Treatment of meningioma: an update

Pediatric meningiomas: a report of 5 cases and review of literature

PURPOSE

The purpose of this paper is to provide novel insight into the rare pediatric meningiomas.

METHODS

We retrospectively analyzed pediatric surgical cases of meningioma during 2002 to 2017 in our institution. The preoperative, intraoperative, and the postoperative status were collected to find any unique features that has not reported in the past.

RESULTS

Nine surgeries out of 5 patients were identified. The mean age was 7 years old (range 1-14 years old). Four patients were females. The mean tumor diameter was 52 mm (range 23-81 mm). The tumor locations were optic nerve sheath, Sylvian fissure, parasagittal, trigone of the lateral ventricle, and cerebellopontine angle. The Sylvian fissure meningioma without dural attachment (MWODA) was found in a 15-month-old female. A relapsed parasagittal meningioma showed regression in histological grade and residual tumor demonstrated spontaneous regression. In the initial surgeries, Simpson grade 1 resection was achieved in 2 cases. The pathological diagnoses were 1 meningothelial, 1 metaplastic, 2 atypical, and 1 clear cell meningiomas. The mean postoperative follow-up period was 71 months. Three patients experienced recurrence of the tumor. At the latest follow-up, all patients were free of radiological tumor recurrence or regrowth with a mean follow-up of 4 years (range 1-6.9 years). All patients were in the modified Rankin scale of 0-1.

CONCLUSIONS

MWODA is not considered to be rare in pediatric meningioma and should be included in the differential diagnosis. We presented a histologically regressed relapsed meningioma, which spontaneously regressed after subtotal resection. In the case of recurrent meningioma, surgical resection and adjuvant radiation therapy could be effective for long-term control of the tumor.

Correlation of volumetric growth and histological grade in 50 meningiomas

INTRODUCTION

Advances in radiological imaging techniques have enabled volumetric measurements of meningiomas to be easily monitored using serial imaging scans. There is limited literature on the relationship between tumour growth rates and the WHO classification of meningiomas despite tumour growth being a major determinant of type and timing of intervention. Volumetric growth has been successfully used to assess growth of low-grade glioma; however, there is limited information on the volumetric growth rate (VGR) of meningiomas. This study aimed to determine the reliability of VGR measurement in patients with meningioma, assess the relationship between VGR and 2016 WHO grading as well as clinical applicability of VGR in monitoring meningioma growth.

METHODS

All histologically proven intracranial meningiomas that underwent resection in a single centre between April 2009 and April 2014 were reviewed and classified according to the 2016 edition of the Classification of the Tumours of the CNS. Only patients who had two pre-operative scans that were at least 3 months apart were included in the study. Two authors performed the volumetric measurements using the Slicer 3D software independently and the inter-rater reliability was assessed. Multiple regression analyses of factors affecting the VGR and VDE of meningiomas were performed using the R statistical software with p < 0.05 considered to be statistically significant.

RESULTS

Of 548 patients who underwent resection of their meningiomas, 66 met the inclusion criteria. Sixteen cases met the exclusion criteria (NF2, spinal location, previous surgical or radiation treatment, significant intra-osseous component and poor quality imaging). Forty-two grade I and 8 grade II meningiomas were included in the analysis. The VGR was significantly higher for grade II meningiomas. Using receiver-operator characteristic (ROC) curve analysis, the optimal threshold that distinguishes between grade I and II meningiomas is 3 cm³/year. Higher histological grade, high initial tumour volume, MRI T2-signal hyperintensity and presence of oedema were found to be significant predictors of higher VGR.

CONCLUSION

Reliable tools now exist to evaluate and monitor volumetric growth of meningiomas. Grade II meningiomas have significantly higher VGR compared with grade I meningiomas and growth of more than 3 cm³/year is strongly suggestive of a higher grade meningioma. A larger, multi-centre prospective study to investigate the applicability of velocity of growth to predict the outcome of patients with meningioma is warranted.

