Treatment of intracranial ependymomas of children: review of a 15-year experience

Anaplastic ependymoma with sclerotic bone metastases

Ependymomas are glial central nervous system (CNS) tumors that arise from the ependymal layer of brain and spinal cord. These are heterogeneous group of tumors with varied histopathological features and prognosis. They frequently relapse at the primary site and may disseminate to other CNS sites. Extraneural metastases are, however, extremely rare. We present a case of ependymoma in a child with widespread metastasis to her bones, a previously unreported event.

Stereotactic radiosurgery for pediatric recurrent intracranial ependymomas

OBJECT

To evaluate the role of stereotactic radiosurgery (SRS) in patients with recurrent or residual intracranial ependymomas after resection and fractionated radiation therapy (RT), the authors assessed overall survival, distant tumor relapse, progression-free survival (PFS), and complications.

METHODS

The authors retrospectively reviewed the records of 21 children with ependymomas who underwent SRS for 32 tumors. There were 17 boys and 4 girls with a median age of 6.9 years (range 2.9-17.2 years) in the patient population. All patients underwent resection of an ependymoma followed by cranial or neuraxis (if spinal metastases was confirmed) RT. Eleven patients had adjuvant chemotherapy. Twelve patients had low-grade ependymomas (17 tumors), and 9 patients had anaplastic ependymomas (15 tumors). The median radiosurgical target volume was 2.2 cm(3) (range 0.1-21.4 cm(3)), and the median dose to the tumor margin was 15 Gy (range 9-22 Gy).

RESULTS

Follow-up imaging demonstrated therapeutic control in 23 (72%) of 32 tumors at a mean follow-up period of 27.6 months (range 6.1-72.8 months). Progression-free survival after the initial SRS was 78.4%, 55.5%, and 41.6% at 1, 2, and 3 years, respectively. Factors associated with a longer PFS included patients without spinal metastases (p = 0.033) and tumor volumes < 2.2 cm(3) (median tumor volume 2.2 cm(3), p = 0.029). An interval ≥ 18 months between RT and SRS was also associated with longer survival (p = 0.035). The distant tumor relapse rate despite RT and SRS was 33.6%, 41.0%, and 80.3% at 1, 2, and 3 years, respectively. Factors associated with a higher rate of distant tumor relapse included patients who had spinal metastases before RT (p = 0.037), a fourth ventricle tumor location (p = 0.002), and an RT to SRS interval < 18 months (p = 0.015). The median survival after SRS was 27.6 months (95% CI 19.33-35.87 months). Overall survival after SRS was 85.2%, 53.2%, and 23.0% at 1, 2, and 3 years, respectively. Adverse radiation effects developed in 2 patients (9.5%).

CONCLUSIONS

Stereotactic radiosurgery offers an additional option beyond repeat surgery or RT in pediatric patients with residual or recurrent ependymomas after initial management. Patients with smaller-volume tumors and a later recurrence responded best to radiosurgery.

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.

Ependymoma of the spinal cord in children and adolescents: a retrospective series from the HIT database

OBJECT

Reports on spinal cord ependymoma in children are rare. The aim of this study was to evaluate the clinical spectrum, treatment, and outcome of children with primary ependymoma of the spinal cord who were registered in the database of the pediatric German brain tumor studies Hirntumor (HIT) '91 and HIT 2000.

METHODS

Between 1991 and 2007, 29 patients (12 male and 17 female, median age at diagnosis 13.6 years) with primary spinal cord ependymoma (myxopapillary ependymoma WHO Grade I, II, and III tumors in 6, 17, and 6 patients, respectively) were identified. Four patients had neurofibromatosis Type 2.

RESULTS

With a median follow-up of 4.2 years (range 0.48-15 years), 28 patients (96.6%) were alive. Seven patients (24.1%) developed progressive disease or relapse, 2 after gross-total resection (GTR) and 5 after incomplete resection or biopsy. One patient with anaplastic ependymoma (WHO Grade III) died 65 months after diagnosis of disease progression. Primary adjuvant treatment (radiotherapy, chemotherapy, or both) was used in 8 (50%) of 16 patients following GTR and in 9 (82%) of 11 patients who underwent less than a GTR. Three additional patients were treated adjuvantly following progression. Estimated progression-free survival and overall survival rates at 5 years were 72.3% (95% CI 50%-86%) and 100%, respectively. Progression-free survival at 5 years is 84.4% (95% CI 50%-96%) for patients following GTR compared with 57.1% (95% CI 25%-69%) for patients who achieved a less than GTR (p = 0.088, log-rank test). A high relapse incidence (4 of 6) was observed among patients with myxopapillary ependymoma.

CONCLUSIONS

Gross-total resection is the mainstay of treatment for patients with primary spinal cord ependymoma and may be achieved in about 50% of the patients using modern surgical techniques. Primary adjuvant treatment was commonly used in children with spinal cord ependymoma irrespective of the extent of resection or tumor grade. The impact of adjuvant treatment on progression-free and overall survival has to be investigated in a prospective trial.

