Craniospinal irradiation as part of re-irradiation for children with recurrent intracranial ependymoma

Dosimetric consequences of adapting the craniocaudal isocenter distance to daily patient position in craniospinal irradiation using volumetric modulated arc therapy

PURPOSE

In craniospinal irradiation, two or three isocenter groups along the craniocaudal axis are required to cover the long treatment target. Adapting the isocenter distance according to daily deviations in patient position is challenging because dosimetric hot or cold spots may occur in the field junction. The aim of this study was to quantify the effect of adapting the isocenter distance to patient position on the dose distribution of the field overlap region in craniospinal irradiation using partial-arc volumetric modulated arc therapy.

METHODS

The magnitude of isocenter distance deviations in craniocaudal direction was quantified by registering the setup images of 204 fractions of 12 patients to the planning images. The dosimetric effect of these deviations was determined by shifting the isocenters of the original treatment plan and calculating the resulting dose distribution.

RESULTS

On fraction-level, deviations larger than 3 mm caused more than 5 percentage point changes in the doses covering 2% (D2%) and 98% (D98%) of the junction volume in several patients. On treatment course-level, the changes in D2% and D98% of the junction volume were less than 5 percentage points in all cases except for one patient.

CONCLUSIONS

Craniocaudal isocenter distance adaptation can be conducted provided that the mean isocenter distance deviation over the treatment course is within 3 mm.

Brain and Brain Stem Necrosis After Reirradiation for Recurrent Childhood Primary Central Nervous System Tumors: A PENTEC Comprehensive Review

PURPOSE

Reirradiation is increasingly used in children and adolescents/young adults (AYA) with recurrent primary central nervous system tumors. The Pediatric Normal Tissue Effects in the Clinic (PENTEC) reirradiation task force aimed to quantify risks of brain and brain stem necrosis after reirradiation.

METHODS AND MATERIALS

A systematic literature search using the PubMed and Cochrane databases for peer-reviewed articles from 1975 to 2021 identified 92 studies on reirradiation for recurrent tumors in children/AYA. Seventeen studies representing 449 patients who reported brain and brain stem necrosis after reirradiation contained sufficient data for analysis. While all 17 studies described techniques and doses used for reirradiation, they lacked essential details on clinically significant dose-volume metrics necessary for dose-response modeling on late effects. We, therefore, estimated incidences of necrosis with an exact 95% CI and qualitatively described data. Results from multiple studies were pooled by taking the weighted average of the reported crude rates from individual studies.

RESULTS

Treated cancers included ependymoma (n = 279 patients; 7 studies), medulloblastoma (n = 98 patients; 6 studies), any CNS tumors (n = 62 patients; 3 studies), and supratentorial high-grade gliomas (n = 10 patients; 1 study). The median interval between initial and reirradiation was 2.3 years (range, 1.2-4.75 years). The median cumulative prescription dose in equivalent dose in 2-Gy fractions (EQD22; assuming α/β value = 2 Gy) was 103.8 Gy (range, 55.8-141.3 Gy). Among 449 reirradiated children/AYA, 22 (4.9%; 95% CI, 3.1%-7.3%) developed brain necrosis and 14 (3.1%; 95% CI, 1.7%-5.2%) developed brain stem necrosis with a weighted median follow-up of 1.6 years (range, 0.5-7.4 years). The median cumulative prescription EQD22 was 111.4 Gy (range, 55.8-141.3 Gy) for development of any necrosis, 107.7 Gy (range, 55.8-141.3 Gy) for brain necrosis, and 112.1 Gy (range, 100.2-117 Gy) for brain stem necrosis. The median latent period between reirradiation and the development of necrosis was 5.7 months (range, 4.3-24 months). Though there were more events among children/AYA undergoing hypofractionated versus conventionally fractionated reirradiation, the differences were not statistically significant (P = .46).

CONCLUSIONS

Existing reports suggest that in children/AYA with recurrent brain tumors, reirradiation with a total EQD22 of about 112 Gy is associated with an approximate 5% to 7% incidence of brain/brain stem necrosis after a median follow-up of 1.6 years (with the initial course of radiation therapy being given with conventional prescription doses of ≤2 Gy per fraction and the second course with variable fractionations). We recommend a uniform approach for reporting dosimetric endpoints to derive robust predictive models of late toxicities following reirradiation.

Challenges in Treating Childhood Infratentorial Ependymoma: A Low- and Middle-Income Country Experience

PURPOSE

Patients and physicians in low- and middle-income countries (LMICs) face challenges owing to limited expertise and suboptimal access to appropriate diagnostic and treatment modalities. We report our experience in treating posterior fossa ependymoma (PFE) at MAHAK, a charity organization in Iran whose radiation oncology department is the only one exclusively dedicated to childhood cancer in the whole country.

METHODS AND MATERIALS

Pediatric patients with PFE referred to MAHAK between November 2008 and January 2016 were identified. Details on investigations and management done before referral were collected. Management at MAHAK and patient outcomes were analyzed.

RESULTS

Of 80 patients diagnosed as having ependymoma, 54 with PFE were identified. Forty-three patients received adjuvant radiation therapy, and 11 were irradiated initially after recurrence. At a median follow-up of 5.1 years (range, 0.3-9.7 years), the latter group had the worst outcome, with a 5-year overall survival (OS) rate of 27% (95% CI, 7%-54%). Patients who started radiation therapy within 77 days after initial surgery had a better outcome compared with those who started later (5-year OS: 74% vs 32%; P = .05). Compliance with follow-up recommendations was poor. Only 22% of the patients had at least 2 IQ test assessments, and 50% showed some decline over time. Three cases of growth hormone deficiency were detected, but none of the patients received replacement therapy.

