Role of radiation therapy in treating intracranial meningiomas

Lack of Impact of Expansion Size From Gross Tumor Volume to Planning Target Volume on Control Rates and Patterns of Recurrence in Fractionated Radiotherapy for WHO Grade 1 Meningiomas

OBJECTIVES

For single-fraction stereotactic radiosurgery (SRS) for WHO grade I meningiomas, no-GTV or minimal-GTV to PTV margin is an accepted practice. We evaluated whether there is a control difference based on GTV to PTV expansion size for fractionated RT.

METHODS

Eighty-seven patients with WHO grade 1 meningioma were identified from an institutional database, treated with either conventional immobilization and radiation treatment delivery techniques (cRT) with 5 to 20 mm PTV expansions or fractionated stereotactic radiotherapy (fSRT) with ≤3 mm GTV to PTV expansions. Kaplan-Meier estimators were used for local failure-free survival (LFFS), marginal-failure-free survival (MFFS), and distant failure-free survival (DFFS) analysis.

RESULTS

The median follow-up duration was 9.0 years. Twenty-five patients (29%) received cRT and 62 patients (71%) received fSRT. The median dose was 54 Gray. There were 4 local (5%), 1 marginal (1%), and 1 distant failure (1%). The fSRT and cRT groups each had 2 local failures; 3/4 local failures occurred in areas near critical organs at risk. For cRT versus fSRT, 5-year and 10-year LFFS were 100% versus 98% (P=0.46) and 94% versus 96% (P=0.34), 5-year and 10-year MFFS were 100% versus 100% and 100% versus 92% (P=0.004), and 5-year and 10-year DFFS were 100% versus 98% at both time points (P=0.65 and P=0.67, respectively).

CONCLUSIONS

In this patient cohort, there was no local control benefit for larger GTV-to-PTV expansions. For patients with tumors not eligible for SRS, fractionated stereotactic treatment workflow with ≤3 mm PTV expansions is an effective approach for WHO grade 1 meningiomas.

Patterns of failure after radiosurgery for WHO grade 1 or imaging defined meningiomas: Long-term outcomes and implications for management

BACKGROUND

We analyzed long-term control and patterns of failure in patients with World Health Organization Grade 1 meningiomas treated with definitive or postoperative stereotactic radiosurgery at the authors' affiliated institution.

METHODS

96 patients were treated between 2004 and 2019 with definitive (n = 57) or postoperative (n = 39) stereotactic radiosurgery. Of the postoperative patients, 17 were treated adjuvantly following subtotal resection and 22 were treated as salvage at time of progression. Patients were treated to the gross tumor alone without margin or coverage of the dural tail to a median dose of 15 Gy. Median follow up was 7.4 years (inter-quartile range 4.8-11.3). Local control, marginal control, regional control, and progression-free survival were analyzed.

RESULTS

Local control at 5 and 10 years was 97 % and 95 %. PFS at 5 and 10 years was 94 % and 90 % with no failures reported after 6 years. Definitive and postoperative local control were similar at 5 (95 % [82-99 %] vs. 100 %) and 10 years (92 % [82-99 %] vs. 100 %). Patients treated with postoperative SRS did not have an increased marginal failure rate (p = 0.83) and only 2/39 (5 %) experienced recurrence elsewhere in the cavity.

CONCLUSIONS

Stereotactic radiosurgery targeting the gross tumor alone provides excellent local control and progression free survival in patients treated definitively and postoperatively. As in the definitive setting, patients treated postoperatively can be treated to gross tumor alone without need for additional margin or dural tail coverage.

Factors associated with radiation toxicity and long-term tumor control more than 10 years after Gamma Knife surgery for non-skull base, nonperioptic benign supratentorial meningiomas

OBJECTIVE

Gamma Knife surgery (GKS) is a well-established treatment for benign intracranial meningiomas; however, the dosimetric factors associated with long-term GKS efficacy and safety remain to be elucidated. Using data obtained with at least 10 years of follow-up, the authors aimed 1) to analyze GKS efficacy and safety for the treatment of benign meningiomas confined to non-skull base, nonperioptic supratentorial locations and 2) to determine the radiation dose window that allows for long-term efficacy and safety, namely the minimum dose to achieve long-term local control (LC) and the maximum safe dose to avoid adverse radiation effects (AREs).

METHODS

A retrospective analysis was performed on patients who underwent GKS for benign meningiomas in the abovementioned location at the authors' institution between 1998 and 2010 and who received follow-up for more than 10 years. The authors meticulously extracted the values of various dosimetric factors by using a dose-volume histogram. Cox proportional hazard regression analyses were performed to investigate the dosimetric factors associated with LC and ARE.

RESULTS

Fifty-five patients (male/female ratio 1:4.2) with 68 tumors were enrolled. The median (range) gross target volume and marginal dose were 4.2 (0.2-31.7) cm3 and 14.3 (9-20) Gy, respectively. In total, 23.5% of tumors progressed at an average of 72 months, with 10- and 15-year progression-free survival rates of 80.9% and 73.5%, respectively. In univariate analysis, higher marginal dose, coverage (%), Dmin, D98%, Dmean, D2%, Dmax, and Paddick conformity index were significantly associated with LC. In multivariate analysis, D98% was the significant factor, with a cutoff value of 11 Gy (HR 0.754, p < 0.001). Symptomatic AREs occurred in 7 patients at an average of 7 months after GKS. AREs were significantly associated with the volume of normal tissue irradiated with more than 14 Gy (nV14Gy), with a cutoff value of 0.66 cm3 (HR 2.459, p = 0.002).

CONCLUSIONS

D98% was a barometer of the minimum required dose associated with long-term LC, and nV14Gy was related to symptomatic AREs. The authors recommend a marginal dose ranging from 11 to 14 Gy to achieve long-term efficacy and safety in patients with non-skull base, nonperioptic benign supratentorial meningiomas, with the assumption of thorough tumor coverage.

Risk factors for peritumoral edema after radiosurgery for intracranial benign meningiomas: a long-term follow-up in a single institution

OBJECTIVE

Peritumoral edema (PTE) is recognized as a complication following stereotactic radiosurgery (SRS). The aim of this paper was to evaluate the risk of post-SRS PTE for intracranial benign meningiomas and determine the predictive factors.

METHODS

Between 2006 and 2021, 227 patients with 237 WHO grade I meningiomas were treated with Novalis linear accelerator SRS. All patients were treated with a single-fraction dose of 11–20 Gy (median 14 Gy). The median tumor volume was 3.32 cm3 (range 0.24–51.7 cm3).