Intracranial and spinal ependymoma: series at Faculdade de Medicina, Universidade de São Paulo

OBJECTIVE

Ependymomas are rare intracranial neuroepithelial tumors and the most common location is intramedullary. The aim was to analyze the characteristics of these tumors to determine the patients' overall survival and the likelihood of recurrence.

METHOD

Data of clinical presentation, tumor location, duration of symptoms, degree of resection and complementary treatment of 34 patients with intracranial ependymoma and 31 with intramedullary ependymoma who underwent surgery in the last ten years were collected and correlated with the recurrence time and overall survival.

RESULTS

There was statistically significant correlation between the degree of resection and intracranial tumor location, although it is not a hallmark of recurrence. Data analyses of intramedullary ependymoma did not show correlation with overall survival and likelihood of recurrence.

CONCLUSION

The location of the intracranial tumor is connected with the degree of resection; however it is not a predictive factor to overall survival.

Primary Myxopapillary Ependymoma of the Medulla

OBJECTIVE

Myxopapillary ependymoma is a subclassification of ependymoma that is thought to be nearly exclusive to the conus medullaris or filum terminale. Primary intracerebral or brainstem myxopapillary ependymomas are rare.

CLINICAL PRESENTATION

An 8-year-old child presented with a 5-month history of nausea and vomiting and a 1-week history of headache. Magnetic resonance imaging revealed a nodular mass in the medulla with an associated cyst extending into the fourth ventricle.

INTERVENTION

A suboccipital craniotomy was performed, and a gross total resection of the lesion and cyst was achieved. Histological examination confirmed the diagnosis of myxopapillary ependymoma. A discussion of other reported cases of extraspinal myxopapillary ependymomas is presented.

CONCLUSION

This is the first report of a case of myxopapillary ependymoma, confirmed by histology, in the medulla. Although rare, myxopapillary ependymomas outside of the filum terminale do exist.

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.

Ependymoma: an update

The authors provide an update on most issues related to biology, diagnosis, and treatment of children with ependymoma based on a literature review. Ependymoma is the third most common brain tumor in children and overall survival ranges from 24% to 75% at 5 years. The extent of surgical resection remains the principal risk factor that clearly influences outcome. The influence of age, location, grade, or stage has proved to be more controversial. Current standard therapy includes surgical resection and radiotherapy. Chemotherapy has a role in infants to avoid/delay radiotherapy and can be helpful to improve resectability. About half of patients will experience relapse, and outcome is dismal. New radiation modalities, reirradiation, chemotherapy, or targeted agents have been tested with promising results. Results of multi-institutional clinical trials are awaited to determine the best first-line treatment, while results of early phase I/ II trials will explore directed therapies based on new biologic factors.

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.

Neuropsychological sequelae and quality of life following treatment of posterior fossa ependymomas in children

INTRODUCTION

Modern treatment of posterior fossa ependymomas in children has improved the overall survival, but as more children live longer, the neuropsychological problems that they endure as result of the disease and its treatment become more the focus of attention.

MATERIAL

Early problems such as cerebellar mutism appear to be related to surgery and do not seem to be influenced in their incidence or outcome by the otherwise beneficial effect of oncological treatment. Indeed, the cause of cerebellar mutism is still elusive. While it was originally believed to be totally reversible, it is increasingly realized that it may be related to more complex delayed neuropsychological problems. Late problems such as the cerebellar cognitive affective syndrome are increasingly being recognized. The deleterious effect of both surgery and radiotherapy that is commonly administered afterwards is now well appreciated.

CONCLUSION

Careful neuropsychological assessment of these children and early intervention will maximize chances for recovery and improvement of academic functions and quality of life issues.

Management strategies for recurrent ependymoma in the paediatric population

INTRODUCTION

The management of recurrent ependymoma within the paediatric population remains a therapeutic challenge. The options available are varied and patients may have already received prior radio- or chemotherapy. As yet, no consensus exists regarding their optimal treatment. We review the literature and present our contemporary management strategies for this interesting group of patients.

RESULTS AND DISCUSSION

Survival following recurrence is poor and those prognostic factors that predispose to recurrence include extent of surgical resection and the timing of administration of adjuvant therapy. The extent of resection at re-operation can confer a survival advantage, without a necessary increase in morbidity. Strategies aimed at improving surgical resection at first diagnosis include improving and centralising post-surgical radiological review, defining what are true residuals, and centralising surgical review of incompletely resected tumours. Re-irradiation can improve survival, and with the use of conformal radiation fields need not necessarily lead to neuropsychological damage. Cisplatin and etoposide remain the most effective chemotherapeutic agents to date and with an increase in the understanding of tumour biology this may improve further. Because of the complex nature of this group of patients, decisions regarding their management require the involvement of a paediatric neurosurgeon, paediatric neuro-oncologist and paediatric radiation oncologist.

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.

