Survival Benefit for Pediatric Patients With Recurrent Ependymoma Treated With Reirradiation

Reirradiation in patients with diffuse intrinsic pontine gliomas: The Canadian experience

OBJECTIVE

Clinical trials have failed to demonstrate a survival benefit of adjuvant chemotherapy in diffuse intrinsic pontine gliomas (DIPG). Radiation therapy (RT) is the only effective treatment thus far and reirradiation (rRT) has become an option at the time of progression. The aim of this study was to review the Canadian experience of DIPG rRT with a focus on the safety and possible efficacy of this approach.

METHOD

We retrospectively reviewed the demographic, clinical, and RT data of patients with DIPG treated in Canada with rRT.

RESULTS

Since January 2011, we identified 16 patients with progressive DIPG who received rRT. Median time from diagnosis to progression was 10.5 months (range, 4-37 months). rRT was given focally in 14 patients at a dose ranging from 21.6 to 36 Gy. rRT was well tolerated by all children but one. All but three patients showed neurological improvement. With a median follow-up from original diagnosis of 19.2 months, all patients died, with a median time from rRT to death of 6.48 months (range, 3.83-13.26 months). When compared to a historic cohort of 46 consecutive patients, the median time from progression to death was 92 days in the non-reirradiated patients versus 218 days in the reirradiated ones (P = 0.0001).

CONCLUSION

In this limited experience, rRT was safe and feasible in patients with progressive DIPG, providing neurological improvement and a prolonged life span in most patients. Prospective Canadian rRT protocols are ongoing to further assess the benefit of this approach, including quality of life assessment.

EANO guidelines for the diagnosis and treatment of ependymal tumors

Ependymal tumors are rare CNS tumors and may occur at any age, but their proportion among primary brain tumors is highest in children and young adults. Thus, the level of evidence of diagnostic and therapeutic interventions is higher in the pediatric compared with the adult patient population.The diagnosis and disease staging is performed by craniospinal MRI. Tumor classification is achieved by histological and molecular diagnostic assessment of tissue specimens according to the World Health Organization (WHO) classification 2016. Surgery is the crucial initial treatment in both children and adults. In pediatric patients with intracranial ependymomas of WHO grades II or III, surgery is followed by local radiotherapy regardless of residual tumor volume. In adults, radiotherapy is employed in patients with anaplastic ependymoma WHO grade III, and in case of incomplete resection of WHO grade II ependymoma. Chemotherapy alone is reserved for young children <12 months and for adults with recurrent disease when further surgery and irradiation are no longer feasible. A gross total resection is the mainstay of treatment in spinal ependymomas, and radiotherapy is reserved for incompletely resected tumors. Nine subgroups of ependymal tumors across different anatomical compartments (supratentorial, posterior fossa, spinal) and patient ages have been identified with distinct genetic and epigenetic alterations, and with distinct outcomes. These findings may lead to more precise diagnostic and prognostic assessments, molecular subgroup-adapted therapies, and eventually new recommendations pending validation in prospective studies.

Significance of cyclin D1 overexpression in progression and radio-resistance of pediatric ependymomas

Due to the limited efficacy of chemotherapy, the applications of adjuvant irradiation play an important role for ependymoma treatment. However, in the young ages, the resistance of residual and recurrent tumor, and long-term intellectual sequelae remain the major obstacles of radiotherapy. Understanding the mechanism of therapeutic failure caused by radio-resistance is, therefore, crucial in ependymoma treatment. Here we retrospectively analyze clinic-pathological factors in 82 cases of ependymoma less than 20 years old and identify radio-resistant genes through gene expression microarray followed by qRT-PCR validation and immunohistochemistry staining. Thirty-one out of 82 (37.8%) patients are under 3-year-old. The 10 years PFS and OS are 38% and 60%. Gross-total resection is the single significant prognostic factor for longer 10 years PFS and OS in the multivariant analysis (p<0.05). According to the microarray analysis, CCND1 is up-regulated in supratentorial and infratentorial ependymomas and is associated with DNA repair. We demonstrated that 24 primary and 16 recurrent ependymomas were up-regulated, and 5 out of 7 paired samples exhibited higher CCND1 expression in recurrent tumors. We also found RAD51, another DNA repair gene, was up-regulated in supratentorial and infratentorial ependymomas. Knocking down CCND1 reduced cell proliferation and repressed several genes associated with S-phase and DNA repair. Homologous recombination activities of DNA repair were significantly decreased in CCND1-deficient cells while the level of γH2AX was increased after irradiation. In summary, these observations suggest a robust role of CCND1 in regulating cell proliferation and radio-resistance in ependymomas, providing a potential therapeutic target for pediatric ependymomas.

Outcomes After Reirradiation for Recurrent Pediatric Intracranial Ependymoma

PURPOSE

To determine the long-term outcomes and the optimal dose and volume for reirradiation of recurrent pediatric ependymoma.

METHODS AND MATERIALS

Patients with recurrent ependymoma treated with a second course of fractionated radiation therapy (RT2) were reviewed retrospectively. Eligible patients had localized, intracranial ependymoma at initial diagnosis that was treated with focal radiation (RT1) without craniospinal irradiation (CSI) and were aged ≤21 years at the time of RT2. The median doses of RT1, focal RT2, and CSI-RT2 were 59.4, 54, and 39.6 Gy, respectively. The primary endpoint, overall survival (OS), was measured from the first day of RT2.

