Treatment options in childhood pontine gliomas

Clinical outcome, radiological findings, and genetic features of IDH-mutant brainstem glioma in adults

BACKGROUND

With the recent advent of genetic testing, IDH-mutant glioma has been found among adult brainstem gliomas. However, the clinical outcome and prognosis of IDH-mutant brainstem gliomas in adults have not been elucidated. This study aimed to investigate the clinical outcome, radiological findings, and genetic features of adult patients with IDH-mutant diffuse brainstem gliomas.

METHODS

Data from adult patients with brainstem glioma at Hokkaido University Hospital between 2006 and 2022 were retrospectively analyzed. Patient characteristics, treatment methods, genetic features, and prognosis were evaluated.

RESULTS

Of 12 patients with brainstem glioma with proven histopathology, 4 were identified with IDH mutation. All patients underwent local radiotherapy with 54 Gray in 27 fractions combined with chemotherapy with temozolomide. Three patients had IDH1 R132H mutation and one had IDH2 R172G mutation. The median progression-free survival and overall survival were 68.4 months and 85.2 months, respectively, longer than that for IDH-wildtype gliomas (5.6 months and 12.0 months, respectively). At the time of initial onset, contrast-enhanced lesions were observed in two of the four cases in magnetic resonance imaging.

CONCLUSION

As some adult brainstem gliomas have IDH mutations, and a clearly different prognosis from those with IDH-wildtype, biopsies are proactively considered to confirm the genotype.

Brain stem tumors in children less than 3 months: Clinical and radiologic findings of a rare disease

PURPOSE

Brain stem tumors in children < 3 months at diagnosis are extremely rare. Our aim is to study a retrospective cohort to improve the understanding of the disease course and guide patient management.

METHODS

This is a multicenter retrospective analysis across the European Society for Pediatric Oncology SIOP-E HGG/DIPG Working Group linked centers, including patients with a brainstem tumor diagnosed between 2009 and 2020 and aged < 3 months at diagnosis. Clinical data were collected, and imaging characteristics were analyzed blindly and independently by two neuroradiologists.

RESULTS

Five cases were identified. No patient received any therapy. The epicenter of two tumors was in the medulla oblongata alone and in the medulla oblongata and the pons in three. For patients with tumor in equal parts in the medulla oblongata and the pons (n = 3), the extension at diagnosis involved the spinal cord; for the two patients with the tumor epicenter in the medulla oblongata alone (n = 2), the extension at diagnosis included the pons (n = 2) and the spinal cord (n = 1). Biopsy was performed in one patient identifying a pilocytic astrocytoma. Two patients died. In one patient, autopsy revealed a high-grade glioma (case 3). Three survivors showed either spontaneous tumor regression (n = 2) or stable disease (n = 1). Survivors were followed up for 10, 7, and 0.6 years, respectively. One case had the typical imaging characteristics of a dorsal exophytic low-grade glioma.

CONCLUSIONS

No patient fulfilled the radiologic criteria defining a high-grade glioma. Central neuroradiological review and biopsy may provide useful information regarding the patient management.

11C-methionine PET imaging characteristics in children with diffuse intrinsic pontine gliomas and relationship to survival and H3 K27M mutation status

PURPOSE

This study aimed to describe ¹¹C-methionine (¹¹C-MET) PET imaging characteristics in patients with paediatric diffuse intrinsic pontine glioma (DIPG) and correlate them with survival and H3 K27M mutation status.

METHODS

We retrospectively analysed 98 children newly diagnosed with DIPG who underwent ¹¹C-MET PET. PET imaging characteristics evaluated included uptake intensity, uniformity, metabolic tumour volume (MTV), and total lesion methionine uptake (TLMU). The maximum, mean, and peak of the tumour-to-background ratio (TBR), calculated as the corresponding standardised uptake values (SUV) divided by the mean reference value, were also recorded. The associations between the PET imaging characteristics and clinical outcomes in terms of progression-free survival (PFS) and overall survival (OS) and H3 K27M mutation status were assessed, respectively.

RESULTS

In univariate analysis, imaging characteristics significantly associated with shorter PFS and OS included a higher uniformity grade, higher TBRs, larger MTV, and higher TLMU. In multivariate analysis, larger MTV at diagnosis, shorter symptom duration, and no treatment were significantly correlated with shorter PFS and OS. The PET imaging features were not correlated with H3 K27M mutation status.

CONCLUSION

Although several imaging features were significantly associated with PFS and OS, only MTV, indicating the size of the active tumour, was identified as a strong independent prognostic factor.

Suggestions for Escaping the Dark Ages for Pediatric Diffuse Intrinsic Pontine Glioma Treated with Radiotherapy: Analysis of Prognostic Factors from the National Multicenter Study

PURPOSE

This multicenter retrospective study aimed to investigate clinical, radiologic, and treatment-related factors affecting survival in patients with newly diagnosed diffuse intrinsic pontine glioma (DIPG) treated with radiotherapy.

MATERIALS AND METHODS

Patients aged <30 years who underwent radiotherapy as an initial treatment for DIPG between 2000 and 2018 were included; patients who did not undergo magnetic resonance imaging at diagnosis and those with pathologically diagnosed grade I glioma were excluded. We examined medical records of 162 patients collected from 10 participating centers in Korea. The patients' clinical, radiological, molecular, and histopathologic characteristics, and treatment responses were evaluated to identify the prognosticators for DIPG and estimate survival outcomes.

RESULTS

The median follow-up period was 10.8 months (interquartile range, 7.5 to 18.1). The 1- and 2-year overall survival (OS) rates were 53.5% and 19.0%, respectively, with a median OS of 13.1 months. Long-term survival rate (≥ 2 years) was 16.7%, and median OS was 43.6 months. Age (< 10 years), poor performance status, treatment before 2010, and post-radiotherapy necrosis were independently associated with poor OS in multivariate analysis. In patients with increased post-radiotherapy necrosis, the median OS estimates were 13.3 months and 11.4 months with and without bevacizumab, respectively (p=0.138).

CONCLUSION

Therapeutic strategy for DIPG has remained unchanged over time, and the associated prognosis remains poor. Our findings suggest that appropriate efforts are needed to reduce the occurrence of post-radiotherapy necrosis. Further well-designed clinical trials are recommended to improve the poor prognosis observed in DIPG patients.

Pediatric Diffuse Midline Gliomas: An Unfinished Puzzle

Diffuse midline glioma (DMG) is a heterogeneous group of aggressive pediatric brain tumors with a fatal prognosis. The biological hallmark in the major part of the cases is H3K27 alteration. Prognosis remains poor, with median survival ranging from 9 to 12 months from diagnosis. Clinical and radiological prognostic factors only partially change the progression-free survival but they do not improve the overall survival. Despite efforts, there is currently no curative therapy for DMG. Radiotherapy remains the standard treatment with only transitory benefits. No chemotherapeutic regimens were found to significantly improve the prognosis. In the new era of a deeper integration between histological and molecular findings, potential new approaches are currently under investigation. The entire international scientific community is trying to target DMG on different aspects. The therapeutic strategies involve targeting epigenetic alterations, such as methylation and acetylation status, as well as identifying new molecular pathways that regulate oncogenic proliferation; immunotherapy approaches too are an interesting point of research in the oncology field, and the possibility of driving the immune system against tumor cells has currently been evaluated in several clinical trials, with promising preliminary results. Moreover, thanks to nanotechnology amelioration, the development of innovative delivery approaches to overcross a hostile tumor microenvironment and an almost intact blood-brain barrier could potentially change tumor responses to different treatments. In this review, we provide a comprehensive overview of available and potential new treatments that are worldwide under investigation, with the intent that patient- and tumor-specific treatment could change the biological inauspicious history of this disease.

Characteristics of children ≤36 months of age with DIPG: A report from the international DIPG registry

BACKGROUND

Children ≤36 months with diffuse intrinsic pontine glioma (DIPG) have increased long-term survival (LTS, overall survival (OS) ≥24 months). Understanding distinguishing characteristics in this population is critical to improving outcomes.

METHODS

Patients ≤36 months at diagnosis enrolled on the International DIPG Registry (IDIPGR) with central imaging confirmation were included. Presentation, clinical course, imaging, pathology and molecular findings were analyzed.

