mean of 16.8 months.

RESULTS

Gross total excision of tumor was achieved in 14 cases, as judged on the basis of intraoperative impression and confirmed with postoperative contrast MR or CT scan. There were 2 unfortunate deaths in the series, one as result of disseminated intravascular coagulation in view of massive blood loss and the other child had evidence of central transtentorial herniation preoperatively which failed to recover. Postoperative cranial radiotherapy was offered to all the 14 remaining cases. Twelve of 14 cases showed evidence of recurrence at follow-up. Recurrence occurred as early at 6 months and as late as 58 months. Only 2 children were recurrence free at follow-up of 6 months and 14 months, respectively. Two operated and irradiated cases of differentiated ependymomas (grade II) developed anaplastic recurrence at follow-up of 5 years and 9 years, respectively, suggesting a malignant transformation of tumor at follow-up. Four out of 12 cases were reoperated for their recurrence in view of localized nature of recurrence and good Karnofsky's performance status.

CONCLUSION

It is obvious that anaplastic ependymomas of the supratentorial compartment are aggressive tumors with high rates of recurrence even after gross total excision and irradiation. Gross total excision and postoperative irradiation are not effective in preventing early recurrence in anaplastic ependymomas, and other factors affecting the outcome need to be analyzed.

Effects of surgical resection and adjuvant therapy on pediatric intracranial ependymomas

The optimal therapy of pediatric ependymomas is controversial. The benefit of surgical resection is widely accepted, but the role of adjuvant therapy is subject to debate. Due to the relatively low survival rates of ependymoma patients, as well as the tumor's high recurrence rates, further research into the efficacy of treatment strategies and adjuvant therapy is necessary. Extent of resection remains the most important determinant of survival in patients with ependymomas. Expectantly, gross total resection yields the best outcome for patients. The optimal roles of chemotherapy and radiation therapy are poorly understood. A closer look at the efficacy of tailored radiation therapy and the possible use of chemotherapy to delay radiation therapy sheds light on potential treatment modalities for ependymomas. The greatest increase in survival on the ependymoma population will likely come from an increase in the rate of complete resections. An improvement in the efficacy of radiation therapy in addition to an understanding of chemotherapy protocols and treatment durations will hopefully provide further means for successfully treating ependymomas.

The role of Gamma Knife Radiosurgery in the management of unresectable gross disease or gross residual disease after surgery in ependymoma

PURPOSE/OBJECTIVE

To evaluate the efficacy and the toxicity of Gamma Knife (GK)-based stereotactic radiosurgery (SRS) in the management of gross disease in ependymoma.

MATERIALS AND METHODS

Eight patients with 13 ependymomas were treated with GK-based SRS in our institution for gross disease. Five patients were treated for recurrent disease that developed after surgery and external beam radiotherapy (EBRT), two received SRS to the gross disease after surgery and EBRT, and one received SRS alone (in a 1.3 year old child). Median EBRT dose was 54.4 Gy (range 50-55.8 Gy). Median SRS dose was 14 Gy (range 12-20 Gy). Seven of eight (87.5%) patients had SRS to a single lesion and one of eight (12.5%) patients had treatment to six tumors in three different sessions.

RESULTS

The median follow up was 30.2 months (range 8-65.4 months). Out of the eight patients treated with SRS, six (75%) were alive, four (50%) were alive with no recurrence, two (25%) were alive with recurrence, and two (25%) died of recurrent disease. Both patients treated with SRS as a boost were alive and without recurrence. Out of the five patients who received SRS as salvage treatment, three (60%) were alive, two (40%) were alive without recurrence, two (40%) developed distant failure, and three (60%) had in-field control. Two patients who received SRS to their brainstem lesions developed symptoms related to radionecrosis and were successfully treated with steroid with good control of symptoms.

CONCLUSIONS

GK-based SRS appears to be a feasible and safe treatment modality for patients with ependymoma with unresectable gross disease or gross residual disease after surgery. SRS provides reasonable local control but out-of-field tumor progression remains an issue. For patients who receive SRS as a boost, the local control appears to be excellent.