RESULTS

We included 101 patients in the study. The median interval between RT1 and RT2 was 26.8 months (interquartile range, 18.0-43.1). The median durations of OS and freedom from progression (FFP) were 75.1 and 27.3 months, respectively. Male sex and anaplastic histology at recurrence were associated with decreased OS and FFP on multivariate analysis. Distant-only failure treated with CSI-RT2 was independently associated with improved OS compared with individuals with local failure treated with focal RT2 (hazard ratio 0.37; 95% confidence interval 0.16-0.87). Among individuals experiencing any distant failure after RT1, gain of chromosome 1q was adversely associated with poorer OS (hazard ratio 3.5; 95% confidence interval 1.1-10.6). No distant-only failures were observed in individuals with RT1 local failure who received CSI-RT2 (n=10). The 10-year cumulative incidence of grade ≥3 radiation necrosis after RT2 was 7.9%.

CONCLUSIONS

Reirradiation for relapsed pediatric ependymoma was well tolerated by most patients and resulted in long-term survival in a subset of patients. The best results were observed in patients who experienced distant-only failure after RT1 and were treated with CSI as part of RT2, without anaplasia at recurrence. The option of reirradiation should be discussed with patients who develop recurrent ependymoma.

Reirradiation for Recurrent Pediatric Central Nervous System Malignancies: A Multi-institutional Review

PURPOSE

Reirradiation has been proposed as an effective modality for recurrent central nervous system (CNS) malignancies in adults. We evaluated the toxicity and outcomes of CNS reirradiation in pediatric patients.

METHODS AND MATERIALS

The data from pediatric patients <21 years of age at the initial diagnosis who developed a recurrent CNS malignancy that received repeat radiation therapy (RT) across 5 facilities in an international pediatric research consortium were retrospectively reviewed.

RESULTS

Sixty-seven pediatric patients underwent CNS reirradiation. The primary diagnoses included medulloblastoma/primitive neuroectodermal tumor (n=20; 30%), ependymoma (n=19; 28%), germ cell tumor (n=8; 12%), high-grade glioma (n=9; 13%), low-grade glioma (n=5; 7%), and other (n=6; 9%). The median age at the first course of RT was 8.5 years (range 0.5-19.5) and was 12.3 years (range 3.3-30.2) at reirradiation. The median interval between RT courses was 2.0 years (range 0.3-16.5). The median radiation dose and fractionation in equivalent 2-Gy fractions was 63.7 Gy (range 27.6-74.8) for initial RT and 53.1 Gy (range 18.6-70.1) for repeat RT. The relapse location was infield in 52 patients (78%) and surrounding the initial RT field in 15 patients (22%). Thirty-seven patients (58%) underwent gross or subtotal resection at recurrence. The techniques used for reirradiation were intensity modulated RT (n=46), 3-dimensional conformal RT (n=9), stereotactic radiosurgery (n=4; 12-13 Gy × 1 or 5 Gy × 5), protons (n=4), combined modality (n=3), 2-dimensional RT (n=1), and brachytherapy (n=1). Radiation necrosis was detected in 2 patients after the first RT course and 1 additional patient after reirradiation. Six patients (9%) developed secondary neoplasms after initial RT (1 hematologic, 5 intracranial). One patient developed a secondary neoplasm identified shortly after repeat RT. The median overall survival after completion of repeat RT was 12.8 months for the entire cohort and 20.5 and 8.4 months for patients with recurrent ependymoma and medulloblastoma after reirradiation, respectively.

CONCLUSIONS

CNS reirradiation in pediatric patients could be a reasonable treatment option, with moderate survival noted after repeat RT. However, prospective data characterizing the rates of local control and toxicity are needed.

Current Clinical Challenges in Childhood Ependymoma: A Focused Review

Ependymoma is a locally aggressive tumor with metastatic potential that arises in diverse locations throughout the brain and spine in children. Tumor and treatment may result in significant morbidity. Cure remains elusive for many patients owing to diverse biology and resistance to conventional therapy. The implementation of systematic postoperative irradiation in clinical trials during the past 20 years has increased the proportion of patients achieving durable disease control with excellent results, as measured by objective functional outcome measures. Clinical, pathologic, and molecular risk stratification should be used to refine treatment regimens for children with ependymoma to reduce the risk of complications associated with therapy and increase the rate of disease control in the setting of combined modality or more intensive therapy. This review covers standards of care and current clinical trials for children with ependymoma, emphasizing the history and evolution of treatment regimens during the past 20 years and the clinical questions they hoped to address.

Proton Beam Therapy for Pediatric Brain Tumor

Cancer is a major cause of childhood death, with central nervous system (CNS) neoplasms being the second most common pediatric malignancy, following hematological cancer. Treatment of pediatric CNS malignancies requires multimodal treatment using a combination of surgery, chemotherapy, and radiotherapy, and advances in these treatments have given favorable results and longer survival. However, treatment-related toxicities have also occurred, particularly for radiotherapy, after which secondary cancer, reduced function of irradiated organs, and retarded growth are significant problems. Proton beam therapy (PBT) is a particle radiotherapy with excellent dose localization that permits treatment of liver and lung cancer by administration of a high dose to the tumor while minimizing damage to surrounding normal tissues. Thus, PBT has the potential advantages for pediatric cancer. In this context, we review the current knowledge on PBT for treatment of pediatric CNS malignancies.

