Refractory Meningiomas Research Articles

Comment on, "Expression of decitabine-targeted oncogenes in meningiomas in vivo".

The study by Canisius et al. (2022) explores the expression of decitabine-targeted oncogenes (TRIM58, FAM84B, ELOVL2, DIO3) in meningiomas, aiming to evaluate decitabine's therapeutic potential for high-grade tumors. Using immunohistochemical staining and RT-PCR in over 100 patient samples, the authors found significant correlations between oncogene expression and tumor grade, with elevated ELOVL2 levels being linked to tumor recurrence. This work highlights the role of decitabine in modulating oncogene expression and suggests its potential in treating refractory meningiomas. Despite the robust methodology, limitations such as the small sample size and the lack of comprehensive molecular data were noted. Future research should incorporate larger sample sizes and advanced genomic techniques like RNA sequencing to better understand oncogenic mechanisms. The study emphasizes the need for further in situ analyses of decitabine's efficacy, setting the foundation for future neuro-oncological treatments.

177Lu-labeled somatostatin receptor targeted radionuclide therapy dosimetry in meningioma: a systematic review.

Few therapeutic options are currently available for refractory meningiomas. Encouraging results have been reported for 177Lu-labeled somatostatin receptor-targeted radiopeptide therapy (SSTR-RT). The current therapeutic scheme is based on the fixed doses that are recommended for neuroendocrine tumor treatment. However, in personalized medicine, tumor dosimetry can be determined from repeat 177Lu scintigraphy. The aim of this review was to report on the methods used for calculating the tumor absorbed dose (AD) in meningioma patients treated with 177Lu-SSTR-RT and their values. The search was performed in Medline, Embase and the Cochrane Library until March 1st, 2024 to retrieve papers related to the topic. The following terms were used for searching: (meningioma) AND ((sstr) OR (receptors somatostatin) OR (somatostatin) OR (octreotide)) AND ((PRRT) OR (radionuclide therapy) OR (dotatate) OR (dotatoc) OR (177Lu-DOTATOC) OR (177Lu-DOTATATE) OR (radiopeptide)). Seven articles (including 46 patients and 108 cycles of treatment) reporting on tumor AD during 177Lu-SSTR-RT were included in the analysis. The methods of acquisition, reconstruction parameters and postimage processing to determine tumor AD were very heterogeneous among the studies. The meningioma AD associated with the agonist 177Lu-SSTR-RT reported in the majority of studies ranged from 0.1-1.5 Gy/GBq, which was lower than that reported for neuroendocrine tumors (1.3-22.9 Gy/GBq). The tumor AD that was reported during treatment with 177Lu-SSTR-RT in refractory meningioma patients is generally low. Harmonization of the methodology for dosimetry calculations is needed to compare the different reported values and optimize treatment at the individual level.

Peptide Receptor Radionuclide Therapy in Advanced Refractory Meningiomas: Efficacy and Toxicity in a Long Follow-up.

Recurrence of meningiomas after surgery and radiotherapy deserves specific attention because of the lack of active third-line therapies. Somatostatin receptors are usually overexpressed on the cell membrane of meningiomas, and this has led the way to a radionuclide theranostic approach. Diagnoses with 68Ga-DOTA-octreotide and peptide receptor radionuclide therapy (PRRT) with 90Y/177Lu-DOTA-octreotide are currently possible options within experimental protocols or as compassionate use in small patient groups. Methods: From October 2009 to October 2021, 42 meningioma patients with radiologic recurrence after standard therapies were treated with 90Y-DOTATOC (dosage of 1.1 or 5.5 GBq) or with 177Lu-DOTATATE (dosage of 3.7 or 5.5 GBq) in a mean of 4 cycles. All patients showed intense uptake at diagnostic 68Ga-DOTATOC PET/CT or in an 111In-octreotide scan. Results: Of 42 patients treated, 5 patients received 90Y-DOTATOC with a cumulative activity of 11.1 GBq and 37 patients received 177Lu-DOTATATE with a cumulative activity of 22 GBq. The disease control rate was 57%. With a median follow-up of 63 mo, median progression-free survival was 16 mo, and median overall survival was 36 mo. Retreatment 177Lu-PRRT was performed in 6 patients with an administered median activity of 13 GBq in a mean of 5 cycles. With a 75.8-mo follow-up, median progression-free survival and overall survival were 6.5 and 17 mo, respectively. Only 1 patient discontinued the treatment because of grade 3 platelet toxicity. A rapidly transient grade 2 neutropenia was recorded in 1 retreated patient. Conclusion: PRRT in patients with advanced meningiomas overexpressing somatostatin receptor 2 was active and well tolerated, showing a 57% disease control rate. Furthermore, PRRT could represent a potential retreatment option. Further studies, also in combination with other treatments, are warranted.

