Radiation therapy of meningiomas

Radiotherapy for meningiomas

Meningiomas are the most common primary central nervous system neoplasm. Despite promising recent progress in elucidating the genomic landscape and underlying biology of these histologically, molecularly, and clinically diverse tumors, the mainstays of meningioma treatment remain maximal safe resection and radiation therapy. The aim of this review of meningioma radiotherapy is to provide a concise summary of the history, current evidence, and future for application of radiotherapy in meningioma treatment.

Coincidental Nasopharyngeal Carcinoma and Ventral Foramen Magnum Meningioma: Case Report and Review of the Literature

Multiple primary tumors at adjacent site are rare. We report a rare case of coincidentally found nasopharyngeal cancer and ventral foramen magnum meningioma. The 68-year-old male patient presented with a year history of ataxia. Radiological examination revealed lesions in the nasopharyngeal space and ventral foramen magnum. A needle aspiration biopsy for nasopharyngeal space and surgical removal for foramen magnum lesion were performed. The pathological diagnoses were nasopharyngeal cancer and meningioma, respectively. The concomitant occurrence of these two tumors is very rare and there is no known association between these two tumors. We report a case of ventral foramen magnum meningioma simultaneously present with nasopharyngeal carcinoma.

Outcomes following upfront radiation versus monitoring in atypical meningiomas: 16-year experience at a tertiary medical center

Background

The role of postoperative upfront radiotherapy (RT) in the management of gross totally resected atypical meningiomas remains unclear. This single-center retrospective review of newly diagnosed histologically confirmed cases of World Health Organization (WHO) Grade II atypical meningioma at Weill Cornell Medicine from 2004 to 2020 aims to compare overall survival (OS) and progression-free survival (PFS) of postoperative upfront RT versus observation, stratified by resection status (gross total resection [GTR] vs subtotal resection [STR]).

Methods

Ninety cases of atypical meningioma were reviewed (56% women; median age 61 years; median follow-up 41 months).

Results

In patients with GTR, hazard ratio (HR) of PFS was 0.09 for postoperative upfront RT versus observation alone (95% confidence interval [CI] 0.01–0.68; P = .02), though HR for OS was not significant (HR 0.46; 95% CI 0.05–4.45; P = .5). With RT, PFS was 100% at 12 and 36 months (compared to 84% and 63%, respectively, with observation); OS at 36 months (OS36) was 100% (compared to 94% with observation). In patients with STR, though PFS at 36 months was higher for RT arm versus observation (84% vs 74%), OS36 was 100% in both arms. HR was not significant (HR 0.76; 95% CI 0.16–3.5; P = .73).

Conclusions

This retrospective study suggests postoperative upfront RT following GTR of atypical meningioma is associated with improved PFS compared to observation. Further studies are required to draw conclusions about OS.

Advances in multidisciplinary therapy for meningiomas

Surgery has long been established as the first-line treatment for the majority of symptomatic and enlarging meningiomas, and evidence for its success is derived from retrospective case series. Despite surgical resection, a subset of meningiomas display aggressive behavior with early recurrences that are difficult to treat. The decision to radically resect meningiomas and involved structures is balanced against the risk for neurological injury in patients. Radiation therapy has largely been used as a complementary and safe therapeutic strategy in meningiomas with evidence primarily stemming from retrospective, single-institution reports. Two of the first cooperative group studies (RTOG 0539 and EORTC 22042) evaluating the outcomes of adjuvant radiation therapy in higher-risk meningiomas have shown promising preliminary results. Historically, systemic therapy has resulted in disappointing results in meningiomas. However, several clinical trials are under way evaluating the efficacy of chemotherapies, such as trabectedin, and novel molecular agents targeting Smoothened, AKT1, and focal adhesion kinase in patients with recurrent meningiomas.

Isolated Extracranial Intraosseous Metastasis of an Intracranial Meningioma following Bevacizumab Therapy: Case Report and Review of the Literature

Meningiomas account for a significant proportion of all primary intracranial tumors; distant metastasis is quite rare. We report a patient with resected, atypical meningioma. The patient's clinical course over 5 years included two craniotomies, a course of radiation, and a shortened course of bevacizumab. Only 5 months after starting bevacizumab, the patient developed an isolated left clavicular pathological fracture attributable to metastatic anaplastic meningioma. This constitutes the first report of meningioma with isolated extracranial intraosseous metastasis in the modern English literature and highlights concerns associated with the use of anti-angiogenic agents in promoting more invasive tumor phenotypes upon disease recurrence.

Classification of Meningiomas Based on Their Surgical Removal, World Health Organization Grade, and Cytogenetic Profile: A Treatment Algorithm

BACKGROUND

Meningiomas are the most common primary intracranial tumor, but the lack of prospective randomized trials has led to different guidelines for their treatment. We proposed a classification of meningiomas that considers surgical removal, histology, and cytogenetic profile, based on a literature review of these 3 criteria. The classification can be used to guide adjuvant treatment and follow-up.

METHODS

A retrospective literature review was performed of PubMed from 2007 to 2016. Search terms were "meningioma," "surgery," "WHO classification," "cytogenetic," and "algorithm."

RESULTS

Meningiomas were classified into 5 groups (A-E) according to the Simpson resection grade, World Health Organization grade, and cytogenetic profile. Adjuvant therapy, follow-up magnetic resonance imaging, and management of recurrence and/or regrowth were proposed according to the classification.