Hypofractionated re-irradiation to the brainstem in children with recurrent brain tumors

To characterize radiation necrosis following hypofractionated brainstem re-irradiation in pediatric patients, we reviewed 23 cases with 28 tumors invading or abutting brainstem and treated with hypofractionated re-irradiation from 2004 to 2014. Re-irradiation delivered total doses of 16-30 Gy in two to five fractions. The most commons regimens used were 24 Gy in three fractions and 25 Gy in five fractions. At median follow-up of 12.8 months, median overall survival was 14.7 months and eight in-field recurrences were detected (median time 10.5 months). Five patients experienced symptomatic brainstem necrosis, and all having received 24 Gy in three fractions. Hypofractionated brainstem re-irradiation may be safer in five fractions.

Prognostic Factors and Survival Outcomes of Intracranial Ependymoma Treated with Multimodality Approach

Objectives:

We aimed to analyze treatment outcomes of intracranial ependymoma (ICE) treated at our institute with multimodality approach.

Materials and Methods:

Demography, treatment details, and survival data of 40 patients (2005–2012) were collected in a predesigned pro forma. Kaplan Meier method was used to analyze disease-free survival (DFS) and the impact of prognostic factors was determined using univariate analysis (log-rank test). Multivariate analysis was performed using Cox-proportional hazard model. SPSS version 21.0 was used for all statistical analysis.

Results:

Male:female ratio was 29:11. Gross total resection: subtotal resection or less was 42.5%: 57.5%. A total of 16 patients (40%) had anaplastic histology. All except two patients received adjuvant radiotherapy. Four patients received concurrent chemotherapy (temozolomide [TMZ]) and 10 patients received adjuvant chemotherapy (6 carboplatin plus etoposide; 4 TMZ). Median follows up was 18 months (2–60 months). Median DFS for the entire cohort was 22.42 months. The estimated 1, 2, and 3 years DFS was found to be 58.5%, 41%, and 30.7%, respectively. On univariate analysis, patients receiving higher radiation dose (56 Gray vs. 60 Gray; hazard ratio [HR] 0.366; 95% confidence interval [CI] 0.142–0.9553; P = 0.02) and lower MIB labeling index (<20 vs. ≥20; HR 0.238; 95% CI 0.092–0.617; P = 0.001) had a better DFS. Higher radiation dose continued to be an independent prognostic factor on multivariate analysis (HR 0.212; 95% CI 0.064–0.856; P = 0.03).

Conclusion:

ICE has guarded prognosis. Adjuvant radiotherapy to a higher radiation dose improves survival. Higher MIB labeling index connotes a dismal survival despite the use of radiotherapy and chemotherapy.

The current consensus on the clinical management of intracranial ependymoma and its distinct molecular variants

Multiple independent genomic profiling efforts have recently identified clinically and molecularly distinct subgroups of ependymoma arising from all three anatomic compartments of the central nervous system (supratentorial brain, posterior fossa, and spinal cord). These advances motivated a consensus meeting to discuss: (1) the utility of current histologic grading criteria, (2) the integration of molecular-based stratification schemes in future clinical trials for patients with ependymoma and (3) current therapy in the context of molecular subgroups. Discussion at the meeting generated a series of consensus statements and recommendations from the attendees, which comment on the prognostic evaluation and treatment decisions of patients with intracranial ependymoma (WHO Grade II/III) based on the knowledge of its molecular subgroups. The major consensus among attendees was reached that treatment decisions for ependymoma (outside of clinical trials) should not be based on grading (II vs III). Supratentorial and posterior fossa ependymomas are distinct diseases, although the impact on therapy is still evolving. Molecular subgrouping should be part of all clinical trials henceforth.

Radiation and subsequent reirradiation outcomes in the treatment of diffuse intrinsic pontine glioma and a systematic review of the reirradiation literature

PURPOSE

Diffuse intrinsic pontine glioma (DIPG) is a devastating pediatric disease, with a median survival of <1 year. Here, we review our institution's DIPG experience over an 8-year interval and perform a systematic review of the literature, specifically evaluating reports of reirradiation (reRT) for DIPG.

METHODS AND MATERIALS

We retrospectively reviewed the medical records of 26 patients who underwent definitive intensity modulated radiation therapy (IMRT) for DIPG at a single institution between 2007 and 2015. Three of these patients underwent reRT for progressive disease. Clinical endpoints, including progression-free survival and overall survival (OS), were assessed. We then performed a thorough PubMed search of the literature discussing reRT for patients with DIPG.

RESULTS

Twenty-four of the 26 patients (92%) completed the initial course of radiation (54 Gy in 1.8-Gy fractions using IMRT). Median age at diagnosis was 6.0 years (range, 2.0-26.5). With respect to systemic therapy, 1 (4.2%) received no systemic therapy, 1 (4.2%) received concurrent systemic therapy alone, 4 (16.7%) received adjuvant therapy alone, and 18 (75%) received a combination of concurrent and adjuvant therapy. Median follow-up time was 11 months from the date of initial diagnosis. Median OS for the cohort was 12 months, with a 1-year OS of 51%. The 3 patients who underwent reRT received 20 Gy in 10 daily fractions using IMRT alone with no treatment toxicity noted.