Late spinal cord metastasis of fourth ventricle ependymoma appeared nineteen years after the initial treatment

Spinal cord dissemination (metastasis) of a fourth ventricle ependymoma more than ten years after surgical resection is extremely rare. In this report, we present an unusual case of a fourth ventricle ependymoma with metastasis to the thoracic spinal cord 19 years after the initial therapy, but without local recurrence. A 37 year-old patient underwent gross total resection of a fourth ventricle ependymoma and postoperative radiation therapy to the posterior fossa. Computed tomography (CT) scanning and/or magnetic resonance (MR) imaging performed during follow up examinations, conducted annually for ten years after the therapy, revealed no evidence of local tumor recurrence. However, 19 years after the initial treatment, the patient complained of back pain and gait disturbances. MR imaging revealed an intradural extramedullary tumor at the Th2-5 levels. MR imaging of the brain revealed no local tumor recurrence or intracranial tumor dissemination. Cerebrospinal fluid cytology revealed no presence of tumor cells. Total resection of the spinal cord tumor was performed, and the tumor was diagnosed as an ependymoma. We describe the clinical features of this rare lesion and particularly emphasize the need for long-term follow up, for more than ten years after the initial treatment, in patients with fourth ventricle ependymoma.

Pediatric brain tumors: current treatment strategies and future therapeutic approaches

Pediatric CNS tumors are the most common solid tumors of childhood and the second most common cancer after hematological malignancies accounting for approximate 20 to 25% of all primary pediatric tumors. With over 3,000 new cases per year in the United States, childhood CNS tumors are the leading cause of death related to cancer in this population. The prognosis for these patients has improved over the last few decades, but current therapies continue to carry a high risk of significant side effects, especially for the very young. Currently a combination of surgery, radiation, and chemotherapy is often used in children greater than 3 years of age. This article will outline current and future therapeutic strategies for the most common pediatric CNS tumors, including primitive neuroectodermal tumors such as medulloblastoma, as well as astrocytomas and ependymomas.

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.

Pediatric ependymoma: biological perspectives

Pediatric ependymomas are enigmatic tumors that continue to present a clinical management challenge despite advances in neurosurgery, neuroimaging techniques, and radiation therapy. Difficulty in predicting tumor behavior from clinical and histological factors has shifted the focus to the molecular and cellular biology of ependymoma in order to identify new correlates of disease outcome and novel therapeutic targets. This article reviews our current understanding of pediatric ependymoma biology and includes a meta-analysis of all comparative genomic hybridization (CGH) studies done on primary ependymomas to date, examining more than 300 tumors. From this meta-analysis and a review of the literature, we show that ependymomas in children exhibit a different genomic profile to those in adults and reinforce the evidence that ependymomas from different locations within the central nervous system (CNS) are distinguishable at a genomic level. Potential biological markers of prognosis in pediatric ependymoma are assessed and the ependymoma cancer stem cell hypothesis is highlighted with respect to tumor resistance and recurrence. We also discuss the shifting paradigm for treatment modalities in ependymoma that target molecular alterations in tumor-initiating cell populations.

Intracranial ependymoma: factors affecting outcome

Ependymomas account for 2-9% of all neuroepithelial tumors, amounting to 6-12% of all intracranial tumors in children and up to 30% of those in children younger than 3 years. Recent findings provide evidence that intracranial and spinal ependymomas share similar molecular profiles with the radial glia of their corresponding locations. The management of intracranial ependymoma is still not optimal. The 5-year progression-free survival for children with ependymoma ranges between 30 and 50% with a worse prognosis for patients with residual disease after surgery. The prognostic relevance of most factors are still being debated. Recent studies, in which the current WHO classification criteria were applied, reported the relationship between histological grade and outcome. Biomolecular studies have identified that gain of 1q25 and EGFR overexpression correlate to poor prognosis, whereas low expression of nucleolin correlated with a favorable outcome. Ependymomas have been considered a 'surgical disease', where completeness of excision can be reached in approximately half of the cases. At present the standard treatment is radiation therapy for all patients after gross-total or near-total resection. For high-risk patients, with residual tumor, an interesting, although experimental, approach could be chemotherapy followed by secondary surgery and postoperative conformal irradiation.

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.

The management of completely resected childhood intracranial ependymoma: the argument for observation only

INTRODUCTION

The management of children with completely resected intracranial ependymomas is controversial. We favor deferring adjuvant radiotherapy in low-risk patients, whereas others recommend radiotherapy.

REVIEW

This article reviews the available evidence for and against deferring radiotherapy in children with low-risk completely resected childhood ependymomas.

A scoring system to quantify late effects in children after treatment for medulloblastoma/ependymoma and its correlation with quality of life and neurocognitive functioning

BACKGROUND

The aim of this study was to quantify the severity of late effects by a simple numerical score (late effects severity score, LESS) in patients who received radiochemotherapy for medulloblastoma or ependymoma. The LESS was correlated with neurocognitive and quality of life (QoL) outcomes.

PATIENTS AND METHODS

The LESS was calculated by assigning 0, 1, or 2 points within each of four different categories (neurology, endocrine, visual/auditory, others). Twenty-three patients with medulloblastoma (n = 18) or ependymoma (n = 5) underwent extensive neurocognitive and QoL testing at a median of 56 months (range, 1-174) after the end of treatment. Eight patients with low-grade glioma (LGG) who underwent tumor resection only served as control group.