RESULTS

Among 1183 patients in IDIPGR, 40 were eligible (median age: 29 months). Median OS was 15 months. Twelve patients (30%) were LTS, 3 (7.5%) very long-term survivors ≥5 years. Among 8 untreated patients, median OS was 2 months. Patients enrolled in the registry but excluded from our study by central radiology review or tissue diagnosis had median OS of 7 months. All but 1 LTS received radiation. Among 32 treated patients, 1-, 2-, 3-, and 5-year OS rates were 68.8%, 31.2%, 15.6% and 12.5%, respectively. LTS had longer duration of presenting symptoms (P = .018). No imaging features were predictive of outcome. Tissue and genomic data were available in 18 (45%) and 10 patients, respectively. Among 9 with known H3K27M status, 6 had a mutation.

CONCLUSIONS

Children ≤36 months demonstrated significantly more LTS, with an improved median OS of 15 months; 92% of LTS received radiation. Median OS in untreated children was 2 months, compared to 17 months for treated children. LTS had longer duration of symptoms. Excluded patients demonstrated a lower OS, contradicting the hypothesis that children ≤36 months with DIPG show improved outcomes due to misdiagnosis.

Intraarterial delivery of bevacizumab and cetuximab utilizing blood-brain barrier disruption in children with high-grade glioma and diffuse intrinsic pontine glioma: results of a phase I trial

OBJECTIVE

Delivery of drugs intraarterially to brain tumors has been demonstrated in adults. In this study, the authors initiated a phase I trial of superselective intraarterial cerebral infusion (SIACI) of bevacizumab and cetuximab in pediatric patients with refractory high-grade glioma (diffuse intrinsic pontine glioma [DIPG] and glioblastoma) to determine the safety and efficacy in this population.

METHODS

SIACI was used to deliver mannitol (12.5 ml of 20% mannitol) to disrupt the blood-brain barrier (BBB), followed by bevacizumab (15 mg/kg) and cetuximab (200 mg/m2) to target VEGF and EGFR, respectively. Patients with brainstem tumors had a balloon inflated in the distal basilar artery during mannitol infusion.

RESULTS

Thirteen patients were treated (10 with DIPG and 3 with high-grade glioma). Toxicities included grade I epistaxis (2 patients) and grade I rash (2 patients). There were no dose-limiting toxicities. Of the 10 symptomatic patients, 6 exhibited subjective improvement; 92% showed decreased enhancement on day 1 posttreatment MRI. Of 10 patients who underwent MRI at 1 month, 5 had progressive disease and 5 had stable disease on FLAIR, whereas contrast-enhanced scans demonstrated progressive disease in 4 patients, stable disease in 2, partial response in 2, and complete response in 1. The mean overall survival for the 10 DIPG patients was 519 days (17.3 months), with a mean posttreatment survival of 214.8 days (7.2 months).

CONCLUSIONS

SIACI of bevacizumab and cetuximab was well tolerated in all 13 children. The authors' results demonstrate safety of this method and warrant further study to determine efficacy. As molecular targets are clarified, novel means of bypassing the BBB, such as intraarterial therapy and convection-enhanced delivery, become more critical. Clinical trial registration no.: NCT01884740 (clinicaltrials.gov).

MR imaging features of diffuse intrinsic pontine glioma and relationship to overall survival: report from the International DIPG Registry

BACKGROUND

This study describes imaging features of diffuse intrinsic pontine glioma (DIPG) and correlates with overall survival (OS) and histone mutation status in the International DIPG Registry (IDIPGR).

METHODS

Four hundred cases submitted to the IDIPGR with a local diagnosis of DIPG and baseline MRI were evaluated by consensus review of 2 neuroradiologists; 43 cases were excluded (inadequate imaging or alternative diagnoses). Agreement between reviewers, association with histone status, and univariable and multivariable analyses relative to OS were assessed.

RESULTS

On univariable analysis imaging features significantly associated with worse OS included: extrapontine extension, larger size, enhancement, necrosis, diffusion restriction, and distant disease. On central review, 9.5% of patients were considered not to have DIPG. There was moderate mean agreement of MRI features between reviewers. On multivariable analysis, chemotherapy, age, and distant disease were predictors of OS. There was no difference in OS between wild-type and H3 mutated cases. The only imaging feature associated with histone status was the presence of ill-defined signal infiltrating pontine fibers.

CONCLUSIONS

Baseline imaging features are assessed in the IDIPGR. There was a 9.5% discordance in DIPG diagnosis between local and central review, demonstrating need for central imaging confirmation for prospective trials. Although several imaging features were significantly associated with OS (univariable), only age and distant disease were significant on multivariable analyses. There was limited association of imaging features with histone mutation status, although numbers are small and evaluation exploratory.

Tumor Response Assessment in Diffuse Intrinsic Pontine Glioma: Comparison of Semiautomated Volumetric, Semiautomated Linear, and Manual Linear Tumor Measurement Strategies

BACKGROUND AND PURPOSE

2D measurements of diffuse intrinsic pontine gliomas are limited by variability, and volumetric response criteria are poorly defined. Semiautomated 2D measurements may improve consistency; however, the impact on tumor response assessments is unknown. The purpose of this study was to compare manual 2D, semiautomated 2D, and volumetric measurement strategies for diffuse intrinsic pontine gliomas.

MATERIALS AND METHODS

This study evaluated patients with diffuse intrinsic pontine gliomas through a Phase I/II trial (NCT02607124). Clinical 2D cross-product values were derived from manual linear measurements (cross-product = long axis × short axis). By means of dedicated software (mint Lesion), tumor margins were traced and maximum cross-product and tumor volume were automatically derived. Correlation and bias between methods were assessed, and response assessment per measurement strategy was reported.

RESULTS

Ten patients (median age, 7.6 years) underwent 58 MR imaging examinations. Correlation and mean bias (95% limits) of percentage change in tumor size from prior examinations were the following: clinical and semiautomated cross-product, r = 0.36, -1.5% (-59.9%, 56.8%); clinical cross-product and volume, r = 0.61, -2.1% (-52.0%, 47.8%); and semiautomated cross-product and volume, r = 0.79, 0.6% (-39.3%, 38.1%). Stable disease, progressive disease, and partial response rates per measurement strategy were the following: clinical cross-product, 82%, 18%, 0%; semiautomated cross-product, 54%, 42%, 4%; and volume, 50%, 46%, 4%, respectively.

CONCLUSIONS

Manual 2D cross-product measurements may underestimate tumor size and disease progression compared with semiautomated 2D and volumetric measurements.

Predicting outcome in childhood diffuse midline gliomas using magnetic resonance imaging based texture analysis

BACKGROUND

Diffuse midline gliomas (DMG) are aggressive brain tumours, previously known as diffuse intrinsic pontine gliomas (DIPG), with 10% overall survival (OS) at 18 months. Predicting OS will help refine treatment strategy in this patient group. MRI based texture analysis (MRTA) is novel image analysis technique that provides objective information about spatial arrangement of MRI signal intensity (heterogeneity) and has potential to be imaging biomarker.

OBJECTIVES

To investigate MRTA in predicting OS in childhood DMG.

METHODS

Retrospective study of patients diagnosed with DMG, based on radiological features, treated at our institution 2007-2017. MRIs were acquired at diagnosis and 6 weeks after radiotherapy (54Gy in 30 fractions). MRTA was performed using commercial available TexRAD research software on T2W sequence and Apparent Diffusion Coefficient (ADC) maps encapsulating tumour in the largest single axial plane. MRTA comprised filtration-histogram technique using statistical and histogram metrics for quantification of texture. Kaplan-Meier survival analysis determined association of MRI texture parameters with OS.

RESULTS

In all, 32 children 2-14 years (median 7 years) were included. MRTA was undertaken on T2W (n=32) and ADC (n=22). T2W-MRTA parameters were better at prognosticating than ADC-MRTA. Children with homogenous tumour texture, at medium scale on diagnostic T2W MRI, had worse prognosis (Mean of Positive Pixels (MPP): P=0.005, mean: P=0.009, SD: P=0.011, kurtosis: P=0.037, entropy: P=0.042). Best predictor MPP was able to stratify patients into poor and good prognostic groups with median survival of 7.5 months versus 17.5 months, respectively.