CONCLUSIONS

Radiation therapy is essential in the definitive management of DIPG. With advances in treatment techniques, it is feasible to reirradiate select patients with progressive disease; however, further research is warranted to optimize dose, delivery, and patient selection in the recurrent/progressive setting. In the future, it may be reasonable to propose more focal delivery of reRT (ie, hypofractionated radiation) in select patients with the goal of reducing treatment time and providing effective palliation.

Treatment implications of posterior fossa ependymoma subgroups

Posterior fossa ependymoma comprises two distinct molecular entities, ependymoma_posterior fossa A (EPN_PFA) and ependymoma_posterior fossa B (EPN_PFB), with differentiable gene expression profiles. As yet, the response of the two entities to treatment is unclear. To determine the relationship between the two molecular subgroups of posterior fossa ependymoma and treatment, we studied a cohort of 820 patients with molecularly profiled, clinically annotated posterior fossa ependymomas. We found that the strongest predictor of poor outcome in patients with posterior fossa ependymoma across the entire age spectrum was molecular subgroup EPN_PFA, which was recently reported in the paper entitled “Therapeutic impact of cytoreductive surgery and irradiation of posterior fossa ependymoma in the molecular era: a retrospective multicohort analysis” in the Journal of Clinical Oncology. Patients with incompletely resected EPN_PFA tumors had a very poor outcome despite receiving adjuvant radiation therapy, whereas a substantial proportion of patients with EPN_PFB tumors can be cured with surgery alone.

[Pediatric ependymomas: Current diagnosis and therapy]

Ependymomas represent 10% of pediatric brain tumors. In the recent WHO 2016 classification, pathology is enriched by localization and molecular biology. Whatever the age, total removal by one or several looks when required remains a major prognostic factor. In children, focal radiation remains a standard, while the role of chemotherapy is matter of randomized studies. In infants, front line chemotherapy is the standard. Inclusion in the SIOP ependymoma II protocol is encouraged. In case of relapse, further surgery and radiation are advised, while inclusion in innovative trials including re-irradiation, and phase I-II should be encouraged. A better understanding of underlying mechanisms of ependymoma cell will provide in the close future, the key to use targeted therapies at time of relapse, and very soon as first line therapy for some subgroups of patients.

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.

Reirradiation of Recurrent Pediatric Brain Tumors after Initial Proton Therapy

PURPOSE

The use of reirradiation for recurrent pediatric brain tumors has been increasing, but the effect of repeat radiation on critical cranial structures is unknown.

METHODS AND MATERIALS

Between July 2009 and May 2013, the records of 12 pediatric patients initially treated with proton therapy and then with reirradiation for recurrent brain tumors were retrospectively reviewed for toxicity and outcomes. Initial and repeat radiation dose distributions were deformed and merged to determine the maximum dose to 0.03 cm3 of the optic chiasm, optic nerves, spinal cord, brainstem, cochleae, pituitary, and uninvolved brain, and to 1 cm3 of the brainstem and brain on individual and composite plans. These dosimetric results were compared with auditory, neurocognitive, ophthalmologic, and endocrine outcomes to identify radiation-associated toxicities.

RESULTS

Median follow-up was 3.5 years from diagnosis. Median ages at initial and repeat radiation were 4.6 and 6.7 years, respectively. All patients initially received proton radiotherapy to a median tumor dose of 55.8 Gy relative biological effectiveness (RBE) (range, 45 to 60 Gy [RBE]). At progression, patients completed a second course of radiation to local fields (n = 7) or the craniospinal axis (n = 5) with a median tumor dose of 40 Gy (RBE) (range, 20 to 54 Gy [RBE]). Median progression-free survival was 22.7 months from the last day of the second radiation course. No patient developed central nervous system necrosis requiring treatment. Of evaluable patients, none developed radiation-related high-grade hearing loss (n = 11), visual pathway deficit (n = 10), or significant change in pre- and post-reirradiation full-scale intelligence quotient (n = 4). Of 11 evaluable patients, 4 (36.4%) developed secondary hypothyroidism and 1 (9.1%) developed growth hormone deficiency.

CONCLUSION

Repeat radiation for recurrent brain tumors after proton therapy may be performed in the pediatric population with acceptable short- and long-term toxicity.

Reirradiation of Pediatric Tumors Using Hypofractionated Stereotactic Radiotherapy

BACKGROUND

This study aimed to evaluate the efficacy and safety of hypofractionated stereotactic radiotherapy for reirradiation of recurrent pediatric tumors.

METHODS AND MATERIALS

The study included 23 pediatric patients who were reirradiated using hypofractionated stereotactic radiotherapy in the radiation oncology department between January 2008 and November 2013. In total, 33 tumors were treated-27 (82%) cranial and 6 (18%) extracranial. Hypofractionated stereotactic radiotherapy was administered due to recurrent disease in 31 (94%) tumors and residual disease in 2 (6%) tumors. The median total dose was 25 Gy (range: 15-40 Gy), and the median follow-up was 20 months (range: 2-68 months).

RESULTS

The 1-year and 2-year local control rates in the entire study population were 42% and 31%, respectively. The median local control time was 11 months (range: 0-54 months) following hypofractionated stereotactic radiotherapy. The patients with tumor response after hypofractionated stereotactic radiotherapy had significantly longer local control than the patients with post-hypofractionated stereotactic radiotherapy tumor progression (21 vs 3 months, P < .001). Tumor volume <1.58 cm³ was correlated (not significantly) with better local control (23 vs 7 months, P = .064).