Surgical Outcomes following Reoperation for Recurrent Intracranial Meningiomas.

Background: We sometimes encounter refractory meningioma cases that are difficult to control, even after achieving a high resection rate or following radiation therapy (RT). In such cases, additional surgical resection might be attempted, but reports regarding outcomes of re-do surgery for recurrent meningiomas are scarce. Methods: This study was a retrospective review of patients who underwent re-do surgery for recurrent meningiomas. The risks of re-doing surgery were statistically analyzed. A comparative analysis between the patients who underwent primary surgery for intracranial meningiomas was also performed. Twenty-six patients underwent re-do surgeries for recurrent meningiomas. Results: At first re-do surgery, gross total resection was achieved in 20 patients (77%). The disease-free survival rate after the first re-do surgery was calculated as 73/58/44% at 1, 2, and 5 years, respectively. A significant factor affecting longer disease-free survival was WHO Grade 1 diagnosis at first re-do surgery (p = 0.02). Surgery-related risks were observed in 10 patients presenting a significant risk factor for skull base location (p = 0.04). When comparing with the risk at primary surgery, the risks of surgical site infection (p = 0.04) and significant vessel injury (p < 0.01) were significantly higher for the re-do surgery. Conclusions: Re-do surgery could increase surgery-related risks compared to the primary surgery; however, it could remain a crucial option, while the indication should be carefully examined in each case.

A 16 year-retrospective study of refractory meningiomas: Prognostic factors and systemic treatments.

2085 Background: Meningiomas are the most common brain tumors, with no established standard systemic treatment for refractory cases after surgical and radiotherapeutic interventions. This study aims to identify prognostic factors for overall survival in refractory meningioma and document patient evolution with systemic treatments. Methods: In a retrospective study, we identified patients with meningioma initially followed at CHUM university hospital between 2006 and 2022. Patients with progression after first-line treatment and over 6 months of follow-up were included. The population was divided into two: group 1 received surgery and/or radiotherapy for progression, and group 2 received additional systemic treatments. Survival analysis with Kaplan-Meier curves and group comparisons (Log-Rank, Fisher's Exact Tests) were conducted. Results: A total of750 patients with meningioma were identified. 99 (13%) progressed after first-line treatment. Among them, 70 (9%) were categorized in group 1 and 29 (4%), in group 2. The median follow-up time from diagnosis was 7.5 years. The overall 10-year survival rate was higher in group 1 compared to group 2 (88% vs 62%). Prognostic factors affecting survival were identified as the following: disease progression after second-line treatment, age ≥ 65 years, and grade 2 or 3. When comparing PFS-1 after first-line treatment, they were similar between group 1 and group 2 (mPFS-1: 2.63 vs 3.49 years; p = 0.421). However, PFS-2 after second-line treatment was significantly shorter in group 2 (mPFS-2 : 12.6 vs 2.3 years ; p &lt; 0.001). Age of ≥ 65 years (10-year survival: 57% vs 89%; p &lt; 0.001) and higher grades (10 year survival: 90% grade 1 vs 58% - grade 2 vs 75% - grade 3; p = 0.027) were associated with lower survival rates. The number of lesions (unique or multiple) and localization (supra or infratentorial) of tumors had no significant impact on survival (p=0.257; p = 0.482). Regarding systemic treatments, 7 patients (25%) received Bevacizumab. It was the treatment associated with the longest PFS (mPFS = 22.5 months) when compared to Hydroxyurea (n=18 [62%], mPFS = 4 months), Somatostatin (n = 5 [17%], mPFS = 8 months), a combination of Hydroxyurea and Somatostatin (n=7 [24%], mPFS = 8 months) and Sunitinib (n=3 [10%], mPFS = 14 months). For patients discontinuing systemic treatment, median survival was 5 months. Systemic treatments were well-tolerated. Among moderate to severe side effects (grade ≥ 2), we documented bradycardia (Somatostatin, n=1), elevated liver enzymes (Sunitinib, n=1), anemia and neutropenia (Hydroxyurea, n=3) and proteinuria (Bevacizumab, n=1). Conclusions: Prognostic factors for survival in meningioma include age ≥ 65 years, grades 2 and 3, and the occurrence of a second progression. Our study highlights Bevacizumab in systemic treatment strategies which was well tolerated in our patients.

