Optic glioma in children: surveillance, resection, or irradiation?

Radiotherapy for pediatric low-grade glioma

INTRODUCTION

Radiotherapy is a highly effective treatment for pediatric low-grade glioma, serving as the standard for evaluating progression-free and overall survival, as well as vision preservation. Despite its proven efficacy, concerns about treatment complications have led to increased use of chemotherapy and targeted therapy, which are associated with poorer progression-free survival outcomes.

METHODS

This review by Indu Bansal and Thomas E. Merchant examines the indications, timing, and results of radiotherapy for pediatric low-grade glioma. The authors provide a comprehensive analysis of clinical management strategies, addressing the controversies surrounding the use and timing of radiotherapy compared to other therapies.

RESULTS

The review highlights that while radiotherapy is essential for certain patients, particularly those who are not candidates for complete resection due to the tumor's infiltrative nature or location, it is often deferred in favor of systemic therapies. This deferral can lead to significant morbidity, including poor visual outcomes. Reports indicate that systemic therapy negatively impacts progression-free survival in patients who eventually undergo radiotherapy. Newer radiotherapy techniques have been developed to minimize complications, offering potential benefits over traditional methods.

DISCUSSION

The evolving clinical management of pediatric low-grade glioma involves balancing the benefits of radiotherapy with concerns about its side effects. Although systemic therapies are increasingly favored, their associated inferior progression-free survival and potential for significant morbidity underscore the need for careful consideration of radiotherapy, particularly in older children, adolescents, or those with progressive disease post-systemic therapy. The emerging role of targeted therapy presents additional challenges, including uncertainties about long-term side effects and its interaction with radiotherapy. Further research is needed to optimize treatment strategies and improve outcomes for pediatric patients with low-grade glioma.

Complications and visual outcomes following surgical resection of pediatric optic pathway/hypothalamic gliomas: a systematic review and meta-analysis

Pediatric optic pathway/hypothalamic gliomas (OPHG) pose challenges in treatment due to their location and proximity to vital structures. Surgical resection plays a key role in the management of OPHG especially when the tumor exhibits mass effect and causes symptoms. However, data regarding outcomes and complications of surgical resection for OPHG remains heterogenous. The authors performed a systematic review on pediatric OPHG in four databases: PubMed, EMBASE, Cochrane Library, and Google Scholar. We included studies that reported on the visual outcomes and complications of OPHG resection. A meta-analysis was performed and reported per the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement. A total of 26 retrospective studies were included. Seven hundred ninety-seven pediatric patients with OPHG undergoing surgical resection were examined. A diagnosis of NF1 was confirmed in 9.7%. Gross total resection was achieved in 36.7%. Intraorbital optic pathway gliomas showed a significantly higher gross total resection rate compared to those located in the chiasmatic/hypothalamic region (75.8% vs. 9.6%). Postoperatively, visual acuity improved in 24.6%, remained unchanged in 68.2%, and worsened in 18.2%. Complications included hydrocephalus (35.4%), anterior pituitary dysfunction (19.6%), and transient diabetes insipidus (29%). Tumor progression post-resection occurred in 12.8%, through a mean follow-up of 53.5 months. Surgical resection remains an essential strategy for treating symptomatic and large pediatric OPHG and can result in favorable vision outcomes in most patients. Careful patient selection is critical. Patients should be monitored for hydrocephalus development postoperatively and followed up to assess for tumor progression and adjuvant treatment necessity.

Postoperative hydrocephalus is a high-risk lethal factor for patients with low-grade optic pathway glioma

OBJECTIVES

To explore the prognostic factors of patients with low-grade optic pathway glioma (OPG) and the optimal treatment to reduce the incidence of postoperative hydrocephalus.

PATIENTS AND METHODS

This single-center study retrospectively analyzed data from 66 patients with OPGs who underwent surgery. The patients were followed, and overall survival (OS) and progression-free survival (PFS) were determined. The effects of different treatments on the hydrocephalus of patients were compared.

RESULTS

Postoperative hydrocephalus was identified as a factor to increase the risk of mortality by 1.99-fold (p = .028). And, 5-year survival rate was significantly lower among patients with postoperative hydrocephalus (p = .027). The main factors leading to preoperative hydrocephalus in patients are large tumor volume and invasion into the third ventricle. Gross total resections (GTR) could reduce the risk of long-term hydrocephalus (p = .046). Age younger than 4 years (p = .046) and tumor invasion range/classification (p = .029) are the main factors to reduce the five-year survival rate. Postoperative radiotherapy (RT) and chemotherapy (CT) had no significant effects on OS. Extraventricular drainage (EVD) was not associated with perioperative infection (p = .798 > .05) and bleeding (p = .09 > .05). Compared with 2 stage surgery (external ventricular drainage or ventriculoperitoneal shunt (VPS) was first placed, followed by tumor resection), 1 stage surgery (direct resection of tumor) had no complication increase.

CONCLUSIONS

Postoperative hydrocephalus is mostly obstructive hydrocephalus, and it is an important factor that reduces the OS of patients with low-grade OPGs. Surgery to remove the tumor to the greatest extent improves cerebrospinal fluid circulation is effective at reducing the incidence postoperative hydrocephalus. For patients whose ventricles are still dilated after surgery, in addition to considering poor ventricular compliance, they need to be aware of the persistence and progression of hydrocephalus.

Pediatric Optic Pathway Gliomas: A Report From Northern Greece

Optic pathway gliomas (OPGs) are the most common pediatric optic nerve tumors. Their behavior ranges between rapid growth, stability, or spontaneous regression. Τhey are characterized by low mortality albeit with significant morbidity. We present the characteristics, management, and outcome of 23 OPG patients (16 females, median age: 4.8 y) managed in a Pediatric Oncology Department in Northern Greece over a 25-year period. Overall, 57% had a background of neurofibromatosis type 1. Diagnosis was based on imaging (10 patients) or biopsy (13 patients). Presenting symptoms were mostly visual impairment/squint (52%). Proptosis/exophthalmos, raised intracranial pressure, and headache were also noted. In 2 occasions, it was detected with surveillance magnetic resonance imaging in the context of neurofibromatosis type 1. Eight patients had unilateral and 2 bilateral optic nerve tumors (Modified Dodge Classification, stage 1a/1b), 3 had chiasmatic (stage 2a/b), and 10 had multiple tumors (stage 3/4). Predominant histology was pilocytic astrocytoma (77%). Management included: observation (4), chemotherapy only (9), surgery only (3), or various combinations (7). Chemotherapy regimens included vincristine and carboplatin, vinblastine, or bevacizumab with irinotecan. Most patients demonstrated a slow disease course with complete response/partial response to chemotherapy and/or surgery, whereas 39% presented ≥1 recurrences. After a median follow-up of 8.5 years (range to 19 y), 20 patients (87%) are still alive with stable disease, in partial/complete remission, or on treatment.