RESULTS

The median follow-up was 52 months (range 12–178 months). The actuarial local tumor control rates at 2, 5, and 10 years after SRS were 99.0%, 96.7%, and 86.3%, respectively. Twenty-seven (11.9%) patients developed new or worsened post-SRS PTE, with a median onset time of 5.2 months (range 1.2–50 months). Only 2 patients developed post-SRS PTE after 24 months. The authors evaluated factors related to new-onset or worsened PTE after SRS. In univariate analysis, initial tumor volume > 10 cm3 (p = 0.03), total marginal dose > 14 Gy (p < 0.001), preexisting edema (p < 0.0001), tumor location (p < 0.001), parasagittal location (p < 0.0001), superior sagittal sinus (SSS) involvement (p < 0.0001), and SSS invasion (p < 0.015) were found to be significant risk factors. In multivariate analysis, total marginal dose > 14 Gy (HR 3.38, 95% CI 1.37–8.33, p = 0.008), preexisting SRS edema (HR 12.86, 95% CI 1.09–4.15, p < 0.0001), tumor location (HR 2.13, 95% CI 1.04–3.72, p = 0.027), parasagittal location (HR 8.84, 95% CI 1.48–52.76, p = 0.017), and SSS invasion (HR 0.34, 95% CI 0.13–0.89, p = 0.027) were significant risk factors. Twelve (5.3%) patients were symptomatic. Ten of 27 patients had complete resolution of neurological symptoms and edema improvement with steroid treatment. Steroid treatment failed in 2 patients, who subsequently required resection for PTE.

CONCLUSIONS

Radiosurgery is a safe and effective method of treating benign intracranial meningiomas according to long-term follow-up. We also identified total marginal dose > 14 Gy, preexisting PTE, parasagittal location, and SSS invasion as predictors of post-SRS PTE. Risk factors for post-SRS PTE should be considered in meningioma treatment.

Pseudoprogression and peritumoral edema due to intratumoral necrosis after Gamma knife radiosurgery for meningioma

Peritumoral cerebral edema is reported to be a side effect that can occur after stereotactic radiosurgery. We aimed to determine whether intratumoral necrosis (ITN) is a risk factor for peritumoral edema (PTE) when gamma knife radiosurgery (GKRS) is performed in patients with meningioma. In addition, we propose the concept of pseudoprogression: a temporary volume expansion that can occur after GKRS in the natural course of meningioma with ITN. This retrospective study included 127 patients who underwent GKRS for convexity meningioma between January 2019 and December 2020. Risk factors for PTE and ITN were investigated using logistic regression analysis. Analysis of variance was used to determine whether changes in tumor volume were statistically significant. After GKRS, ITN was observed in 34 (26.8%) patients, and PTE was observed in 10 (7.9%) patients. When postoperative ITN occurred after GKRS, the incidence of postoperative PTE was 18.970-fold (p = 0.009) greater. When a 70% dose volume ≥ 1 cc was used, the possibility of ITN was 5.892-fold (p < 0.001) higher. On average, meningiomas with ITN increased in volume by 128.5% at 6 months after GKRS and then decreased to 94.6% at 12 months. When performing GKRS in meningioma, a 70% dose volume ≥ 1 cc is a risk factor for ITN. At 6 months after GKRS, meningiomas with ITN may experience a transient volume expansion and PTE, which are characteristics of pseudoprogression. These characteristics typically improve at 12 months following GKRS.

Clinical presentation, diagnostic findings and outcome of dogs undergoing surgical resection for intracranial meningioma: 101 dogs

Background

Meningioma is the most common primary brain neoplasm in dogs. Further information is required regarding the expected long-term prognosis of dogs following the surgical resection of an intracranial meningioma together with the influence of adjunctive therapies. Whilst there have been several studies reporting the long-term outcome of intracranial meningioma resection following surgery alone, surgery with the use of an ultrasonic aspirator, surgery combined with radiotherapy and surgery combined with the addition of hydroxyurea, it is currently unclear which type of adjunctive therapy is associated with the most favourable outcomes. The objective of this study is to describe the presentation and outcome of dogs undergoing surgery for the resection of an intracranial meningioma and the effect of clinical factors, adjunctive therapies and meningioma histopathological subtype on the long-term outcome.

Results

A hundred and one dogs that had intracranial surgery for meningioma resection were investigated from four referral centres. 94% of dogs survived to hospital discharge with a median survival time of 386 days. Approximately 50% of dogs survived for less than a year, 25% survived between 1 and 2 years, 15% survived between 2 and 3 years and 10% survived for greater than 3 years following discharge from hospital. One or more adjunctive therapies were used in 75 dogs and the analysis of the data did not reveal a clear benefit of a specific type of adjunctive therapy. Those dogs that had a transfrontal approach had a significantly reduced survival time (MST 184 days) compared to those dogs that had a rostrotentorial approach (MST 646 days; p < 0.05). There was no association between meningioma subtype and survival time.

Conclusions

This study did not identify a clear benefit of a specific type of adjunctive therapy on the survival time. Dogs that had a transfrontal approach had a significantly reduced survival time. Intracranial surgery for meningioma resection offers an excellent prognosis for survival to discharge from hospital with a median long term survival time of 386 days.

Adjuvant radiotherapy in grossly total resected grade II atypical meningiomas. A protective effect on recurrence? A systematic review and meta-analysis

INTRODUCTION

Management of grade II Atypical Meningiomas (AM) remains controversial. Conflicting evidences exist on the possible protective effect of adjuvant radiotherapy (ART) on recurrence in grossly resected AMs. The aim of this meta-analysis is to evaluate the role of ART in grossly resected (Simpson grades 1-3) AMs on the recurrence and survival.

EVIDENCE ACQUISITION

Data were retrieved from comparative studies of AMs undergone surgical resection alone vs. surgery+ART. Only grossly total resected AMs (Simpson grade 1,2,3) were included. The individual and pooled odds ratio (OR) for the crude recurrence, progression free survival (PFS) at 1, 3 and 5-years, as well as for the overall survival (OS) at 5-years were calculated by using the Mantel-Haenszel model in surgery alone vs. surgery+ART.

EVIDENCE SYNTHESIS

11 studies were considered eligible. 8 were included for the outcome "crude recurrence"; 6 for PFS at 1-3 years, 7 for PFS at 5-years; 6 for the OS at 5-years. Results suggest that surgery+ART might have a protective role on recurrence in gross-totally resected AMs (OR:1.66). Specifically, surgery+ART slightly improved PFS at 1-year (OR:0.92) and more consistently at 3- and 5-years (OR:0.31 and 0.35 respectively) hence favoring a combined approach.

CONCLUSIONS

Current literature on the impact of ART after gross total resection of AM are still heterogeneous and not systematically reported. The present meta-analysis suggests a possible protective role of postoperative RT against long-term recurrence as compared to surgical resection alone.