CONCLUSIONS

The proposed meningioma classification was based on our experience and retrospective evidence collated from the literature and supported by recommendations. The application of the classification criteria yielded an algorithm for treatment and follow-up of patients with meningioma.

Lessons from surgical outcome for intracranial meningioma involving major venous sinus

Intracranial meningiomas involving the major venous sinus (MVS) pose several complication risks upon performing radical resection. Some surgeons consider MVS invasion a contraindication for a complete resection of meningioma, and others suggest total resection followed by venous reconstruction. The aim of the study was to analyze our surgical results and discuss management strategy for intracranial meningiomas involving the MVS. Between 1993 and 2011, 107 patients with intracranial meningiomas involving MVS underwent surgery in our institution. Clinicoradiological features including pathological features and operative findings were retrospectively analyzed. Median follow-up duration was 60.2 months (range, 6.2-218.2 months). Distributions of tumor cases according to the involved sinus were as follows: 86% parasagittal, 10.3% tentorial, and 3.7% peritorcular. Simpson Grade I/II removal was achieved in 93 of 107 patients (87%). Partially or totally occluded MVS by their meningiomas (Sindou classification IV and V) was found in 39 patients (36%). Progression rate was 12% (13/107) and progression-free survival rates were 89%, 86%, and 80% at 5, 7, and 10 years, respectively. Sindou classification (IV/V) and Karnofsky performance status (KPS) score 6 month after the surgery (KPS < 90) were predictive factors for progression in our study (P = 0.044 and P = 0.001, respectively). The resection degree did not reach statistical significance (P = 0.484). Interestingly, there was no progression in patients that underwent radiation therapy or gamma knife radiosurgery for residual tumor. There were no perioperative deaths. Complication rate was 21% with brain swelling being the most common complication. There was no predictive factor for occurrence of postoperative complication in this study. In conclusion, complete tumor resection with sinus reconstruction did not significantly prevent tumor recurrence in intracranial meningioma involving MVS. Considering the complications from this procedure as it has possibly related with reduced postoperative KPS score, the tumor should be removed as much as possible while leaving remnant portion with significant invasion of sinus or drainage vein. Following radiation therapy or gamma knife radiosurgery for a remnant or recurred meningioma might then be justified.

Foramen Magnum Meningioma: a Case Report and Review of Literature

Introduction:

Meningiomas are slow-growing benign tumors that arise at any location where arachnoid cells reside. Although meningiomas account for a sizable proportion of all primary intracranial neoplasms (14.3–19%), only 1.8 to 3.2% arise at the foramen magnum. Their indolent development at the craniocervical junction makes clinical diagnosis complex and often leads to a long interval between onset of symptoms and diagnosis.

Case report:

We report a case of a 79-year-old male patient, presented with ataxia and sense of threatening fainting during verticalization. Magnetic resonance imaging revealed the presence of meningioma in the right side of craniospinal junction.

Case-Based Review: meningioma

Meningioma is by far the most common primary intracranial tumor in adults. Treatment of meningioma is complex due to a tremendous amount of variability in tumor behavior. Many patients are incidentally found to have tumors that will remain asymptomatic throughout their lives. It is important to identify these patients so that they can be spared from potentially morbid interventions. On the other end of the spectrum, high-grade meningiomas can behave very aggressively. When treatment is necessary, surgical resection is the cornerstone of meningioma therapy. Studies spanning decades have demonstrated that extent of resection correlates with prognosis. Radiation therapy, either in the form of external beam radiation therapy or stereotactic radiosurgery, represents another important therapeutic tool that can be used in place of or as a supplement to surgery. There are no chemotherapeutic agents of proven efficacy against meningioma, and chemotherapy treatment is generally reserved for patients who have exhausted surgical and radiotherapy options. Ongoing and future studies will help to answer unresolved questions such as the optimum use of radiation in resected WHO grade II meningiomas and the efficacy of additional chemotherapy agents.

Epidemiology of meningiomas post-Public Law 107-206: The Benign Brain Tumor Cancer Registries Amendment Act

BACKGROUND

The current analysis follows the implementation of Public Law 107-260, the Benign Brain Tumor Cancer Registries Amendment Act, which mandated the collection of nonmalignant brain tumors.

METHODS

Meningiomas were selected from the Surveillance, Epidemiology, and End Results (SEER) Program database for the years 2004 to 2011. Demographic and clinical characteristics, initial treatment patterns, and survival outcomes were evaluated using surveillance epidemiology statistical methods.

RESULTS

The average annual age-adjusted incidence rate per 100,000 population was 7.62 (95 % confidence interval [CI], 7.55-7.68) for all meningiomas, 7.18 (95% CI, 7.12-7.25) for benign meningiomas, 0.32 (95% CI, 0.31-0.33) for borderline malignant meningiomas, and 0.12 (95% CI, 0.11-0.12) for malignant meningiomas. The annual rates increased for benign and borderline malignant tumors but decreased for malignant tumors. The rates for women exceeded those for men, especially for those with benign meningiomas. Black race was associated with significantly higher rates as was advancing age. Greater than 80% of tumors were located in cerebral meninges. Diagnostic confirmation through pathology occurred for approximately 50% of benign tumors, 90% of borderline malignant tumors, and 80% of malignant tumors. No initial treatment was reported for greater than 60% of benign tumors, 29% of borderline malignant tumors, or 31% of malignant tumors. The 5-year relative survival estimates for benign tumors, borderline malignant tumors, and malignant tumors were 85.6% (95% confidence interval [CI], 85%-86.2%), 82.3% (95% CI, 79.3%-84.8%), and 66% (95% CI, 60.6%-70.9%), respectively. Predictors of poorer survival were advanced age, being male gender, black race, no initial treatment, and malignant tumor behavior.