Long-term outcomes of symptomatic optic pathway glioma: 32-year experience at a single Western Australian tertiary pediatric oncology center

Introduction

Optic pathway gliomas (OPGs) are associated with significant risk of visual and endocrine morbidity, but data on long-term outcomes in symptomatic patients is sparse. This study reviews the clinical course, disease progression, survival outcomes and long-term sequelae in pediatric patients with symptomatic OPGs in our institution over three decades.

Methods

Retrospective review of patients with symptomatic OPG treated in a single tertiary pediatric oncology center from 1984 to 2016.

Results

A total of 37 patients were diagnosed with symptomatic OPG. Decreased visual acuity was the commonest presenting symptom (75.7%). Surgical intervention was performed in 62.2%; 56.5% underwent biopsy, 26.1% surgical debulking and 17.4% had orbital decompression with cystic fenestration and cosmetic optic nerve excision at different treatment intervals. CSF diversion was performed in 47.8% patients. Histopathologic examination confirmed 86% to be pilocytic astrocytoma and 1 ganglioglioma. 46% received chemotherapy and 48% had radiotherapy, at different intervals. Median follow-up was 13.74 years. In NF1 patients, overall survival (OS) was 100% at 5 years and 55.6 ± 24.8% at 25 years while progression-free-survival (PFS) was 50 ± 15.8% at 5 and 20 years. In non-NF1 patients, OS was 96.2 ± 3.8% at 5 years and 87.4 ± 9% at 25-years. 5-year PFS was 53.8 ± 9.8% and 25-year PFS was 49.0 ± 10%. Cumulative PFS was 53 ± 8.3% at 5 years and 49.7 ± 8.4% at 20 years while cumulative OS was 97.2 ± 2.7% at 5 years and 77.5 ± 10.8% at 25 years. 59.5% patients developed post-operative endocrinopathy. Long-term vision was normal in 8.1%, improved in 13.5%, stabilized in 40.5% but worsened in 37.8% patients. Three patients treated with radiotherapy developed second brain tumors.

Conclusion

25-year OS in this cohort was 77.5% but survivorship carried significant long-term morbidities including radiation-induced second malignant brain tumors.

Management of Optic Pathway Glioma: A Systematic Review and Meta-Analysis

Background: OPG accounts for 3−5% of childhood central nervous system (CNS) tumors and about 2% of pediatric glial lesions. Methods: Article selection was performed by searching PubMed, Web of Science, and Cochrane databases. Results: The pooled mortality rate was 0.12 (95%CI 0.09−0.14). Due to the unrepresentative data, improved and not changed outcomes were classified as favorable outcomes and worsened as unfavorable. Meta-analyses were performed to determine the rate of clinical and radiological favorable outcomes. In terms of visual assessment, the pooled rate of a favorable outcome in chemotherapy, radiotherapy, and surgery was 0.74, 0.81, and 0.65, respectively, and the overall pooled rate of the favorable outcome was 0.75 (95%CI 0.70−0.80). In terms of radiological assessment, the rate of a favorable outcome following chemotherapy, radiotherapy, and surgery was 0.71, 0.74, and 0.67, respectively, and the overall pooled rate of the favorable outcome is 0.71 (95%CI 0.65−0.77). The subgroup analysis revealed no significant difference in the rate of clinical and radiological favorable outcomes between the different treatment modalities (p > 0.05). Conclusion: Our analyses showed that each therapeutic modality represents viable treatment options to achieve remission for these patients.

Munda P. Treatment Practices in Optic Nerve Glioma

Optic nerve glioma (OPG) is a rare tumor in children and adolescents. It comprises 1–5% of central nervous system tumors. It can be sporadic or associated with the neurofibromatosis 1 (NF1) gene. These are usually slow-growing tumors and may remain localized to the optic nerve or can have encroached upon adjoining structures like optic chiasma, opposite optic nerve, and hypothalamus. So, there may be decreased or loss of vision, proptosis, focal neurological symptoms, precocious puberty, and short stature. Due to the involvement of these critical structures, its treatment should be based on multidisciplinary consensus. The treatment modalities include surgery, RT, and chemotherapy. The aim of the treatment should be to preserve vision. However, the timing and selection of optimal treatment modalities are always a clinical dilemma. Recently, there have been promising results with newer techniques of radiotherapy and chemotherapy.

Optic Pathway Glioma in Children with Neurofibromatosis Type 1: A Multidisciplinary Entity, Posing Dilemmas in Diagnosis and Management Multidisciplinary Management of Optic Pathway Glioma in Children with Neurofibromatosis Type 1

Introduction

Neurofibromatosis type 1 (NF1) has an incidence of 1 in 2,000 to 3,000 individuals and in 15% is associated with optic pathway glioma (OPG). Given the variability in clinical presentation and related morbidity, a multidisciplinary approach for diagnosis and management of children with NF1 and OPG is required, but often lacks coordination and regular information exchange. Herein we summarize our experience and describe the care pathways/network provided by a multidisciplinary team. The role of the distinct team members is elucidated as well as the care amendments made over time.

Methods

We performed a retrospective single-center observational study, including children treated at our institution between 1990 and 2021. Inclusion criteria were clinical diagnosis of NF1, radiographic and/or histopathological diagnosis of OPG and age below 18 years. Patients being treated elsewhere were excluded from the study. Data was abstracted from each child’s health record using a standardized data collection form. Characteristics of children with NF1 and OPG were described using means (SD) and percentages. Outcomes were determined using Kaplan-Meier estimates.

Results

From 1990 to 2021, 1,337 children were followed in our institution. Of those, 195 were diagnosed with OPG (14.6%), including 94 (48.21%) females and 101 (51.79%) males. Comprehensive data were available in 150 patients. The mean (SD) age at diagnosis was 5.31(4.08) years (range: 0.8–17.04 years). Sixty-two (41.3%) patients remained stable and did not undergo treatment, whereas 88 (58.7%) patients required at least one treatment. The mean (SD) duration of follow up was 8.14 (5.46) years (range: 0.1–25.9 years; median 6.8 years). Overall survival was of 23.6 years (±1.08), comprising 5 deaths. A dedicated NF clinic, including pediatricians and a nurse, provides regular follow up and plays a central role in the management of children with NF1, identifying those at risk of OPG, coordinating referrals to Neuroradiology and other specialists as indicated. All children are assessed annually by Ophthalmology. Comprehensive care was provided by a multidisciplinary team consisting of Dermatology, Genetics, Neuro-oncology, Neuroradiology, Neurosurgery, Ophthalmology and Pediatrics.

Conclusions

The care of children with NF1 and OPG is optimized with a multidisciplinary team approach, coordinated by a central specialty clinic.

