Postoperative radiotherapy for ganglioglioma; report of three cases and review of the literature

Pearls and Pitfalls of Imaging in Pediatric Brain Tumors

The central nervous system (CNS) tumors constitute the most common type of solid tumors in the pediatric population. The cerebral and cerebellar parenchyma are the most common site of pediatric CNS neoplasms. Imaging plays an important role in detection, characterization, staging and prognostication of brain tumors. The focus of the current article is pediatric brain tumor imaging with emphasis on pearls and pitfalls of conventional and advanced imaging in various pediatric brain tumor subtypes. The article also elucidates changes in brain tumor terms and entities as applicable to pediatric patients, updated as per World Health Organization (WHO) 2016 classification of primary CNS tumors. This classification introduced the genetic and/or molecular information of primary CNS neoplasms as part of comprehensive tumor pathology report in the routine clinical workflow. The concepts from 2016 classification have been further refined based on current research, by the Consortium to Inform Molecular and Practical Approaches to CNS Tumor Taxonomy (cIMPACT-NOW) group and published in the form of updates. The updates serve as guidelines in the time interval between WHO updates and expect to be broadly adopted in the subsequent WHO classification. The current review covers most pediatric brain tumors except pituitary tumors, meningeal origin tumors, nerve sheath tumors and CNS lymphoma/leukemia.

Diagnosis and Therapeutic Management of Ventricular Gangliogliomas: An Illustrated Review

BACKGROUND

Gangliogliomas (GGs) are extremely rare benign neoplasms frequently located within the temporal lobe that usually present with seizures. GGs growing predominantly within the ventricular system (VGGs) are even more infrequent, so definite conclusions concerning their diagnosis and therapeutic management are lacking.

METHODS

A retrospective review of case reports of VGGs was performed from the introduction of modern imaging techniques, including 4 new illustrative cases treated in our department.

RESULTS

Thirty-four cases were collected. Ages ranged from 10 to 71 years (mean, 26.62 years), and 55.9% were male. Most patients developed symptoms related to high intracranial pressure. The lateral ventricles were predominantly involved (58.8%). Obstructive hydrocephalus was observed in 54.5% of patients. Cystic degeneration and calcification were frequently observed. Surgical treatment was carried out in all cases. Morbidity and mortality were 17.6% and 2.9%, respectively. Gross total tumor resection was achieved in 64.5% of patients. Four patients experienced tumor dissemination along the neural axis. More than 90% of patients maintained a good functional status at last follow-up.

CONCLUSIONS

Despite their low incidence, a diagnosis of VGGs should be considered in young male adults who progressively develop intracranial hypertension, caused by a ventricular mass showing signs of cystic degeneration and calcification. Maximal and safe surgical resection represents the gold standard for the treatment of symptomatic VGGs, although total removal is frequently precluded by difficulties in defining appropriate tumor boundaries. Adjuvant radiotherapy should be considered if an incomplete resection was carried out, especially in World Health Organization grade III neoplasms.

Glioneuronal tumors: clinicopathological findings and treatment options

Glioneuronal tumors are very rare CNS neoplasms that demonstrate neuronal differentiation, composed of mixed glial and neuronal cells. The majority of these lesions are low grade and their correct classification is crucial in order to avoid misidentification as ‘ordinary’ gliomas and prevent inappropriate aggressive treatment; nevertheless, precise diagnosis is a challenge due to phenotypic overlap across different histologic subtype. Surgery is the standard of therapeutic approach; literature concerning the benefit of adjuvant treatments is inconclusive and a globally accepted treatment of recurrence does not exist. Targetable mutations in the genes BRAF and FGFR1/2 are recurrently found in these tumors and could take a promising role in future treatment management.

Natural course and prognosis of anaplastic gangliogliomas: a multicenter retrospective study of 43 cases from the French Brain Tumor Database

Background

Anaplastic gangliogliomas (GGGs) are rare tumors whose natural history is poorly documented. We aimed to define their clinical and imaging features and to identify prognostic factors.

Methods

Consecutive cases of anaplastic GGGs in adults prospectively entered into the French Brain Tumor Database between March 2004 and April 2014 were screened. After diagnosis was confirmed by pathological review, clinical, imaging, therapeutic, and outcome data were collected retrospectively.