CONCLUSIONS

Access to pediatric neurosurgery, anesthesia, and timely radiation therapy are among the most challenging obstacles to be overcome in LMICs. Our series confirmed that chemotherapy is not an appropriate option for delaying radiation therapy, especially in young children. The importance of long-term follow-up should be acknowledged by the parents and medical team.

Respective Roles of Surgery, Chemotherapy, and Radiation Therapy for Recurrent Pediatric and Adolescent Ependymoma: A National Multicentric Study

PURPOSE

Half of the children and adolescents treated for intracranial ependymoma experience recurrences that are not managed in a standardized manner. This study aimed to retrospectively evaluate recurrence treatments.

METHODS AND MATERIALS

We assessed overall survival (OS) and progression-free survival (PFS) after a first relapse in a population of patients from the Pediatric Ependymoma Photons Protons and Imaging study (PEPPI study) who were treated with surgery and radiation therapy in French Society of Childhood Cancer reference centers between 2000 and 2013. Data were analyzed using the Cox model as well as a landmark analysis at 4 months that accounted for the guarantee-time bias.

RESULTS

The median follow-up of the whole population of 202 patients was 105.1 months, with a 10-year OS of 68.2% and PFS of 45.5%. Among the 100 relapse cases, 68.0% were local relapses, 20.0% were metastatic, and 12.0% were combined (local and metastatic). Relapses were treated by surgery (n = 79) and/or reirradiation (n = 52) and/or chemotherapy (n = 22). The median follow-up after relapse was 77.8 months. The OS and PFS at 5 years were 43.1% and 16.2%, respectively. After surgery or radiation therapy of the first relapse, OS and PFS were more favorable, whereas treatments that included chemotherapy with or without focal treatment were associated with worse OS and PFS. In the multivariate analysis, stereotactic hypofractionated reirradiation after surgery was associated with a significantly better outcome (OS, P = .030; PFS, P = .008) and chemotherapy with a worse outcome (OS, P = .028; PFS, P = .033).

CONCLUSIONS

This analysis of relapse treatments within the PEPPI study determined that irrespective of whether the relapse was localized or metastatic, treatments that included surgery and/or reirradiation had better outcomes.

Re-irradiation in Paediatric Tumours of the Central Nervous System: National Guidelines from the Swedish Workgroup of Paediatric Radiotherapy

There is a lack of clinical protocols for re-irradiation in paediatric central nervous system (CNS) tumours. To fill this void, the Swedish Workgroup of Paediatric Radiotherapy (SBRTG) compiled national guidelines on re-irradiation in paediatric CNS tumours (diffuse intrinsic pontine glioma, ependymoma, germinoma and medulloblastoma). These have been in clinical practice since 2019 in all paediatric radiotherapy centres in Sweden. Since the implementation, the guidelines have been complemented with a yearly review on clinical outcome and toxicities in all paediatric patients treated according to the guidelines. This article presents the Swedish national guidelines on re-irradiation in paediatric CNS tumours.

The evolving role of reirradiation in the management of recurrent brain tumors

Despite aggressive management consisting of surgery, radiation therapy (RT), and systemic therapy given alone or in combination, a significant proportion of patients with brain tumors will experience tumor recurrence. For these patients, no standard of care exists and management of either primary or metastatic recurrent tumors remains challenging.Advances in imaging and RT technology have enabled more precise tumor localization and dose delivery, leading to a reduction in the volume of health brain tissue exposed to high radiation doses. Radiation techniques have evolved from three-dimensional (3-D) conformal RT to the development of sophisticated techniques, including intensity modulated radiation therapy (IMRT), volumetric arc therapy (VMAT), and stereotactic techniques, either stereotactic radiosurgery (SRS) or stereotactic radiotherapy (SRT). Several studies have suggested that a second course of RT is a feasible treatment option in patients with a recurrent tumor; however, survival benefit and treatment related toxicity of reirradiation, given alone or in combination with other focal or systemic therapies, remain a controversial issue.We provide a critical overview of the current clinical status and technical challenges of reirradiation in patients with both recurrent primary brain tumors, such as gliomas, ependymomas, medulloblastomas, and meningiomas, and brain metastases. Relevant clinical questions such as the appropriate radiation technique and patient selection, the optimal radiation dose and fractionation, tolerance of the brain to a second course of RT, and the risk of adverse radiation effects have been critically discussed.

Re-irradiation for recurrent/progressive pediatric brain tumors: from radiobiology to clinical outcomes

INTRODUCTION

Brain tumors are the most common solid tumors in children. Neurosurgical excision, radiotherapy, and/or chemotherapy represent the standard of care in most histopathological types of pediatric central nervous system (CNS) tumors. Even though the successful cure rate is reasonable, some patients may develop recurrence locally or within the neuroaxis.