The Simpson grade: abandon the scale but preserve the message

The Simpson grading scale, developed in 1957 by Donald Simpson, has been considered the gold standard for defining the surgical extent of resection for WHO grade I meningiomas. Since its introduction, the scale and its modifications have generated enormous controversy. The Simpson grade is based on an intraoperative visual assessment of resection, which is subjective and notoriously inaccurate. The majority of studies in which the grading system was used were performed before routine postoperative MRI surveillance was employed, rendering assessments of extent of resection and the definition of recurrence inconsistent. The infiltration and proliferation potential of tumor components such as hyperostotic bone and dural tail vary widely based on tumor location, as does the molecular biology of the tumor, rendering a universal scale for all meningiomas unfeasible. While extent of resection is clearly important at reducing recurrence rates, achieving the highest Simpson grade resection should not always be the goal of surgery. Donald Simpson's name and his scale deserve to be recognized and preserved in the historical pantheon of pioneering and transformative neurosurgical concepts. Nevertheless, his eponymous scale is no longer relevant in modern meningioma surgery. While his message of maximizing extent of resection and minimizing morbidity is still germane, a single measure using subjective criteria cannot be applied universally to all meningiomas, regardless of location. Meningioma surgery should be performed with the goal of achieving maximal safe resection, ideally guided by molecularly tagged fluorescent labeling and assessed using objective criteria, including postoperative MRI as well as molecularly tagged scans such as [68Ga]-DOTATATE-PET.

Late Recurrence of Metastatic Meningioma in the Lung in a Patient with Endometrial Cancer: A Case Report

Patient: Female, 58-year-old

Final Diagnosis: Meningioma

Symptoms: Abdominal pain • bleeding • headache

Medication: —

Clinical Procedure: —

Specialty: Oncology

Long-term outcomes of patients with unresectable benign meningioma treated with proton beam therapy

This study aimed to evaluate the long-term efficacy of proton beam therapy (PBT) for unresectable benign meningiomas at the University of Tsukuba, Japan. From 1986-1998, 10 patients were treated at the Particle Radiation Medical Science Center (PRMSC) with a relative biological effectiveness (RBE) value of 1.0 using an accelerator built for physics experiments. The total dose was compensated with an X-ray in three patients. Following that, from 2002-2017, 17 patients were treated with a RBE value of 1.1 at the Proton Medical Research Center (PMRC) which was built for medical use. At the PRMSC, the total dose ranged from 50.4-66 Gy (median: 54 Gy). During the follow-up, which lasted between 3.8 and 31.6 years (median: 25.1 years), the 5-, 10-, 15-, 20- and 30-year local control rates were 100%, and the 5-, 10-, 15-, 20- and 30-year survival rates were 90, 80, 70, 70 and 36%, respectively. One patient died of brainstem radiation necrosis 5.1 years after PBT. At PMRC, the total dose ranged from 45.0-61.2 GyE, with a median of 50.4 GyE. During the follow-up, which lasted between 3 and 17 years with a median of 10.5 years, the 5-, 10- and 15-year local control rates were 94.1%, and the 5-, 10- and 15-year survival rates were 100, 100 and 88.9%, respectively. Neither malignant transformation nor secondary malignancy was observed, indicating that fractionated PBT may be effective and safely control benign unresectable meningioma even for the lifelong period of time.

Review of Atypical and Anaplastic Meningiomas: Classification, Molecular Biology, and Management

Although the majority of meningiomas are slow-growing and benign, atypical and anaplastic meningiomas behave aggressively with a penchant for recurrence. Standard of care includes surgical resection followed by adjuvant radiation in anaplastic and partially resected atypical meningiomas; however, the role of adjuvant radiation for incompletely resected atypical meningiomas remains debated. Despite maximum treatment, atypical, and anaplastic meningiomas have a strong proclivity for recurrence. Accumulating mutations over time, recurrent tumors behave more aggressively and often become refractory or no longer amenable to further surgical resection or radiation. Chemotherapy and other medical therapies are available as salvage treatment once standard options are exhausted; however, efficacy of these agents remains limited. This review discusses the risk factors, classification, and molecular biology of meningiomas as well as the current management strategies, novel therapeutic approaches, and future directions for managing atypical and anaplastic meningiomas.

Adjuvant Radiotherapy Did Not Reduce Recurrence of World Health Organization Grade I Meningiomas with Venous Sinus Involvement: A Propensity Score Adjusted Analysis and Literature Review

BACKGROUND

Most meningiomas are classified as World Health Organization (WHO) grade I. Adjuvant radiation therapy (RT) is commonly recommended for subtotal resections with documented progressive regrowth of lesions with venous sinus involvement. We investigated if recurrence of WHO grade I meningiomas was influenced by adjuvant RT.

METHODS

From 2000 to 2014, patients with grade I meningiomas with at least one venous sinus involvement and at least 4 years of follow-up were included. Demographics, venous sinus involvement, histology, and extent of resection (EOR) were characterized. Because patients undergoing RT tend to differ from those for whom adjuvant therapy was not prescribed, we used propensity scores to adjust for confounding variables.

RESULTS

Sixty-two patients were included; of these, 18 (29.0%) had recurrences. The mean age was 52.8 ± 12.3 years, and 79.0% were women. A total of 34 cases (54.8%) were submitted to adjuvant RT. Adjuvant RT was more frequent in those who had tumor recurrence (77.8% vs. 45.5%, P = 0.020). RT was more frequent in superior sagittal sinus (SSS) invasion (76.5% vs. 50.0%, P = 0.030) and less prevalent after gross total resection (GTR) (32.4% vs. 67.9%, P = 0.005). Propensity score adjusted analysis suggested no adjuvant RT benefit (odds ratio [OR], 2.51; 95% confidence interval [CI], 0.68-9.28; P = 0.167), independent of the EOR. SSS involvement increased recurrence risk (OR, 12.69; 95% CI, 1.46-110.27; P = 0.021), whereas GTR tended to decrease it (OR, 0.26; 95% CI, 0.06-1.09; P = 0.065).

CONCLUSIONS

Adjuvant RT does not seem to be a pivotal criterion to reduce the recurrence rate in patients with grade I meningioma, even when venous sinuses are involved.