CONCLUSIONS

The current analysis demonstrates that there is an increasing incidence of nonmalignant meningiomas, probably because of reporting learning curves associated with the implementation of Public Law 107-260. The high proportion of cases who receive no initial treatment is a survival outcome concern, especially for patients with malignant meningiomas.

Meningiomas: knowledge base, treatment outcomes, and uncertainties. A RANO review

Evolving interest in meningioma, the most common primary brain tumor, has refined contemporary management of these tumors. Problematic, however, is the paucity of prospective clinical trials that provide an evidence-based algorithm for managing meningioma. This review summarizes the published literature regarding the treatment of newly diagnosed and recurrent meningioma, with an emphasis on outcomes stratified by WHO tumor grade. Specifically, this review focuses on patient outcomes following treatment (either adjuvant or at recurrence) with surgery or radiation therapy inclusive of radiosurgery and fractionated radiation therapy. Phase II trials for patients with meningioma have recently completed accrual within the Radiation Therapy Oncology Group and the European Organisation for Research and Treatment of Cancer consortia, and Phase III studies are being developed. However, at present, there are no completed prospective, randomized trials assessing the role of either surgery or radiation therapy. Successful completion of future studies will require a multidisciplinary effort, dissemination of the current knowledge base, improved implementation of WHO grading criteria, standardization of response criteria and other outcome end points, and concerted efforts to address weaknesses in present treatment paradigms, particularly for patients with progressive or recurrent low-grade meningioma or with high-grade meningioma. In parallel efforts, Response Assessment in Neuro-Oncology (RANO) subcommittees are developing a paper on systemic therapies for meningioma and a separate article proposing standardized end point and response criteria for meningioma.

Management of petroclival meningiomas: a review of the development of current therapy

The surgical management of petroclival meningioma remains challenging, due to the difficulty of accessing the region and the vital structures adjacent to the origin of these tumors. Petroclival meningiomas were originally considered largely unresectable. Until the 1970s, resection carried a 50% mortality rate, with very high rates of operative morbidity if attempted. However, in the past 40 years, advances in neuroimaging and approaches to the region were refined, and results from resection of petroclival meningiomas have become more acceptable. Today, the developments of a multitude of surgical approaches as well as innovations in neuroimaging and stereotactic radiotherapy have proved powerful options for multimodality management of these challenging tumors.

Role of external beam radiotherapy in the treatment of relapsing meningioma

The role of radiotherapy in the treatment of relapsing meningiomas is not well established. Data of patients treated with radiotherapy for a relapsing meningioma were retrospectively analyzed. Overall survival (OS) was the primary endpoint of the analysis. Local control and acute and late toxicity rates have been also reported. From April 1986 to February 2011, 37 patients with a diagnosis of recurrent meningioma were treated. Median age was 64 years (range 36-79). A total of 18, 10, 5 and 4 patients were affected by relapsing benign, atypical, malignant meningiomas and meningiosarcomas, respectively (WHO classification). Median dose was 60 Gy (range 46-66 Gy). The median follow-up was 42 months (range 3-300 months). OS at 1, 3, 5 and 8 years was 81, 55.6, 43.9 and 25.8%, respectively (median OS 45 months). A strong statistical trend was observed toward better OS rates in patients treated with radiotherapy at first recurrence compared to those treated at the second (or more) recurrence (OS 50.5 vs. 30.8%, p=0.055). A statistical impact of the histology (WHO I vs. II, III and IV) on 5-year OS was also observed (OS 60 vs. 30%, 0 and 0%, p=0.010). Radiotherapy has been well tolerated, with no G2-4 neurological toxicity (RTOG toxicity score). Conventional radiation therapy has an important role in multidisciplinary approach in the treatment of recurrence of meningiomas. The histological type and the timing of the radiotherapy are prognostic factors in terms of survival.

Differential diagnosis of intracranial meningiomas based on magnetic resonance spectroscopy

BACKGROUND AND PURPOSE

To determine in vivo magnetic resonance spectroscopy (MRS) characteristics of intracranial meningiomas and to assess MRS reliability in meningioma grading and discrimination from tumours of similar radiological appearance, such as lymphomas, schwannomas and haemangiopericytomas.

MATERIAL AND METHODS

Analysis of spectra of 14 patients with meningiomas, 6 with schwannomas, 2 with lymphomas, 2 with haemangiopericytomas and 17 control spectra taken from healthy hemispheres.

RESULTS

All the patients with meningiomas had a high Cho signal (long TE). There were very low signals of Naa and Cr in the spectra of 10 patients. A reversed Ala doublet was seen only in 2 cases. Four patients had a negative Lac signal, whereas 3 had high Lac-Lip spectra. Twelve spectra showed high Cho signals (short TE). In one case the Cho signal was extremely low. All spectra displayed a very low Cr signal, but high Glx and Lac-Lip signals. Ala presence was found only in 3 patients. The mean Cho/Cr ratio (PRESS) was 5.97 (1.12 in normal brain, p < 0.05). Lac-Lip was present in all the meningiomas (STEAM). The Ala signal was seen only in 2 spectra with long TE and in 3 sequences of the short TE sequences. There were both β/γ-Glx and α-Glx/glutathione signals in all 14 meningiomas.