RESULTS

Patients with medulloblastoma/ependymoma had significantly higher LESS and significantly lower Wechsler Adult Intelligence Scale (WAIS)/Wechsler Intelligence Scales for Children (WISC) scores compared to patients with LGG. There was no statistically significant correlation between neurocognitive performance and QoL. The total LESS was negatively correlated with WAIS/WISC, attention, concentration, and verbal learning scores. Comparison of QoL and late effects in patients with medulloblastoma/ependymoma demonstrated a significant negative correlation only for neurological late effects and the KINDL score suggesting that younger patients with more severe late effects reported on a worse QoL.

CONCLUSIONS

This LESS seems to be a simple and practical tool to quantify late effects in former brain tumor patients. Although both groups differ significantly with regard to neurocognitive parameters and severity of late effects, this does not apply for all QoL outcomes. Neurological late effects seem to be most predictive for an impaired QoL in younger children.

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.

Proton radiotherapy for childhood ependymoma: initial clinical outcomes and dose comparisons

PURPOSE

To report preliminary clinical outcomes for pediatric patients treated with proton beam radiation for intracranial ependymoma and compare the dose distributions of intensity-modulated radiation therapy with photons (IMRT), three-dimensional conformal proton radiation, and intensity-modulated proton radiation therapy (IMPT) for representative patients.

METHODS AND MATERIALS

All children with intracranial ependymoma confined to the supratentorial or infratentorial brain treated at the Francis H. Burr Proton Facility and Harvard Cyclotron between November 2000 and March 2006 were included in this study. Seventeen patients were treated with protons. Proton, IMRT, and IMPT plans were generated with similar clinical constraints for representative infratentorial and supratentorial ependymoma cases. Tumor and normal tissue dose-volume histograms were calculated and compared.

RESULTS

At a median follow-up of 26 months from the start date of radiation therapy, local control, progression-free survival, and overall survival rates were 86%, 80%, and 89%, respectively. Subtotal resection was significantly associated with decreased local control (p = 0.016). Similar tumor volume coverage was achieved with IMPT, proton therapy, and IMRT. Substantial normal tissue sparing was seen with proton therapy compared with IMRT. Use of IMPT will allow for additional sparing of some critical structures.

CONCLUSIONS

Preliminary disease control with proton therapy compares favorably with the literature. Dosimetric comparisons show the advantage of proton radiation compared with IMRT in the treatment of ependymoma. Further sparing of normal structures appears possible with IMPT. Superior dose distributions were accomplished with fewer beam angles with the use of protons and IMPT.

Intensity-modulated radiation therapy in childhood ependymoma

PURPOSE

To determine the patterns of failure after intensity-modulated radiation therapy (IMRT) for localized intracranial ependymoma.

METHODS AND MATERIALS

From 1994 to 2005, 22 children with pathologically proven, localized, intracranial ependymoma were treated with adjuvant IMRT. Of the patients, 12 (55%) had an infratentorial tumor and 14 (64%) had anaplastic histology. Five patients had a subtotal resection (STR), as evidenced by postoperative magnetic resonance imaging. The clinical target volume encompassed the tumor bed and any residual disease plus margin (median dose 54 Gy). Median follow-up for surviving patients was 39.8 months.

RESULTS

The 3-year overall survival rate was 87% +/- 9%. The 3-year local control rate was 68% +/- 12%. There were six local recurrences, all in the high-dose region of the treatment field. Median time to recurrence was 21.7 months. Of the 5 STR patients, 4 experienced recurrence and 3 died. Patients with a gross total resection had significantly better local control (p = 0.024) and overall survival (p = 0.008) than those with an STR. At last follow-up, no patient had developed visual loss, brain necrosis, myelitis, or a second malignancy.

CONCLUSIONS

Treatment with IMRT provides local control and survival rates comparable with those in historic publications using larger treatment volumes. All failures were within the high-dose region, suggesting that IMRT does not diminish local control. The degree of surgical resection was shown to be significant for local control and survival.

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.

Childhood intracranial ependymoma: twenty-year experience from a single institution

BACKGROUND

Because few large studies of pediatric ependymoma treatment are available, the authors believed that a retrospective review of treatment outcomes from a single institution would yield potentially valuable information regarding potential prognostic factors. In this article, they report their 20-year institutional experience with this disease.

METHODS

Medical records were reviews of patients with intracranial ependymoma who received their initial treatment at the Children's Hospital of Philadelphia (CHOP)/Hospital of the University of Pennsylvania (HUP) between January 1980 and December 2000. Of the 61 patients who were identified, 49 patients underwent primary therapy at CHOP/HUP and formed the basis for the study. Actuarial overall survival (OS) and progression-free survival (PFS) were determined by the Kaplan-Meier method. Univariate and multivariate analyses were performed using the log-rank test and Cox proportional-hazards models.

RESULTS

With median follow-up of 110.2 months, the 5-year OS and PFS rates were 66.2% and 40.7%, respectively. Older age and higher radiation dose significantly predicted for improved OS. Anaplastic histology predicted for decreased PFS. Cervical spinal cord extension resulted in decreased OS primarily caused by failures outside the primary site. Patients who had a favorable prognosis (aged >/=3 years, no dissemination or cord extension, complete resection, and radiation dose >/=54 grays [Gy]) had 5-year OS and PFS rates of 83.1% and 60.6%, respectively.