Intermediate-risk meningioma: initial outcomes from NRG Oncology RTOG 0539

OBJECTIVE This is the first clinical outcomes report of NRG Oncology RTOG 0539, detailing the primary endpoint, 3-year progression-free survival (PFS), compared with a predefined historical control for intermediate-risk meningioma, and secondarily evaluating overall survival (OS), local failure, and prospectively scored adverse events (AEs). METHODS NRG Oncology RTOG 0539 was a Phase II clinical trial allocating meningioma patients to 1 of 3 prognostic groups and management strategies according to WHO grade, recurrence status, and resection extent. For the intermediate-risk group (Group 2), eligible patients had either newly diagnosed WHO Grade II meningioma that had been treated with gross-total resection (GTR; Simpson Grades I-III) or recurrent WHO Grade I meningioma with any resection extent. Pathology and imaging were centrally reviewed. Patients were treated with radiation therapy (RT), either intensity modulated (IMRT) or 3D conformal (3DCRT), 54 Gy in 30 fractions. The RT target volume was defined as the tumor bed and any nodular enhancement (e.g., in patients with recurrent WHO Grade I tumors) with a minimum 8-mm and maximum 15-mm margin, depending on tumor location and setup reproducibility of the RT method. The primary endpoint was 3-year PFS. Results were compared with historical controls (3-year PFS: 70% following GTR alone and 90% with GTR + RT). AEs were scored using NCI Common Toxicity Criteria. RESULTS Fifty-six patients enrolled in the intermediate-risk group, of whom 3 were ineligible and 1 did not receive RT. Of the 52 patients who received protocol therapy, 4 withdrew without a recurrence before 3 years leaving 48 patients evaluable for the primary endpoint, 3-year PFS, which was actuarially 93.8% (p = 0.0003). Within 3 years, 3 patients experienced events affecting PFS: 1 patient with a WHO Grade II tumor died of the disease, 1 patient with a WHO Grade II tumor had disease progression but remained alive, and 1 patient with recurrent WHO Grade I meningioma died of undetermined cause without tumor progression. The 3-year actuarial local failure rate was 4.1%, and the 3-year OS rate was 96%. After 3 years, progression occurred in 2 additional patients: 1 patient with recurrent WHO Grade I meningioma and 1 patient with WHO Grade II disease; both remain alive. Among 52 evaluable patients who received protocol treatment, 36 (69.2%) had WHO Grade II tumors and underwent GTR, and 16 (30.8%) had recurrent WHO Grade I tumors. There was no significant difference in PFS between these subgroups (p = 0.52, HR 0.56, 95% CI 0.09-3.35), validating their consolidation. Of the 52 evaluable patients, 44 (84.6%) received IMRT, and 50 (96.2%) were treated per protocol or with acceptable variation. AEs (definitely, probably, or possibly related to protocol treatment) were limited to Grade 1 or 2, with no reported Grade 3 events. CONCLUSIONS This is the first clinical outcomes report from NRG Oncology RTOG 0539. Patients with intermediate-risk meningioma treated with RT had excellent 3-year PFS, with a low rate of local failure and a low risk of AEs. These results support the use of postoperative RT for newly diagnosed gross-totally resected WHO Grade II or recurrent WHO Grade I meningioma irrespective of resection extent. They also document minimal toxicity and high rates of tumor control with IMRT. Clinical trial registration no.: NCT00895622 (clinicaltrials.gov).

Recurrence pattern analysis after [68Ga]-DOTATATE-PET/CT -planned radiotherapy of high-grade meningiomas

Background

The aim of the present study was to evaluate the influence of the applied safety margins of modern intensity-modulated radiotherapy (IMRT) in patients with high-grade meningiomas on local control and recurrence patterns.

Methods

Twenty patients with a neuropathological diagnosis of a high-grade meningioma (WHO°II or °III) treated with adjuvant or definitive radiotherapy between 2010 and 2015 were included in the present retrospective analysis. All patients were planned PET-based. Recurrence patterns were assessed by means of MRI and/or DOTATATE-PET/computertomography (CT).

Results

The median follow-up was 31.0 months [95% confidence interval (CI): 20.1–42.0] and the progression-free survival (PFS) after 24 months was 87.5%. Overall, four patients had a local recurrence of their meningioma. Of these, three were located in field according to the prior radiotherapy treatment region, while only one patient had a distant relapse. There were no independent factors influencing progression-free or overall survival (OS).

Conclusion

After radiotherapy (RT), patients with atypical or anaplastic meningiomas still have a defined risk of tumor recurrence. The aim of the present study was to examine mono-institutional data concerning target volume definition and recurrence patterns after radiotherapy of high-grade meningiomas as there are limited data available. Our data suggest that extended safety margins are necessary to achieve a favorable local control for high-grade meningiomas.

Radiosurgery and stereotactic radiotherapy with cyberknife system for meningioma treatment

Objective The aim of this work was to evaluate the impact of stereotactic radiosurgery/fractionated stereotactic radiotherapy with the Cyberknife system on local disease control, clinical outcome and toxicity in patients with meningioma, according to the site and histological grade of lesion. From January 2013 to April 2017, 52 patients with intracranial meningiomas were treated with the Cyberknife system. Twenty-four patients had undergone previous surgery: 38% gross total resection, 10% subtotal resection; 27 patients underwent no surgery; 22 patients had a recurrence of meningioma. Methods Radiosurgery was used for lesions smaller than 2 cm, stereotactic radiotherapy for lesions larger than 2 cm, or smaller but close to a critical site such as the optical chiasm, optic pathway or brainstem. Results Local control and clinical outcomes were analysed. Median follow-up was 20 months: six patients died, one after re-surgery died from post-surgical sepsis, three from heart disease. Progression-free survival had a mean value of 38.3 months and overall survival of 41.6 months. We evaluated at 12 months 28 patients (100% local control); at 24 months 19 patients (89% local control); at 36 months nine patients (89% local control). At baseline, 44/52 patients (85%) were symptomatic: 19 visual disorders, 17 motor disorders, six hearing disorders, 10 headache and six epilepsy. Visual symptoms remained unchanged in 52%, improved in 32%, resolved in 16%. Headache was improved in 40%, resolved in 10%, unchanged in 50%. Epilepsy was resolved in 17%, unchanged in 33%, worsened in 33%. Conclusions Stereotactic radiosurgery/fractionated stereotactic radiotherapy with Cyberknife provides a good local disease control, improving visual, hearing and motor symptoms.

[Relevance of Simpson's grading system for resections in WHO grade I meningiomas]

OBJECT

The aim of this study is to assess if the recurrence rates and recurrence/progression-free survivals (RFS) are different after Simpson's grades I, II, III and IV resections in World Health Organization (WHO) grade I meningiomas.

MATERIAL AND METHODS

A retrospective review was conducted on the data of patients who underwent surgical treatment of WHO grade I meningiomas located in convexity, falx/parasagittal, and skull base (anterior/media/posterior) between June 1991 and December 2011. In Simpson's grade IV resections, surgical treatment was supplemented with radiotherapy/radiosurgery on the tumour remains. A comparison was made on the recurrence rates and RFSs between Simpson's grades I, II, III, and IV resections, both overall and in tumour subsets according to their location.