AREA COVERED

The management of these recurrences is not easy; however, significant advances in neurosurgery, radiation techniques, radiobiology, and the introduction of newer biological therapies, have improved the results of their salvage treatment. In many cases, salvage re-irradiation is feasible and has achieved encouraging results. The results of re-irradiation depend upon several factors. These factors include tumor type, extent of the second surgery, tumor volume, location of the recurrence, time that elapses between the initial treatment, the combination with other treatment agents, relapse, and the initial response to radiotherapy.

EXPERT OPINION

Reviewing the radiobiological basis and clinical outcome of pediatric brain re-irradiation revealed that re-irradiation is safe, feasible, and indicated for recurrent/progressive different tumor types such as; ependymoma, medulloblastoma, diffuse intrinsic pontine glioma (DIPG) and glioblastoma. It is now considered part of the treatment armamentarium for these patients. The challenges and clinical results in treating recurrent pediatric brain tumors were highly documented.

Salvage craniospinal irradiation for recurrent intracranial germinoma: a single institution analysis

This study investigated the effectiveness and safety of low-dose salvage craniospinal irradiation (CSI) for recurrent germinoma. We retrospectively reviewed long-term tumor control and late adverse effects in 15 recurrent germinoma patients treated at our hospital between 1983 and 2019. Following the first recurrence of germinoma, seven were treated with 24-30 Gy of salvage CSI, three underwent non-CSI, and five were treated with only chemotherapy. CSI achieved a significantly better recurrence-free survival rate after the first recurrence compared to other strategies (100% vs 33%, p < 0.001: log-rank test). To evaluate the safety of salvage CSI, we assessed the outcomes at the final follow-up of seven patients who received salvage CSI at first recurrence and three patients who received salvage CSI at second recurrence. The median follow-up period was 220 months after initial treatment. Five patients who received 40-50 Gy of radiation therapy or underwent multiple radiation therapy before salvage CSI were classified into Group A, whereas five patients treated with platinum-based chemotherapy and 24-32 Gy of radiation therapy to the primary site, whole ventricle, or whole brain were classified into Group B. In Group A, one had endocrine dysfunction and the other had visual dysfunction. None were socially independent. Meanwhile, in Group B, no endocrine or visual dysfunction was found, and three patients were socially independent. Salvage CSI achieved excellent tumor control in recurrent germinoma and was safe in patients initially treated with low-dose radiation therapy and chemotherapy.

Recurrent pediatric infratentorial ependymomas: a systematic review and meta-analysis on outcomes and molecular classification

OBJECTIVE

The aim of this study was to summarize the prognosis of recurrent infratentorial ependymomas based on treatment and molecular characterization.

METHODS

Following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines, the authors searched the PubMed, Scopus, Embase, and Ovid databases for studies on recurrent infratentorial ependymomas in patients younger than 25 years of age. Exclusion criteria included case series of fewer than 5 patients and studies that did not provide time-dependent survival data.

RESULTS

The authors' database search yielded 482 unique articles, of which 18 were included in the final analysis. There were 479 recurrent infratentorial pediatric ependymomas reported; 53.4% were WHO grade II and 46.6% were WHO grade III tumors. The overall mortality for recurrent infratentorial pediatric ependymomas was 49.1% (226/460). The pooled mean survival was 30.2 months after recurrence (95% CI 22.4-38.0 months). Gross-total resection (GTR) was achieved in 243 (59.0%) patients at initial presentation. The mean survival postrecurrence for those who received initial GTR was 42.3 months (95% CI 35.7-47.6 months) versus 26.0 months (95% CI 9.6-44.6 months) for those who received subtotal resection (STR) (p = 0.032). There was no difference in the mean survival between patients who received GTR (49.3 months, 95% CI 32.3-66.3 months) versus those who received STR (41.4 months, 95% CI 11.6-71.2 months) for their recurrent tumor (p = 0.610). In the studies that included molecular classification data, there were 169 (83.3%) posterior fossa group A (PFA) tumors and 34 (16.7%) posterior fossa group B (PFB) tumors, with 28 tumors harboring a 1q gain. PFA tumors demonstrated worse mean postprogression patient survival (24.7 months, 95% CI 15.3-34.0 months) compared with PFB tumors (48.0 months, 95% CI 32.8-63.2 months) (p = 0.0073). The average postrecurrence survival for patients with 1q+ tumors was 14.7 months.

CONCLUSIONS

The overall mortality rate for recurrent infratentorial ependymomas was found to be 49.1%, with a pooled mean survival of 30.2 months in the included sample population. More than 80% of recurrent infratentorial ependymomas were of the PFA molecular subtype, and both PFA tumors and those with 1q gain demonstrated worse prognosis after recurrence.

Outcomes following management of relapsed pediatric posterior fossa ependymoma in the molecular era

PURPOSE

The overall survival and prognostic factors for children with multiply recurrent posterior fossa ependymoma are not well understood. We aimed to assess prognostic factors associated with survival for relapsed pediatric posterior fossa ependymoma.

METHODS

An institutional database was queried for children with a primary diagnosis of posterior fossa ependymoma from 2000 to 2019. Kaplan-Meier survival analysis and Cox-proportional hazard regression were used to assess the relationship between treatment factors and overall survival.