CONCLUSIONS

In this study of patients with pediatric intracranial ependymoma, OS and PFS rates were concordant with the rates published in other modern series. The finding of a dose response up to 54 Gy supported the current trend toward dose escalation. Tumor extension to the cervical spine was identified as a predictor for failure outside of the primary site. Although the survival rates were encouraging, there is still significant room for improvement in the management of this disease.

Primary postoperative chemotherapy without radiotherapy for intracranial ependymoma in children: the UKCCSG/SIOP prospective study

BACKGROUND

Over half of childhood intracranial ependymomas occur in children younger than 5 years. As an adjuvant treatment, radiotherapy can be effective, but has the potential to damage the child's developing nervous system at a crucial time-with a resultant reduction in IQ and cognitive impairment, endocrinopathy, and risk of second malignancy. We aimed to assess the role of a primary chemotherapy strategy in avoiding or delaying radiotherapy in children younger than 3 years with intracranial ependymoma.

METHODS

Between December, 1992, and April, 2003, we enrolled 89 children with ependymoma who were aged 3 years or younger at diagnosis, of whom nine had metastatic disease on pre-operative imaging. After maximal surgical resection, children received alternating blocks of myelosuppressive and non-myelosuppressive chemotherapy every 14 days for an intended duration of 1 year. Radiotherapy was withheld unless local imaging (ie, from the child's treatment centre) showed progressive disease.

FINDINGS

50 of the 80 patients with non-metastatic disease progressed, 34 of whom were irradiated for progression. The 5-year cumulative incidence of freedom from radiotherapy for the 80 non-metastatic patients was 42% (95% CI 32-53). With a median follow-up of 6 years (range 1.5-11.3), overall survival for the non-metastatic patients at 3 years was 79.3% (95% CI 68.5-86.8) and at 5 years 63.4% (51.2-73.4). The corresponding values for event-free survival were 47.6% (36.2-58.1) and 41.8% (30.7-52.6). There was no significant difference in event-free or overall survival between complete and incomplete surgical resection, nor did survival differ according to histological grade, age at diagnosis, or site of disease. In 47 of 59 (80%) patients who progressed, relapse resulted from local control only. The median time to progression for the 59 patients who progressed was 1.6 years (range 0.1-10.2 years). The median age at irradiation of the whole group was 3.6 years (range 1.5-11.9). For the 80 non-metastatic patients, the 23 who achieved the highest relative dose intensity of chemotherapy had the highest post-chemotherapy 5-year overall survival of 76% (95% CI 46.6-91.2), compared with 52% (33.3-68.1) for the 32 patients who achieved the lowest relative dose intensity of chemotherapy.

INTERPRETATION

This protocol avoided or delayed radiotherapy in a substantial proportion of children younger than 3 years without compromising survival. These results suggest, therefore, that primary chemotherapy strategies have an important role in the treatment of very young children with intracranial ependymoma.

Ependymoma

Ependymomas are rare tumours of neuroectodermal origin classified as myxopapillary ependymoma and subependymoma (grade I), ependymoma (grade II) and anaplastic ependymoma (grade III). The more common location is infratentorial (60%). Age <40 years and extent of surgery appear related to better prognosis, while the role of other prognostic factors, such as tumour grade and tumour site are equivocal. This emphasizes the role of surgery as the standard treatment. Postoperative radiotherapy is indicated in high-grade ependymomas, and is recommended in low-grade ependymomas after subtotal or incomplete resection (confirmed by postoperative MR). Deferral of radiotherapy until recurrence may be considered on an individual basis for patients with MR confirmation of a radical resection. Recommended dose to involved fields is 45-54 Gy for low-grade (grade II) and 54-60 Gy for high-grade ependymomas (grade III). There is no proof that postoperative chemotherapy improves the outcome. At recurrence, platinum-, nitrosourea- or temozolomide-based chemotherapy can be administered, although there is no evidence of efficacy.

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.

Salvage treatment for childhood ependymoma after surgery only: Pitfalls of omitting “at once” adjuvant treatment

PURPOSE

To discuss the results obtained by giving adjuvant treatment for childhood ependymoma (EPD) at relapse after complete surgery only.

METHODS AND MATERIALS

Between 1993 and 2002, 63 children older than 3 years old entered the first Italian Association for Pediatric Hematology and Oncology protocol for EPD (group A), and another 14 patients were referred after relapsing after more tumor excisions only (group B). Prognostic factors were homogeneously matched in the two groups. We report on the outcome of group B.

RESULTS

Mean time to first local progression in group B had been 14 months. Tumors originated in the posterior fossa (PF) in 10 children and were supratentorial (ST) in 4; 11 had first been completely excised (NED) and 3 had residual disease (ED). Diagnoses were classic EPD in 9 patients, anaplastic in 5. Eight children were referred NED and 6 ED after two or more operations, 5 had cranial nerve palsy, 1 had recurrent meningitis, and 2 had persistent hydrocephalus. All received radiotherapy (RT) to tumor bed and 5 also had pre-RT chemotherapy. Six of 14 patients (6/10 with PF tumors) had a further relapse a mean 6 months after the last surgery; 4 of 6 died: progression-free survival and overall survival at 4 years after referral were 54.4% and 77%, respectively. Considering only PF tumors and setting time 0 as at the last surgery for group B, progression-free survival and overall survival were 32% and 50% for group B and 52% (p < 0.20)/70% (p < 0.29) for the 46 patients in group A with PF tumors. Local control was 32% in group B and 70.5% in group A (p = 0.02).