RESULTS

A total of 208 meningiomas were included in this study. There were no significant differences in recurrence rates and RFSs between Simpson's grades I, II, III, and IV. No significant differences were noted between the different degrees of Simpson in any of the location groups. In convexity meningiomas, the recurrence rates were 7% and 33% in Simpson's grades I and III resections, respectively (P=.131).

CONCLUSIONS

It has been shown that the rates of tumour control in meningiomas are not related to Simpson grades. In falx/parasagittal and skull base meningiomas, more aggressive attempts of tumour resection must be balanced against the risks of damaging critical neurovascular structures. In convexity meningiomas, a Simpson's grade I resection should be attempted first.

[Prognostic variability in atypical meningioma with complete resection. Proposed treatment algorithm]

OBJECTIVE

The authors attempt to show how the current prognostic factors that try to assess the risk of recurrence of atypical meningiomas are insufficient to predict the future of this disease.

MATERIALS AND METHOD

Using data obtained from hospital databases, a sample of 27 patients was obtained with pathological diagnosis of atypical meningioma, and who had a minimum follow-up time of 6months after diagnosis. Later prognostic factors (age <50years, male gender, bone involvement, peri-lesional swelling, tumour volume, location, Ki67/MIB-1) were evaluated after the stratification of patients undergoing complete resection in recurrencies and non-recurrencies. Univariate analysis was performed using Mann-Whitney test, χ(2) homogeneity test/Fisher exact test. Finally, multivariate analysis was performed using binary logistic regression to obtain the values for R(2) Nagelkerke and the Hosmer-Lemeshow to evaluate the goodness of fit.

RESULTS

The uni- and multivariate analysis showed no statistically significant differences between recurrent and non-recurrent subgroups of patients undergoing complete resection. It is noted in the results that for each year of age above 50 years, the risk of recurrence is decreased by 5.8%.

CONCLUSIONS

Although current prognostic factors may show an increased risk of recurrence once patients are stratified by the two most important factors (pathology and extent of resection), those factors are insufficient to predict the ultimate outcome of patients affected by this pathology.

Imaging and extent of surgical resection predict risk of meningioma recurrence better than WHO histopathological grade

BACKGROUND

Risk stratification of meningiomas by histopathological grade alone does not reliably predict which patients will progress/recur after treatment. We sought to determine whether preoperative imaging and clinical characteristics could predict histopathological grade and/or improve prognostication of progression/recurrence (P/R).

METHODS

We retrospectively reviewed preoperative MR and CT imaging features of 144 patients divided into low-grade (2007 WHO grade I; n = 118) and high-grade (2007 WHO grades II/III; n = 26) groups that underwent surgery between 2002 and 2013 (median follow-up of 49 months).

RESULTS

Multivariate analysis demonstrated that the risk factors most strongly associated with high-grade histopathology were male sex, low apparent diffusion coefficient (ADC), absent calcification, and high peritumoral edema. Remarkably, multivariate Cox proportional hazards analysis demonstrated that, in combination with extent of resection, ADC outperformed WHO histopathological grade for predicting which patients will suffer P/R after initial treatment. Stratification of patients into 3 risk groups based on non-Simpson grade I resection and low ADC as risk factors correlated with the likelihood of P/R (P < .001). The high-risk group (2 risk factors; n = 39) had a 45% cumulative incidence of P/R, whereas the low-risk group (0 risk factors; n = 31) had no P/R events at 5 years after treatment. Independent of histopathological grade, high-risk patients who received adjuvant radiotherapy had a lower 5-year crude rate of P/R than those without (17% vs 59%; P = .04).

CONCLUSIONS

Patients with non-Simpson grade I resection and low ADC meningiomas are at significantly increased risk of P/R and may benefit from adjuvant radiotherapy and/or additional surgery.

Fractionated radiotherapy and radiosurgery of intracranial meningiomas

This review focuses on the role of radiosurgery and fractionated radiotherapy in the management of intracranial meningiomas, which are the most common benign intracranial tumors. Whenever feasible, surgery remains a cornerstone of treatment in effective health care treatment where modern radiotherapy plays an important role. Irradiation can be proposed as first-line treatment, as adjuvant treatment, or as a second-line treatment after recurrence. Stereotactic radiosurgery consists of delivering, a high-dose of radiation with high precision, to the tumor in a single-fraction with a minimal exposure of surrounding healthy tissue. Stereotactic radiosurgery, especially with the gamma knife technique, has reached a high level of success for the treatment of intracranial meningiomas with excellent local control and low morbidity. However, stereotactic radiosurgery is limited by tumor size,<3-4cm, and location, i.e. reasonable distance from the organs at risk. Fractionated radiation therapy is an interesting alternative (5 to 6weeks treatment time) for large inoperable tumors. The results of fractionated radiation therapy seem encouraging as regards both local control and morbidity although long-term prospective studies are still needed.

Evolution of the human hip. Part 1: the osseous framework

Extensive osseous adaptations of the lumbar spine, pelvis, hip and femur characterize the emergence of the human bipedal gait with its ‘double extension’ of the lumbar spine and hip. To accommodate lumbar lordosis, the pelvis was ‘compacted’, becoming wider and shorter, as compared with the non-human apes. The hip joint acquired a much more extended position, which can be seen in a broader evolutionary context of verticalization of limbs. When loaded in a predominantly vertical position, the femur can be built lighter and longer than when it is loaded more horizontally because bending moments are smaller. Extension of the hip joint together with elongation of the femur increases effective leg length, and hence stride length, which improves energy efficiency. At the hip joint itself, the shift of the hip’s default working range to a more extended position influences concavity at the head–neck junction and femoral neck anteversion.

Immunohistochemical analysis of cyclooxygenase-2 and brain fatty acid binding protein expression in grades I-II meningiomas: correlation with tumor grade and clinical outcome after radiotherapy

This study was done to evaluate the association of cyclooxygenase 2 (COX-2) and brain fatty acid binding protein (BFABP) with tumor grade and outcome of grades I-II meningiomas treated with radiotherapy. From 1996 to 2008, 40 patients with intracranial grades I-II meningiomas were treated with radiotherapy. Immunohistochemical staining for COX-2 and BFABP were performed on formalin-fixed paraffin-embedded tissues. COX-2 expression was significantly associated with BFABP status and both COX-2 (P < 0.01) and BFABP (P = 0.01) expression were stronger in the grade II meningiomas than in grade I tumors. Among the clinicopathologic factors, age and COX-2 status were prognostic in progression-free survival. Patients with moderate or strong COX-2 expression had worse outcome than those with negative or weak COX-2 expression (P = 0.03) after controlling for potential confounders. Our results suggest that the molecular biomarker COX-2 has prognostic significance in intracranial grades I-II meningiomas following radiotherapy.