RESULTS

There were 60 patients identified; molecular subtype was available for 56, of which 49 (87.5%) were PF-A and 7 (12.5%) were PF-B. Relapse occurred in 29 patients (48%) at a mean time of 24 months following primary resection. Median 50% survival was 12.3 years for all patients and 3.3 years following diagnosis of first relapsed disease. GTR was associated with significantly improved survival following primary resection (HR 0.373, 95% CI 0.14-0.96). Presence of recurrent disease was significantly associated with worse survival (p < 0.0001). At recurrent disease diagnosis, disseminated disease was a negative prognostic factor (HR 11.0 95% CI 2.7-44) while GTR at first relapse was associated with improved survival HR 0.215 (95% CI: 0.048-0.96, p = 0.044). Beyond first relapse, the impact of GTR was not significant on survival, though surgery compared to no surgery was favorable with HR 0.155 (95% CI: 0.04-0.59).

CONCLUSIONS

Disseminated disease at recurrence and extent of resection for first relapsed disease were important prognostic factors. Surgery compared to no surgery was associated with improved survival for the multiply recurrent ependymoma cohort.

Ependymomas in Children and Adults

Ependymomas account for approximately 5% of all CNS tumors in adults and around 10% in the pediatric population. Contrary to traditional theories supporting that ependymomas arise from ependymal cells, recent studies propose radial glial cells as the cells of origin. In adults, half of the ependymomas arise in the spinal cord, whereas in the pediatric population, almost 90% of ependymomas are located intracranially. Most of the ependymomas are usually low-grade tumors except anaplastic variants and some cases of RELA-fusion-positive ependymomas, a molecular variant consisting the most recent addition to the 2016 World Health Organization (WHO) classification. Of note, the recently described molecular classification of ependymomas into nine distinct subgroups appears to be of greater clinical utility and prognostic value compared to the traditional histopathological classification, and parts of it are expected to be adopted by the WHO in the near future. Clinical manifestations depend on the location of the tumor with infratentorial ependymomas presenting with acute hydrocephalus. Gross total resection should be the goal of treatment. The prognostic factors of patients with ependymomas include age, grade, and location of the tumor, with children with intracranial, anaplastic ependymomas having the worst prognosis. In general, the 5-year overall survival of patients with ependymomas is around 60-70%.

Role of Radiotherapy in Patients With Relapsed Medulloblastoma

During the last three decades, the management of medulloblastoma (MBL) has made enormous progress with a multidisciplinary approach, incorporating surgery, radiotherapy (RT), and chemotherapy. Despite this improvement, 20%-30% of patients with MBL remain at risk of disease recurrence, with its relapse being possibly fatal. To date, the salvage treatment for relapse remains challenging, and various approaches have been suggested for the retreatment. In this review, I have described the characteristics of patients with relapsed MBL, patterns of relapse and the most commonly prescribed treatment. Further, I have reviewed the studies on re-irradiation and its associated issues to conclusively suggest the RT recommendations for patients with relapsed MBL.

Encouraging early outcomes with image guided pencil beam proton therapy for cranio-spinal irradiation: first report from India

BACKGROUND

To report our experience with image guided pencil beam proton beam therapy (PBT) for craniospinal irradiation (CSI).

MATERIALS AND METHODS

Between January 2019 and December 2021, we carried out a detailed audit of the first forty patients treated with PBT. We had recorded acute toxicities, reporting early outcomes and discuss limitations of current contouring guidelines during CSI PBT planning.

RESULTS

Median age of the patient cohort was 8 years, and histologies include 20 medulloblastoma, 7 recurrent ependymoma, 3 pineoblastoma, 3 were germ cell tumors and remaining 7 constituted other diagnoses. Forty percent patients received concurrent chemotherapy. Median CSI dose was 23.4 Gy (Gray; range 21.6-35 Gy). Thirty-five patients (87.5%) completed their CSI without interruption, 5 required hospital admission. No patient had grade 2/ > weight loss during the treatment. Forty-five percent (18) developed grade 1 haematological toxicities and 20% (8) developed grade 2 or 3 toxicities; none had grade 4 toxicities. At median follow up of 12 months, 90% patients are alive of whom 88.9% are having local control. Special consideration with modification in standard contouring used at our institute helped in limiting acute toxicities in paediatric CSI patients.

CONCLUSION

Our preliminary experience with modern contemporary PBT using pencil beam technology and daily image guidance in a range of tumours suitable for CSI is encouraging. Patients tolerated the treatment well with acceptable acute toxicity and expected short-term survival outcome. In paediatric CSI patients, modification in standard contouring guidelines required to achieve better results with PBT.

The comparison of acute toxicities associated with craniospinal irradiation between photon beam therapy and proton beam therapy in children with brain tumors

Introduction

This study aimed to evaluate acute toxicities associated with irradiation between the X‐CSI (photon beam craniospinal irradiation) and P‐CSI (proton beam craniospinal irradiation) groups in children with brain tumors.

Methods

Sixty‐two consecutive patients who received initial craniospinal irradiation (CSI) for brain tumors in our center between January 1, 2011 and May 31, 2021, were included in the study. Acute toxicities were retrospectively evaluated during CSI using Common Terminology Criteria for Adverse Events version 5.0. Maximum grades of fatigue, headache, insomnia, nausea, vomiting, dermatitis, constipation, abdominal pain, oropharyngeal mucositis, and hematological toxicities were evaluated.