The role of imaging features and resection status in the survival outcome of sporadic optic pathway glioma children receiving different adjuvant treatments

Optic pathway glioma (OPG) is a rare brain tumor affecting children, with no standard treatment strategy. This study described the sporadic OPG survival outcomes after surgical treatment and analyzed the role of imaging features and resection status in children receiving different adjuvant treatments. This retrospective study included 165 OPG patients whose clinical information were obtained from the hospital record system. Tumor volume and residual tumor volume were calculated by delineating the lesion area. Kaplan-Meier method and Cox proportional hazards model were conducted to analyze the independent prognosis factor. A total of 165 patients were included in this study. Respectively, the 5-year overall survival (OS) and progression-free survival (PFS) were 87.58% and 77.87%. Residual tumor size and first adjuvant treatment (AT) after surgery were both associated with PFS. In patients with small-size residual tumors, there was no significant difference in PFS between the AT treatment groups. Moreover, age, exophytic cystic components, leptomeningeal metastases, and AT were associated with OS. In patients with exophytic cystic components and those with leptomeningeal metastases, there was no significant difference in OS. Our results revealed that OPG patients could avoid or defer AT by maximized resection. Age ≤ 2 years was a disadvantageous factor for OS. Patients with exophytic cystic components were more likely to benefit from primary surgery, and CT or RT was not beneficial for these patients. Patients with leptomeningeal metastases had a poor prognosis regardless of the treatment they received. Future prospective clinical studies are needed to develop more effective treatment regimens.

Gamma Knife Radiosurgery in the Management of Hypothalamic Glioma: A Case Report with Long-Term Follow-Up

BACKGROUND

Optic pathway/hypothalamic gliomas are rare pediatric brain tumors. The management paradigm for these challenging tumors includes chemotherapy, radiotherapy, or surgical resection, but the optimal management strategy remains elusive. Gamma knife radiosurgery (GKRS) has emerged as a promising treatment for such lesions as documented by a small number of cases in the literature.

CASE PRESENTATION

We present a rare case of hypothalamic glioma in a 13-year-old girl who was referred to our service due to growth of an incidentally diagnosed hypothalamic lesion following head injury at the age of 8 years. The lesion demonstrated hypointensity on T1- and hyperintensity on T2-weighted imaging without contrast enhancement. Given the growth of the lesion on serial imaging, a stereotactic biopsy was performed demonstrating low-grade glioma. The patient underwent GKRS treatment with a marginal dose of 15 Gy at 50% isodose line for a tumor volume of 2.2 mL. Annual radiological surveillance over the next 17 years demonstrated a gradual shrinkage of the lesion until it completely disappeared. The patient is currently a healthy 31-year-old female without any visual, endocrine, or neurocognitive deficits.

CONCLUSION

The outcome obtained after extended follow-up in our patient highlights the safety and efficacy of GKRS in the management of hypothalamic gliomas in pediatrics, which in turn can avoid potentially serious complications of surgery in this vulnerable patient population, especially in this sensitive location.

Optic Nerve Gliomas

Objectives  To describe the diagnostic and management features of optic nerve gliomas. Design  Literature review. Results  Optic nerve gliomas are generally benign in the pediatric age group although they are usually malignant and aggressive in adults. As such, the mechanisms by which these lesions are diagnosed, the systemic implications, the goals of intervention, and the nature of therapeutic management all differ between these tumors. Conclusions  This article addresses these lesions and discusses the diagnostic and therapeutic paradigms by which they may be approached.

Optic pathway tumor in children: Toward a new classification for neurosurgical use

OBJECT

Optic pathway tumors (OPT) represent a challenge for pediatric neurosurgeons. Role of surgery is debated due to the high risk of iatrogenic damage, and in lasts decades it lost its importance in favor of chemotherapy. However, in some cases surgery is necessary to make biomolecular and histological diagnosis, to manage intracranial hypertension (IH) and to cooperate with medical therapies in controlling tumor relapse. With the aim to standardize selection of surgical OPT cases, we propose a simple, practical and reproducible classification.

METHODS

We retrospectively analyzed data of 38 patients with OPT treated at our institution (1990-2018). After careful analysis of MRI images, we describe a new classification system. Group 1: lesion limited to one or both optic nerve(s). Group 2: chiasmatic lesions extending minimally to hypothalamus. Group 3: hypothalamo-chiasmatic exophitic lesions invading the third ventricle; they can be further divided on the base of concomitant hydrocephalus. Group 4: hypothalamo-chiasmatic lesions extending widely in lateral direction, toward the temporal or the frontal lobes. Patients' data and adopted treatment are reported and analyzed, also depending on this classification.

RESULTS

Twenty children were operated on for treatment of OPT during the study period. Permanent clinical impairment was noted in 5 (25%) of operated patients, while visual improvement was noted in 1 patient. OS rate was 100% at 5 years, with a median follow up of 9 years (ranging from 2 to 23). Prevalence of intracranial hypertension and proportion of first-line surgical treatment decision were significantly higher in groups 3-4 compared to groups 1-2 (P<0.001 for both tests).

CONCLUSION

Surgery can offer a valuable therapeutic complement for OPT without major risk of iatrogenic damage. Surgery is indispensable in cases presenting with IH, as in groups 3 and 4 lesions. Eligibility of patients to surgery can be based on this new classification system.

Neurofibromatosis 1-associated optic pathway gliomas

BACKGROUND

Optic Pathway Gliomas (OPG) are the most common brain tumor in Neurofibromatosis 1 patients (NF1). They are found along the optic pathway and may involve the optic nerves, chiasm, retro-chiasmatic structures, and the optic radiations. NF1 associate OPG (NF1-OPG) have variable presentation, disease course and response to treatment. The optimal management is patient-specific and should be tailored by a multidisciplinary team. Age, sex, histology, and molecular markers may be important factors in the individualized decision-making process. Chemotherapy is the first-line treatment in cases of progressive tumors, and visual preservation is the main goal of treatment.

PURPOSE

In this paper we will review the disease, practical management, and recent advances of NF1-OPG.

Retrospective Multicentric Study on Non-Optic CNS Tumors in Children and Adolescents with Neurofibromatosis Type 1

s: The natural history of non-optic central nervous system (CNS) tumors in neurofibromatosis type 1 (NF1) is largely unknown. Here, we describe prevalence, clinical presentation, treatment, and outcome of 49 non-optic CNS tumors observed in 35 pediatric patients (0-18 years). Patient- and tumor-related data were recorded. Overall survival (OS) and progression-free survival (PFS) were evaluated. Eighteen patients (51%) harbored an optic pathway glioma (OPG) and eight (23%) had multiple non-optic CNS lesions. The majority of lesions (37/49) were managed with a wait-and-see strategy, with one regression and five reductions observed. Twenty-one lesions (42.9%) required surgical treatment. Five-year OS was 85.3%. Twenty-four patients progressed with a 5-year PFS of 41.4%. Patients with multiple low-grade gliomas progressed earlier and had a lower 5-year PFS than those with one lesion only (14.3% vs. 57.9%), irrespective of OPG co-presence. Non-optic CNS tumors are common in young patients with NF1. Neither age and symptoms at diagnosis nor tumor location influenced time to progression in our series. Patients with multiple lesions tended to have a lower age at onset and to progress earlier, but with a good OS.