Minimally invasive surgery of the anterior skull base: transorbital approaches

Minimally invasive approaches are becoming increasingly popular to access the anterior skull base. With interdisciplinary cooperation, in particular endonasal endoscopic approaches have seen an impressive expansion of indications over the past decades. The more recently described transorbital approaches represent minimally invasive alternatives with a differing spectrum of access corridors. The purpose of the present paper is to discuss transorbital approaches to the anterior skull base in the light of the current literature. The transorbital approaches allow excellent exposure of areas that are difficult to reach like the anterior and posterior wall of the frontal sinus; working angles may be more favorable and the paranasal sinus system can be preserved while exposing the skull base. Because of their minimal morbidity and the cosmetically excellent results, the transorbital approaches represent an important addition to established endonasal endoscopic and open approaches to the anterior skull base. Their execution requires an interdisciplinary team approach.

Novel therapies for meningiomas

Although advances in surgery, radiation therapy and stereotactic radiosurgery have significantly improved the treatment of meningiomas, there remains an important subset of patients who remain refractory to conventional therapy. Treatment with chemotherapeutic agents such as hydroxyurea and alpha-interferon has provided minimal benefit. In this review, the role of newly emerging novel therapies for meningiomas, with a focus on targeted molecular agents, will be discussed.

A microcosting study of microsurgery, LINAC radiosurgery, and gamma knife radiosurgery in meningioma patients

The aim of the present study is to determine and compare initial treatment costs of microsurgery, linear accelerator (LINAC) radiosurgery, and gamma knife radiosurgery in meningioma patients. Additionally, the follow-up costs in the first year after initial treatment were assessed. Cost analyses were performed at two neurosurgical departments in The Netherlands from the healthcare providers' perspective. A total of 59 patients were included, of whom 18 underwent microsurgery, 15 underwent LINAC radiosurgery, and 26 underwent gamma knife radiosurgery. A standardized microcosting methodology was employed to ensure that the identified cost differences would reflect only actual cost differences. Initial treatment costs, using equipment costs per fraction, were <euro>12,288 for microsurgery, <euro>1,547 for LINAC radiosurgery, and <euro>2,412 for gamma knife radiosurgery. Higher initial treatment costs for microsurgery were predominantly due to inpatient stay (<euro>5,321) and indirect costs (<euro>4,350). LINAC and gamma knife radiosurgery were equally expensive when equipment was valued per treatment (<euro>2,198 and <euro>2,412, respectively). Follow-up costs were slightly, but not significantly, higher for microsurgery compared with LINAC and gamma knife radiosurgery. Even though initial treatment costs were over five times higher for microsurgery compared with both radiosurgical treatments, our study gives indications that the relative cost difference may decrease when follow-up costs occurring during the first year after initial treatment are incorporated. This reinforces the need to consider follow-up costs after initial treatment when examining the relative costs of alternative treatments.

Exploring new frontiers in molecular imaging: Emergence of 68Ga PET/CT

Since US Food and Drug Administration approval of 18-fluorodeoxyglucose as a positron tracer, and the development of hybrid positron emission tomography/computed tomography machines, there has been a great increase in clinical application and progress in the field of nuclear molecular imaging. However, not underestimating the value of ¹⁸F, there are known limitations in the use of this cyclotron-produced positron tracer. We hence turn our focus to an emerging positron tracer, ⁶⁸Ga, and examine the advantages, current clinical uses and potential future applications of this radioisotope.

Targeted drug therapy for meningiomas

✓ Although advances in surgery, radiation therapy, and stereotactic radiosurgery have significantly improved the treatment of meningiomas, there remains an important subset of patients whose tumors are refractory to conventional therapy. Treatment with traditional chemotherapeutic agents has provided minimal benefit. In this review, the role of targeted molecular therapies for recurrent or progressive meningiomas is discussed.