Long-term efficacy of fractionated radiotherapy for benign meningiomas

PURPOSE

To assess long term efficacy of fractionated stereotactic radiotherapy (fSRT) in the treatment of benign intracranial meningiomas.

MATERIALS AND METHODS

Retrospective study of 222 patients with histologically confirmed (58%) and unverified presumed (42%) grade I intracranial meningioma treated with fSRT in a single institution to doses of 50-55Gy in 30-33 fractions.

RESULTS

At a median follow-up of 43months (range 3-144) the 5 and 10years local control (LC) were 93% and 86%. Patients with tumors involving the optic nerve (42 patients) and patients with cavernous sinus/parasellar region meningiomas (78 patients) had 5 and 10years LC of 100%. The 5 and 10years survival probabilities were 93% and 84%. On multivariate analysis gender and tumor site were independent predictors of LC. Worsening of pre-existing cranial nerve deficit occurred in 8 (3.5%) and onset of new deficit in 1 (0.5%) patient. Two patients with optic nerve sheath meningioma (1%) developed radiation retinopathy. There were no cases of radiation necrosis or second brain tumors.

CONCLUSION

fSRT achieves excellent medium and long term tumor control with minimal morbidity particularly in patients with benign meningiomas involving the parasellar region and the optic nerves and questions the role of other treatment modalities for tumors at these locations.

Radiosurgery for parasagittal and parafalcine meningiomas

Object

Parasagittal and parafalcine (PSPF) meningiomas represent the second most common location for intracranial meningiomas. Involvement of the superior sagittal sinus or deep draining veins may prevent gross-total resection of these tumors without significant morbidity. The authors review their results for treatment of PSPF meningiomas with radiosurgery.

Methods

The authors retrospectively reviewed the institutional review board–approved University of Virginia Gamma Knife database and identified 65 patients with 90 WHO Grade I parasagittal (59%) and parafalcine (41%) meningiomas who had a mean MRI follow-up of 56.6 months. The patients' mean age was 57 years, the median preradiosurgery Karnofsky Performance Status score was 80, and the median initial tumor and treatment volumes were 3 and 3.7 cm3, respectively. The median prescription dose was 15 Gy, isodose line was 40%, and the number of isocenters was 5. Kaplan-Meier analysis was used to determine progression-free survival (PFS). Univariate and multivariate Cox regression analyses were used to identify factors associated with PFS.

Results

The median overall PFS was 75.6 months. The actuarial tumor control rate was 85% at 3 years and 70% at 5 years. Parasagittal location, no prior resection, and younger age were found to be independent predictors of tumor PFS. For the 49 patients with clinical follow-up (mean 70.8 months), the median postradiosurgery Karnofsky Performance Status score was 90. Symptomatic postradiosurgery peritumoral edema was observed in 4 patients (8.2%); this group comprised 3 patients (6.1%) with temporary and 1 patient (2%) with permanent clinical sequelae. Two patients (4.1%) died of tumor progression.

Conclusions

Radiosurgery offers a minimally invasive treatment option for PSPF meningiomas, with a good tumor control rate and an acceptable complication rate comparable to most surgical series.

Frameless stereotactic radiosurgery for the treatment of primary intracranial tumours in dogs

Stereotactic radiosurgery (SRS) is a procedure that delivers a single large radiation dose to a well-defined target. Here, we describe a frameless SRS technique suitable for intracranial targets in canines. Medical records of dogs diagnosed with a primary intracranial tumour by imaging or histopathology that underwent SRS were retrospectively reviewed. Frameless SRS was used successfully to treat tumours in 51 dogs with a variety of head sizes and shapes. Tumours diagnosed included 38 meningiomas, 4 pituitary tumours, 4 trigeminal nerve tumours, 3 gliomas, 1 histiocytic sarcoma and 1 choroid plexus tumour. Median survival time was 399 days for all tumours and for dogs with meningiomas; cause-specific survival was 493 days for both cohorts. Acute grade III central nervous system toxicity (altered mentation) occurred in two dogs. Frameless SRS resulted in survival times comparable to conventional radiation therapy, but with fewer acute adverse effects and only a single anaesthetic episode required for therapy.

Five fraction image-guided radiosurgery for primary and recurrent meningiomas

PURPOSE

Benign tumors that arise from the meninges can be difficult to treat due to their potentially large size and proximity to critical structures such as cranial nerves and sinuses. Single fraction radiosurgery may increase the risk of symptomatic peritumoral edema. In this study, we report our results on the efficacy and safety of five fraction image-guided radiosurgery for benign meningiomas.

MATERIALS/METHODS

Clinical and radiographic data from 38 patients treated with five fraction radiosurgery were reviewed retrospectively. Mean tumor volume was 3.83 mm(3) (range, 1.08-20.79 mm(3)). Radiation was delivered using the CyberKnife, a frameless robotic image-guided radiosurgery system with a median total dose of 25 Gy (range, 25-35 Gy).

RESULTS

The median follow-up was 20 months. Acute toxicity was minimal with eight patients (21%) requiring a short course of steroids for headache at the end of treatment. Pre-treatment neurological symptoms were present in 24 patients (63.2%). Post treatment, neurological symptoms resolved completely in 14 patients (58.3%), and were persistent in eight patients (33.3%). There were no local failures, 24 tumors remained stable (64%) and 14 regressed (36%). Pre-treatment peritumoral edema was observed in five patients (13.2%). Post-treatment asymptomatic peritumoral edema developed in five additional patients (13.2%). On multivariate analysis, pre-treatment peritumoral edema and location adjacent to a large vein were significant risk factors for radiographic post-treatment edema (p = 0.001 and p = 0.026 respectively).

CONCLUSION

These results suggest that five fraction image-guided radiosurgery is well tolerated with a response rate for neurologic symptoms that is similar to other standard treatment options. Rates of peritumoral edema and new cranial nerve deficits following five fraction radiosurgery were low. Longer follow-up is required to validate the safety and long-term effectiveness of this treatment approach.

Long-term impact of cognitive deficits and epilepsy on quality of life in patients with low-grade meningiomas

BACKGROUND

WHO Grade I meningiomas are common, usually benign, primary brain tumors. Little is known about the health-related quality of life (HRQOL) of patients with meningiomas.

OBJECTIVE

To investigate the long-term HRQOL in patients with meningiomas and its association with cognitive deficits and epilepsy.

METHODS

HRQOL was assessed by the Short-Form Health Survey questionnaire (SF-36) in 89 patients with WHO Grade I meningiomas at least 1 year following neurosurgery with or without radiotherapy. Cognitive functioning was measured by a neuropsychological test battery, and epileptic seizure frequency and antiepileptic drug (AED) use were determined for each patient. HRQOL of patients was compared to that of 89 healthy controls individually matched for age, sex, and educational level.