CONCLUSIONS

MRS is unable to discriminate low and high grade meningiomas. The method seems to be helpful in discriminating lymphomas (absent Glx signal), schwannomas (mI signal in the short TE sequences) and haemangiopericytomas (presence of mI band) from meningiomas.

The role of intraoperative magnetic resonance imaging in complex meningioma surgery

Intraoperative magnetic resonance imaging (iMRI) has gained importance in the treatment of gliomas and sellar tumors. In intracranial meningiomas, the extent of surgical tumor removal is one of the most important factors in the prevention of tumor recurrence and patient survival. Complex meningiomas located at the skull base or near eloquent brain regions show higher recurrence rates, morbidity and mortality. The aim of this study was to evaluate whether iMRI contributes to more extensive surgical resection in these tumors. Patients undergoing complex meningioma resection using iMRI from January 2007 to January 2011 were included in this study. The indication for iMRI-guided tumor resection included patients presenting with meningiomas located in the skull base or compressing eloquent brain areas in whom a radical resection was considered to be difficult. Intraoperative 0.15-T MRI scan (PoleStar; Medtronic Navigation, Louisville, CO, USA) was performed before and after maximal possible resection using standard microsurgical and neuronavigation techniques. All patients underwent fluorescence-guided resection. The following data were analyzed: tumor localization, histological grade, Simpson resection grade, duration of the procedure, iMRI scan time, iMRI findings, resection extent based on postresection iMRI, hospitalization time, surgical complications and outcome, and MRI follow-up 2-27months postoperation. Twenty-seven consecutive patients undergoing complex meningioma resection using iMRI were included. In this series, only one patient (3.4%) underwent resection of tumor remnant after iMRI, although without improvement of the Simpson resection grade. Temporary neurologic deficits were found in 8 patients (27.6%) postoperatively, whereas 11 patients (37.9%) had permanent postoperative neurologic deficits. In one case (3.4%), fatal postoperative bleeding occurred which was not detected by iMRI. Our results show that iMRI has no influence on intraoperative strategy in terms of resection grade or detection of early postoperative complications. The benefits of iMRI in complex meningioma surgery are therefore doubtful; however, it may still prove to be effective in certain subsets of complex meningiomas.

Fractionated proton radiotherapy for benign cavernous sinus meningiomas

PURPOSE

To evaluate the efficacy of fractionated proton radiotherapy for a population of patients with benign cavernous sinus meningiomas.

METHODS AND MATERIALS

Between 1991 and 2002, 72 patients were treated at Loma Linda University Medical Center with proton therapy for cavernous sinus meningiomas. Fifty-one patients had biopsy or subtotal resection; 47 had World Health Organization grade 1 pathology. Twenty-one patients had no histologic verification. Twenty-two patients received primary proton therapy; 30 had 1 previous surgery; 20 had more than 1 surgery. The mean gross tumor volume was 27.6 cm(3); mean clinical target volume was 52.9 cm(3). Median total doses for patients with and without histologic verification were 59 and 57 Gy, respectively. Mean and median follow-up periods were 74 months.

RESULTS

The overall 5-year actuarial control rate was 96%; the control rate was 99% in patients with grade 1 or absent histologic findings and 50% for those with atypical histology. All 21 patients who did not have histologic verification and 46 of 47 patients with histologic confirmation of grade 1 tumor demonstrated disease control at 5 years. Control rates for patients without previous surgery, 1 surgery, and 2 or more surgeries were 95%, 96%, and 95%, respectively.

CONCLUSIONS

Fractionated proton radiotherapy for grade 1 cavernous sinus meningiomas achieves excellent control rates with minimal toxicities, regardless of surgical intervention or use of histologic diagnosis. Disease control for large lesions can be achieved by primary fractionated proton therapy.

Intracranial meningiomas in patients with uterine sarcoma treated with long-term megestrol acetate therapy

OBJECTIVE

To report a series of four patients with uterine sarcoma, including one with müllerian adenosarcoma (MA) and three with low-grade endometrial stromal sarcoma (LGESS), who developed intracranial meningiomas while receiving the progesterone agonist megestrol acetate.

METHODS

The hospital records, imaging studies, and pathology slides of four patients who were treated for uterine sarcomas and subsequently developed intracranial meningiomas were reviewed.

RESULTS

All patients underwent surgery for their gynecologic cancers and received maintenance therapy with long-term hormonal suppression with megestrol acetate. Each of the four patients later developed neurologic symptoms secondary to intracranial meningiomas. Three patients had more than one meningioma. Histopathologic examination of all excised tumors showed strong immunoreactivity for progesterone receptors (PRs).

CONCLUSIONS

Patients with uterine sarcoma subtypes LGESS and MA may be predisposed to develop meningiomas, particularly in the setting of long-term treatment with megestrol acetate. Alternatively, preexisting, clinically silent meningiomas in these patients may have progressed to the point of clinical symptoms in the presence of the progesterone agonist megestrol acetate. Without previous imaging studies showing the presence or absence of meningioma before initiation of megestrol acetate treatment, there is no way to draw definitive conclusions regarding this possibility. Clinical and neuroradiologic surveillance for meningiomas should be strongly considered in patients with these uterine sarcoma subtypes, particularly in patients undergoing long-term suppressive therapy with megestrol acetate.