Results

Thirty‐six patients received X‐CSI, and 26 patients received P‐CSI. The median dose of CSI was 18.0 Gy in the X‐CSI group and 23.4 Gy (relative biological effectiveness) in the P‐CSI group (p < 0.001). The P‐CSI group had a lower incidence of more than grade 2 nausea (11.5% vs. 69.4%, p = 0.008) and vomiting (7.7% vs. 38.8%, p < 0.001), compared with the X‐CSI group. Multivariate logistic regression analysis with adjustments for potential confounding factors of doses of CSI showed that proton radiation therapy was associated with a marked reduced risk of more than grade 2 nausea and vomiting during CSI (adjusted odds ratio, 0.050; 95% confidential interval, 0.011–0.24; p < 0.001).

Conclusion

The present study suggests that P‐CSI reduces the acute gastrointestinal toxicities associated with irradiation.

Relapsed Medulloblastoma in Pre-Irradiated Patients: Current Practice for Diagnostics and Treatment

Relapsed medulloblastoma (rMB) accounts for a considerable, and disproportionate amount of childhood cancer deaths. Recent advances have gone someway to characterising disease biology at relapse including second malignancies that often cannot be distinguished from relapse on imaging alone. Furthermore, there are now multiple international early-phase trials exploring drug-target matches across a range of high-risk/relapsed paediatric tumours. Despite these advances, treatment at relapse in pre-irradiated patients is typically non-curative and focuses on providing life-prolonging and symptom-modifying care that is tailored to the needs and wishes of the individual and their family. Here, we describe the current understanding of prognostic factors at disease relapse such as principal molecular group, adverse molecular biology, and timing of relapse. We provide an overview of the clinical diagnostic process including signs and symptoms, staging investigations, and molecular pathology, followed by a summary of treatment modalities and considerations. Finally, we summarise future directions to progress understanding of treatment resistance and the biological mechanisms underpinning early therapy-refractory and relapsed disease. These initiatives include development of comprehensive and collaborative molecular profiling approaches at relapse, liquid biopsies such as cerebrospinal fluid (CSF) as a biomarker of minimal residual disease (MRD), modelling strategies, and the use of primary tumour material for real-time drug screening approaches.

Polish Multi-Institutional Study of Children with Ependymoma-Clinical Practice Outcomes in the Light of Prospective Trials

We performed a multi-institutional analysis of 74 children with ependymoma to evaluate to what extent the clinical outcome of prospective trials could be reproduced in routine practice. The evaluation of factors that correlated with outcome was performed with a log rank test and a Cox proportional-hazard model. Survival was estimated with the Kaplan–Meier method. The majority of patients had brain tumours (89%). All had surgery as primary treatment, with adjuvant radiotherapy (RTH) and chemotherapy (CTH) applied in 78% and 57%, respectively. Median follow-up was 80 months and 18 patients died. Five- and 10-year overall survival (OS) was 83% and 73%. Progression was observed in 32 patients, with local recurrence in 28 cases. The presence of metastases was a negative prognostic factor for OS. Five- and 10-year progression-free survival (PFS) was 55% and 40%, respectively. The best outcome in patients with non-disseminated brain tumours was observed when surgery was followed by RTH (+/−CTH afterwards; p = 0.0001). Children under 3 years old who received RTH in primary therapy had better PFS (p = 0.010). The best outcome of children with ependymoma is observed in patients who received radical surgery followed by RTH, and irradiation should not be omitted in younger patients. The role of CTH remains debatable.

Treatment and outcome of intracranial ependymoma after first relapse in AIEOP 2 nd protocol

BACKGROUND

More than 40% of patients with intracranial ependymoma need a salvage treatment within 5 years after diagnosis, and no standard treatment is available as yet. We report the outcome after first relapse of 64 patients treated within the 2 nd AIEOP protocol.

METHODS

We considered relapse sites and treatments ,i.e. various combinations of complete/incomplete surgery, if followed by standard or hypo-fractionated radiation(RT) ± chemotherapy(CT). Molecular analyses were available for 38/64 samples obtained at first diagnosis. Of the 64 cases, 55 were suitable for subsequent analyses.

RESULTS

The median follow-up was 147 months after diagnosis, 84 after first relapse, 5-year EFS/OS were 26.2%/30.8% (median EFS/OS 13/32 months) after relapse. For patients with a local relapse(LR), the 5-year cumulative incidence of second LRs was 51.6%, with a 5-year event-specific probability of being LR-free of 40.0%. Tumor site/grade, need for shunting, age above/below 3 years, molecular subgroup at diagnosis, had no influence on outcomes. Due to variation in the RT dose/fractionation used and the subgroup sizes it was not possible to assess the impact of the different RT modalities. Multivariable analyses identified completion of surgery, absence of symptoms at relapse, and female sex as prognostically favorable. Tumors with a 1q gain carried a higher cumulative incidence of dissemination after first relapse.

CONCLUSIONS

Survival after recurrence was significantly influenced by symptoms and completeness of surgery. Only a homogeneous protocol with well posed, randomized questions could clarify the numerous issues, orient salvage treatment and ameliorate prognosis for this group of patients.

Craniospinal irradiation as part of re-irradiation for children with recurrent medulloblastoma

BACKGROUND

Many studies have demonstrated in the last years that once medulloblastoma has recurred, the probability of regaining tumor control is poor despite salvage therapy. Although re-irradiation has an emerging role in other relapsed brain tumors, there is a lack of strong data on re-irradiation for medulloblastoma.