Current treatment of optic nerve gliomas

PURPOSE OF REVIEW

Optic pathway gliomas are low-grade neoplasms that affect the precortical visual pathway of children and adolescents. They can affect the optic nerve, optic chiasm, optic tracts and radiations and can either be sporadic or associated with neurofibromatosis type one. Gliomas isolated to the optic nerve (ONG) represent a subgroup of optic pathway gliomas, and their treatment remains controversial. New developments in ONG treatment have emerged in recent years, and it is necessary for clinicians to have a current understanding of available therapies.

RECENT FINDINGS

The current review of the literature covers the background of and recent developments in ONG treatment, with a focus on standard chemotherapy, new molecularly targeted therapies, radiation therapy and surgical resection and debulking.

SUMMARY

Although standard chemotherapy remains the mainstay of ONG treatment, newer molecularly targeted therapies such as mitogen-activated protein kinase kinase inhibitors and bevacizumab represent a promising new treatment modality, and clinical studies are ongoing.

Monitoring optic chiasmatic-hypothalamic glioma volumetric changes by MRI in children under clinical surveillance or chemotherapy

PURPOSE

Optic pathway gliomas represent 5% of pediatric brain tumors and are typically low-grade lesions. Because of their unpredictable clinical course, adequate treatment approaches have been controversial, involving surveillance, surgery, chemotherapy, and radiotherapy. In this study, we use volumetric imaging to compare evolution of optic chiasmatic-hypothalamic gliomas (OCHG) treated with and without chemotherapy, analyzing tumor volume variation during the overall period.

METHODS

A total of 45 brain MRI were retrospectively analyzed for 14 patients with OCHG. Volumetric assessment of the lesions was performed by a neuroradiologist, using software DISPLAY. OCHG patients were allocated into two groups: group 1 (n = 8) who underwent chemotherapy and group 2 (n = 6) who did not receive chemotherapy. Outcome analysis was performed comparing tumor volume evolution of these two groups.

RESULTS

The results showed a reduction of 4.4% of the volume of the lesions for group 1 after the end of chemotherapy, with an increase of 5.3% in volume in the late follow-up examination. For group 2, we found a slight reduction (5%) of the overall volume of the lesions, both with no statistical significance (p > 0.05).

CONCLUSIONS

From the limited series analyzed in this study, no significant differences were observed in relation to the volume change of lesions treated or not treated with chemotherapy. Larger prospective clinical trials are needed to better evaluate the effect of chemotherapy and radiological response of OCHG.

Radiotherapy in the Management of Paediatric Low-Grade Gliomas

Paediatric low-grade (World Health Organization grade I-II) gliomas (LGGs) represent a spectrum of primary central nervous system tumours. Local tumour control is the cornerstone in the general management of childhood gliomas. Surgery is the primary treatment of choice in the majority. Non-surgical treatments are recommended for progressive or symptomatic inoperable disease. Although chemotherapy is increasingly used as first non-surgical treatment, radiotherapy remains standard as salvage treatment or as primary treatment in selected cases in which surrounding normal tissue can be optimally preserved. The role of targeted therapies is currently under investigation in clinical trials. Modern high-precision radiotherapy techniques, including proton therapy, have the potential to improve long-term toxicities. There is therefore an urgent need for prospective studies to compare the efficacy and safety of modern radiotherapy with systemic treatment in children with LGGs. New information on molecular genetic patterns in LGGs may also have an impact on the selection and sequencing of radiotherapy.

Management of Optic Chiasmatic/ Hypothalamic Astrocytomas in Children

Objective:

The management of optic chiasmatic gliomas is controversial, partly related to failure to separate out those tumors involving the optic chiasm only (chiasmatic tumors) from those also involving the hypothalamus (chiasmatic/hypothalamic tumors). The purpose of this study was: (i) to analyze the outcomes of chiasmatic and chiasmatic/hypothalamic tumors separately; and (ii) to determine the appropriateness of recommending radical surgical resection for the chiasmatic/hypothalamic tumors.

Methods:

A retrospective chart review of all newly diagnosed tumors involving the optic chiasm from 1982-1996 at British Columbia’s Children’s Hospital was performed.

Results:

There were 32 patients less than 16 years of age, 14 with chiasmatic and 18 with chiasmatic/hypothalamic astrocytomas, with an average duration of follow-up of 5.8 years and 6.3 years, respectively. Ten of the patients with chiasmatic tumors and none with chiasmatic/hypothalamic tumors had neurofibromatosis I. Thirteen of the 14 chiasmatic tumors were managed with observation only, and none had progression requiring active intervention. For the chiasmatic/hypothalamic tumors, eight patients had subtotal resections (>95% resection), six had partial resections (50-95%), three had limited resections (<50%), and one had no surgery. There were fewer complications associated with the limited resections, especially with respect to hypothalamic dysfunction. There was no correlation between the extent of resection (subtotal, partial, or limited) and the time to tumor progression (average 18 months).

Conclusions:

In conclusion, chiasmatic and chiasmatic/hypothalamic tumors are different entities, which should be separated out for the purposes of any study. For the chiasmatic/hypothalamic tumors, there was more morbidity and no prolongation of time to progression when radical resections were compared to more limited resections. Therefore, if surgery is performed, it may be appropriate to do a surgical procedure that strives only to provide a tissue diagnosis and to decompress the optic apparatus and/or ventricular system.

Single-session Gamma Knife radiosurgery for optic pathway/hypothalamic gliomas

OBJECTIVE Because of their critical and central location, it is deemed necessary to fractionate when considering irradiating optic pathway/hypothalamic gliomas. Stereotactic fractionated radiotherapy is considered safer when dealing with gliomas in this location. In this study, the safety and efficacy of single-session stereotactic radiosurgery for optic pathway/hypothalamic gliomas were reviewed. METHODS Between December 2004 and June 2014, 22 patients with optic pathway/hypothalamic gliomas were treated by single-session Gamma Knife radiosurgery. Twenty patients were available for follow-up for a minimum of 1 year after treatment. The patients were 5 to 43 years (median 16 years) of age. The tumor volume was 0.15 to 18.2 cm³ (median 3.1 cm³). The prescription dose ranged from 8 to 14 Gy (median 11.5 Gy). RESULTS The mean follow-up period was 43 months. Five tumors involved the optic nerve only, and 15 tumors involved the chiasm/hypothalamus. Two patients died during the follow-up period. The tumors shrank in 12 cases, remained stable in 6 cases, and progressed in 2 cases, thereby making the tumor control rate 90%. Vision remained stable in 12 cases, improved in 6 cases, and worsened in 2 cases in which there was tumor progression. Progression-free survival was 83% at 3 years. CONCLUSIONS The initial results indicate that single-session Gamma Knife radiosurgery is a safe and effective treatment option for optic pathway/hypothalamic gliomas.