CONCLUSIONS

DMG with more homogeneous texture on diagnostic MRI is associated with worse prognosis. Texture parameter MPP is the most predictive marker of OS in childhood DMG.

Personalized Treatment of H3K27M-Mutant Pediatric Diffuse Gliomas Provides Improved Therapeutic Opportunities

Diffuse gliomas with K27M histone mutations (H3K27M glioma) are generally characterized by a fatal prognosis, particularly affecting the pediatric population. Based on the molecular heterogeneity observed in this tumor type, personalized treatment is considered to substantially improve therapeutic options. Therefore, clinical evidence for therapy, guided by comprehensive molecular profiling, is urgently required. In this study, we analyzed feasibility and clinical outcomes in a cohort of 12 H3K27M glioma cases treated at two centers. Patients were subjected to personalized treatment either at primary diagnosis or disease progression and received backbone therapy including focal irradiation. Molecular analyses included whole-exome sequencing of tumor and germline DNA, RNA-sequencing, and transcriptomic profiling. Patients were monitored with regular clinical as well as radiological follow-up. In one case, liquid biopsy of cerebrospinal fluid (CSF) was used. Analyses could be completed in 83% (10/12) and subsequent personalized treatment for one or more additional pharmacological therapies could be recommended in 90% (9/10). Personalized treatment included inhibition of the PI3K/AKT/mTOR pathway (3/9), MAPK signaling (2/9), immunotherapy (2/9), receptor tyrosine kinase inhibition (2/9), and retinoic receptor agonist (1/9). The overall response rate within the cohort was 78% (7/9) including one complete remission, three partial responses, and three stable diseases. Sustained responses lasting for 28 to 150 weeks were observed for cases with PIK3CA mutations treated with either miltefosine or everolimus and additional treatment with trametinib/dabrafenib in a case with BRAFV600E mutation. Immune checkpoint inhibitor treatment of a case with increased tumor mutational burden (TMB) resulted in complete remission lasting 40 weeks. Median time to progression was 29 weeks. Median overall survival (OS) in the personalized treatment cohort was 16.5 months. Last, we compared OS to a control cohort (n = 9) showing a median OS of 17.5 months. No significant difference between the cohorts could be detected, but long-term survivors (>2 years) were only present in the personalized treatment cohort. Taken together, we present the first evidence of clinical efficacy and an improved patient outcome through a personalized approach at least in selected cases of H3K27M glioma.

Diffuse Intrinsic Pontine Glioma: From Diagnosis to Next-Generation Clinical Trials

PURPOSE OF REVIEW

This review of diffuse intrinsic pontine glioma (DIPG) provides clinical background, a systematic approach to diagnosis and initial care, and synthesizes historical, modern, and future directions for treatment. We present evidence supporting neurosurgical biopsy, early palliative care involvement, limitation of glucocorticoid use, and the leveraging of preclinical DIPG models as a pipeline to next-generation clinical trials.

RECENT FINDINGS

New molecular understanding of pediatric high-grade gliomas has led to the reclassification of DIPG as one member of a family of diffuse gliomas occurring in the midline of the central nervous system that exhibit pathognomonic mutations in genes encoding histone 3 (H3 K27M). DIPG remains a clinically relevant term, though diagnostically the 80% of DIPG cases that exhibit the H3 K27M mutation have been reclassified as diffuse midline glioma, H3 K27M-mutant. Re-irradiation has been shown to be well-tolerated and of potential benefit. Epigenetic targeting of transcriptional dependencies in preclinical models is fueling molecularly targeted clinical trials. Chimeric antigen receptor T cell immunotherapy has also demonstrated efficacy in preclinical models and provides a promising new clinical strategy. DIPG is a universally fatal, epigenetically driven tumor of the pons that is considered part of a broader class of diffuse midline gliomas sharing H3 K27M mutations. Radiation remains the standard of care, single-agent temozolomide is not recommended, and glucocorticoids should be used only sparingly. A rapid evolution of understanding in the chromatin, signaling, and immunological biology of DIPG may soon result in clinical breakthroughs.

Clinical, Radiologic, Pathologic, and Molecular Characteristics of Long-Term Survivors of Diffuse Intrinsic Pontine Glioma (DIPG): A Collaborative Report From the International and European Society for Pediatric Oncology DIPG Registries

Purpose Diffuse intrinsic pontine glioma (DIPG) is a brainstem malignancy with a median survival of < 1 year. The International and European Society for Pediatric Oncology DIPG Registries collaborated to compare clinical, radiologic, and histomolecular characteristics between short-term survivors (STSs) and long-term survivors (LTSs). Materials and Methods Data abstracted from registry databases included patients from North America, Australia, Germany, Austria, Switzerland, the Netherlands, Italy, France, the United Kingdom, and Croatia. Results Among 1,130 pediatric and young adults with radiographically confirmed DIPG, 122 (11%) were excluded. Of the 1,008 remaining patients, 101 (10%) were LTSs (survival ≥ 2 years). Median survival time was 11 months (interquartile range, 7.5 to 16 months), and 1-, 2-, 3-, 4-, and 5-year survival rates were 42.3% (95% CI, 38.1% to 44.1%), 9.6% (95% CI, 7.8% to 11.3%), 4.3% (95% CI, 3.2% to 5.8%), 3.2% (95% CI, 2.4% to 4.6%), and 2.2% (95% CI, 1.4% to 3.4%), respectively. LTSs, compared with STSs, more commonly presented at age < 3 or > 10 years (11% v 3% and 33% v 23%, respectively; P < .001) and with longer symptom duration ( P < .001). STSs, compared with LTSs, more commonly presented with cranial nerve palsy (83% v 73%, respectively; P = .008), ring enhancement (38% v 23%, respectively; P = .007), necrosis (42% v 26%, respectively; P = .009), and extrapontine extension (92% v 86%, respectively; P = .04). LTSs more commonly received systemic therapy at diagnosis (88% v 75% for STSs; P = .005). Biopsies and autopsies were performed in 299 patients (30%) and 77 patients (10%), respectively; 181 tumors (48%) were molecularly characterized. LTSs were more likely to harbor a HIST1H3B mutation (odds ratio, 1.28; 95% CI, 1.1 to 1.5; P = .002). Conclusion We report clinical, radiologic, and molecular factors that correlate with survival in children and young adults with DIPG, which are important for risk stratification in future clinical trials.

A phase I/II study of gemcitabine during radiotherapy in children with newly diagnosed diffuse intrinsic pontine glioma

The purpose of this phase I/II, open-label, single-arm trial is to investigate the safety, tolerability, maximum tolerated dose and preliminary efficacy of the potential radiosensitizer gemcitabine, administered concomitantly to radiotherapy, in children with newly diagnosed diffuse intrinsic pontine glioma (DIPG). Six doses of weekly gemcitabine were administered intravenously, concomitantly to 6 weeks of hyperfractionated radiotherapy. Successive cohorts received increasing doses of 140, 175 and 200 mg/m² gemcitabine, respectively, following a 3 + 3 dose-escalation schedule without expansion cohort. Dose-limiting toxicities (DLT) were monitored during treatment period. Clinical response was assessed using predefined case report forms and radiological response was assessed using the modified RANO criteria. Quality of life (QoL) was assessed using PedsQL questionnaires. Between June 2012 and December 2016, nine patients were enrolled. Treatment was well tolerated, and no DLTs were observed up to the maximum dose of 200 mg/m². All patients experienced reduction of tumor-related symptoms. QoL tended to improve during treatment. PFS and MOS were 4.8 months (95% CI 4.0–5.7) and 8.7 months (95% CI 7.0–10.4). Classifying patients according to the recently developed DIPG survival prediction model, intermediate risk patients (n = 4), showed a PFS and MOS of 6.4 and 12.4 months, respectively, versus a PFS and MOS of 4.5 and 8.1 months, respectively, in high risk patient (n = 5). Gemcitabine up to 200 mg/m²/once weekly, added to radiotherapy, is safe and well tolerated in children with newly diagnosed DIPG. PFS and MOS were not significantly different from literature.