Phase II study of subcutaneous octreotide in adults with recurrent or progressive meningioma and meningeal hemangiopericytoma

The objective of this phase II study was to evaluate the efficacy and safety of subcutaneous octreotide therapy for the treatment of recurrent meningioma and meningeal hemangiopericytoma. Octreotide is an agonist of somatostatin receptors, which are frequently expressed in meningioma, and reports have suggested that treatment with somatostatin agonists may lead to objective response in meningioma. Patients with recurrent/progressive meningioma or meningeal hemangiopericytoma were eligible for enrollment; those with atypical/anaplastic meningioma or hemangiopericytoma must have experienced disease progression despite radiotherapy or have had a contraindication to radiation. Patients received subcutaneous octreotide with a goal dose of 500 μg 3 times per day, as tolerated. Imaging was performed every 3 months during therapy. The primary outcome measure was radiographic response rate. Eleven patients with meningioma and 1 with meningeal hemangiopericytoma were enrolled during the period 1992-1998. Side effects included diarrhea (grade 1 in 4 patients and grade 2 in 2), nausea or anorexia (grade 1 in 4 patients), and transaminitis (grade 1 in 1 patient). One patient developed extra hepatic cholangiocarcinoma, which was likely unrelated to octreotide therapy. No radiographic responses were observed. Eleven of the 12 patients experienced progression, with a median time to progression of 17 weeks. Two patients experienced long progression-free intervals (30 months and ≥18 years). Eleven patients have died. Median duration of survival was 2.7 years. Immunohistochemical staining of somatostatin receptor Sstr2a expression in a subset of patients did not reveal a correlation between level of expression and length of progression-free survival. Octreotide was well-tolerated but failed to produce objective tumor response, although 2 patients experienced prolonged stability of previously progressive tumors.

Rate of progression and severity of neuro-ophthalmologic manifestations of cavernous sinus meningiomas

The progression of neuro-ophthalmologic signs and symptoms caused by cavernous sinus meningiomas (CSMs) was evaluated in 24 patients. Ten patients had primary involvement of the cavernous sinus by meningioma, and 14 patients had extension of a sphenoid ridge meningioma into the cavernous sinus. Eighteen patients were followed after intradural meningioma debulking. Two of these patients underwent conventional radiation therapy after surgery. The other six patients were followed without treatment. Optic neuropathy caused by extension of the CSM was the most frequently (67%) seen manifestation at the beginning of the follow-up period. Proptosis (50%), ocular motor nerve palsies (46%), and trigeminal neuropathy (33%) were also common. During a mean follow-up period of 57 months, 14 patients (58%) had no change in neurologic status, four patients (17%) had improvement in one or more parameters and six patients (25%) worsened. The patients who worsened had progression of preexisting cranial nerve palsies (two patients), developed new cranial neuropathies (three patients), or both (one patient). Patients who worsened had a significantly longer mean follow-up (76 months) than patients who remained stable or improved (47 months) (p = 0.01). Although the signs and symptoms of CSMs may worsen with time, the rate is slow and the degree is mild. These factors are important when considering treatment options.

Huge meningiomas: a review of 93 cases

Between 1972 and 1996, 450 consecutive patients with intracranial meningiomas were operated on at Cukurova University School of Medicine. By size, intracranial meningiomas were classified as huge (>6 cm minimum diameter when extrapolated to anatomic size) or not huge (<6 cm). The present study involves 93 patients who underwent 109 craniotomies for the removal of huge meningiomas. All patients are adult, with 31 men and 62 women or a 1:2 male to female ratio, with a mean age of 48.7 +/- 2.3 years at the time of diagnosis. The average duration of observed survival in 85 patients followed in the computed tomography (CT) era was 4.8 years and that of 8 patients in the pre-CT era was 8.8 years. Eleven patients died by the last follow-up assessment. Seventy-nine patients were still alive at the last follow-up assessment. The overall postoperative mortality rate was 3.2%. The overall recurrence rate was 19%. In descending order of frequency, the first five anatomic locations of the huge meningiomas were the parasagittal region in 18 patients (19.3%), the cerebral convexity in 15 (16.1%), the olfactory groove in 15 (16.1%), the falx in 12 (12.9%), and the tuberculum sellae in 11 (11.8%). The overall results of surgical treatment in 93 patients were total removal in 59 (63.4%), radical subtotal in 18 (18.3%), and subtotal in 16 (17.2%), with good outcome in 69 (74.1%), fair in 16 (17.2%), and poor in 5 (5.3%). In conclusion, the huge size of meningiomas affects the extent of removal, recurrence rate, postoperative outcome, operative morbidity and mortality rates, and survival time negatively.

Gamma Knife surgery for convexity, parasagittal, and falcine meningiomas

OBJECT

The aim of this study was to evaluate the outcomes in patients with convexity, parasagittal, or falcine meningiomas treated using Gamma Knife surgery (GKS) and to determine management strategy considering a risk of radiation-induced edema.

METHODS

One hundred twelve patients who harbored 125 convexity, parasagittal, or falcine meningiomas were assessed. Forty-six patients underwent GKS as the initial treatment. The median tumor diameter was 25 mm, and median tumor volume was 8 cm(3). The median maximum and margin doses were 30 and 16 Gy, respectively.