CONCLUSIONS

Relapsers after surgery only, especially if with PF-EPD, do worse than those treated after first diagnosis; subsequent surgery for tumor relapse has severe neurologic sequelae.

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.

Ependymoma: new therapeutic approaches including radiation and chemotherapy

Recent advances in neuroimaging, neurosurgery and radiation therapy have improved disease control and functional outcomes for children with ependymoma, including children under the age of 3 years. The rate of gross-total resection has been increased to 85% in some series and 3 year progression-free survival after radiation therapy as high as 75% has been reported along with significant reductions in neurologic, endocrine and cognitive deficits. Based on these advances and renewed interest in radiation therapy as a frontline treatment modality, attention has been refocused on disease control instead of radiotherapy avoidance. Future research in the treatment of this tumor, that afflicts fewer than 200 children in the US each year, will focus on molecular biology, clarifying risk factors for tumor control and late effects, and testing novel agents.

Role of radiotherapy in anaplastic ependymoma in children under age of 3 years: Results of the prospective German brain tumor trials HIT-SKK 87 and 92

BACKGROUND AND PURPOSE

To evaluate the outcome of very young children with anaplastic ependymoma after delayed or omitted radiotherapy (RT).

MATERIALS AND METHODS

Children under age of 3 years with anaplastic ependymoma were enrolled in the HIT-SKK 87 trial from 1987. After surgery, low-risk patients (R0, M0) received maintenance chemotherapy until elective RT at age of three. In high-risk patients (R+, M+) intensive induction chemotherapy was followed by maintenance chemotherapy and subsequently delayed RT. If there was, progression radiotherapy started immediately. In the HIT-SKK 92, trial MTX-based chemotherapy was applied. RT was administered in non-responders only.

RESULTS

Thirty-four children with anaplastic ependymoma were eligible (age 1.0-33.0 months). All children received chemotherapy. In 13 children, no RT was administered. Preventive RT after chemotherapy was given in nine, and salvage RT in 12 children. OS and PFS rates after 3-year were 55.9 and 27.3%, respectively. Twenty-five children relapsed. Positive impact on survival was observed in children with higher age, M0-stage, complete resection, and treatment with radiotherapy. Without RT only 3/13, children survived.

CONCLUSION

Delaying RT jeopardizes survival even after intensive chemotherapy. Predominant site of failure is the primary tumor site. RT of the neuraxis should be omitted in localized disease.

Is gross-total resection sufficient treatment for posterior fossa ependymomas?

Object. The goals of this study were to analyze outcomes in patients with posterior fossa ependymomas, determine whether gross-total resection (GTR) alone is appropriate treatment, and evaluate the role of radiation therapy.

Methods. All patients with newly diagnosed intracranial ependymomas treated at Barrow Neurological Institute between 1983 and 2002 were identified. Those with supratentorial primary lesions, subependymomas, or neuraxis dissemination were excluded. Forty-five patients met the criteria for the study. Gross-total resection was accomplished in 32 patients (71%) and subtotal resection (STR) in 13 (29%). Radiation therapy was given to 25 patients: 13 following GTR and 12 after STR. The radiation fields were craniospinal followed by a posterior fossa boost in six patients and posterior fossa or local only in the remaining patients.

With a median follow-up period of 66 months, the median duration of local control was 73.5 months with GTR alone, but has not yet been reached for patients with both GTR and radiotherapy (p = 0.020). The median duration of local control following STR and radiotherapy was 79.6 months. The 10-year actuarial local control rate was 100% for patients who underwent GTR and radiotherapy, 50% for those who underwent GTR alone, and 36% for those who underwent both STR and radiotherapy, representing significant differences between the GTR-plus-radiotherapy and GTR-alone cohorts (p = 0.018), and between the GTR-plus-radiotherapy and the STR-plus-radiotherapy group (p = 0.003). There was no significant difference in the 10-year actuarial local control rate between the GTR-alone and STR-plus-radiotherapy cohorts (p = 0.370). The 10-year overall survival was numerically superior in patients who underwent both GTR and radiotherapy: 83% compared with 67% in those who underwent GTR alone and 43% in those who underwent both STR and radiotherapy. These differences did not achieve statistical significance. Univariate analyses revealed that radiotherapy, tumor grade, and extent of resection were significant predictors of local control.

Conclusions. Gross-total resection should be the intent of surgery when it can be accomplished with an acceptable degree of morbidity. Even after GTR has been confirmed with postoperative imaging, however, adjuvant radiotherapy significantly improves local control. The authors currently recommend the use of postoperative radiotherapy, regardless of whether the resection is gross total or subtotal.