Results

Forty-three patients with anaplastic GGG (median age, 49.4 y) from 18 centers were included. Presenting symptoms were neurological deficit (37.2%), epileptic seizure (37.2%), or increased intracranial pressure (25.6%). Typical imaging findings were unifocal location (94.7%), contrast enhancement (88.1%), central necrosis (43.2%), and mass effect (47.6%). Therapeutic strategy included surgical resection (95.3%), adjuvant radiochemotherapy (48.8%), or radiotherapy alone (27.9%). Median progression-free survival (PFS) and overall survival (OS) were 8.0 and 24.7 months, respectively. Three- and 5-year tumor recurrence rates were 69% and 100%, respectively. The 5-year survival rate was 24.9%. Considering unadjusted significant prognostic factors, tumor midline crossing and frontal location were associated with shorter OS. Temporal and parietal locations were associated with longer and shorter PFS, respectively. None of these factors remained statistically significant in multivariate analysis.

Conclusions

We report a large series providing clinical, imaging, therapeutic, and prognostic features of adult patients treated for an intracerebral anaplastic GGG. Our results show that pathological diagnosis is difficult, that survivals are only slightly better than for glioblastomas, and that complete surgical resection followed with adjuvant chemoradiotherapy offers longer survival.

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.

Treatment and outcomes for gangliogliomas: a single-center review of 16 patients

Background

Ganglioglioma is a rare and slowly growing benign tumor. We investigated the outcomes of patients who underwent different combination treatments.

Methods

Between 1998 and 2012, 16 patients, including 11 men and 5 women, with a median age of 12.5 years (range, 2.5-65 years) were treated for intracranial gangliogliomas at our institution. The median follow-up period was 5.7 years (range, 48 days-15.6 years). Fifteen cases were included in the outcome assessment because one patient was lost to follow-up. Complete resection was achieved in 8 (53%) patients. Six (40%) patients underwent incomplete resection with or without adjuvant radiotherapy, and one patient with a brainstem tumor underwent only stereotactic biopsy.

Results

Gangliogliomas predominantly affected young (87.5%), male patients and most frequently presented with seizures (64%). Of eight patients who underwent complete resection, seven did not show recurrence, whereas only three of six with incomplete resection showed no recurrence. Four patients with recurrence received salvage treatments (two repeat surgeries and two radiosurgeries). A tumor control rate of 93% (14/15) was achieved at the last follow-up. No recurrence or malignant changes were observed after a median follow-up of 12 and 4.5 years in four patients who received gamma knife (GK) radiosurgery as adjuvant and salvage treatment.

Conclusion

Complete resection produced the best outcomes and incomplete resection followed by adjuvant or salvage treatments showed favorable outcomes. In patients who are not eligible for complete resection because of tumor location or potential neurologic deficits following surgery, GK radiosurgery should be considered for the treatment of residual or recurrent tumors.

Intramedullary gangliogliomas: clinical features, surgical outcomes, and neuropathic scoliosis

Intramedullary spinal cord gangliogliomas are rare tumors composed of glial components and ganglion cells. These gangliogliomas are generally considered as slow-growing tumors, corresponding histologically to WHO grade I or II. There are few reports of large case series of intramedullary spinal cord gangliogliomas from a single center. We retrospectively reviewed a consecutive series of 18 patients with pathologically diagnosed ganglioglioma. Clinical manifestations, radiological features, treatment and follow-up data, and concomitant scoliosis were investigated. The mean age at diagnosis was 27.5 years, with a slight female predominance. The primary clinical symptoms were sensorimotor deficits. Magnetic resonance (MR) imaging manifestations varied considerably. Some associated, but not necessary, features were found, such as young age at onset, large tumor dimension, and bony changes. Scoliosis was observed in seven patients. Remnant tumor progression was observed in five patients during the follow-up period, and no deaths occurred. The last neurological evaluation showed functional improvement from preoperative status in five patients. Differential diagnosis of ganglioglioma based on MR images alone is challenging, but the combination of some characteristic features can be helpful. An accurate diagnosis of ganglioglioma depends on pathological criteria. Despite the benign course of ganglioglioma, considerable growth may affect its resectability and prognosis. The extent of resection should be meticulously planned, and the potential risk of recurrence and neurological deterioration should be evaluated. The concomitant scoliosis is noteworthy.