RESULTS

The median follow-up period was 72 months. The actuarial 5- and 10-year progression-free survival rates were 78% and 55%, respectively. The actuarial 5- and 10-year local tumor control rates were 87% and 71%, respectively. Of 29 tumors that developed postradiosurgical edema, 7 were symptomatic. The actuarial symptomatic radiation-induced edema rate was 7%. The incidence of this complication was significantly higher in patients who underwent GKS as the initial treatment. Six of 46 patients for whom GKS was the initial treatment had preradiosurgical edema. Of these 6 patients, 4 developed severe panhemispheric edema after GKS (2 patients with parasagittal tumors, 1 with a falx tumor, and 1 with a convexity tumor).

CONCLUSIONS

Gamma Knife surgery is an effective treatment for convexity, parasagittal, and falcine meningiomas as the initial or adjuvant treatment. However, GKS should be restricted to small- to medium-sized tumors, particularly in patients with primary tumors, because radiation-induced edema is more common in convexity, parasagittal, and falcine meningiomas than skull base meningiomas.

Perioperative and Long-term Outcomes From the Management of Parasagittal Meningiomas Invading the Superior Sagittal Sinus

BACKGROUND:

Parasagittal meningiomas invading the superior sagittal sinus (SSS) pose formidable obstacles to surgical management. Invasion is often considered a contraindication to surgery because of associated morbidity, such as cerebral venous thrombosis.

OBJECTIVE:

We report our most recent experience with the resection of parasagittal meningiomas invading the SSS.

METHODS:

Between 1992 and 2004, 110 patients with parasagittal meningiomas underwent surgery at the Johns Hopkins Medical Institutions. Clinical charts, radiological studies, pathological features, and operative notes were retrospectively analyzed; only those patients with minimum 24 months follow-up (n = 61) were further studied.

RESULTS:

Tumor distribution by location along the SSS was: 21% anterior, 62% middle, and 17% posterior. All patients were managed with initial surgical resection with radiosurgery for residual/recurrent disease if indicated (19.6%). Pathological examination revealed 80% grade I meningiomas, 13% grade II meningiomas, and 7% grade III meningiomas. Simpson grade I/II resection was achieved in 81% of patients. Major complications included venous thrombosis/infarction (7%), intraoperative air embolism (1.5%), and death (1.5%); long-term outcomes assessed included recurrence (11%) and improvement in Karnofsky Performance Score (85%).

CONCLUSION:

On the basis of our study, the incidence of postoperative venous sinus thrombosis is 7% in the setting of a recurrence rate of 11% with a mean follow-up of 41 months. In comparison with the published literature, the data corroborate the rationale for our treatment paradigm; lesions invading the sinus can initially be resected to the greatest extent possible without excessive manipulation of vascular structures, whereas residual/recurrent disease can be observed and managed with radiosurgery.

Hepatic Metastasis via a Ventriculo-Peritoneal Shunt from an Intracranial Meningioma: Case Report and Review of the Literature

Meningiomas are slow-growing intracranial/intraspinal tumours, with a wide range of histopathological variants. The more aggressive atypical and malignant types can disseminate via the venous system, lymphatics or cerebrospinal fluid, with the lungs and pleura being the most common site of extracranial metastasis. We look at a 68-year-old woman presenting with abdominal pain, who had previously been treated for an intracranial meningioma with a ventriculo-peritoneal shunt in situ. Investigation revealed a lesion in segment 4 of the liver with the shunt tip being in close proximity. Biopsy was consistent with metastatic meningioma. A liver resection was subsequently performed. We postulate that this is the first reported case of dissemination of an intracranial meningioma via cerebrospinal fluid by means of a ventriculo-peritoneal shunt.

[Optic nerve sheath meningiomas]

Optic nerve sheath meningiomas account for one-third of optic nerve tumors, 1-2 % of all meningiomas, and 2-3.5 % of all orbital tumors. Loss of vision is the main clinical sign. Diagnosis is easily made after the neuroradiological evaluation. Fractionated stereotactic radiotherapy (RSF) is now the gold standard treatment for controlling tumor volume and preserving visual acuity.

Extraneural metastases from cranial meningioma: a case report

Extracranial metastases from brain meningiomas is a rare, but well-documented entity. Metastases occur mostly in the lungs, pleura and liver, but may also affect lymph nodes and bones. We report here on a patient who was treated for an atypical brain meningioma with multiple surgeries and multiple sessions of stereotactic radiosurgery with good control of his brain disease. Thirteen years after diagnosis, he developed bilateral large sacroiliac and abdominal metastases.

Multiple extracranial metastases of atypical meningiomas

Meningiomas are usually benign neoplasms in which extracranial metastases occur very rarely. We report a case of multiple extracranial metastases of an atypical meningioma following a local recurrence. A 68-year-old man presented with left-side motor weakness and dysarthria for two weeks. A computed tomography (CT) scan and magnetic resonance imaging (MRI) showed an intraventricular tumor. We performed a total mass removal, and the histopathologic findings were consistent with benign meningioma. Eight months later, the meningioma recurred. We performed a reoperation and whole brain radiation therapy postoperatively. The histopathologic findings showed atypical meningioma. Six months later, CT and MRI revealed metastases to multiple vertebrae, lung, ribs and perirenal soft tissue so a decompressive laminectomy with mass removal was performed. The histopathologic findings of the spinal tumors showed atypical meningioma. The results from perirenal biopsies were consistent with metastatic meningioma. In conclusion, extracranial metastasis as well as local recurrence must be considered in atypical or anaplastic meningioma. There must be regular follow-ups. Finally, an evaluation of the chest, abdomen and bone is necessary, especially when related symptoms or signs develop.