Long-term survival of an infant with diffuse brainstem lesion diagnosed by prenatal MRI: a case report and review of the literature

BACKGROUND

We describe a unique case of expansive diffuse brainstem lesion diagnosed prenatally by magnetic resonance imaging (MRI) with long-term survival. Findings of fetal and postpartum MRI were highly consistent with the characteristics of diffuse brainstem glioma.

METHODS

Diagnosis was based on the features of MRI, and histopathology was not confirmed by biopsy. Although the prognosis of diffuse brainstem tumor is usually poor, this child was asymptomatic at birth and the neurological condition is still normal at 4 years of age without any treatment.

RESULTS

During routine imaging follow-up, diameters of the expansion have remained stable, while the size of the lesion compared to the posterior fossa size has diminished. In addition to brainstem tumor, a skin lesion of the back was observed and MRI of the thoracic spine showed a large asymptomatic extradural cystic lesion suggesting an arachnoid cyst. The pontine tumor of this infant, in agreement with a few previously reported cases, suggests a subgroup of beneficial outcome of expansive diffuse brainstem lesions, particularly in the neonatal period.

DISCUSSION

In this article, we discuss the prognosis and characteristics of pediatric brainstem tumors and differential diagnosis of neonatal brainstem lesions.

Focal brainstem gliomas. Advances in intra-operative management

Improved neuronavigation guidance as well as intraoperative imaging and neurophysiologic monitoring technologies have enhanced the ability of neurosurgeons to resect focal brainstem gliomas. In contrast, diffuse brainstem gliomas are considered to be inoperable lesions. This article is a continuation of an article that discussed brainstem glioma diagnostics, imaging, and classification. Here, we address open surgical treatment of and approaches to focal, dorsally exophytic, and cervicomedullary brainstem gliomas. Intraoperative neuronavigation, intraoperative neurophysiologic monitoring, as well as intraoperative imaging are discussed as adjunctive measures to help render these procedures safer, more acute, and closer to achieving surgical goals.

Postnatal growth of the human pons: a morphometric and immunohistochemical analysis

Despite its critical importance to global brain function, the postnatal development of the human pons remains poorly understood. In the present study, we first performed magnetic resonance imaging (MRI)-based morphometric analyses of the postnatal human pons (0-18 years; n = 6-14/timepoint). Pons volume increased 6-fold from birth to 5 years, followed by continued slower growth throughout childhood. The observed growth was primarily due to expansion of the basis pontis. T2-based MRI analysis suggests that this growth is linked to increased myelination, and histological analysis of myelin basic protein in human postmortem specimens confirmed a dramatic increase in myelination during infancy. Analysis of cellular proliferation revealed many Ki67(+) cells during the first 7 months of life, particularly during the first month, where proliferation was increased in the basis relative to tegmentum. The majority of proliferative cells in the postnatal pons expressed the transcription factor Olig2, suggesting an oligodendrocyte lineage. The proportion of proliferating cells that were Olig2(+) was similar through the first 7 months of life and between basis and tegmentum. The number of Ki67(+) cells declined dramatically from birth to 7 months and further decreased by 3 years, with a small number of Ki67(+) cells observed throughout childhood. In addition, two populations of vimentin/nestin-expressing cells were identified: a dorsal group near the ventricular surface, which persists throughout childhood, and a parenchymal population that diminishes by 7 months and was not evident later in childhood. Together, our data reveal remarkable postnatal growth in the ventral pons, particularly during infancy when cells are most proliferative and myelination increases.

Survival prediction model of children with diffuse intrinsic pontine glioma based on clinical and radiological criteria

BACKGROUND

Although diffuse intrinsic pontine glioma (DIPG) carries the worst prognosis of all pediatric brain tumors, studies on prognostic factors in DIPG are sparse. To control for confounding variables in DIPG studies, which generally include relatively small patient numbers, a survival prediction tool is needed.

METHODS

A multicenter retrospective cohort study was performed in the Netherlands, the UK, and Germany with central review of clinical data and MRI scans of children with DIPG. Cox proportional hazards with backward regression was used to select prognostic variables (P < .05) to predict the accumulated 12-month risk of death. These predictors were transformed into a practical risk score. The model's performance was validated by bootstrapping techniques.

RESULTS

A total of 316 patients were included. The median overall survival was 10 months. Multivariate Cox analysis yielded 5 prognostic variables of which the coefficients were included in the risk score. Age ≤3 years, longer symptom duration at diagnosis, and use of oral and intravenous chemotherapy were favorable predictors, while ring enhancement on MRI at diagnosis was an unfavorable predictor. With increasing risk score categories, overall survival decreased significantly. The model can distinguish between patients with very short, average, and increased overall survival (medians of 7.0, 9.7, and 13.7 mo, respectively). The area under the receiver operating characteristic curve was 0.68.

CONCLUSIONS

We developed a DIPG survival prediction tool that can be used to predict the outcome of patients and for stratification in trials. Validation of the model is needed in a prospective cohort.

Antigen-specific immune responses and clinical outcome after vaccination with glioma-associated antigen peptides and polyinosinic-polycytidylic acid stabilized by lysine and carboxymethylcellulose in children with newly diagnosed malignant brainstem and nonbrainstem gliomas

PURPOSE

Diffuse brainstem gliomas (BSGs) and other high-grade gliomas (HGGs) of childhood carry a dismal prognosis despite current treatments, and new therapies are needed. Having identified a series of glioma-associated antigens (GAAs) commonly overexpressed in pediatric gliomas, we initiated a pilot study of subcutaneous vaccinations with GAA epitope peptides in HLA-A2-positive children with newly diagnosed BSG and HGG.

PATIENTS AND METHODS

GAAs were EphA2, interleukin-13 receptor alpha 2 (IL-13Rα2), and survivin, and their peptide epitopes were emulsified in Montanide-ISA-51 and given every 3 weeks with intramuscular polyinosinic-polycytidylic acid stabilized by lysine and carboxymethylcellulose for eight courses, followed by booster vaccinations every 6 weeks. Primary end points were safety and T-cell responses against vaccine-targeted GAA epitopes. Treatment response was evaluated clinically and by magnetic resonance imaging.

RESULTS

Twenty-six children were enrolled, 14 with newly diagnosed BSG treated with irradiation and 12 with newly diagnosed BSG or HGG treated with irradiation and concurrent chemotherapy. No dose-limiting non-CNS toxicity was encountered. Five children had symptomatic pseudoprogression, which responded to dexamethasone and was associated with prolonged survival. Only two patients had progressive disease during the first two vaccine courses; 19 had stable disease, two had partial responses, one had a minor response, and two had prolonged disease-free status after surgery. Enzyme-linked immunosorbent spot analysis in 21 children showed positive anti-GAA immune responses in 13: to IL-13Rα2 in 10, EphA2 in 11, and survivin in three.

CONCLUSION

GAA peptide vaccination in children with gliomas is generally well tolerated and has preliminary evidence of immunologic and clinical responses. Careful monitoring and management of pseudoprogression is essential.

Management of diffuse pontine gliomas in children: recent developments

The prognosis for children with diffuse intrinsic pontine gliomas (DIPGs) is dismal. Although DIPGs constitute only 10-15 % of all pediatric brain tumors, they are the main cause of death in this group with a median survival of less than 12 months. Standard therapy involves radiotherapy, which produces transient neurologic improvement. Despite several clinical trials having been conducted, including trials on targeted agents to assess their efficacy, there is no clear improvement in prognosis. However, knowledge of DIPG biology is increasing, mainly as a result of research using biopsy and autopsy samples. In this review, we discuss recent studies in which systemic therapy was administered prior to, concomitantly with, or after radiotherapy. The discussion also includes novel therapeutic options in DIPG. Continuing multimodal and multitargeted therapies might lead to an improvement in the dismal prognosis of the disease.