RESULTS

As a group, patients with meningiomas did not differ from healthy controls on 7 out of 8 SF-36 scales; the only difference was that patients reported more role limitations caused by physical problems (P < .05). Patients with meningiomas had significant impairment in 4 of 6 cognitive domains, most pronounced in the domain of executive functioning. Both impaired cognitive functioning and AED use were associated with a compromised HRQOL. Of the 23 patients using AEDs, HRQOL was significantly impaired on 5 out of 8 SF-36 scales. In patients using AED, neither cognitive functioning nor HRQOL differed between those with and those without seizure control.

CONCLUSION

The HRQOL of most patients with WHO Grade I meningiomas is comparable to that of the general population. However, HRQOL is worse in patients with major cognitive deficits and those using AEDs, irrespective of seizure control.

The transmembrane chemokines CXCL16 and CX3CL1 and their receptors are expressed in human meningiomas

Meningiomas are common slowly growing benign tumors, however, anaplastic meningiomas have an aggressive biological and clinical behavior associated with high rates of recurrence and unfavorable prognosis. Since the molecular mechanisms involved in progression of meningiomas are not yet fully understood and recent investigations have suggested a possible role of chemokines in tumor biology, the aim of the study was to investigate the expression of CX3CL1/CX3CR1 and CXCL16/CXCR6 on mRNA and protein level in human meningiomas. Quantitative reverse-transcription polymerase chain reaction, immunohistochemistry and double immuno-staining techniques were used for the investigations. We showed that mRNA and protein expression of the chemokine/receptor pairs CX3CL1/CX3CR1 and CXCL16/CXCR6 were detectable in human meningioma samples. Double immunostaining revealed that the chemokines/receptors were predominantly expressed in the tumor cells themselves, in infiltrating microglia cells/macrophages and endothelial cells of blood vessels. Nevertheless, not all cells of different kinds were positive for different chemokine/receptors. Of note, in comparison to more benign meningioma samples, CX3CR1 and CXCL16 were found to be expressed at lower levels in anaplastic variants. Moreover, a positive correlation between expression levels of ligands and corresponding receptors could be observed for some malignancy grades. Taken together, these results showed that chemokines and their receptors are involved in the pathogenesis of human meningiomas. Our results provide an interesting basis for further investigations that should be performed to characterize the functional roles of chemokines and their receptors in human meningiomas, and also enhance future therapeutic design.

Chemotherapy: What is its role in meningioma?

While strong evidence exists for the standard therapy for meningiomas, inclusive of surgery and/or radiation therapy, for those tumors which recur, progress or are inoperable, the optimal medical therapies are yet to be elucidated. This article reviews the current literature for chemotherapeutic options for this subset of tumors, including cytotoxic agents, biologic agents, targeted molecular agents and hormonal agents. At this point in time, the most data is with hydroxyurea and somatostatin, although further trials with combination and targeted molecular therapies are still underway.

α3β1 integrin promotes radiation-induced migration of meningioma cells

Cell motility is influenced by the microenvironment, signal transduction and cytoskeleton rearrangement. Cancer cells become resistant to these control mechanisms and gain the ability to move throughout the body and invade healthy tissues, which leads to metastatic disease. Integrins respond to context-dependent cues and promote cell migration and survival in cancer cells. In the present study, we analyzed the role of integrins in radiation-induced migration of meningioma cells. Migration and cell proliferation assays revealed that radiation treatment (7 Gy) significantly increased migration and decreased proliferation in two cell lines, IOMM-Lee and CH-157-MN. α3 and β1 integrins were overexpressed at both the protein and transcript levels after radiation treatment and a function-blocking α3β1 antibody inhibited the radiation-induced migration. Immunofluorescence studies illustrated the localization of α3 integrin and F-actin at the migration front of irradiated cells. Further, an increase in phosphorylation of FAK and ERK was observed, while both FAK phosphorylation inhibitor and FAK shRNA inhibited ERK phosphorylation and downregulated uPA and vinculin. In addition to the co-localization of FAK and ERK at the migration front, these FAK-inhibition results link the downstream effects of ERK to FAK. Correspondingly, U0126 quenched ERK phosphorylation and reduced the expression of molecules involved in migration. Furthermore, brain sections of the animals implanted with tumors followed by radiation treatment showed elevated levels of α3 integrin and active ERK. Taken together, our results show that radiation treatment enhances the migration of meningioma cells with the involvement of α3β1 integrin-mediated signaling via FAK and ERK.

Hydroxyurea for recurrent surgery and radiation refractory meningioma: a retrospective case series

Hydroxyurea (HU), an orally administered chemotherapy, has become the de facto standard therapeutic agent in patients with surgically and radiation refractory meningiomas based on a limited literature. A retrospective case series of 60 patients with recurrent WHO grade 1 meningioma treated with HU following progression after surgery and radiotherapy was conducted with primary study objective progression free survival (PFS) at 6- and 12-months. Sixty patients (45 women; 15 men: median age 61.5 years, range 26-88) with recurrent meningioma were treated with HU (1000 mg/m(2)/day orally divided twice per day; one cycle operationally defined as 4-weeks of daily HU). All patients had progressed radiographically after prior therapy with surgery (60/60) and radiotherapy (external beam radiotherapy 60/60; stereotactic radiotherapy 53/60). No patient received prior chemotherapy or targeted therapy before instituting HU. Patients received 1-12 cycles (median 2.0) of HU with modest toxicity (10% grade 3 + anemia or fatigue). There were no radiographic responses, 35% of patients had stable disease and 65% manifested progressive disease. Duration of stable disease ranged from 3 to 12 months (median 4.0 months). The overall PFS was 10% (median PFS 2.0 months). The majority of patients (80%) following progression on HU were subsequently treated on an investigational trial. In this retrospective case series, HU though generally well tolerated and convenient, appeared to have very limited activity which raises questions of what constitutes effective salvage therapy and indicates an unmet need for alternative treatments for recurrent meningiomas.

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.

Meningiomas

OPINION STATEMENT

Meningiomas are extra-axial dural-based tumors. They are the most common intracranial tumors, occur in mid to late life, and have a female predilection. Symptoms are a function of location. Meningiomas are usually benign, but atypical and malignant forms exist. Treatment is indicated for symptomatic lesions or when neurologic symptoms may shortly occur. Surgical resection can be curative; however, because of their location, some lesions are amenable only to partial resection. Radiation therapy is used for incompletely removed symptomatic lesions, lesions that are not surgically accessible, and small symptomatic lesions. For higher grade meningiomas, radiation is used after surgery. For lesions that recur or grow despite surgery and radiation, systemic chemotherapy can be tried. There is no optimal agent, but hydroxyurea is used most often with very modest success; hormonal approaches have not been successful. Targeting somatostatin receptors or receptor tyrosine kinases using novel agents appears to have some activity and is an area of clinical research.