CONCLUSION

Reirradiation of pediatric tumors using hypofractionated stereotactic radiotherapy is a safe and effective therapeutic approach. This treatment modality should be considered as a treatment option in selected pediatric patients.

Re-irradiation of recurrent pediatric ependymoma: modalities and outcomes: a twenty-year survey

Background

Standard treatment for recurrent ependymomas is not defined. Re- irradiation has been proposed but its modalities and results are still to be explored.

Patients and methods

From June 1994 to December 2013, 32 pediatric patients with ependymoma were re-irradiated for local (n = 15) or metastatic (n = 17) relapses. Files were reviewed retrospectively.

Results

Local relapses were treated with hypofractionated focal radiotherapy (hypoFFRT) (n = 8) or focal fractionated radiotherapy (FFRT) (n = 7). Metastatic relapses were treated with hypoFFRT (n = 3), FFRT (n = 3), spinal radiotherapy (n = 4) and craniospinal irradiation (CSI) (n = 7). Median PFS and OS after re-irradiation were 1.2 and 3.5 years respectively with a median follow-up of 2.1 years (0.2–11.4). For local relapses, median PFS was 2.5 years for patients treated with hypoFFRT versus 1.2 years for patients treated with FFRT (p = 0.2). For metastatic relapses, median PFS was 0.7 years for patients treated with focal radiotherapy (hypoFFRT, FFRT, spinal radiotherapy) versus 6.8 years for patients treated with CSI (p = 0.073). 15 patients achieved greater PFS after second radiotherapy (RT2) than after first radiotherapy (RT1). 27 patients (84 %) had surgery before re-irradiation. PFS was better for patients with GTR before RT2 (14.7 vs 6.7 months) (p = 0.05). 5 patients developed radionecrosis; only one required corticosteroids.

Conclusion

Re-irradiation at relapse is a safe, feasible and potentially curative treatment. Metastatic relapse may require CSI even when isolated and re-operated. For local relapses, considering conflicting results in the literature, a randomized trial is warranted to explore fractionated focal radiotherapy versus hypofractionated focal irradiation.

Final results of the second prospective AIEOP protocol for pediatric intracranial ependymoma

BACKGROUND

This prospective study stratified patients by surgical resection (complete = NED vs incomplete = ED) and centrally reviewed histology (World Health Organization [WHO] grade II vs III).

METHODS

WHO grade II/NED patients received focal radiotherapy (RT) up to 59.4 Gy with 1.8 Gy/day. Grade III/NED received 4 courses of VEC (vincristine, etoposide, cyclophosphamide) after RT. ED patients received 1-4 VEC courses, second-look surgery, and 59.4 Gy followed by an 8-Gy boost in 2 fractions on still measurable residue. NED children aged 1-3 years with grade II tumors could receive 6 VEC courses alone.

RESULTS

From January 2002 to December 2014, one hundred sixty consecutive children entered the protocol (median age, 4.9 y; males, 100). Follow-up was a median of 67 months. An infratentorial origin was identified in 110 cases. After surgery, 110 patients were NED, and 84 had grade III disease. Multiple resections were performed in 46/160 children (28.8%). A boost was given to 24/40 ED patients achieving progression-free survival (PFS) and overall survival (OS) rates of 58.1% and 68.7%, respectively, in this poor prognosis subgroup. For the whole series, 5-year PFS and OS rates were 65.4% and 81.1%, with no toxic deaths. On multivariable analysis, NED status and grade II were favorable for OS, and for PFS grade II remained favorable.

CONCLUSIONS

In a multicenter collaboration, this trial accrued the highest number of patients published so far, and results are comparable to the best single-institution series. The RT boost, when feasible, seemed effective in improving prognosis. Even after multiple procedures, complete resection confirmed its prognostic strength, along with tumor grade. Biological parameters emerging in this series will be the object of future correlatives and reports.

Advances in Management of Pediatric Ependymomas

Ependymomas are a heterogeneous group of neuroepithelial tumors of children and adults. In pediatric cases, the standard of care has long consisted of neurosurgical resection to the greatest extent acceptable followed by adjuvant involved field irradiation. Complete macroscopic surgical resection has remained the only consistent clinical variable known to improve survival. Adjuvant chemotherapy has yet to predictably affect outcome, possibly due to the molecular heterogeneity of histologically similar tumors. The administration of chemotherapy subsequently remains limited to clinical trials. However, recent comprehensive genomic, transcriptomic, and epigenetic interrogations of ependymomas have uncovered unique molecular characteristics and subtypes that correlated with clinical features such as age, neuroanatomical location, and prognosis. These findings represent a potential paradigm shift and provide a biologic rationale for targeted therapeutic strategies and risk-adapted administration of conventional treatment modalities. In this review, we focus on intracranial WHO grade II and III ependymoma of children and discuss conventional management strategies, followed by recent biologic findings and novel therapeutics currently under investigation.

Pediatric Brain Tumors: Current Knowledge and Therapeutic Opportunities

Great progress has been made in many areas of pediatric oncology. However, tumors of the central nervous system (CNS) remain a significant challenge. A recent explosion of data has led to an opportunity to understand better the molecular basis of these diseases and is already providing a foundation for the pursuit of rationally chosen therapeutics targeting relevant molecular pathways. The molecular biology of pediatric brain tumors is shifting from a singular focus on basic scientific discovery to a platform upon which insights are being translated into therapies.