Clinico-radiologic characteristics of long-term survivors of diffuse intrinsic pontine glioma

Diffuse intrinsic pontine glioma (DIPG) is the deadliest central nervous system tumor in children. The survival of affected children has remained poor despite treatment with radiation therapy (RT) with or without chemotherapy. We reviewed the medical records of all surviving patients with DIPG treated at our institution between October 1, 1992 and May 31, 2011. Blinded central radiologic review of the magnetic resonance imaging at diagnosis of all surviving patients and 15 controls with DIPG was performed. All surviving patients underwent neurocognitive assessment during follow-up. Five (2.6 %) of 191 patients treated during the study period were surviving at a median of 9.3 years from their diagnosis (range 5.3-13.2 years). Two patients were younger than 3 years, one lacked signs of pontine cranial nerve involvement, and three had longer duration of symptoms at diagnosis. One patient had a radiologically atypical tumor and one had a tumor originating in the medulla. All five patients received RT. Chemotherapy was variable among these patients. Neurocognitive assessments were obtained after a median interval of 7.1 years. Three of four patients who underwent a detailed evaluation showed cognitive function in the borderline or mental retardation range. Two patients experienced disease progression at 8.8 and 13 years after diagnosis. A minority of children with DIPG experienced long-term survival with currently available therapies. These patients remained at high risk for tumor progression even after long follow-ups. Four of our long-term survivors had clinical and radiologic characteristics at diagnosis associated with improved outcome.

Pediatric diffuse intrinsic pontine glioma patients from a single center

BACKGROUND

The prognosis of children with diffuse intrinsic pontine gliomas (DIPG) is dismal. This study aims to evaluate the characteristics and treatment outcome of children with DIPG in a single center.

METHODS

We reviewed the outcome of children with DIPG treated at the Oncology Institute of Istanbul University from February 1999 to May 2012.

RESULTS

Fifty children (26 female, 24 male) with the median age of 7 years were analyzed. The median duration of symptoms was 30 days. All patients received radiotherapy (RT). Before the year 2000, 12 patients received only RT. Thirty-eight had concomitant and/or adjuvant chemotherapy with RT. Between 2000 and 2004, 17 patients received cis-platinum or vincristine as sensitizers during RT and CCNU + vincristine combination after RT. Since 2004, 21 patients received temozolomide (TMZ) concomitantly during RT and as adjuvant chemotherapy after RT. The median survival time of all patients was 13 months (1-160 months). Patients receiving RT + TMZ had a significantly higher overall survival than patients with only RT (p = 0.018). Patients receiving RT + chemotherapy other than TMZ also had a significantly higher overall survival than patients receiving only RT (p = 0.013). Patients receiving RT + TMZ + and chemotherapy other than TMZ had a significantly higher survival than patients receiving only RT (p = 0.005).

CONCLUSION

In our series, patients receiving RT + TMZ and also patients receiving RT + chemotherapy other than TMZ had a significantly higher overall survival than patients treated with only RT. Hence, administering chemotherapy during and after RT seems to prolong survival in some DIPG patients.

Nimotuzumab treatment of malignant gliomas

INTRODUCTION

In spite of new alkylating medication and recently accumulated knowledge about genomics, the prognosis of malignant gliomas remains poor. The introduction of single substances interfering with tumour proliferation dynamics has been disappointing and the lessons learned indicate that a complicated network of proliferation needs time consuming, in-depth analysis in order to more specifically treat now distinguishable subgroups of a disease, which too long was thought of as a uniform entity.

AREAS COVERED

The clinical trials using the EGFR antibody nimotuzumab in the treatment of malignant gliomas are reviewed. Pending conformation in future studies the antibody might be part of the treatment of MGMT-negative, EGFR-amplified, not completely resected gliomas of adulthood and juvenile DIPG (pontine gliomas). Upcoming genomic results of the different tumour entities may suggest certain combination partners of the antibody. Recent studies of nimotuzumab indicate the reason for the lack of toxicity, which is the most attractive argument for its clinical use besides modest efficacy.

EXPERT OPINION

We await the final results on the use of the antibody together with vinorelbine and radiation therapy for the therapy of DIPG. Adult patients with MGMT-negative, EGFR amplified, not totally resected GBM may also profit from this combination therapy. TK-inhibitors combined with the antibody and irradiation may be an option for a therapeutic trial in paediatric patients.

The effects of temozolomide delivered by prolonged intracerebral microinfusion against the rat brainstem GBM allograft model

OBJECTIVE

Diffuse intrinsic brainstem gliomas are considered to be inoperable. We report our initial experience of temozolomide (TMZ) administration into brainstem by intracerebral (i.c.) microinfusion using a rat brainstem glioblastoma allograft model.

METHODS

Forty-eight Fischer 344 female rats were used. In a feasibility study, various doses of i.c.-TMZ (1-10 mg) were administered into the brainstem using AlzetTM pumps in order to evaluate survival rates and neurotoxicity. For tumor implantation, rats received an injection of 10(5) 9 L gliosarcoma cells. For local therapy, 5 days after inoculation, a total amount of 1 mg of TMZ or saline was administered into the brainstem at 1 μl/h over 7 days (n = 8/group). For systemic therapy, rats were treated with an orally administered maximum daily dose of 50 mg/kg TMZ for 5 consecutive days. Survival time and neurological deficit were recorded as outcome parameters.

RESULTS

In the neurotoxicity study, low dose TMZ (1 mg) was feasible to be administered into brainstem over 7 days without neurological deficit. Using high dose TMZ (5-10 mg), marked neurotoxic effect was observed. In the brainstem tumor study, survival was significantly prolonged in low dose i.c.-TMZ group compared to control rats (median survival 23.5 versus 29.5 days; p < 0.01). Systemic therapy with maximal oral-TMZ dose resulted in longer survival time compared to low dose i.c.-TMZ group (median survival 33.5 versus 29.5 days; p < 0.01).

CONCLUSIONS

i.c.-TMZ is feasible and effective against rat brainstem glioblastoma allograft. However, we could not show superior potential of i.c.-TMZ compared to oral-TMZ administration. Modification of TMZ infusion with systemic therapy warrants future investigations.

Pediatric high grade glioma of the spinal cord: results of the HIT-GBM database

Little is known about pediatric spinal cord high grade gliomas (SCHGG) beyond their dismal prognosis. Here, we analyzed the HIT-GBM(®) database for the influence of surgical resection on survival. Between 1991 and 2010 the HIT-GBM group collected data from European children diagnosed with high grade glioma. Patients with the following inclusion criteria were analyzed in this study: astrocytic histology, WHO grade III or IV, age at diagnosis <18 years, and tumor localized to the spinal cord. 28 patients (mean age 11.28 years, 14 male) with primary SCHGG were identified. The tumor sizes were measured by the span across adjacent vertebrae and varied greatly (range: 1-20, median: 4). Histology was classified as WHO grade III in 15 and grade IV in 13 tumors. Of note, the four largest tumors identified were WHO grade III. Surgery was classified as complete resection (n = 6), subtotal resection (STR) (n = 7), partial resection (n = 12) or biopsy only (n = 3). 27 patients received chemotherapy, 22 of which also received radiation. With the mean follow-up time of 2.88 (SD ± 2.95) years, 14 patients were still alive resulting in a median overall survival of 2.5 years (SE ± 1.6). The positive prognostic indicators for overall survival were: age younger than 5 years (P = 0.047), WHO grade III (P = 0.046), absence of necrosis (P = 0.025) and gross total resection (GTR) (P = 0.012). The prognosis of SCHGG might not be as miserable as generally assumed. GTR is of benefit. Larger data sets and meta-analysis are necessary to identify patient sub-groups.

Treatment of recurrent diffuse intrinsic pontine glioma: the MD Anderson Cancer Center experience

Recurrent diffuse intrinsic pontine gliomas (DIPG) are traditionally treated with palliative care since no effective treatments have been described for these tumors. Recently, clinical studies have been emerging, and individualized treatment is attempted more frequently. However, an informative way to compare the treatment outcomes has not been established, and historical control data are missing for recurrent disease. We conducted a retrospective chart review of patients with recurrent DIPG treated between 1998 and 2010. Response progression-free survival and possible influencing factors were evaluated. Thirty-one patients were identified who were treated in 61 treatment attempts using 26 treatment elements in 31 different regimens. The most frequently used drugs were etoposide (14), bevacizumab (13), irinotecan (13), nimotuzumab (13), and valproic acid (13). Seven patients had repeat radiation therapy to the primary tumor. Response was recorded after 58 treatment attempts and was comprised of 0 treatment attempts with complete responses, 7 with partial responses, 20 with stable diseases, and 31 with progressive diseases The median progression-free survival after treatment start was 0.16 years (2 months) and was found to be correlated to the prior time to progression but not to the number of previous treatment attempts. Repeat radiation resulted in the highest response rates (4/7), and the longest progression-free survival. These data provide a basis to plan future clinical trials for recurrent DIPG. Repeat radiation therapy should be tested in a prospective clinical study.