Long-term outcomes for low-grade intracranial ganglioglioma: 30-year experience from the Mayo Clinic

OBJECT

Gangliogliomas comprise less than 1% of all brain tumors and occur most often in children. Therefore, there are a limited number of patients and data involving the use or role of adjuvant therapy after subtotal resections (STRs) of gangliogliomas. The objective of this study was to examine and review the Mayo Clinic experience of 88 patients with gangliogliomas, their follow-up, risk of recurrence, and the role of radiation therapy after STR or only biopsy.

METHODS

Eighty-eight patients with gangliogliomas diagnosed between 1970 and 2007 were reviewed. Data on clinical outcomes and therapy received were analyzed. The Kaplan-Meier method was used to estimate progression-free survival (PFS) and overall survival.

RESULTS

The median age at diagnosis was 19 years. The median potential follow-up as of June 2008 was 142 months (range 9-416 months). Fifteen-year overall survival was 94%, median PFS was 5.6 years, with a 10-year PFS rate of 37%. Progression-free survival was dramatically affected by extent of initial resection (p < 0.0001).

CONCLUSIONS

This single-institution retrospective series of patients with gangliogliomas is unique given its large cohort size with a long follow-up duration, and confirms the excellent long-term survival rate in this group. The study also shows the importance of resection extent on likelihood of recurrence. Patients with gangliogliomas who undergo STR or biopsy alone have poor PFS. Radiation therapy may delay time to progression in patients with unresectable disease.

Early surgical intervention in adult patients with ganglioglioma is associated with improved clinical seizure outcomes

Gangliogliomas are rare central nervous system tumors, most commonly affecting children and young adults. Chronic seizure and epilepsy are the most frequent presentation of patients with gangliogliomas. In this report, we review the modern literature regarding the effects of early surgical intervention on the clinical outcome of patients with ganglioglioma. A boolean search of PubMed using key words "ganglioglioma", "adult", "seizure control", "treatment", "surgical intervention", and "observation", alone and in combination was performed. The inclusion criteria for articles were that: (i) clinical outcomes were reported specifically for gangliogliomas; (ii) data were reported for adult patients older than the age of 18 years; (iii) treatment data were included for the treatment of gangliogliomas; and (iv) ganglioglioma was the only pathological diagnosis for the evaluation of the tumor. Data were analyzed as a whole then stratified into two groups: early and late treatment intervention. The query identified a total of 99 articles including 1,089 cases of ganglioglioma meeting our inclusion and exclusion criteria. There was a 55% prevalence of males, representing a statistically significant predilection (51-59%, 95% confidence interval). Seizure control was significantly improved when surgical intervention occurred less than 3 years after symptom onset (78% versus 48%; p = 0.0001). Ganglioglioma in adults represents a rare group of tumors, and our systematic analysis suggests a higher prevalence in males. Our findings also support that an early surgical intervention is significantly associated with improved clinical seizure control.

Intraventricular ganglioglioma: a short illustrated review

The following review of the literature describes the ganglioglioma, an uncommon mixed glioneuronal neoplasm, most often of low-grade histology, with a small, albeit well-documented, malignant potential. These tumors exhibit a strong epileptogenic propensity and most often present as new onset seizures or are discovered after a long history of refractory epilepsy. Despite their indolent course, the importance of gross total resection is well recognized to prevent anaplastic and malignant degeneration. Morphologically, the neoplasm is often cystic with an enhancing mural nodule, but can also be entirely solid. They are most often found in the temporal lobe but have been found throughout the neuraxis. An exceedingly rare location of the ganglioglioma is within the lateral ventricle. A systematic literature search revealed only eight reports documenting the occurrence of a ganglioglioma within the lateral ventricle. We describe an illustrative case of an intraventricular ganglioglioma with a prominent cystic component and enhancing mural nodule, which represents the classic radiographic appearance of gangliogliomas described in other locations. A superior parietal lobule approach offered excellent surgical access for tumor removal and the patient has remained free of neurological deficits following surgery. Regardless of location within the central nervous system, ganglioglioma should be on the differential diagnosis for any cystic mass with a mural nodule, particularly in the setting of epilepsy.