Intracranial meningiomas of atypical (WHO grade II) histology

Atypical (WHO grade II) meningiomas occupy an intermediate risk group between benign (WHO grade I) and anaplastic (WHO grade III) meningiomas. Although grade II meningiomas have traditionally been recognized in only about 5% of cases, after changes in diagnostic criteria with the current 2007 WHO standards, they now comprise approximately 20-35% of all meningiomas. Given the magnitude of this change, much work is now needed to solidify the adoption of these standards, to render inter-observer and inter-institutional comparisons more uniform, and to more carefully define the incidence of grade II histology. However, it is clear that they carry a several-fold increased risk of recurrence, as well as an increased rate of mortality. We will discuss the definition, diagnosis, and treatment of patients with atypical meningioma; review the current phase II cooperative trials; and draw attention to some questions timely for pre-clinical and clinical research.

A comparison of World Health Organization tumor grades at recurrence in patients with non–skull base and skull base meningiomas

Object

Despite a favorable outcome for most patients with WHO Grade I meningiomas, a subset of these patients will have recurrent or progressive disease that advances to a higher grade and requires increasingly aggressive therapy. The goal of this study was to identify clinical characteristics associated with the recurrence of benign meningiomas and their acceleration to atypical and malignant histological types.

Methods

Records of 216 patients with WHO Grade I, II, or III meningioma that were initially treated between 1965 and 2001 were retrospectively reviewed. Median follow-up was 7.2 years.

Results

Patients with non–skull base cranial meningiomas (82 of 105 [78%]) were more likely to have undergone a gross-total resection than patients with skull base meningiomas (32 of 78 [41%]; p < 0.001). Consequently, patients with Grade I non–skull base cranial meningiomas had better 5-year recurrence-free survival (69%) than patients with Grade I skull base meningiomas (56%) or Grade II or III tumors at any site (50%; p = 0.005). Unexpectedly, patients with non–skull base tumors who experienced a recurrence (8 of 22 [36%]) were more likely than patients with skull base tumors (1 of 19 [5%]) to have a higher grade tumor at recurrence (p = 0.024). Furthermore, the median MIB-1 labeling index of Grade I non–skull base cranial meningiomas (2.60%) was significantly higher than that of Grade I skull base tumors (1.35%; p = 0.016).

Conclusions

Cranial meningiomas that occur outside of the skull base are more likely to have a higher MIB-1 labeling index and recur with a higher grade than those within the skull base, suggesting that non–skull base cranial tumors may have a more aggressive biology than skull base tumors.

Radiation techniques in neuro-oncology

Radiation therapy plays a critical role in the management of tumors of the brain. A variety of radiotherapy techniques have been used to treat these tumors. This review describes both classic and more recent and advanced techniques available to manage these tumors. Included is a discussion of standard two- and three-dimensional radiation, as well as intensity-modulated radiotherapy, image-guided radiation therapy, stereotactic radiosurgery, and heavy particles.

The surgical management and outcomes for spheno-orbital meningiomas: a 7-year review of multi-disciplinary practice

AIMS/PURPOSE

Spheno-orbital meningiomas account for 9% of all adult intracranial meningiomas. Complete resection is extremely difficult with this condition. We report on our experience in the surgical management of spheno-orbital meningiomas.

METHODS

A retrospective review was performed of all patients with spheno-orbital meningiomas who underwent joint neurosurgical and ophthalmic procedures between January 2000 and December 2007. Radiological findings, presenting clinical signs, indications for surgery, surgical approach, histopathological findings, surgical complications and post-operative results were recorded.

RESULTS

Twelve patients were included in the study. Visual function deterioration was the main indication for surgery. Six patients underwent an optic canal decompression along with their initial tumour resection and all 12 patients underwent an extensive lateral orbital wall decompression. Post-operatively 6 patients had reduced proptosis. Two patients had an improvement in their visual acuity, 5 patients had a stable visual acuity and 5 patients had a progressive deterioration in visual acuity following surgery. Six patients maintained a stable visual field. Cranial nerve palsy was the commonest post-operative complication. Three patients required postoperative fractionated radiotherapy. Three patients required further surgery.

CONCLUSION

Spheno-orbital meningiomas are difficult tumours to manage. Surgical resection can reduce the degree of proptosis and stabilise visual function in patients with failing vision, although sustained improvement is difficult to achieve if the tumour behaves in an aggressive manner. The risk of post-operative visual loss is considerable, either due to surgery or tumour progression. Outcomes from surgical decompression may not necessarily be better than the natural history of these tumours.

PREDICTORS OF PERITUMORAL EDEMA AFTER STEREOTACTIC RADIOSURGERY OF SUPRATENTORIAL MENINGIOMAS

OBJECTIVE

Anecdotal evidence suggests that radiosurgical ablation of parasagittal meningiomas may be associated with increased risk of subsequent edema. Potential predictors of postradiosurgical peritumoral edema, including parasagittal tumor location, tumor size, and treatment dose, were evaluated.

METHODS

We retrospectively reviewed records of 102 patients with 111 supratentorial meningiomas treated with CyberKnife (Accuray, Inc., Sunnyvale, CA) stereotactic radiosurgery (SRS). A median marginal dose of 18.0 Gy (range, 11.3–25.0 Gy) was delivered in 1 to 5 sessions (fractions). Potential predictors of posttreatment symptomatic edema were evaluated using Fisher's exact test.

RESULTS

Of the 102 patients followed for a mean of 20.9 months (range, 6–77 mo), 15 (14.7%) developed symptomatic edema after SRS. Nine of 31 with parasagittal meningiomas (29.0%) and 6 of 80 with nonparasagittal supratentorial meningiomas (7.5%) developed symptomatic edema (P = 0.0053). Compared with patients with meningiomas in nonmidline supratentorial locations, patients with parasagittal meningiomas were more than 4 times as likely to develop symptomatic edema after SRS (odds ratio, 4.1; 95% confidence interval, 1.5–11.5). The 6-, 12-, and 18-month actuarial rates of symptomatic edema development were significantly greater for patients with parasagittal meningiomas than for patients with nonparasagittal meningiomas (17.8 versus 1.3%, 25.4 versus 5.8%, and 35.2 versus 7.8%, respectively).

CONCLUSION

Patients with parasagittal meningiomas are at greater risk of developing peritumoral symptomatic edema after SRS. Close follow-up after SRS may be particularly important in such patients. These results highlight the need to pursue strategies that could decrease the incidence of postradiosurgical edema in patients with parasagittal meningioma.