Prognostic Factors and Results of Radiation Therapy in Optic Pathway Tumors

Aims and Background

The role of radiotherapy in the management of patients with optic pathway tumors remains controversial. This study analyzes the outcome of patients treated with radiotherapy and attempts to identify the groups of patients that may require early therapy.

Methods

We retrospectively reviewed 36 patients with optic pathway tumors treated with radiotherapy alone (26 patients) or with postoperative radiotherapy (10 patients). Seven patients had optic nerve tumors and 29 patients had chiasmal tumors. The actuarial progression free survival and observed survival probabilities were calculated using the Kaplan-Meier method and differences between curves were evaluated by the Mantel-Cox test. The obtained significant variables in the univariate analysis were analyzed using the Cox proportional hazards model.

Results

The 10-year actuarial progression-free survival (10-y PFS) rate was 86% for patients with optic nerve gliomas and 47% for patients with chiasmal tumors. The 10-year actuarial observed survival (10-y OS) rate was 75% for patients with optic nerve gliomas and 53% for patients with chiasmal gliomas. In the group of patients with chiasmal tumors, progression-free survival and observed survival rates were significantly lower in infants (10-y PFS: 30%; 10-y OS: 37%), in patients with neurological deficits (10-y PFS and 10-y OS: 23%), in patients with signs of elevated intracranial pressure (10-y PFS and 10-y OS: 9%), with hydrocephalus (10-y PFS and 10-y OS: 0%), or with impairment of consciousness (10-y PFS and 10-y OS: 17%). Evaluation by computed tomography scanning was associated with a significantly higher probability of PFS. Radiation doses lower than 50 Gy were associated with significantly lower PFS and OS rates. In the Cox multivariate analysis, presence of neurological deficits and radiation dose significantly influenced observed survival. Presence of hydrocephalus significantly influenced progression-free survival.

Conclusions

The prognosis of patients with chiasmal gliomas presenting with neurologic deficits is poor and should be treated at diagnosis. A minimum tumor dose of 50 Gy is recommended.

Analysis of Survival Prognosis for Children with Symptomatic Optic Pathway Gliomas Who Received Surgery

OBJECTIVE

The feasibility and prognosis of surgical treatment for children with optic pathway gliomas (OPGs) is controversial. Therefore this study attempted to evaluate the effects of surgery and discuss prognostic factors related to the survival of children with symptomatic OPGs.

MATERIALS AND METHODS

One-hundred twenty-five children diagnosed with OPGs underwent surgery in the Department of Neurosurgery, Beijing Tiantan Hospital from 2003-2016. In this retrospective study, their demographics, clinical characteristics, treatments, and survival outcomes were investigated and summarized.

RESULTS

Among the 125 patients, the 5-year overall survival (OS) rate and progression-free survival (PFS) rate were 84.1% and 70.6%, respectively. In the univariate analysis, patients who received postoperative radiotherapy (RT) after surgery had significantly better 5-year OS and PFS rates than patients who did not receive RT (P < 0.001 for both comparisons), patients who were 3 years old had better PFS rates than younger patients (P < 0.001), and patients with endocrinology symptoms had significantly worse PFS rates than patients with other symptoms (P = 0.049). In the multiple regression analysis, postoperative treatment with RT and tumors with a lower pathologic grade were better predictors of OS. An age older than 3 years and postoperative treatment with RT were better predictors of PFS.

CONCLUSIONS

Surgery is safe and feasible for children with large volumes of OPGs and symptoms of functional impairment and obstructive hydrocephalus. Furthermore, adjuvant RT after surgery may significantly improve OS and PFS. The pathologic grade is an independent prognostic factor for OS, and the age at diagnosis is an independent prognostic factor for PFS.

Optic Pathway Gliomas: Clinical Manifestation, Treatment, and Follow-Up

OBJECTIVE

Optic pathway gliomas (OPG) are infrequent pediatric brain tumors that affect the optic nerve and the visual pathway in the brain. A wide spectrum of signs and symptoms, such as visual impairment, nystagmus, proptosis, and visual loss, may occur at different stages. Other manifestations, such as hydrocephalus, diancephalic syndrome, neurologic deficits, and growth and developmental delays, may be present as well. Surgical resection, chemotherapy, and radiotherapy are used as treatment strategies. The purpose of this study is to evaluate the clinical presentation of OPG patients and their final outcomes in response to treatment.

METHODS

Thirty-seven patients with an initial diagnosis of OPG were studied as part of a single-center retrospective cohort for their clinical presentation, treatment, and response to treatment over a 10-year period.

RESULTS

The mean age of the patients was 37.1 months, and there was a nearly equal sex distribution. The most prevalent manifestation was visual impairment (94.4%), and other symptoms included nystagmus (50%), growth and developmental delays (27.8%), neurological deficits (19.4%), diencephalic syndrome (13.5%), proptosis (11.1%), and hydrocephalus (29.7%). Tumor staging revealed that 10.8% of the cases were stage A, 54.1% were stage B, and 35.1% were stage C. In 30 evaluable patients, the response to treatment included complete response (CR; 23.3%), partial response (PR; 43.3%), stable disease (23.3%), progressive disease (3.3%), and death due to disease (6.7%). A significant association was detected between tumor staging and the response to treatment, with higher rates of CR and PR in stage B and a higher mortality rate in stage C (p = 0.005).

CONCLUSION

OPG occur more commonly in the first decade of life, with visual disturbance as the most prevalent symptom. Tumor staging and the treatment strategy are proposed to affect the response to treatment, although the specific tumor behavior in each patient should be considered as well.

Principles of radiation therapy

Although resection remains the mainstay in the treatment of gliomas, microscopically complete resection of most central nervous system tumors remains challenging, and is, in fact, rarely accomplished. Considering their invasive nature, gross total resections to clearly negative margins often do or would require removal or transection of functional brain, with likely serious neurologic deficits. Consequently, radiotherapy has emerged as an indispensable component of therapy. It is delivered primarily by external-beam radiotherapy or brachytherapy techniques. Herein, we present the biologic principles, techniques, and applications of radiotherapy in glioma treatment today.

Mortality in Children with Optic Pathway Glioma Treated with Up-Front BB-SFOP Chemotherapy

BACKGROUND

In terms of overall survival (OS), limited data are available for the very long-term outcomes of children treated for optic pathway glioma (OPG) with up-front chemotherapy. Therefore, we undertook this study with the aim of clarifying long-term OS and causes of death in these patients.