Magnetic resonance spectroscopic detection of lactate is predictive of a poor prognosis in patients with diffuse intrinsic pontine glioma

Diffuse brainstem glioma has a poor prognosis, and there are few long-term survivors. We looked for clinical, conventional magnetic resonance (MR), and MR spectroscopic (MRS) findings predictive of the prognosis of patients with brainstem glioma. Our institutional review board approved this retrospective study of 23 patients with diffuse intrinsic pontine or diffuse medullary brainstem glioma treated during the period 2000-2009. To evaluate prognostic values, we performed a Kaplan-Meier survival analysis (log-rank test) that incorporated the patients' age and sex, symptom duration, the presence or absence of cranial nerve palsy, long tract sign, ataxia, and cysts, the chemotherapeutic regimen, Gd enhancement, longitudinal and cerebellar extension, basilar artery encasement, and MRS parameters. Of the 23 diffuse brainstem gliomas, 19 were located at the pons (ratio of male to female patients, 1.1:1). The mean age of the 23 patients was 15.9 years (range, 4-50 years); 16 were aged <20 years. The duration of overall survival was 19.7 months; in patients with diffuse intrinsic pontine glioma, it was 16.6 months, and in patients aged <20 years, it was 11.8 months. Clinical and conventional MR findings at presentation were not predictive of the prognosis in children with diffuse intrinsic pontine glioma. In addition, a patient age <20 years and the detection of lactate by MRS were poor prognostic factors. The MRS detection of lactate is a prognostic factor in patients with diffuse intrinsic pontine glioma. Additional studies of larger patient populations using other imaging modalities are needed.

Tumors of the central nervous system in children and adolescents

BACKGROUND

Multimodal treatment approaches for children with tumors of the central nervous system (CNS) have markedly contributed to improved survival. Before 1970, the survival rate among children with medulloblastoma, the most common malignant CNS tumor in children, was about 20%. At present, in contrast, cure can be achieved in more than 75% of children with a favorable constellation of risk factors. In this review article for clinicians, we give an overview of the current understanding of the pathology, presenting manifestations, early diagnosis, and treatment of CNS tumors in children and adolescents.

METHODS

We report the research findings of the German Treatment Network "HIT" and selectively review the pertinent literature.

RESULTS

Treatment-optimizing clinical trials have improved survival from all types of CNS tumors in children and adolescents. Biological features of the tumors now serve as the basis for improved stratification for multimodal, risk-adapted treatment. Targeted biological strategies are being developed. Difficulties remain, however, in the care of infants with CNS tumors and in the treatment of metastatic disease, tumors of certain histological types, and tumors in certain anatomical sites. Many of the affected children suffer from late effects of their disease and its treatment that can irreversibly impair their development.

CONCLUSION

Children with a suspected or confirmed diagnosis of brain tumor should be referred early to a center with the relevant experience. Standardized diagnostic and therapeutic methods have markedly improved the chance of cure. Current research on molecular signaling pathways seems likely to lead to the development of new treatments, particularly for tumors currently associated with lower rates of survival. The long-term side effects of treatment must be systematically monitored so that they can be avoided in future, and so that appropriate support measures can be provided to the affected children.

Temozolomide in the treatment of children with newly diagnosed diffuse intrinsic pontine gliomas: a report from the Children's Oncology Group

An open-label phase II study (ACNS0126) testing the efficacy of chemoradiotherapy with temozolomide (TMZ) followed by adjuvant TMZ was conducted by the Children's Oncology Group. During the period from July 6, 2004 through September 6, 2005, 63 children with newly diagnosed diffuse intrinsic pontine glioma (DIPG) were enrolled in the study. All patients received TMZ at a dosage of 90 mg/m(2)/day for 42 days to a dose of 59.4 Gy. Four weeks following irradiation, TMZ was given at a dosage of 200 mg/m(2)/day for 5 days every 28 days, for a total of 10 cycles. The primary objective of the statistical analysis was to determine whether the current treatment produced a 1-year event-free survival (EFS) rate higher than the historical baseline of 21.9% observed in CCG-9941. The mean 1-year EFS (± standard deviation) was 14% ± 4.5%, compared with 21.9% ± 5% for CCG-9941. The P value of the test of comparison of 1-year EFS, based on a 1-sided, 1-sample test of proportions, was .96. There was no evidence that temozolomide produced a 1-year EFS rate higher than 21.9%. The mean 1-year OS (± standard deviation) was 40% ± 6.5%, compared with 32% ± 6% for CCG-9941. The median time to death was 9.6 months. Chemoradiotherapy with TMZ followed by adjuvant TMZ is not more effective than previously reported regimens for the treatment of children with DIPG.

A phase II study of gefitinib and irradiation in children with newly diagnosed brainstem gliomas: a report from the Pediatric Brain Tumor Consortium

This phase II study was designed to assess the safety and efficacy of gefitinib given with and following radiation therapy in children newly diagnosed with a poor prognosis brainstem glioma. Eligible patients were those with a previously untreated nondisseminated diffuse intrinsic brainstem glioma. Histological confirmation was not required, provided patients had a characteristic clinical history and MRI findings. Treatment consisted of gefitinib, administered orally, 250 mg/m(2)/day, during standard external beam radiotherapy, continuing for up to 13 monthly courses in the absence of disease progression or unacceptable toxicity. Toxicities, particularly intratumoral hemorrhage, were monitored. Pharmacokinetics and investigational imaging studies were performed in consenting patients. Forty-three eligible patients were included in the study. Therapy was well tolerated; only 4 patients were withdrawn from the study for dose-limiting toxicity after receiving therapy for 6, 9, 17, and 24 weeks. The 12- and 24-month progression-free survival rates were 20.9 ±5.6 % and 9.3 ±4%, respectively. Overall survival rates were 56.4 ±7.6% and 19.6 ±5.9%, respectively, which appear nominally superior to other contemporaneous Pediatric Brain Tumor Consortium trials. Three patients remain progression-free survivors with ≥36 months follow-up. The observation that a subset of children with this generally fatal tumor experienced long-term progression-free survival, coupled with recent observations regarding the molecular features of brainstem gliomas, raises the possibility that prospective molecular characterization may allow enrichment of treatment responders and improvement in outcome results in future studies of biologically targeted agents.

Nimotuzumab for pediatric diffuse intrinsic pontine gliomas

INTRODUCTION

Diffuse intrinsic pontine gliomas (DIPG) have a poor prognosis: the median survival rate is less than one year. Radiotherapy is the only effective treatment affording an overall survival of 6 - 9 months. So far, no improvement has been achieved with the addition of single/poly-chemotherapy regimens. An urgent need is to advance in this field, from both the biological and the clinical points of view.

AREAS COVERED

Among the few studies providing biological information on DIPG, Gilbertson's group demonstrated a significant increase in EGFR expression. The activity of nimotuzumab, a humanized anti-EGFR monoclonal antibody, was therefore studied within a Phase II trial in 47 relapsing pediatric patients with DIPG and high-grade gliomas, showing an interesting, persistent response, especially in the first group treated. A multicenter exploratory study combining nimotuzumab and radiotherapy showed disease control and an overall patient survival similar to previous experiences along with an improvement in the quality of patient survival and no severe side effects.

EXPERT OPINION

We recommend considering this combination in the armamentarium against DIPG. It might be improved by adding other target drugs/low-toxicity chemotherapy regimens with a synergistic effect with the anti-EGFR component.

Measuring performance status in pediatric patients with brain tumors--experience of the HIT-GBM-C protocol

BACKGROUND

Measuring the quality of life or performance status in pediatric neurooncology has proven a challenge. Here, we report in a treatment protocol for pediatric patients with high-grade glioma and diffuse intrinsic pontine glioma.