METHODS

This is a retrospective cohort study of patients aged 18 years or under, treated at least by a second course of external beam for recurrence medulloblastoma at Garrahan Hospital between 2009 and 2020. Twenty-four patients met eligibility criteria for inclusion. All patients received upfront radiotherapy as part of the curative-intent first radiotherapy, either craniospinal irradiation (CSI) followed by posterior fossa boost in 20 patients or focal posterior fossa radiation in 4 infants. The second course of radiation consisted of CSI in 15 and focal in 9. The 3-year post first failure OS (50% vs. 0%; p = 0.0010) was significantly better for children who received re-CSI compared to children who received focal re-irradiation. Similarly, the 3-year post-re-RT PFS (31% vs. 0%; p = 0.0005) and OS (25% vs. 0%; p = 0.0003) was significantly improved for patients who received re-CSI compared to patients who received focal re-irradiation. No symptomatic intratumoral haemorrhagic events or symptomatic radionecrosis were observed. Survivors fell within mild to moderate intellectual disability range, with a median IQ at last assessment of 58 (range 43-69).

CONCLUSIONS

Re-irradiation with CSI is a safe and effective treatment for children with relapsed medulloblastoma; improves disease control and survival compared with focal re-irradiation. However this approach carries a high neurocognitive cost.

Outcomes after first relapse of childhood intracranial ependymoma

BACKGROUND

Ependymoma is the third most common malignant CNS tumor in children. Despite multimodal therapy, prognosis of relapsed ependymoma remains poor. Approaches to therapy for relapsed ependymoma are varied. We present a single-institution retrospective review of the outcomes after first relapse of intracranial ependymoma in children.

PROCEDURE

We performed a retrospective, IRB-approved chart review of patients with recurrent intracranial ependymoma treated at Dana-Farber/Boston Children's Cancer and Blood Disorders Center from 1990 to 2019.

RESULTS

Thirty-four patients with relapsed intracranial ependymoma were identified. At initial diagnosis, 11 patients had supratentorial disease, 22 with posterior fossa disease and one with metastatic disease. Median time-to-first relapse was 14.9 months from initial diagnosis (range 1.4-52.5). Seven patients had metastatic disease at first relapse. Gross total resection (GTR) was associated with improved 5-year progression-free survival (PFS) relative to subtotal resection (STR) and no surgery (p = .005). Localized disease at relapse was associated with improved 5-year overall survival (OS) when compared to metastatic disease (p = .02). Irradiation at first relapse seemed to delay progression but was not associated with statistically prolonged PFS or OS. Tumor location, histology, and chromosomal 1q status did not impact outcome at first relapse, although available molecular data were limited making definitive conclusions difficult. Median time-to-second relapse was 10 months (range 0.7-124). Five-year PFS and OS after first relapse were 19.9% and 45.1%, respectively. Median PFS and OS were 10.0 and 52.5 months after first relapse, respectively.

CONCLUSIONS

Relapsed intracranial ependymoma has a poor prognosis despite multimodal therapy. Novel therapeutic strategies are desperately needed for this disease.

Local and systemic therapy of recurrent ependymoma in children and adolescents: short- and long-term results of the E-HIT-REZ 2005 study

BACKGROUND

Survival in recurrent ependymomas in children and adolescents mainly depends on the extent of resection. Studies on repeated radiotherapy and chemotherapy at relapse have shown conflicting results.

METHODS

Using data from the German multi-center E-HIT-REZ-2005 study, we examined the role of local therapy and the efficacy of chemotherapy with blockwise temozolomide (TMZ) in children and adolescents with recurrent ependymomas.

RESULTS

Fifty-three patients with a median age of 6.9 years (1.25-25.4) at first recurrence and a median follow-up time of 36 months (2-115) were recruited. Gross- and near-total resection (GTR/NTR) were achieved in 34 (64.2%) patients and associated with a markedly improved 5-year overall survival (OS) of 48.7% vs. 5.3% in less than GTR/NTR. Radiotherapy showed no improvement in OS following complete resection (OS: 70 (CI: 19.9-120.1) vs. 95 (CI: 20.7-169.4) months), but an advantage was found in less than GTR/NTR (OS: 22 (CI: 12.7-31.3) vs. 7 (CI: 0-15.8) months). Following the application of TMZ, disease progression was observed in most evaluable cases (18/21). A subsequent change to oral etoposide and trofosfamide showed no improved response. PF-A EPN were most abundant in relapses (n = 27). RELA-positive EPN (n = 5) had a 5-year OS of 0%.

CONCLUSION

The extent of resection is the most important predictor of survival at relapse. Focal re-irradiation is a useful approach if complete resection cannot be achieved, but no additional benefit was seen after GTR/NTR. Longer-term disease stabilization (>6 months) mediated by TMZ occurred in a small number of cases (14.3%).

Second series by the Italian Association of Pediatric Hematology and Oncology of children and adolescents with intracranial ependymoma: an integrated molecular and clinical characterization with a long-term follow-up

BACKGROUND

A prospective 2002-2014 study stratified 160 patients by resection extent and histological grade, reporting results in 2016. We re-analyzed the series after a median of 119 months, adding retrospectively patients' molecular features.

METHODS

Follow-up of all patients was updated. DNA copy number analysis and gene-fusion detection could be completed for 94/160 patients, methylation classification for 68.