Holistic and network analysis of meningioma pathogenesis and malignancy

Meningiomas, which originate from arachnoid cells and constitute the largest subgroup of all intracranial tumors, are generally benign, yet have the capacity to progress into a higher histological grade of malignancy associated with an increase in biological aggressivity and/or capacity to recur. To elucidate meningioma pathogenesis and malignancy, we applied a holistic and network approach analyzing cDNA and tissue microarray results. A potential pathway leading to meningioma angiogenesis, apoptosis and proliferation was evidenced as well as a regulatory network of the biomarkers including Ki-67, AR, CD34, P53, c-MYC, etc. which might support clinical research. In this potential pathway, ITGB1 could be the most important "superoncogene" playing a vital role in apoptosis and proliferation, while FOXO3A, MDM4 and MT3 are important to the malignancy process. Some genes are first reported that could explain why radiation induces meningioma and why more female than male patients are affected. Further, we present the hypothesis that HIV-Tat protein might have a close relationship with meningioma pathogenesis and malignancy.

The Application of Surgical Cordectomy in the Management of an Intramedullary-Extramedullary Atypical Meningioma

BACKGROUND

The English literature describes only four cases of intraspinal tumors requiring surgical intervention in the form of cordectomy; none of these cases was for meningiomas. Intraspinal meningiomas, typically extramedullary-intradural, require treatment in the form of resection with dural margin excision. The presentation of an intramedullary atypical World Health Organization grade II meningioma is rare. The authors report a case of a transformed intramedullary-extramedullary atypical meningioma treated with cordectomy.

METHODS

The patient was a 65-year-old woman who presented with a recurrent thoracic meningioma status post three attempted resections, radiation therapy, and a trial of hydroxyurea chemotherapy. The patient presented paraplegic with reports of burning paresthesias bilaterally in her upper extremities 12 months after her third resection attempt.

RESULTS

Magnetic resonance imaging on this current presentation revealed a heterogeneously enhancing hypointense mass extending from T2 to T6. Extension of abnormal T2 signal within the cord superiorly to C7 was noted with a 1-cm enhancing extra-axial lesion at T10 and an extradural mass posteriorly T12 also noted. The patient underwent a T2-T7 laminectomy with a T2-T8 cordectomy. Two months postoperatively, the patient was doing well with no further deterioration in neurologic function.

CONCLUSIONS

This case highlights the viability of surgical cordectomy in the treatment of varying intramedullary processes under appropriate indications.

Gamma knife radiosurgery of radiation-induced intracranial tumors: Local control, outcomes, and complications

PURPOSE

To determine local control (LC) and complication rates for patients who underwent radiosurgery for radiation-induced intracranial tumors.

METHODS AND MATERIALS

Review of a prospectively maintained database (2,714 patients) identified 16 patients (20 tumors) with radiation-induced tumors treated with radiosurgery between 1990 and 2004. Tumor types included typical meningioma (n=17), atypical meningioma (n=2), and schwannoma (n=1). Median patient age at radiosurgery was 47.5 years (range, 27-70 years). The median tumor margin dose was 16 Gy (range, 12-20 Gy). Median follow-up was 40.2 months (range, 10.8-146.2 months). Time-to-event outcomes were calculated with Kaplan-Meier estimates.

RESULTS

Three-year and 5-year LC rates were 100%. Three-year and 5-year overall survival rates were 92% and 80%, respectively. Cause-specific survival rates at 3 and 5 years were 100%. Three patients died: 1 had in-field progression 65.1 months after radiosurgery and later died of the tumor, 1 died of progression of a preexisting brain malignancy, and 1 died of an unrelated cause. One patient had increased seizure activity that correlated with development of edema seen on neuroimaging.

CONCLUSIONS

LC, survival, and complication rates in our series are comparable to those in previous reports of radiosurgery for intracranial meningiomas. Also, LC rates with radiosurgery are at least comparable to those of surgical series for radiation-induced meningiomas. Radiosurgery is a safe and effective treatment option for radiation-induced intracranial tumors, most of which are typical meningiomas.