METHODS

We initiated and analyzed a historical cohort study of 180 children with OPG treated in France with BB-SFOP chemotherapy between 1990 and 2004. The survival distributions were estimated using Kaplan-Meier method. The effect of potential risk factors on the risk of death was described using Cox regression analysis.

RESULTS

The OS was 95% [95% CI: 90.6-97.3] 5 years after diagnosis and significantly decreased over time without ever stabilizing: 91.6% at 10 years [95% CI: 86.5-94.8], 80.7% at 15 years [95% CI: 72.7-86.8] and 75.5% [95% CI: 65.6-83] at 18 years. Tumor progression was the most common cause of death (65%). Age and intracranial hypertension at diagnosis were significantly associated with a worse prognosis. Risk of death was increased by 3.1[95% CI: 1.5-6.2] (p=0.002) for patients less than 1 year old at diagnosis and by 5.2[95% CI: 1.5-17.6] (p=0.007) for patients with initial intracranial hypertension. Boys without diencephalic syndrome had a better prognosis (HR: 0.3 [95% CI: 0.1-0.8], p=0.007).

CONCLUSIONS

This study shows that i) in children with OPG, OS is not as favorable as previously described and ii) patients can be classified into 2 groups depending on risk factors (age, intracranial hypertension, sex and diencephalic syndrome) with an OS rate of 50.4% at 18 years [95% CI: 31.4-66.6] in children with the worst prognosis. These findings could justify, depending on the initial risk, a different therapeutic approach to this tumor with more aggressive treatment (especially chemotherapy) in patients with high risk factors.

Optic pathway gliomas

Optic pathway gliomas (OPGs) are among the most challenging neoplasms in modern pediatric neuro-oncology. Recent technological advances in imaging, surgery, and chemotherapy may lead to better understanding of the pathophysiology and better clinical results. This chapter reviews these advances and the current treatment paradigms.

Radiotherapy in pediatric pilocytic astrocytomas. A subgroup analysis within the prospective multicenter study HIT-LGG 1996 by the German Society of Pediatric Oncology and Hematology (GPOH)

PURPOSE

We evaluated clinical outcomes in the subset of patients who underwent radiotherapy (RT) due to progressive pilocytic astrocytoma within the Multicenter Treatment Study for Children and Adolescents with a Low Grade Glioma HIT-LGG 1996.

PATIENTS AND METHODS

Eligibility criteria were fulfilled by 117 patients. Most tumors (65 %) were located in the supratentorial midline, followed by the posterior fossa (26.5 %) and the cerebral hemispheres (8.5 %). Median age at the start of RT was 9.2 years (range 0.7-17.4 years). In 75 cases, external fractionated radiotherapy (EFRT) was administered either as first-line nonsurgical treatment (n = 58) or after progression following primary chemotherapy (n = 17). The median normalized total dose was 54 Gy. Stereotactic brachytherapy (SBT) was used in 42 selected cases.

RESULTS

During a median follow-up period of 8.4 years, 4 patients (3.4 %) died and 33 (27.4 %) experienced disease progression. The 10-year overall (OS) and progression-free survival (PFS) rates were 97 and 70 %, respectively. No impact of the RT technique applied (EFRT versus SBT) on progression was observed. The 5-year PFS was 76 ± 5 % after EFRT and 65 ± 8 % after SBT. Disease progression after EFRT was not influenced by gender, neurofibromatosis type 1 (NF1) status, tumor location (hemispheres versus supratentorial midline versus posterior fossa), age or prior chemotherapy. Normalized total EFRT doses of more than 50.4 Gy did not improve PFS rates.

CONCLUSION

EFRT plays an integral role in the treatment of pediatric pilocytic astrocytoma and is characterized by excellent tumor control. A reduction of the normalized total dose from 54 to 50.4 Gy appears to be feasible without jeopardizing tumor control. SBT is an effective treatment alternative.

Visual outcomes in pediatric optic pathway glioma after conformal radiation therapy

PURPOSE

To assess visual outcome prospectively after conformal radiation therapy (CRT) in children with optic pathway glioma.

METHODS AND MATERIALS

We used CRT to treat optic pathway glioma in 20 children (median age 9.3 years) between July 1997 and January 2002. We assessed changes in visual acuity using the logarithm of the minimal angle of resolution after CRT (54 Gy) with a median follow-up of 24 months. We included in the study children who underwent chemotherapy (8 patients) or resection (9 patients) before CRT.

RESULTS

Surgery played a major role in determining baseline (pre-CRT) visual acuity (better eye: P=.0431; worse eye: P=.0032). The visual acuity in the worse eye was diminished at baseline (borderline significant) with administration of chemotherapy before CRT (P=.0726) and progression of disease prior to receiving CRT (P=.0220). In the worse eye, improvement in visual acuity was observed in patients who did not receive chemotherapy before CRT (P=.0289).

CONCLUSIONS

Children with optic pathway glioma initially treated with chemotherapy prior to receiving radiation therapy have decreased visual acuity compared with those who receive primary radiation therapy. Limited surgery before radiation therapy may have a role in preserving visual acuity.

Pediatric suprasellar lesions

Pediatric brain tumors have always been challenging as well as intriguing in their anatomical, surgical, and postsurgical management-related issues. They are a heterogeneous set of pathologies involving different age groups in childhood and also differ widely from their adult counterparts as far as adjuvant therapies are concerned. Though neurosurgeons across the world are radical in surgery for most of the pediatric tumors, it can often be at the cost of future quality of life in suprasellar tumors. As the time has gone by, the pendulum has swung toward rather conservative and maximal safe surgical resections with adjuvant therapies coming to the forefront. Hence, the aim is to achieve a good quality of life for these children along with a control of tumor growth (rather than cure) and to again tackle the tumors, if required, once these children reach adolescence or adulthood. We have reviewed the literature for different pediatric suprasellar tumors and discussed their current management giving our perspective with illustrative cases.

Neuro-oncology of Neurofibromatosis Type 1

Neurofibromatosis type 1 (NF1) is an autosomal dominant disorder with an incidence of about 1:2500 to 1:3000. It is caused by a germline inactivating mutation of the NF1 gene on chromosome 17. Patients with NF1 are at increased risk of developing a variety of tumors of the peripheral and central nervous system, including neurofibromas, plexiform neurofibromas, malignant peripheral nerve sheath tumors, and low-grade gliomas of the optic nerves and other cerebral structures. Rarely, they develop high-grade gliomas. Although they are rare, these hereditary tumor syndromes involving the nervous system must be recognized in patients and their families, as early diagnosis may alter management and ultimately improve outcome. Additional insight into the molecular mechanisms causing these syndromes and their relationship with the clinical features will allow the development and implementation of screening and prevention strategies for these diseases. Management of these lesions is difficult and requires specific skills and the collaborative work of neurosurgeons, radiation therapists, neurologists, and oncologists. Ideally, patients should be managed in comprehensive centers with specific expertise in the management of patients with NF1. This review describes current and developing therapies for managing the neuro-oncologic manifestations of NF1.