RESULTS

Progression-free survival (PFS) and overall survival (OS) at 5/10 years were 66/58%, and 80/73%. Ten patients had late relapses (range 66-126 mo), surviving after relapse no longer than those relapsing earlier (0-5 y). On multivariable analysis a better PFS was associated with grade II tumor and complete surgery at diagnosis and/or at radiotherapy; female sex and complete resection showed a positive association with OS. Posterior fossa (PF) tumors scoring ≥0.80 on DNA methylation analysis were classified as PFA (n = 41) and PFB (n = 9). PFB patients had better PFS and OS. Eighteen/32 supratentorial tumors were classified as RELA, and 3 as other molecular entities (anaplastic PXA, LGG MYB, HGNET). RELA had no prognostic impact. Patients with 1q gain or cyclin-dependent kinase inhibitor 2A (CDKN2A) loss had worse outcomes, included significantly more patients >3 years old (P = 0.050) and cases of dissemination at relapse (P = 0.007).

CONCLUSIONS

Previously described prognostic factors were confirmed at 10-year follow-up. Late relapses occurred in 6.2% of patients. Specific molecular features may affect outcome: PFB patients had a very good prognosis; 1q gain and CDKN2A loss were associated with dissemination. To draw reliable conclusions, modern ependymoma trials need to combine diagnostics with molecular risk stratification and long-term follow-up.

Reirradiation practices for children with diffuse intrinsic pontine glioma

Background

Diffuse intrinsic pontine gliomas (DIPGs) are a leading cause of brain tumor deaths in children. Current standard of care includes focal radiation therapy (RT). Despite clinical improvement in most patients, the effect is temporary and median survival is less than 1 year. The use and benefit of reirradiation have been reported in progressive DIPG, yet standardized approaches are lacking. We conducted a survey to assess reirradiation practices for DIPG in North America.

Methods

A 14-question REDCap survey was disseminated to 396 North American physicians who care for children with CNS tumors.

Results

The response rate was 35%. Participants included radiation-oncologists (63%; 85/135) and pediatric oncologists/neuro-oncologists (37%; 50/135). Most physicians (62%) treated 1 to 5 DIPG patients per year, with 10% treating more than 10 patients per year. Reirradiation was considered a treatment option by 88% of respondents. Progressive disease and worsening clinical status were the most common reasons to consider reirradiation. The majority (84%) surveyed considered reirradiation a minimum of 6 months following initial RT. Doses varied, with median total dose of 2400 cGy (range, 1200-6000 cGy) and fraction size of 200 cGy (range, 100-900 cGy). Concurrent use of systemic agents with reirradiation was considered in 46%, including targeted agents (37%), biologics (36%), or immunotherapy (25%). One-time reirradiation was the most common practice (71%).

Conclusion

Although the vast majority of physicians consider reirradiation as a treatment for DIPG, total doses and fractionation varied. Further clinical trials are needed to determine the optimal radiation dose and fractionation for reirradiation in children with progressive DIPG.

Reevaluating surgery and re-irradiation for locally recurrent pediatric ependymoma—a multi-institutional study

Background

The goal of this study was to evaluate extent of surgical resection, and timing and volume of re-irradiation, on survival for children with locally recurrent ependymoma.

Methods

Children with locally recurrent ependymoma treated with a second course of fractionated radiotherapy (RT2) from 6 North American cancer centers were reviewed. The index time was from the start of RT2 unless otherwise stated.

Results

Thirty-five patients were included in the study. The median doses for first radiation (RT1) and RT2 were 55.8 and 54 Gy, respectively. Median follow-up time was 5.6 years. Median overall survival (OS) for all patients from RT2 was 65 months. Gross total resection (GTR) was performed in 46% and 66% of patients prior to RT1 and RT2, respectively. GTR prior to RT2 was independently associated with improved progression-free survival (PFS) for all patients (HR 0.41, P = 0.04), with an OS benefit (HR 0.26, P = 0.03) for infratentorial tumors. Median PFS was superior with craniospinal irradiation (CSI) RT2 (not reached) compared to focal RT2 (56.9 months; log-rank P = 0.03). All distant failures (except one) occurred after focal RT2. Local failures after focal RT2 were predominantly in patients with less than GTR pre-RT2.

Conclusions

Patients with locally recurrent pediatric ependymoma should be considered for re-treatment with repeat maximal safe resection (ideally GTR) and CSI re-irradiation, with careful discussion of the potential side effects of these treatments.

Surveillance imaging in pediatric ependymoma

BACKGROUND

Management of pediatric patients with ependymoma includes posttreatment surveillance imaging to identify asymptomatic recurrences. However, it is unclear whether early detection translates into improved survival. The objective was to determine whether detection of ependymoma relapses on surveillance imaging translates into a survival benefit.

PROCEDURE

Patients with ependymoma aged <21 years at diagnosis treated in the Nemours' Children's Health System between January 2003 and October 2016 underwent chart review. Relapsed patients' charts were assessed for details of initial therapy, surveillance imaging regimen, details of relapse including detection and therapy, and outcome. Median follow up of the entire cohort was 6.5 years from diagnosis and 3.5 years from relapse.