Postoperative radiation therapy for grade II and III intracranial ependymoma

PURPOSE

To retrospectively determine the long-term outcome of intracranial ependymoma patients treated with surgery and postoperative radiation therapy.

METHODS AND MATERIALS

Sixty patients were treated at our institution between 1964 and 2000. Forty patients had World Health Organization Grade II ependymoma, and 20 patients had Grade III ependymoma. The median patient age was 10.7 years. The majority of patients were male (55%), had infratentorial tumors (80%), and had subtotal resections (72%). Postoperative radiation therapy was delivered to all patients to a median total dose of 50.4 Gy. Craniospinal radiation therapy was used in the earlier era in only 12 patients (20%).

RESULTS

The median follow-up of surviving patients was 12.5 years. The 5-year and 10-year disease-free survival rates for all patients were 58.4% and 49.5%, respectively. The 5-year and 10-year overall survival rates for all patients were 71.2% and 55.0%, respectively. Supratentorial tumor location was independently associated with a worse disease-free survival. Subtotal resection and supratentorial location predicted a worse overall survival, but this failed to reach statistical significance. No statistically significant effect on prognosis was observed with tumor grade, patient age, or radiation dose or volume.

CONCLUSION

Our long-term follow-up indicates that half of ependymoma patients will have disease recurrences, indicating the need for more effective treatments.

Intracranial ependymomas in childhood: recurrence, reoperation, and outcome

INTRODUCTION

Intracranial ependymomas (IE) in children are aggressive tumors, and total resection (TR) is considered to be the most powerful predictor of outcome. The data regarding recurrent IE (RIE), in particular the role of reoperation, are scarce in the literature.

METHODS AND RESULTS

We studied 70 cases of IE in children operated on for IE since the advent of computed imaging. TR was achieved at initial surgery in 38 out of 70 cases. After a mean follow-up of 76.1 months, 33 out of 70 tumors had progressed. Eighteen were reoperated, achieving TR in 12 out of 18 cases. The morbidity associated with reoperation was minimal, especially compared with the first operation. After a mean follow-up of 74.7 months after reoperation, 10 out of 18 patients had died of tumor progression, 1 had a stable tumor, and 7 were tumor free. When TR was achieved, the overall survival rate was 7 out of 12.

CONCLUSION

Total resection is the only curative treatment for RIE and is often possible, especially when the initial resection was total.

Multivariate analysis of clinical prognostic factors in children with intracranial ependymomas

The optimal postoperative management of pediatric intracranial ependymomas is controversial. We analyzed clinical prognostic factors for their influence on outcome in such children. Our retrospective series included 15 with supratentorial and 28 with infratentorial tumors. Twenty ependymomas were grade II, and 23 were anaplastic. Complete resection was performed in 18 patients, incomplete resection in 19, and stereotactic biopsy in 6. Radiotherapy was done in 31 patients and chemotherapy in 13. The surviving patients have been followed 8-232 months (median: 69 months). The median survival time was 30 months, and 5-year overall survival and progression-free survival rates were 53.9% and 45.9%, respectively. By tumor site: supratentorial, 56.6% and 50.9%; infratentorial, 52.3% and 42.5%. Multivariate analysis identified complete resection (5-year progression-free survival, 71.8%) and age <3 years old as significant favorable and adverse prognostic features (relative risk, 2.59; 95% CI, 1.05-6.38), respectively. Twenty-six children relapsed 1-107 months after diagnosis (median: 12 months). Relapses were local in 22 cases, and combined local and distant in three cases. Only one of 15 patients with supratentorial tumors developed isolated spinal metastasis. Failure at the primary site is the major obstacle to improve cure rates. The extent of surgical resection and age were the only statistically significant prognostic factors.

Radiation-induced impairment of hippocampal neurogenesis is associated with cognitive deficits in young mice

Advances in the management of pediatric brain tumors have increased survival rates in children, but their quality of life is impaired due to cognitive deficits that arise from irradiation. The pathogenesis of these deficits remains unknown, but may involve reduced neurogenesis within the hippocampus. To determine the acute radiosensitivity of the dentate subgranular zone (SGZ), 21-day-old C57BL/J6 male mice received whole brain irradiation (2-10 Gy), and 48 h later, tissue was assessed using immunohistochemistry. Proliferating SGZ cells and their progeny, immature neurons, were decreased in a dose-dependent fashion. To determine if acute changes translated into long-term alterations in neurogenesis, mice were given a single dose of 5 Gy, and 1 or 3 months later, proliferating cells were labeled with 5-bromo-2'-deoxyuridine (BrdU). Confocal microscopy was used to determine the percentage of BrdU-labeled cells that showed mature cell phenotypes. X-rays significantly reduced the production of new neurons at both time points, while glial components showed no change or small increases. Measures of activated microglia and infiltrating, peripheral monocytes indicated that reduced neurogenesis was associated with a chronic inflammatory response. Three months after irradiation, changes in neurogenesis were associated with spatial memory retention deficits determined using the Morris water maze. Behavioral training and testing increased the numbers of immature neurons, most prominently in irradiated animals. These data provide evidence that irradiation of young animals induces a long-term impairment of SGZ neurogenesis that is associated with hippocampal-dependent memory deficits.