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.

Radiotherapy as an adjuvant in the management of intracranial meningiomas: are we practising evidence-based medicine?

Although increasingly used, the precise role of radiotherapy in the management of meningiomas is still disputed. The objective of this study, therefore, was to appraise the evidence for adjuvant radiotherapy in benign and atypical intracranial meningiomas, and to compare and contrast it with the current opinion and practice of neurosurgeons in the United Kingdom and the Republic of Ireland. The use of radiotherapy as a primary treatment strategy or its use in the treatment of recurrence was not considered. We performed a systematic review of the evidence for adjuvant radiotherapy in benign and atypical intracranial meningiomas, surveyed current opinion amongst neurosurgeons involved in such cases and ascertained local practice using data from the regional cancer registry. Overall, 10 cohorts were identified that fulfilled our eligibility criteria. Four studies showed significantly improved local control in patients receiving adjuvant radiotherapy for incompletely resected grade I meningiomas. Our survey demonstrated that the vast majority (98%) of neurosurgeons would not recommend adjuvant radiotherapy in grade I meningioma. In grade II meningioma, most (80%) would not advocate adjuvant radiotherapy if completely excised, but the majority (59%) would recommend radiotherapy in cases of subtotal resection. Significant variation in opinion between centres exists, however, particularly in cases of completely resected atypical meningiomas (p = 0.02). Data from the Eastern Cancer Registration and Information Centre appears to be in line with these findings: less than 10% of patients with grade I meningiomas, but almost 30% of patients with grade II meningiomas received adjuvant radiotherapy in the Eastern region. In conclusion, our study has highlighted significant variation in opinion and practice, reflecting a lack of class 1 evidence to support the use of adjuvant radiotherapy in the treatment of meningiomas. Efforts are underway to address this with a randomized multicentre trial comparing a policy of watchful waiting versus adjuvant irradiation.

Foramen magnum meningiomas: detailed surgical approaches and technical aspects at Lariboisière Hospital and review of the literature

Foramen magnum meningiomas are challenging tumors, requiring special considerations because of the vicinity of the medulla oblongata, the lower cranial nerves, and the vertebral artery. After detailing the relevant anatomy of the foramen magnum area, we will explain our classification system based on the compartment of development, the dural insertion, and the relation to the vertebral artery. The compartment of development is most of the time intradural and less frequently extradural or both intraextradural. Intradurally, foramen magnum meningiomas are classified posterior, lateral, and anterior if their insertion is, respectively, posterior to the dentate ligament, anterior to the dentate ligament, and anterior to the dentate ligament with extension over the midline. This classification system helps to define the best surgical approach and the lateral extent of drilling needed and anticipate the relation with the lower cranial nerves. In our department, three basic surgical approaches were used: the posterior midline, the postero-lateral, and the antero-lateral approaches. We will explain in detail our surgical technique. Finally, a review of the literature is provided to allow comparison with the treatment options advocated by other skull base surgeons.

Role of radiation therapy in treating intracranial meningiomas

Surgery is the mainstay for many patients with meningiomas, and it remains the standard. In large single-institution series, gross-total resection has been reported to achieve 5-, 10-, and 15-year recurrence-free survival rates of approximately 90, 80, and 70%, respectively. There are a growing number of series of patients with prolonged follow-up in which authors have evaluated fractionated external-beam radiation therapy (EBRT) either as an adjuvant to surgery for subtotally resected, recurrent, or higher-grade meningiomas, or as an alternative to surgery. The primary focus of this review is EBRT, but to lend perspective, a comparative analysis of surgery and radiosurgery is also provided.

Optic nerve sheath meningioma: current diagnosis and treatment

✓Optic nerve sheath meningiomas (ONSMs) are rare tumors of the anterior visual pathway and constitute approximately 2% of all orbital tumors and 1–2% of all meningiomas. Untreated ONSMs almost always lead to progressive visual decline, color blindness, and finally complete loss of vision. Although resection is warranted in cases of widespread ONSM, surgery can lead to significant morbidity. Recently, stereotactic fractionated radiotherapy has shown effectiveness in improving or stabilizing remaining visual function with minimal procedural morbidity in patients with ONSM. The authors review the incidence, histopathological characteristics, clinical presentation, neuroimaging findings, and current treatment modalities for ONSMs, with an emphasis on fractionated stereotactic radiotherapy.

New prospects for management and treatment of inoperable and recurrent skull base meningiomas

Skull base, including optic nerve, cavernous sinus, clival and foramen magnum tumors represent a major challenge for neurosurgeons and neuro-oncologists. Growth regulatory signaling pathways for these tumors are of increasing interest as potential targets for new chemotherapy. Those differentially activated in various grades of meningiomas are currently being identified as well. This article reviews some recent findings pathways that appear to regulate meningioma growth. Potential targets for novel therapies are also discussed.

Detection and treatment of optic nerve sheath meningioma

Optic nerve sheath meningioma is an uncommon tumor of middle age. Patients most often present with progressive visual loss, mild proptosis, and, occasionally, ocular motility defect. With modern neuroimaging, these tumors are relatively easy to diagnose. However, the computed tomography scan or magnetic resonance imaging scan obtained must be a high-resolution study focused on the optic nerve. Clinical observation may be appropriate for patients with relatively preserved vision. However, when vision deteriorates, fractionated stereotactic radiotherapy is indicated and can often restore or preserve visual function.