Survival analysis of children with primary malignant brain tumors in England and Wales: a population-based study

Primary malignant brain tumor is the second most common cancer in children. To investigate factors affecting children's survival at a population level, data of 3,169 patients (age<15 years) from the Cancer Registry in England and Wales were used. They were diagnosed during 1971-1990 and followed up until 1995. Variables including age, gender, morphology, WHO grade, tumor site, socioeconomic status, geographical region, and period of diagnosis were available for analysis using the Kaplan-Meier method and the Cox hazards ratio (HR) regression. Results showed that the median survival and the 1-, 5-, and 10-year crude survival rate for this population were 8.7 years, 72.4, 54.0, and 49.2% respectively. Survival was influenced by age (HR 0.88/5 years), morphology (ependymoma HR 2.43), WHO grades (HR 1.42/grade), tumor sites (brain stem HR 2.11), and periods of diagnosis (HR 0.88/5 years). Gender, socioeconomic status, and geographical region did not affect their survival. Results from this population-based data are very helpful for comparison with other hospital-based studies and for public health purposes.

Ependymal tumors in childhood

BACKGROUND

Ependymal tumors are classified as ependymoma (benign or low grade) versus anaplastic ependymoma (malignant or high grade). Ependymomas represent 5-10% of intracranial neoplasm in children. In this study, demographic data and the treatment results of pediatric patients with ependymal tumors, treated in a single institute, is reported.

PATIENTS AND METHODS

Between 1989 and 2001, 40 (22 M/18 F) previously untreated patients with a median age of 5.5 years (3 months-15 years), of histologically proven ependymal tumors (except ependymoblastomas) were referred to the Institute of Oncology, University of Istanbul. The localization was supratentorial in 18, infratentorial in 20, both supra and infratentorial in two patients. Histologic subgroups were 18 ependymomas (43.6%), and 22 anaplastic ependymomas (56.4%). Total tumor resection was performed in 20 patients (50%), subtotal in 18 patients (45%), and biopsy only in 2 patients (5%). Postoperative treatment consisted of regional (8 patients) or craniospinal (CSI) (9 patients) radiotherapy (RT) in patients with ependymoma; regional (7 patients) or CSI RT (14 patients) with chemotherapy (ChT) in patients with anaplastic ependymoma; ChT only (1 patient) in patients less than 3 years of age. The standard technique for posterior fossa irradiation was parallel-opposed lateral fields and total dose was 45-54 Gy. Between September 1989 and May 1991 patients received regimen A, which consisted of RT followed by eight-in-one ChT, given every 4 weeks for eight courses. Patients who were treated between June 1991 and July 1994, received regimen B, which included two courses of postoperative "VEC" (vincristine, etoposide, cisplatin) ChT, administered every 3 weeks, followed by RT applied with low dose concomitant cisplatin used as a radiosensitizer. Patients with objective response to postoperative "VEC" continued to have "VEC" after completion of RT for six more courses. From August 1994 on, patients received regimen C, consisting of RT and concomitant infusion of cisplatin followed by "VCPCU" (vincristine, cyclophosphamide, procarbazine, lomustine) administered every 4 weeks for eight courses.

RESULTS

A total of 40 patients were included in the outcome and survival data. The 5-year overall survival (OS) rate was 64.9%, and the 5-year progression-free survival rate was 50.8% for the whole series. Median time for progression or relapse was 24.3 months and there were 19 patients (43.6%) with relapse or progression. Non-metastatic patients (P = 0.0008, 5-year OS rate was 82% vs. 29%), and totally resected patients (P = 0.01, 5-year OS rate was 80% vs. 55%), and > or =3 years of age (P = 0.04, 5-year OS rate was 75% vs. 38%) had significantly better outcome.

CONCLUSIONS

The majority of complete responders were patients who had total tumor removal. Treatment failure occurred mainly within the first 2 years, and outcome was dismal for patients who relapsed or had progressive disease. The median age at diagnosis is 6 years in our patient group; younger children (less than 3 years old) have less favorable outcome. There was no significant difference in survival or progression-free survival between the two histologic subtypes.