RESULTS

Ninety of 198 (45%) patients experienced relapse with 61 (68%) detected by surveillance imaging and 29 (32%) detected based on symptoms. Five-year OS in the surveillance group was 67% (confidence interval [CI] 55-82%, SE 0.1) versus 51% (CI 35-73%, SE 0.19) in the symptoms group (P = .073). From relapse, the 3-year OS in the surveillance group was 62% (CI 50-78%, SE 0.11) versus 55% (CI 39-76%, SE 0.17) in the symptoms group (P = .063) and the 3-year SPFS was 45% (CI 33-61%, SE 0.16) in the surveillance group versus 32% (CI 19-55%, SE 0.27) in the symptoms group (P = .028).

CONCLUSION

Surveillance imaging may identify recurrences in patients when they are more amenable to salvage therapy, resulting in superior 3-year SPFS, but given limited salvage options for children with recurrent ependymoma, the survival advantage of frequent surveillance imaging in asymptomatic patients remains ambiguous.

Extent of re-excision, sequence/timing of salvage re-irradiation, and disease-free interval impact upon clinical outcomes in recurrent/progressive ependymoma

PURPOSE

To report clinical outcomes of salvage re-irradiation (re-RT) in recurrent/progressive ependymoma.

METHODS

Medical records of patients treated with curative-intent re-RT as multi-modality management for recurrent/progressive ependymoma were analyzed retrospectively. The linear-quadratic model was used to provide estimates of biologically effective dose (BED) of irradiation using an α/β value of 2 for late CNS toxicity for each course of irradiation and summated to derive cumulative BED without correcting for the assumed recovery.

RESULTS

A total of 55 patients (median age 10 years at index diagnosis) treated with curative-intent re-RT between 2010 and 2018 were included. Median time to first recurrence was 29 months with an inter-quartile range (IQR) of 16-64 months. Majority (n = 46, 84%) of patients underwent surgical re-excision of recurrent disease. Median interval from first course of irradiation (RT1) to second course (RT2) was 35 months (IQR = 26-66 months) with a median re-RT dose of 54 Gy in 30 fractions (range 40-60 Gy), resulting in median cumulative equivalent dose in 2 Gy fraction (EQD2) of 106.2 Gy (range 92.4-117.6 Gy). Volume of re-RT was based on location and pattern of relapse, comprising uni-focal (n = 49, 89%), multi-focal (n = 3, 5.5%), or craniospinal irradiation (CSI) in 3 (5.5%) patients respectively. Thirty-six (66%) patients received platinum-based salvage chemotherapy either before or after RT2. At a median follow up of 37 months (range 6-80 months), the Kaplan-Meier estimates of 3-year progression-free survival (PFS) and overall survival (OS) for the entire study cohort were 40% and 51% respectively. Gross total resection at recurrence; early salvage re-RT (prior to chemotherapy, if any); and longer (> 2 years) disease-free interval (DFI) were associated with better survival outcomes. Salvage re-RT was generally well tolerated with only 3 (5.5%) patients developing symptomatic radiation necrosis necessitating corticosteroids.

CONCLUSION

Extent of re-excision, sequence/timing of re-RT, and DFI impact upon outcomes in curative-intent, multi-modality salvage therapy for recurrent ependymoma.

Repeat irradiation for children with supratentorial high-grade glioma

BACKGROUND

There are very few studies about the role of repeat irradiation (RT2) for children with recurrent supratentorial high-grade glioma (HGG). It was the aim of this study to assess the effectiveness and safety of RT2 in this population.

PROCEDURE

This was a retrospective cohort study of 40 children age 18 years and under with recurrent supratentorial HGG who had received at least one course of RT. In-field reirradiation volumes included focal or whole brain RT, with doses ranging from 30 to 54 Gy. The primary endpoint was overall survival (OS) from the first day of RT2.

RESULTS

Fourteen patients underwent RT2. The median survival of these patients was 6.5 months. Patients with ≥12 months elapsed time between RT1 and RT2 experienced longer OS than patients who had < 12 months (P = 0.009). There was no difference in OS between patients with or without germline mutations (e.g., Lynch, Li-Fraumeni, or constitutional mismatch-repair deficiency, P = 0.20). Ten patients received RT2 that overlapped with RT1 volumes for locally recurrent disease. Of this group, 80% experienced clinical benefit from in-field RT2, defined as clinical/radiologic response or stable disease. Ninety-three percent completed the prescribed course of RT2, with one patient developing grade 3 radiation necrosis four months after RT2. When compared with 26 patients who were not offered reirradiation, those selected for RT2 had improved median survival from the time of first disease progression (9.4 vs 3.8 months, P = 0.005).

CONCLUSIONS

Reirradiation for children with recurrent supratentorial HGG is a safe, effective treatment that provides short-term disease control.

Current and Emerging Methods of Management of Ependymoma

PURPOSE OF REVIEW

This review discusses the evidence base behind current and emerging strategies of management of intracranial and spinal ependymomas in children, with a particular focus on aspects of surgical techniques, challenges and complications.

RECENT FINDINGS

The cornerstone of management remains maximal safe resective surgery, which has repeatedly been shown to correlate with improved survival. This is followed by focal conformal radiotherapy, although good results using proton beam therapy, with the potential for diminished side effects, are emerging. The role of chemotherapy remains largely unproven for paediatric ependymoma. Despite optimal management strategies, many children with ependymoma suffer from tumour recurrence. The standard of care for paediatric ependymoma comprises surgery and radiotherapy. Results of ongoing clinical trials will help shape its management in order to leverage our increasingly sophisticated understanding of the genetic drivers behind these tumours into survival benefit for this challenging group of patients.