PROCEDURE

The Fertigkeitenskala Münster-Heidelberg (FMH) is a 56-item quantitative measure of health status. The number of yes answers is transformed to age-dependent percentiles. Physicians were also asked the patients' health status by their own judgment on a 1-5 scale: normal, mild handicap, age-normal activity severely reduced but patient not in bed, in bed, and in ICU.

RESULTS

Assessments were available from 50 of 97 eligible patients. For 22 patients both questionnaire and the physicians score obtained. At the beginning of the treatment, only 5 patients scored over 40 FMH%, and 4 of these survived. Of 16 patients who initially scored less than 40 FMH%, 15 died. During later assessments, most FMH measures became gradually worse. FMH scores improved in three patients. The physician's judgment was documented at diagnosis and during treatment (n = 50). Per physician, 22% of the patients were normal before chemotherapy, decreasing to 16% in the middle of the protocol. At diagnosis only 16% of patients had severely reduced activity, which increased to 30.6% in the middle of the protocol. The FMH% correlated well with the physicians' judgments (P < 0.005).

CONCLUSION

The FMH scale is easily obtained and provides a valid assessment of health status. Patients with poor performance at diagnosis had a poorer prognosis.

High dose methotrexate for pediatric high grade glioma: results of the HIT-GBM-D pilot study

We conducted a phase II study to test methotrexate (5 g/m(2)), as a single agent prior to radiochemotherapy for pediatric high-grade glioma and diffuse intrinsic pontine glioma. Thirty patients (19 male, median age 10.8) were enrolled. Tumors were located as follows: cortex 10, pons 7, other 13. Tumor resection was classified as gross total in 6, subtotal in 6, partial in 4, biopsy in 11 and not performed in 3. WHO grading of the histology was: IV: 11, III: 12 and II: 3. Patients received methotrexate 5 g/m(2) in 24-hour infusions on days 1 and 15. Subsequently 54 Gy radiation was administered with simultaneous chemotherapy including cisplatin, etoposide, vincristine and ifosfamide as previously described. Eight 6-weeks cycles of maintenance chemotherapy consisted of vincristine 1.5 mg/m(2) on days 1, 8 and 15; lomustine 100 mg/m(2) on day 2 and prednisone 40 mg/kg on days 1-17. Event-free survival rates in the whole group of 30 patients were: 43, 20, and 13% after 1, 2 and 5 years, respectively. The response evaluation after methotrexate was available in 19 of the 24 patients who started treatment with measurable disease: CR: 0, PR: 1, SD 18, PD: 0. After radiochemotherapy the response of 24 patients with measurable disease was CR: 1, PR 10, SD 12, PD 1. Both response and event-free survival were superior to the control group of 330 patients treated in various protocols of the same cooperative group. In subgroup analyses the use of dexamethasone during early treatment was linked to poor event free survival. Giving two cycles of high-dose methotrexate prior to radiochemotherapy was feasible, and the approach was taken forward to a randomized phase III trial.

Role of temozolomide in the treatment of newly diagnosed diffuse brainstem glioma in children: experience at a single institution

PURPOSE

The purpose of this study was to assess the efficacy of TMZ on diffuse brainstem glioma, either concomitant with radiotherapy or as an adjuvant treatment after radiotherapy in children.

METHODS AND MATERIALS

Eighteen children (median age at diagnosis was 8.3 years) meet the following criteria: (1) newly diagnosed diffuse brainstem glioma; (2) aged less than 18 years old, which were treated with TMZ at Taipei Veterans General Hospital from January 2004 to December 2008. They were divided into two groups according to treatment modalities: a radiotherapy alone followed by adjuvant TMZ (RT+TMZ) group received conventional radiation after initial diagnosis, and a concomitant chemoradiotherapy followed by adjuvant TMZ (CCRT+TMZ) group received concurrent chemotherapy during radiation with TMZ (75 mg/M(2)/day). After completion of the radiotherapy, TMZ (150 mg/M(2)) was administered once per day for five consecutive days for all enrolled patients in each 28-day cycle. We evaluated the progression-free survival in both groups of patients.

RESULTS

There were 10 patients in RT+TMZ group and eight in CCRT+TMZ group. All patients experienced progression of disease. Twelve patients (75%) died, and all deaths were attributed to the disease progression. The median progression-free survival (PFS) was 7.4 months for the RT+TMZ group and 6.4 months for the CCRT+TMZ group. The 6-month and 1-year PFS in the RT+TMZ group were 70% (SD 14%) and 30% (SD 14%), respectively, and in the CCRT+TMZ group, they were 50% (SD 17%) and 0%, respectively. The log-rank test in PFS between the two groups was not statistically significant.

CONCLUSIONS

In this study, CCRT with TMZ followed by adjuvant TMZ did not result in a better outcome when compared with RT alone followed by adjuvant TMZ. In addition, TMZ either as adjuvant therapy or as CCRT did not improve the prognosis of the patients with newly diagnosed diffuse brainstem glioma.

A prospective study of temozolomide plus thalidomide during and after radiation therapy for pediatric diffuse pontine gliomas: preliminary results of the Korean Society for Pediatric Neuro-Oncology study

This prospective study was performed to determine the efficacy and safety of temozolomide (TMZ) plus thalidomide during and after radiation therapy (RT) in pediatric patients with newly diagnosed diffuse pontine glioma (DPG). Seventeen patients with pediatric DPG were enrolled between November 2004 and March 2008. The median age was eight years (range, 3-16 years); seven patients were male and ten were female. With the exception of one glioblastoma case, which was diagnosed via open biopsy, all diagnoses were established using neuroradiological studies. The authors used the Korean Society for Pediatric Neuro-Oncology (KSPNO)-A053 protocol. The mean follow-up period was 12 months (range, 8.5-25 months). Five patients were withdrawn from the study. The rates of response to treatment and survival were analyzed in 12 patients. Ten out of the 12 patients showed a partial response (PR), whereas one patient exhibited stable disease (SD) and another patient had progressive disease (PD). The tumor control rate was 92% (11/12) and the response rate was 83% (10/12). The median progression-free survival (PFS) of the 12 patients was 7.2 months (95% confidence interval (CI), 3.6-10.7). Six-month and twelve-month PFS were 58.3 and 16.7%, respectively. Overall survival (OS) was 12.7 months (95% CI, 10.4-15.1). One and two-year survival were 58.3 and 25%, respectively. The main adverse effect was hematological toxicity, with four patients exhibiting grade 3 or 4 toxicity. All patients tolerated the regimen well enough to continue the adjuvant chemotherapy. No Pneumocystis jiroveci pneumonia was noted. The TMZ plus thalidomide regimen was safe and tolerated well enough to be administered on an outpatient basis. Larger studies are required to demonstrate the efficacy of this regimen.

Intensive chemotherapy improves survival in pediatric high-grade glioma after gross total resection: results of the HIT-GBM-C protocol

BACKGROUND

The authors hypothesized that intensified chemotherapy in protocol HIT-GBM-C would increase survival of pediatric patients with high-grade glioma (HGG) and diffuse intrinsic pontine glioma (DIPG).

METHODS

Pediatric patients with newly diagnosed HGG and DIPG were treated with standard fractionated radiation and simultaneous chemotherapy (cisplatin 20 mg/m2 x 5 days, etoposide 100 mg/m2 x 3 days, and vincristine, and 1 cycle of cisplatin + etoposide + ifosfamide 1.5 g/m x 5 days [PEI] during the last week of radiation). Subsequent maintenance chemotherapy included further cycles of PEI in Weeks 10, 14, 18, 22, 26, and 30, followed by oral valproic acid.

RESULTS

Ninety-seven (pons, 37; nonpons, 60) patients (median age, 10 years; grade IV histology, 35) were treated. Resection was complete in 21 patients, partial in 29, biopsy only in 26, and not performed in 21. Overall survival rates were 91% (standard error of the mean [SE] +/- 3%), 56%, and 19% at 6, 12, and 60 months after diagnosis, respectively. When compared with previous protocols, there was no significant benefit for patients with residual tumor, but the 5-year overall survival rate for patients with complete resection treated on HIT-GBM-C was 63% +/- 12% SE, compared with 17% +/- 10% SE for the historical control group (P = .003, log-rank test).

CONCLUSIONS

HIT-GBM-C chemotherapy after complete tumor resection was superior to previous protocols.