Re-irradiation of Recurrent Pineal Germ Cell Tumors with Radiosurgery: Report of Two Cases and Review of Literature

Primary intracranial germ cell tumors are rare, representing less than 5% of all central nervous system tumors. Overall, the majority of germ cell tumors are germinomas and approximately one-third are non-germinomatous germ cell tumors (NGGCT), which include teratoma, embryonal carcinoma, yolk sac tumor (endodermal sinus tumor), choriocarcinoma, or mixed malignant germ cell tumor. Germ cell tumors may secrete detectable levels of proteins into the blood and/or cerebrospinal fluid, and these proteins can be used for diagnostic purposes or to monitor tumor recurrence. Germinomas have long been known to be highly curable with radiation therapy alone. However, many late effects of whole brain or craniospinal irradiation have been well documented. Strategies have been developed to reduce the dose and volume of radiation therapy, often in combination with chemotherapy. In contrast, patients with NGGCT have a poorer prognosis, with about 60% cured with multimodality chemoradiation. There are no standard approaches for relapsed germ cell tumors. Options may be limited by prior treatment. Radiation therapy has been utilized alone or in combination with chemotherapy or high-dose chemotherapy and transplant. We discuss two cases and review options for frameless radiosurgery or fractionated radiotherapy.

Radiosurgery for Pediatric Brain Tumors

The utility of radiosurgery for pediatric brain tumors is not well known. For children, radiosurgery may have an important role for treating unresectable tumors, residual disease, or tumors in the recurrent setting that have received prior radiotherapy. The available evidence demonstrates utility for some children with primary brain tumors resulting in good local control. Radiosurgery can be considered for limited residual disease or focal recurrences. However, the potential toxicities are unique and not insignificant. Therefore, prospective studies need to be performed to develop guidelines for indications and treatment for children and reduce toxicity in this population.

Temozolomide Treatment for Pediatric Refractory Anaplastic Ependymoma with Low MGMT Protein Expression

The benefit of postoperative chemotherapy for anaplastic ependymoma remains unknown. We report two pediatric patients with refractory anaplastic ependymoma treated with temozolomide (TMZ). We did not detect O(6) -methylguanine-DNA methyltransferase (MGMT) promoter methylation in tumor samples; however, MGMT protein expression was low. With TMZ treatment, one patient had a 7-month complete remission; the other, stable disease for 15 months. Three other patients did not respond to TMZ; two had high and one low MGMT expression, and two showed no MGMT promoter methylation. These findings suggest that TMZ may be effective for pediatric refractory anaplastic ependymoma with low MGMT protein expression.

Re-irradiation of recurrent anaplastic ependymoma using radiosurgery or fractionated stereotactic radiotherapy

PURPOSE

Recurrent ependymomas were retreated with stereotactic radiosurgery (SRS) or fractionated stereotactic radiotherapy (FSRT). The efficacy, toxicities, and differences between SRS and FSRT were analyzed.

METHODS

Eight patients with recurrent ependymomas fulfilling the criteria described below were evaluated. Inclusion criteria were: (1) the patient had previously undergone surgery and conventional radiotherapy as first-line treatment; (2) targets were located in or adjacent to the eloquent area or were deep-seated; and (3) the previously irradiated volume overlapped the target lesion.

RESULTS

FSRT was delivered to 18 lesions, SRS to 20 lesions. A median follow-up period was 23 months. The local control rate was 76 % at 3 years. No significant differences in local control were observed due to tumor size or fractionation schedule. Lesions receiving >25 Gy/5 fr or 21 Gy/3 fr did not recur within 1 year, whereas no dose-response relationship was observed in those treated with SRS. No grade ≥2 toxicity was observed.

CONCLUSION

Our treatment protocol provided an acceptable LC rate and minimal toxicities. Because local recurrence of tumors may result in patient death, a minimum dose of 21 Gy/3 fr or 25 Gy/5 fr or higher may be most suitable for treatment of these cases.

DIPG in Children - What Can We Learn from the Past?

Brainstem tumors represent 10–15% of pediatric central nervous system tumors and diffuse intrinsic pontine glioma (DIPG) is the most common brainstem tumor of childhood. DIPG is almost uniformly fatal and is the leading cause of brain tumor-related death in children. To date, radiation therapy (RT) is the only form of treatment that offers a transient benefit in DIPG. Chemotherapeutic strategies including multi-agent neoadjuvant chemotherapy, concurrent chemotherapy with RT, and adjuvant chemotherapy have not provided any survival advantage. To overcome the restrictive ability of the intact blood–brain barrier (BBB) in DIPG, several alternative drug delivery strategies have been proposed but have met with minimal success. Targeted therapies either alone or in combination with RT have also not improved survival. Five decades of unsuccessful therapies coupled with recent advances in the genetics and biology of DIPG have taught us several important lessons (1). DIPG is a heterogeneous group of tumors that are biologically distinct from other pediatric and adult high grade gliomas (HGG). Adapting chemotherapy and targeted therapies that are used in pediatric or adult HGG for the treatment of DIPG should be abandoned (2). Biopsy of DIPG is relatively safe and informative and should be considered in the context of multicenter clinical trials (3). DIPG probably represents a whole brain disease so regular neuraxis imaging is important at diagnosis and during therapy (4). BBB permeability is of major concern in DIPG and overcoming this barrier may ensure that drugs reach the tumor (5). Recent development of DIPG tumor models should help us accurately identify and validate therapeutic targets and small molecule inhibitors in the treatment of this deadly tumor.