A multivariate analysis of factors determining tumor progression in childhood low-grade glioma: a population-based cohort study (CCLG CNS9702)

The purpose of this study was to identify risk factors for the progression of low-grade glioma in children from a large population-based cohort. Patient and tumor details of a national cohort of children with low-grade glioma, recruited into an international multidisciplinary clinical strategy, were subjected to univariate and multivariate analyses of progression-free survival and overall survival. From the cohort of 798 patients, 639 patients were eligible, with a median age 6.71 years (0.26-16.75 years); 49% were males; 15.9% had neurofibromatosis type 1, 63.7% pilocytic astrocytoma, 5.9% fibrillary astrocytoma, 4.2% mixed neuronal-glial tumors, and 3.6% others; 21.1% were diagnosed clinically. Anatomically implicated were 31.6% cerebellum, 24.6% chiasma/hypothalamus, 16.0% cerebral hemispheres, 9.9% brain stem, 6.1% other supratentorial midline structures, 5.9% optic nerve only, 4.5% spinal cord, and 1.4% others. The 5-year overall survival and progression-free survival in the whole cohort were 94.6% and 69.4%, respectively. There was a significant association between age and site (P < .001) and extent of tumor resection and site (P < .001). Multivariate analysis identified young age, fibrillary astrocytoma, and extent of surgical resection as significant independent risk factors for progression. Hypothalamic/chiasmatic tumors demonstrated the most sustained tendency to progress. In conclusion, the influence of age and anatomical site upon the risk of tumor progression suggests that these factors strongly influence tumor behavior for the majority of pilocytic tumors. Age <1 year and 1-5 years, fibrillary histology, completeness of resection, and chiasmatic location are candidates for stratification in future studies.

[Optic nerve glioma in children]

Optic pathway gliomas are rare tumors accounting for 3-5% of brain tumors in children; 90% are observed in children. They account for 4% of orbital tumors in children. Association with NF 1 is classical and the incidence of NF 1 in patients with optic pathway gliomas is estimated at 30-58%. Usually these tumors are pilocytic astrocytomas and their regression, particularly in patients with NF 1, has been described. Exophthalmos and loss of visual acuity or blindness are the usualpresentation in progressive disease. CT and above all MRI study of the orbit and the brain are necessary to make a complete evaluation of the disease. Gross total removal of the tumor provides 100% cure, but surgery can be proposed only for growing tumor with severe exophthalmos and no useful field of view or blindness. Chemotherapy must be proposed as first-line treatment for growing tumor with moderate exophthalmos and useful vision when the tumor is strictly confined in the orbit. The place of radiotherapy for pure intraorbital gliomas has not been defined and proton beam therapy has to be evaluated.

Natural history and outcome of optic pathway gliomas in children

BACKGROUND

The optimal management of optic pathway gliomas (OPGs) is complicated by their variable natural history, the association with neurofibromatosis type 1 (NF1) and difficulties in defining progression and response to treatment.

METHODS

This study is a retrospective review of all children presenting to a single institution with an OPG between 1990 and 2004.

RESULTS

Of the 133 children included, 78 (59%) had NF1; 87 (71 NF1) were observed initially, of whom 23 (11 NF1) subsequently required treatment. Forty-six patients received immediate treatment. Initial treatment, without or with an observation period, comprised chemotherapy alone (32, 11 NF1); debulking + chemotherapy (15, 4 NF1); gross total resection (6); radiotherapy (2); debulking + radiotherapy (3); and debulking only (12, 3 NF1). Overall, 16 patients were irradiated during the study period. Four children died (overall survival at 5 and 10 years was 97.6% and 94.6% for those who required treatment). Progression-free survival (PFS) for the 69 patients who needed treatment was 48%. There was no difference in PFS between chemotherapy versus chemotherapy + debulking or debulking alone. PFS for the NF1 patients who required treatment was similar to that of non-NF1 patients. Mean follow-up time was 9.0 (range 0.6-18.0, median 8.6) years.

CONCLUSIONS

The study confirms the complexity of OPGs and that NF1 is a major determinant of the resultant behavior of the tumor.

Neurooncology of familial cancer syndromes

The majority of tumors of the nervous system are sporadic. However, a subset of patients with tumors and their families are predisposed to developing cancers of the central nervous system and other organs because of a germline mutation. In the last decade, many of the genes responsible for these typically autosomal dominant familial tumor syndromes have been identified. Additionally, our understanding of the mechanisms of carcinogenesis in these syndromes has increased, allowing for more targeted therapies for these patients as well as those with sporadic cancers. Because these patients present a unique set of issues regarding diagnosis and neurooncological management, the most common familial cancer syndromes involving the nervous system are reviewed: neurofibromatosis type 1 and 2; tuberous sclerosis complex; von Hippel Lindau, Li-Fraumeni, Gorlin, and Turcot syndrome.

Pediatric low-grade gliomas

Pediatric low-grade gliomas encompass a heterogeneous set of tumors of different histologies. Cerebellar pilocytic astrocytomas occur most frequently followed by supratentorial diffuse fibrillary astrocytomas. Recent research has implicated activation of the RAS/RAF/MEK pathway in tumorigenesis of these tumors. Surgery is the mainstay of therapy. Overall survival rates for patients whose tumors are completely resected are 90% or greater, 10 years from diagnosis. Conversely, most optic pathway/hypothalamic, deep midline, and brain stem gliomas have minimal potential for resection; these tumors can be difficult to treat and deserve special attention. Combination chemotherapy is currently recommended as front-line adjuvant treatment for progressive or recurrent tumors. Second-line radiotherapy can also improve overall survival but is associated with more frequent and significant neurocognitive, endocrine, and other long-term toxicities.

Natural history and clinical management of optic pathway glioma

Twenty-five consecutive unselected patients with optic pathway glioma (OPG) were primarily observed and treated if progression was evident. Diagnosis was based on MRI. The natural history of the OPG disease was more indolent in 12 patients with neurofibromatosis 1 (NF1) than in the others, and regressions were commonly observed. Thirteen non-NF1 patients had larger rumours at diagnosis and more progressions. There were five intra-orbital optic nerve tumours (one with progression), 19 chiasmatic tumours (12 with progression) and one diffuse tumour. OPG emerges before the age of 7 years in NF1 patients, and in non-NF1 patients also in older patients including adults. Progressive intra-orbital OPGs are best treated by surgical resection. Progressive chiasmatic tumours are best treated by radiotherapy and respond well by marked regression. Exceptionally, exophytic chiasmatic tumours may be treated by chiasm preserving surgery.