Outcome and prognostic features in pediatric gliomas: a review of 6212 cases from the Surveillance, Epidemiology, and End Results database

BACKGROUND

Pediatric gliomas are rare and heterogeneous tumors. The Surveillance, Epidemiology, and End Results (SEER) database allows a large-scale analysis of the clinical characteristics and prognostic features of these tumors.

METHODS

The authors analyzed available SEER data on 6212 patients younger than 20 years at diagnosis of glioma (1973-2005), according to 4 age categories: <1 year, 1-3 years, 3-5 years, and 5-20 years.

RESULTS

The overall 5- and 10-year survival estimates were 71%+/-0.62% (standard error) and 68%+/-0.67%, respectively. Forty-one percent of gliomas were cerebral; the frequency of cerebellar tumors (22%-32% of gliomas) increased sharply after the first year of life. Of the tumors for which grade was available, 77% were low grade (grade I or II). Tumor grade emerged as the most significant independent prognostic factor in all age groups except the youngest age group, in which extent of resection was most significant. Surgery other than gross total resection was an adverse prognostic factor (hazard ratio, 2.18; 95% confidence interval, 1.78-2.67). Age<3 years predicted a greater likelihood of survival in patients with high-grade gliomas and brainstem tumors. Conversely, age<3 years predicted a lower likelihood of survival in patients with low-grade gliomas. Children aged<1 year received less radiotherapy than older patients (P<.0001) and were less likely to undergo gross total resection (P<.0001).

CONCLUSIONS

The survival of children with gliomas is influenced by histologic subtype, age, and extent of resection. Despite its limitations, the SEER database provides a useful tool for studies of rare tumors such as pediatric gliomas.

Brainstem gliomas--retrospective analysis of 86 patients

Brainstem gliomas constitute 10% of brain tumors in children and less than 2% in adults. Since therapeutic options are limited and brainstem gliomas are associated with a high morbidity and mortality, we sought to analyze the prognostic factors associated with a better outcome. We reviewed the records of 86 patients with brainstem gliomas treated between 1996 and 2006. We recorded demographic and clinical variables as well as radiological findings and survival. Patients were divided in two groups regarding overall survival: late progressors (survival >or=12 months) or early progressors (survival<12 months). Of 86 patients with brainstem gliomas, 55.8% were females. The mean age at diagnosis was 14.2 years (range 1 to 52 years). Twenty-four (27.9%) patients were adults. Lesions were located at pons in 75.6% of patients, midbrain in 15.1% and medulla in 9.3%. There was no difference between early and late progressors concerning gender, age at onset, location at pons, presence of necrosis or contrast enhancement observed at MRI or surgical resection. In both univariate and multivariate analysis, only a short duration of symptoms before diagnosis (<3 months) was associated with a worst prognosis (odds ratio 5.59, 95% CI 1.94 to 16, p=0.0014). A short duration of symptoms, which may imply a more aggressive tumor, was associated with a worst prognosis in patients with brainstem gliomas. This information may be useful in the selection of patients for future therapeutic trials.

Treatment of diffuse intrinsic brainstem gliomas: failed approaches and future strategies

Diffuse intrinsic pontine gliomas constitute ~ 60-75% of tumors found within the pediatric brainstem. These malignant lesions present with rapidly progressive symptoms such as cranial nerve, long tract, or cerebellar dysfunctions. Magnetic resonance imaging is usually sufficient to establish the diagnosis and obviates the need for surgical biopsy in most cases. The prognosis of the disease is dismal, and the median survival is < 12 months. Resection is not a viable option. Standard therapy involves radiotherapy, which produces transient neurological improvement with a progression-free survival benefit, but provides no improvement in overall survival. Clinical trials have been conducted to assess the efficacy of chemotherapeutic and biological agents in the treatment of diffuse pontine gliomas. In this review, the authors discuss recent studies in which systemic therapy was administered prior to, concomitantly with, or after radiotherapy. For future perspective, the discussion includes a rationale for stereotactic biopsies as well as possible therapeutic options of local chemotherapy in these lesions.

Neurological grading, survival, MR imaging, and histological evaluation in the rat brainstem glioma model

OBJECTIVE

Convection-enhanced delivery using carboplatin in brainstem glioma models was reported to prolong survival. Functional impairment is of additional importance to evaluate the value of local chemotherapy. We established a neurological scoring system for the rat brainstem glioma model.

MATERIAL AND METHODS

In 46 male Fisher rats stereotactically 10(5) F-98 cells were implanted at 1.4-mm lateral to midline and at the lambdoid suture using guided screws. Following 4 days local delivery was performed using Alzet pumps (1 microl/h over 7 days) with either vehicle (5% dextrose) or carboplatin via one or two cannulas, respectively. All rats were subsequently tested neurologically using a specified neurological score. In 38 animals survival time was recorded. Representative MR imaging were acquired in eight rats, respectively, at day 12 after implantation. HE staining was used to evaluate tumor extension.

RESULTS

Neurological scoring showed significantly higher impairment in the high dose carboplatin group during the treatment period. Survival was significantly prolonged compared to control animals in the high dose carboplatin-one cannula group as well as in both low dose carboplatin groups (18.6 +/- 3 versus 26.3 +/- 9, 22.8 +/- 2, 23.6 +/- 2 days; p < 0.05). Overall neurological grading correlated with survival time. MR imaging showed a focal contrast enhancing mass in the pontine brainstem, which was less exaggerated after local chemotherapy. Histological slices visualized decreased cellular density in treatment animals versus controls.

CONCLUSION

Local chemotherapy in the brainstem glioma model showed significant efficacy for histological changes and survival. Our neurological grading enables quantification of drug and tumor-related morbidity as an important factor for functional performance during therapy.

Diffuse pontine glioma in Jordan and impact of up-front prognosis disclosure with parents and families

For patients with diffuse pontine glioma, our institution offers local radiotherapy and supportive care only. The prognosis and do-not-resuscitate orders are discussed upfront with patients' parents. To investigate the effectiveness of this policy, we retrospectively reviewed records of patients with diffuse pontine glioma treated at the institution over a 49-month period. This study included 19 children (16 girls and 3 boys). The median age at diagnosis was 7 years. One patient remained alive at the end of the study, 2 were lost to follow-up, and 16 were confirmed dead. The median survival was 8.2 months. Do-not-resuscitate discussion was documented for 14 patients and successfully initiated for 11. None of those confirmed dead had been offered life support. Contrary to the common belief, our study showed that do not resuscitate should be addressed in Muslim patients with high-risk malignancies. We also found that diffuse pontine glioma warrants further study in developing countries.

Brainstem glioma progression in juvenile and adult rats

OBJECT

Brainstem gliomas are common in children and have the worst prognosis of any brain tumor in this age group. On the other hand, brainstem gliomas are rare in adults, and the authors of some clinical studies have suggested that this lesion behaves differently in adults than in children. In the present study, the authors test an orthotopic C6 brainstem glioma model in juvenile and adult rats, and investigate the biological behavior of this lesion in the 2 age groups.

METHODS

The C6 glioma cells were stereotactically implanted into the pons of juvenile or adult male rats. Neurological presentation and survival time were recorded. Tumor proliferation and the number of apoptotic cells in brainstem gliomas of young and adult rats were determined by immunohistochemical staining with Ki 67 and terminal deoxynucleotidyl transferase 2'-deoxyuridine 5'-triphosphate-mediated nick-end labeling assay.

RESULTS

Striking differences in the onset of neurological signs, duration of symptoms, survival time, tumor growth pattern, tumor proliferation, and number of apoptotic cells were found between the gliomas in the 2 groups of rats. The lesions were relatively focal in adult rats but more diffuse in young rats. Furthermore, brainstem gliomas in adult rats were less proliferative and had more apoptotic cells than those in young rats.

CONCLUSIONS

The authors found that the C6 brainstem glioma model in young and adult rats closely imitates the course of brainstem glioma in humans both in neurological findings and histopathological characteristics. Their findings also suggest that the different growth pattern and invasiveness of these lesions in children compared with that in adults could be due to different cellular environments in the 2 age groups, and warrants further investigation into the difference in the host response to brainstem gliomas in children and adults.