Primary radiotherapy for optic nerve sheath meningioma

Radiotherapy has recently been recognized as the treatment of choice for most primary optic nerve sheath meningiomas (ONSM). Radiotherapy is incorporated into the treatment of non optic nerve sheath meningiomas for unresectable or subtotally resected tumors. Most primary ONSM are not surgically approachable without a high risk of visual deterioration. Radiotherapy has been found to prevent or delay tumor growth for the majority of patients and improve vision in some. We review the rational and current methods of the use of radiotherapy for these tumors.

Visual changes after gamma knife surgery for optic nerve tumors

Tumors involving the optic nerve (optic glioma, optic nerve sheath meningioma) are benign but difficult to treat. Gamma knife surgery (GKS) may be a useful treatment. The authors present data obtained in three such cases and record the effects of GKS.

Visual changes after gamma knife surgery for optic nerve tumors

✓ Tumors involving the optic nerve (optic glioma, optic nerve sheath meningioma) are benign but difficult to treat. Gamma knife surgery (GKS) may be a useful treatment. The authors present data obtained in three such cases and record the effects of GKS.

Treatment of meningioma: an update

Aggressive surgical resection continues to be the mainstay of current meningioma management, with advances in microsurgical techniques facilitating the safety and effectiveness of this approach. Complete surgical removal of meningiomas provides the optimal opportunity for long-term remission. Advances in skull base surgical approaches have greatly improved patient outcomes for tumors in precarious locations once thought to be inoperable. For tumors that recur or are unresectable, stereotactic radiosurgery and conformal fractionated radiation therapy can provide safe, palliative treatment with favorable long-term outcomes. Additionally, advances in the understanding of molecular biologic and biochemical mechanisms underlying meningioma growth offer unique opportunities for potential treatment adjuncts for atypical and malignant tumors. This review discusses current understanding of meningioma pathology and accepted meningioma treatment paradigms. The technologic advances and experimental strategies for the future treatment of complex intracranial meningiomas are also discussed.

The value of routine electroencephalographic recordings in predicting postoperative seizures associated with meningioma surgery

We analyzed the incidence of postoperative seizures in patients undergoing craniotomy for meningioma removal in order to determine whether EEG recordings are able to predict the incidence of postoperative seizures. We included 102 patients who had undergone surgery on intracranial meningiomas. Pre- and postoperative EEG images were divided into groups showing epileptiform activity including spikes or sharp waves, focal slowing, and normal activity. Follow-up was carried out using a standardized telephone questionnaire by an independent investigator after a mean of 889 days. Seizure outcome was determined by patient reports to the interviewer. Preoperatively obtained, abnormal EEGs correlated significantly to preoperative seizures (P<0.0005), but neither preoperative nor postoperative EEGs correlated to the incidence of postoperative seizures. It would seem that, while evaluation of some clinical parameters revealed a statistically significant correlation, pre- and early postoperative EEGs after meningioma surgery are not useful in determining the risk of postoperative seizures.

Update on treatment modalities for optic nerve sheath meningiomas

Optic nerve sheath meningiomas (ONSMs) represent 1 to 2% of all meningiomas and one third of all optic nerve tumors. The management of ONSMs is controversial. Traditional surgical removal often results in postoperative blindness in the affected eye and thus has been abandoned as a treatment option in most patients. Surgery may be unnecessarily aggressive, especially if the patient has useful vision. When these tumors are left untreated, however, ensuing progressive visual impairment may lead to complete blindness. More recently, radiotherapy has gained wider acceptance as a treatment for these lesions. The authors of some reports have suggested that fractionated stereotactic radiosurgery (SRS) may be the best option for treating primary ONSMs. In patients with documented progressive visual deterioration, fractionated SRS may be effective in improving or stabilizing remaining functional vision. The authors review the clinical presentation, radiographic characteristics, and management of ONSMs, emphasizing the use of fractionated SRS.

Stereotactic fractionated radiotherapy in patients with optic nerve sheath meningioma

PURPOSE

To evaluate the effectiveness of stereotactic fractionated radiotherapy (SFRT) in the treatment of optic nerve sheath meningioma (ONSM). METHODS AND MARERIALS: Between 1994 and 2000, a total of 39 patients with either primary (n = 15) or secondary (n = 24) ONSM were treated with SFRT and received a median total tumor dose of 54 Gy using 1.8 Gy/fraction.

RESULTS

The radiographic response to SFRT was documented in all patients as stable disease (no change) except for 1 patient with a partial response. After a median follow-up of 35.5 months, all patients with ONSM were alive without recurrence. The visual fields and visual acuity were improved in 6 of 15 and 1 of 16 examined eyes in patients with primary ONSM, respectively, and in 6 of 24 and 7 of 26 examined eyes in patients with secondary ONSM, respectively. Stable visual fields and visual acuity was observed in 8 of 14 and 15 of 16 patients with primary ONSM, respectively, and in 17 of 24 and 19 of 26 patients with secondary ONSM, respectively. Except for reversible alopecia and erythema, no other SFRT-related toxicity was observed.

CONCLUSION

SFRT represents a very effective and low-toxic treatment modality for ONSM. Despite a median follow-up of 3 years, this series of primary ONSM holds promise for future studies. It adds substantial evidence that SFRT may definitely become a standard treatment approach in selected cases of ONSM.