Anterior Visual Pathway Gliomas: The Last 30 Years

Modern neuroimaging provides excellent characterization of anterior visual pathway gliomas, often obviating the need for biopsy of the tumor. Management remains controversial, but if there is progression, chemotherapy is preferred for young patients. Stereotactically guided conformal radiotherapy and proton beam radiotherapy allow smaller, more precise doses of radiation to be administered and can be considered in older children with progressive disease. A mouse model of NF-1 with optic pathway gliomas has the potential to provide important insights into the development of gliomas as well as serving as a model for their effective treatment.

Radiation therapy for visual pathway tumors

The multimodality management of visual pathway tumors frequently involves radiation. Most commonly, photons are delivered via multiple focused beams aimed at the tumor while sparing adjacent tissues. The dose can be delivered in multiple treatments (radiation therapy) or in a single treatment (radiosurgery). Children with visual pathway gliomas should be treated with chemotherapy alone, delaying the use of radiation therapy until progression. Definitive radiation therapy of optic nerve sheath meningiomas results in stable vision in most patients. Radiation therapy or radiosurgery for pituitary tumors can result in control of both tumor growth and hormone hypersecretion. Postoperative radiation therapy or radiosurgery of craniopharyngiomas significantly improves local control rates compared with surgery alone. Radiation therapy is highly effective for eradicating orbital pseudolymphoma and lymphoma. The risk of complications from radiation treatment is dependent on the organ at risk, the cumulative dose it receives, and the dose delivered per fraction.

Responsiveness of progressive optic pathway tumors to cisplatin-based chemotherapy in children

BACKGROUND

Though the pathology of optic pathway tumor is mostly pilocytic astrocytoma, the benign tumor behaves like malignant tumor because total resection is not feasible. Adjuvant chemotherapy might be a reasonable strategy for management of these low grade tumors which keep growing. We evaluate the responsiveness of optic pathway tumor to cisplatin-based chemotherapy.

METHODS

Patients with unresectable and progressive optic pathway tumors received conventional chemotherapy including cisplatin, etoposide, and vinblastine were enrolled in this study from 1992 to 2007. Patients treated with radiotherapy previously were excluded. Brain MRI was performed every 3 months to evaluate the objective response to chemotherapy.

RESULTS

There are seven girls and nine boys enrolled in this study. The median age at diagnosis was 30 months old (range from 3 months to 11 years old). The median follow-up duration was 81.5 months (range from 24 months to 14.5 years). The pathology showed pilocytic astrocytomas in 11 patients, astrocytoma in one patient, and anaplastic astrocytomas in two patients. The 6-month progression-free survival (PFS) is 100%, 12-month PFS is 81.3%, 3-year PFS is 71.4% and 5-year PFS is 55.5% respectively. The toxicity of the cisplatin-based chemotherapy showed mild bone marrow suppression in 13 patients (81.3%), infection in nine patients (56.3%), gastrointestinal discomfort in seven patients (43.8%), renal insufficiency in two patient (12.5%), cerebral salt wasting syndrome with hyponatremia in one patient (6.25%) and high pitch hearing loss in two patients (12.5%).

CONCLUSION

Cisplatin-based chemotherapy is an effective regimen for control of progressive optic pathway tumors.

Outcome analysis of childhood low-grade astrocytomas

BACKGROUND

We aimed to determine the long-term natural history of low-grade astrocytomas (LGA) in children, with respect to pathology, and to evaluate influence of treatment on survival.

PATIENTS AND METHODS

A consecutive cohort of patients < or =21 years with surgically confirmed LGA from 1965 to 1996 was assembled. All available pathology specimens were reviewed, masked to original diagnosis, patient data, and neuroimaging.

RESULTS

Two hundred seventy-eight children (160 males; mean age 9.1 years; tumor location: 77 cerebrum, 62 cerebellum, 51 hypothalamic, 30 thalamus, 9 ventricle, 40 brainstem, and 9 spine) were assessed. Among 246 specimens reviewed, diagnoses were 135 pilocytic astrocytoma (PA), 27 diffuse astrocytoma (DA), 75 unclassifiable well-differentiated astrocytoma (NOS), and 9 subependymal giant cell astrocytoma. At 5 and 10 years from initial surgery, for all LGA overall survival (OS) was 87% and 83%, while progression-free survival (PFS) was 55% and 42%, respectively. Original pathology diagnoses did not predict PFS (P = 0.47), but reviewed diagnoses were significantly associated with PFS (P = 0.007). Reviewed diagnoses were highly associated with OS (P < 0.0001), with 5-year OS for PA 96%, DA 48%, and NOS 86%; these differences remained significant when stratified by location or extent of resection. Among patients with residual tumor after surgery, 5-year PFS was 48% with observation alone (n = 114), no different (P = 0.32) from that achieved with immediate irradiation (n = 86).

CONCLUSION

LGA, particularly PA, have excellent long-term OS. While tumor location and resection extent affect outcome, pathologic diagnosis when carefully interpreted significantly influences long-term survival. Immediate postoperative irradiation does not confer an advantage in delaying first progression in children with residual PA.

Management of optic-hypothalamic gliomas in children: still a challenging problem

Optic pathway-hypothalamic gliomas (OPHGs) are rare, often unresectable tumors that mostly occur in childhood. Their biological behavior is unpredictable, although they tend to follow an aggressive clinical course in infants and a benign course in children with neurofibromatosis type 1. Optimal management is still controversial. Nonprogressing OPHGs are usually followed by surveillance alone. Surgery is advocated for progressing tumors to decompress the optic pathways, obtain a quick relief from intracranial hypertension and allow histologic examination (when needed). The current trend is in favor of conservative surgical behavior, except for resectable tumors. Chemotherapy is increasingly used in the management of OPHGs, especially in infants, to delay radiotherapy. Carboplatin and vincristine are the most frequently used drugs, although several chemotherapeutic agents in different combinations are currently employed with good results. Radiotherapy is utilized in children over 5 years of age as an adjuvant or as an alternative to surgery. The prognosis of OPHGs is quite good, with regard to the overall survival rate (70-100% at 5 years), but less favorable in terms of late morbidity.

Advances in radiation therapy for brain tumors

Radiation therapy is used postoperatively as adjunctive therapy to decrease local failure; to delay tumor progression and prolong survival; as a curative treatment; as a therapy that halts further tumor growth; to alter function; and for palliation. Registration of MRI scan data sets with the treatment-planning CT scan is essential for accurate definition of the tumor and surrounding organs at risk. Integrating additional imaging studies that reflect the biologic characteristics of central nervous system tumors is an area of active research. Conformal treatment delivery is used to spare adjacent normal tissue from receiving unnecessary dose. In the dose range used when treating these tumors, the probability of causing serious late toxicity is relatively low and secondary malignancies are rare.