Factors contributing to resectability and seizure outcomes in 44 patients with ganglioglioma

OBJECTIVES

The purpose of this retrospective study was to evaluate causes contributing to surgical resectability and seizure outcomes depending on various clinical and surgical factors.

PATIENTS AND METHODS

The records of 44 patients with gangliogliomas surgically treated between April 1986 and March 2007, were retrospectively reviewed to assess presenting symptoms, resectability and seizure outcomes.

RESULTS

Tumors were located in the supratentorial areas in 33 cases, the infratentorial area in 9 cases and the spinal cord in 2 cases. Thirty-five cases underwent gross total removal and 9 cases underwent subtotal resection. Only 2 cases underwent postoperative radiotherapy and 2 cases underwent gamma knife surgery. Twenty-six patients presented seizure symptoms of which 22 cases were located in temporal lobe and 4 cases were located in the extratemporal lobe. Twenty-three patients (88.5%) were seizure-free after surgery. Two patients were Engel class II and another was Engel class III.

CONCLUSION

We concluded that tumor location and seizure-presenting symptoms are good predictors of gross total removal. Gross total removal of ganglioglioma had a better chance of leaving the patient seizure free after surgery rather incomplete resection. Our data do not support the concept that surgical methods, invasive monitoring and surrounding cortical malformation correlated with seizure-free outcome.

Radiotherapy after subtotally resected or recurrent ganglioglioma

PURPOSE

Gangliogliomas can recur after subtotal resection (STR). The role of postoperative radiation therapy (RT) is undefined.

METHODS AND MATERIALS

Eight consecutive patients with low-grade gangliogliomas (n = 7) or anaplastic gangliogliomas (n = 1) were treated with RT between 1987 and 2004. Median age was 17 years. Five patients received adjuvant RT after STR at a median time of 6 weeks after surgery. Three patients received salvage RT at a median time of 17 months after surgery. The median dose of RT was 54 Gy. Control was defined as no progressive disease on serial imaging. Median follow-up was 8.8 years.

RESULTS

Of the 7 patients with low-grade gangliogliomas, 3 were controlled after RT and 4 recurred locally. Recurrences were controlled with further surgery (n = 2), chemotherapy (n = 1), or re-irradiation (n = 1) (median follow-up, 9 years after salvage therapy). Patients who received adjuvant RT after STR of their low-grade gangliogliomas had an overall local control rate of 75%. All 3 patients who were treated with salvage RT had recurrences in the treated area alone (n = 2) or in the treated area with leptomeningeal spread (n = 1). The patient with an anaplastic ganglioglioma was treated with adjuvant RT, and had recurrence in the radiation field after 4 months, then died 1 month later.

CONCLUSIONS

Adjuvant RT may be indicated to treat select patients with subtotally resected gangliogliomas. Salvage RT for recurrence is probably less effective for long-term control; however, patients who recur may still be candidates for effective salvage therapies in the absence of malignant transformation.

Postoperative radiotherapy in cranial ganglioglioma

We performed an institutional database search for patients with ganglioglioma in order to evaluate postoperative radiotherapy in the light of our experience. This search identified 5 patients with a mean age of 23.3 (range, 9-54 years) treated between April 1994 and April 2003. The latter date was chosen to allow a minimum follow-up of 1 year at the time of our analysis. Median follow up was 7 years (range, 1.5-11 years). Gross total tumor resection could only be achieved in one case, while other four patients had been referred after subtotal tumor excisions. All patients were treated postoperatively with conventionally fractionated (1.8-2 Gy/day) external beam radiotherapy (EBRT) to a total dose of 54-60 Gy. Patients were treated with megavoltage beams using Co(60 )or 6-MV photons. None of the patients were lost to follow up with a median follow up time of 80 months (range, 5.5-122.5 months) and all patients were alive with no evidence of disease at last follow-up. We believe that long term follow-up is necessary to observe the relapse patterns and the significance of postoperative radiotherapy needs to be further evaluated with large patient numbers to remark a conclusive statement.