Posterior fossa ependymoma: current insights

BACKGROUND

Ependymoma is the third most common malignant tumor of the posterior fossa and is a major cause of neurological morbidity and mortality in children. Current treatments, particularly surgery and external beam irradiation result in relatively poor outcomes with significant neurological and cognitive sequelae from treatment. Historical approaches have considered all ependymomas as similar entities based on their morphological appearance.

RESULTS

Recent advances in genomics and epigenetics have revealed, however, that ependymomas from different CNS locations represent distinct entities. Moreover, ependymoma of the posterior fossa, the most common location in children, is actually comprised of two distinct molecular variants. These two variants have marked differences in demographics, transcriptomes, structure, methylation patterns, and clinical outcomes. This allows for the development of new biology-based clinical risk stratification, which can both prioritize patients for de-escalation of therapy and identify those who will benefit from novel therapeutic strategies. Indeed, the identification of these two variants allows an opportunity for robust preclinical modeling for development of novel therapeutic strategies.

CONCLUSIONS

Herein, we have summarized our current clinical approach to diagnosis and treatment of posterior fossa ependymoma, recent advances in understanding the biology of posterior fossa ependymoma and how these new insights can be translated into the clinic to form the basis of the next generation of clinical trials.

Temozolomide as salvage treatment for recurrent intracranial ependymomas of the adult: a retrospective study

BACKGROUND

Few data are available on temozolomide (TMZ) in ependymomas.We investigated the response, survival, and correlation with MGMT promoter methylation in a cohort of patients with adult intracranial ependymoma receiving TMZ as salvage therapy after failure of surgery and radiotherapy.

PATIENTS AND METHODS

We retrieved clinical information from the institutional database and follow-up visits, and response to TMZ on MRI was evaluated according to the MacDonald criteria.

RESULTS

Eighteen patients (median age, 42 y), with either WHO grade III (10) or grade II (8) ependymoma were evaluable. Tumor location at diagnosis was supratentorial in 11 patients and infratentorial in 7. Progression before TMZ was local in 11 patients, local and spinal in 6 patients, and spinal only in one patient. A median of 8 cycles of TMZ (1-24) was administered. Response to TMZ consisted of complete response (CR) in one (5%) patient, partial response (PR) in 3 (17%) patients, stable disease (SD) in 7 (39%) patients, and progressive disease (PD) in 7 (39%) patients. Maximum response occurred after 3, 10, 14, and 15 cycles, respectively, with neurological improvement in 2 patients. All 4 responding patients were chemotherapy naïve. Both anaplastic (2) and grade II (2) tumors responded. Median progression-free survival and overall survival were 9.69 months (95% CI, 3.22-30.98) and 30.55 months (95% CI, 12.85-52.17), respectively. MGMT methylation was available in 11 patients and was not correlated with response or outcome.

CONCLUSION

TMZ has a role in recurrent chemo-naïve adult patients with intracranial ependymoma, regardless of tumor grade and MGMT methylation. We suggest that, after failure of surgery and radiotherapy, TMZ should be considered as a possible first-line treatment for recurrent ependymoma.

Paediatric intracranial anaplastic ependymoma: the role of multiple surgical resections for disease relapse in maintaining quality of life and prolonged survival

INTRODUCTION

Ependymoma is the third most common intracranial glioma in children. The treatment of choice for these tumours remains gross total resection followed by radiotherapy. There are two principal histological subtypes, namely classic (∼70%) and anaplastic (∼30%) ependymoma.

CASE

We present the case of a 12-year-old girl with an anaplastic ependymoma of the left temporal lobe. She underwent initial image-guided resection following biopsy. A postoperative MRI showed a macroscopic resection. She subsequently relapsed and indeed had 11 local and distant relapses managed by 12 separate craniotomies and tumour resection, 4 courses of radiotherapy and chemotherapy.

CONCLUSION

For patients with multiple relapses, surgery should be considered primarily to re-resect any symptomatic lesion. This case demonstrates that multiple tumour resections can be undertaken with limited morbidity for the patient and with maintenance of quality of life. Repeated focal irradiation can also be used to control the disease with limited morbidity.

A retrospective analysis of recurrent intracranial ependymoma

BACKGROUND

Recurrence occurs in almost 50% of patients with intracranial ependymoma, and their outcome following recurrence is poor.

METHODS

We retrospectively reviewed the medical records of 22 patients with intracranial ependymoma and subsequent relapse(s) (59 recurrences) treated at Children's Hospital Los Angeles or New York University between January 1997 and December 2012.