Preliminary Results From a Phase II Trial of Conformal Radiation Therapy and Evaluation of Radiation-Related CNS Effects for Pediatric Patients With Localized Ependymoma

Purpose

We conducted a phase II trial of conformal radiation therapy (CRT) for localized childhood ependymoma to determine whether the irradiated volume could be reduced to decrease CNS-related side effects without diminishing the rate of disease control.

Patients and Methods

Between July 1997 and January 2003, 88 pediatric patients (median age, 2.85 ± 4.5 years) received CRT in which doses (59.4 Gy to 73 patients or 54.0 Gy after gross-total resection to 15 patients younger than 18 months) were administered to the gross tumor volume and a margin of 10 mm. Patients were categorized according to extent of resection (underwent gross total resection, n = 74; near-total resection, n = 6; subtotal resection, n = 8), prior chemotherapy (n = 16), tumor grade (anaplastic, n = 35), and tumor location (infratentorial, n = 68). An age-appropriate neurocognitive battery was administered before and serially after CRT.

Results

The median length of follow-up was 38.2 months (± 16.4 months); the 3-year progression-free survival estimate was 74.7% ± 5.7%. Local failure occurred in eight patients, distant failure in eight patients, and both in four patients. The cumulative incidence of local failure as a component of failure at 3 years was 14.8% ± 4.0%. Mean scores on all neurocognitive outcomes were stable and within normal limits, with more than half the cohort tested at or beyond 24 months.

Conclusion

Limited-volume irradiation achieves high rates of disease control in pediatric patients with ependymoma and results in stable neurocognitive outcomes.

Ependymal tumors

Ependymal tumors are rare malignancies that arise from the cells that line the ventricles and central canal of the spinal cord. Although they are more common in children, adults may also be effected by ependymal tumors. Prognosis is dependent on tumor location, histology, especially for myxopapillary tumors that tend to occur in the lumbar spine, extent of surgical resection, and stage of disease. Standard therapy consists of complete resection when feasible. The exact role of adjuvant radiotherapy in patients with radiographically confirmed complete resection is poorly defined. Patients with known residual disease may benefit from local radiation therapy, but the extent of radiation field and total dose are controversial. Even in patients treated with involved field radiotherapy, most relapses occur within the original tumor bed, thus local control remains the biggest obstacle to effective therapy. Chemotherapy has little impact against this tumor and has no role in the adjuvant setting, outside of a well designed clinical trial, with the possible exception of children younger than 5 years in an effort to delay radiation. A minority of patients may respond to one of several chemotherapy regimens at the time of recurrence, but the impact of this therapy is limited. Newer treatment strategies are needed.

Review of radiotherapy dose and volume for intracranial ependymoma

BACKGROUND

Radiotherapy (RT) is well established in the management of intracranial ependymoma (EP) and post-operative RT is employed for the majority of patients. There are no randomised trials of RT in EP and evidence for dose and volume relies on retrospective single institution series, usually comprising a heterogeneous mix of relatively small numbers of patients recruited over several decades.

PROCEDURE

The literature including RT dose and response data reported since the early 1990s was reviewed.

RESULTS

Five-year overall survival (OS) ranges from 40 to 79%. There is some evidence of a dose response relationship from <45 Gy to >50 Gy. In the majority of series outcome is related to WHO grade and extent of resection. There is no evidence of benefit for 'prophylactic' craniospinal RT (CSRT). In all series there is a significant risk of local recurrence, usually within the target volume. Early results of conformal RT have suggested that a margin for CTV of 1 cm around the post-operative tumour bed and any residual GTV is feasible.

CONCLUSIONS

The main aims of future studies will be to maximise the number of patients achieving complete resection, and RT dose escalation. Hyperfractionated radiotherapy (HFRT) has been employed in some studies and results are awaited. The role of CSRT needs to be evaluated further for patients presenting with leptomeningeal metastases. Multi-institutional and international studies are necessary to improve understanding of the clinical behaviour, biology and management of EP.

Intraventricular gliomas

Gliomas are the most common primary brain tumor in adults, and those within or relating to the ventricular surface represent a less common but important subcategory. The most common intraventricular gliomas include ependymomas, SEs, and SEGAs. Other less common varieties have been reported, including chordoid gliomas, glioblastoma multiforme, and mixed glial-neuronal tumors. Each type of intraventricular glioma is associated with its own unique constellation of epidemiologic, clinical, radiologic, and pathologic defining characteristics. Each tumor type has its own management considerations and nuances with unique prognostic indicators and outcomes. The outcome for certain intraventricular gliomas (especially ependymomas) remains relatively poor. Future advancements in surgical technique are likely to have only a modest impact on improvement of outcome. Translational research aiming to advance the knowledge of tumor biology into new targeted cellular and molecular therapies holds tremendous promise to improve the overall outcome. Additionally, more thorough delineation of prognostic factors as well as modifications and refinements to radiation and chemotherapy may help to improve the still significantly poor outcomes for patients harboring these lesions. Future cooperative intra- and interinstitutional efforts between scientists and clinicians will hopefully culminate in an improved outlook and eventual cure for patients with gliomas.