RESULTS

Median duration of follow-up was 52 months (7-171 months). Median age at initial diagnosis was 4 years (0.3-19 years) with 8 patients younger than 3 years at presentation. Eleven patients had anaplastic and 11 cellular pathologies. Eighteen patients had infratentorial tumors at diagnosis and 3 (all infratentorial) had metastatic spinal cord involvement at presentation. Cerebrospinal fluid involvement was not identified at diagnosis or relapse. Median time to first recurrence was 16 months (1.3 to 115 months). The number of recurrences in each patient ranged from 1 to 9 (median = 2). Thirty-seven recurrences (63%) were detected asymptomatically by surveillance imaging. Fifteen recurrences (26%) arose outside the initial tumor site. Recurrences were treated by surgical resection (45), with irradiation (30), and with various oral chemotherapies (23) with (7) or without (16) conventional chemotherapy. The 5 and 10 year overall survival rates from first recurrence were 0.37 ± 0.14 and 0.25 ± 0.14.

CONCLUSION

Prolonged (5-10 year) survival from first relapse was noted in over one-quarter of our patients. It remains unclear whether early radiographic diagnosis, differing treatment modalities beyond radical surgical resection or possibly unrecognized biological differences contributed towards this prolonged survival.

Timing of adjuvant radiotherapy and treatment outcome in childhood ependymoma

BACKGROUND

Several trials incorporating adjuvant focal RT for treatment of young children with ependymoma have demonstrated improved survival with acceptable adverse effects. The optimal timing of RT administration is, however, unknown.

PROCEDURE

A retrospective review of territory-wide database was performed to identify pediatric patients with ependymoma diagnosed between 1995 and 2011. OS and EFS were compared between patients receiving upfront RT (<150 days of diagnosis), delayed RT (≥150 days of diagnosis), or no RT.

RESULTS

Thirty-one patients with intracranial ependymoma were identified. Median age was 3.5 years and 14 (45%) were male. Primary tumor was supratentorial in 10 (32%) and infratentorial in 21 (68%). All patients underwent initial surgery, with gross-total resection (GTR) in 27 (87%). Twelve (39%) received upfront RT, 10 (32%) had delayed RT and 9 (29%) had no RT. During the study period, there were 11 relapses (35%) and 10 deaths (32%). Five-year OS was 69.9% and 5yr-EFS was 49.3%. In univariate analysis, GTR led to improved OS (P < 0.001) and EFS (P = 0.004); superior OS and EFS was observed in patients who received RT when compared with those without (P = 0.018 and 0.011, respectively). Upfront RT also resulted in better OS and EFS than delayed RT (P = 0.049 and 0.014, respectively). No significant effect on survival was observed with age, sex, tumor location, RT dosage, and protocol used. In multivariate analysis, GTR significantly improved OS (P = 0.002) and EFS (P = 0.004).

CONCLUSIONS

Our results support the early initiation of adjuvant RT in the multi-modal management of pediatric ependymomas.

Epigenomic alterations define lethal CIMP-positive ependymomas of infancy

Ependymomas are common childhood brain tumours that occur throughout the nervous system, but are most common in the paediatric hindbrain. Current standard therapy comprises surgery and radiation, but not cytotoxic chemotherapy as it does not further increase survival. Whole-genome and whole-exome sequencing of 47 hindbrain ependymomas reveals an extremely low mutation rate, and zero significant recurrent somatic single nucleotide variants. Although devoid of recurrent single nucleotide variants and focal copy number aberrations, poor-prognosis hindbrain ependymomas exhibit a CpG island methylator phenotype. Transcriptional silencing driven by CpG methylation converges exclusively on targets of the Polycomb repressive complex 2 which represses expression of differentiation genes through trimethylation of H3K27. CpG island methylator phenotype-positive hindbrain ependymomas are responsive to clinical drugs that target either DNA or H3K27 methylation both in vitro and in vivo. We conclude that epigenetic modifiers are the first rational therapeutic candidates for this deadly malignancy, which is epigenetically deregulated but genetically bland.

An overview of the management of adult ependymomas with emphasis on relapsed disease

Ependymomas are rare neoplasms of the central nervous system. Disease-free survival after relapse is poor and approaches to treatment in recurrent disease often palliative. This overview summarises the management of primary disease for which broad consensus exists. We also extensively review treatment options in relapsed disease for which approaches to treatment are varied due to the paucity of literature evidence. Incorporated in this overview is a survey of UK neuro-oncology units to form a snapshot of current UK practise with respect to preferred systemic therapy regimens for patients with recurrent ependymoma. The outcome reflects a preference for mainly oral-based regimens. Universal guidance is lacking in the management of non-operable irradiated recurrent ependymoma and there are worthy therapeutic avenues for further investigation, in particular the role of radical re-irradiation and also the potential of bevacizumab in advanced disease. It is hoped that advances can be achieved by multicentre collaboration in future studies to overcome the difficulties posed by achieving meaningful data in such a rare tumour with extensive natural history.

Multidisciplinary management of pediatric intracranial ependymoma

Pediatric intracranial ependymoma is a rare disease representing approximately 7% of brain tumors in children aged 15 years or younger. Due to the relative rarity of these tumors, a clear standard therapy has been difficult to establish. The mainstay of treatment is surgical resection and the majority of data demonstrate improved outcome with gross total resection. The standard of care also includes postoperative radiation therapy for most patients with grade II and III tumors. Chemotherapy has been used in many capacities in this disease; however, its optimal role is yet to be defined. Current controversies such as treatment with surgery alone in completely resected tumors, use of chemotherapy for subtotally resected tumors and use of adjuvant postradiation chemotherapy are incorporated into the design of the current Children's Oncology Group clinical trial.