NIMG-74. COMPARING VOLUMETRIC GROWTH-RATE AND RANO CRITERIA IN DETERMINING THE RESPONSE OF MENINGIOMA TO BEVACIZUMAB THERAPY

Abstract Meningioma is the most prevalent primary tumor in the central nervous system (CNS). Although mostly benign, 15- 20% are aggressive and tend to recur and progress despite surgery and adjuvant radiation. Recent publications show that bevacizumab, a vascular endothelial growth factor inhibitor, effectively treats these refractory meningiomas. The standard method to monitor treatment’s effect on imaging is Response Assessment in Neuro-Oncology criteria (RANO). Recently, an alternative tool called 3D volumetric growth rate (3DVGR) has emerged. Our aim is to compare the effectiveness of conventional RANO criteria and the 3DVGR measure in evaluating the response to bevacizumab treatment in patients with refractory meningiomas. We will also assess their correlation with clinical outcomes over a period of up to 9 months. 68 MRI scans of 20 patients with aggressive meningiomas treated with bevacizumab were evaluated. For each tumor both RANO and 3DVGR were conducted in two subsequent head MRI studies acquired prior to the initiation of bevacizumab treatment and then in at least one exam within 6 months post-treatment. Measurements were obtained using PACS and BRAIN LAB software by two radiologists. A total of 43 lesions derived from 20 patients were included in the analysis. The mean age was 65.5; mean number of radiation treatments was 2.66; mean number of pre-surgical treatments was 2.7 and mean number of bevacizumab cycles was 22.7. All lesions showed a decrease or stabilization in growth rate compared to baseline. More specifically, 34 out of 43 lesions (79%) showed a negative growth rate value indicating decrease in tumor size. Comparison of treatment response using RANO criteria was not always in concordance with the 3DVGR measurement and showed inaccurate correlation with clinical outcome. 3DVGR measure seems to be more precise compared to RANO criteria. Furthermore, our results show great promise for treatment of refractory meningiomas with bevacizumab.

KS03.5.A COMPARING VOLUMETRIC GROWTH-RATE AND RANO CRITERIA IN DETERMINING THE RESPONSE OF MENINGIOMA TO BEVACIZUMAB THERAPY

Abstract INTRODUCTION Meningioma is the most prevalent primary tumor in the central nervous system (CNS). Although mostly benign, 15- 20% are aggressive and tend to recur and progress despite surgery and adjuvant radiation. Recent publications show that bevacizumab, a vascular endothelial growth factor inhibitor, effectively treats these refractory meningiomas. The standard method to monitor treatment’s effect on imaging is Response Assessment in Neuro-Oncology criteria (RANO). Recently, an alternative tool called 3D volumetric growth rate (3DVGR) has emerged as a result of significant advancements in the accuracy of volumetric measurement techniques. Our aim is to compare the effectiveness of conventional RANO criteria and the emerging 3DVGR measure in evaluating the response to bevacizumab treatment in patients with refractory meningiomas. We will also assess their correlation with clinical outcomes over a period of up to 9 months. METHODS 68 MRI scans of 20 patients with aggressive meningiomas that progressed after radiation therapy and then received Bevacizumab were evaluated. Scans were obtained from two tertiary cancer centers. For each tumor both RANO and 3DVGR were conducted in two subsequent head MRI studies acquired prior to the initiation of bevacizumab treatment and then in at least one exam within 6 months post-treatment. Measurements were obtained using PACS and BRAIN LAB software by two radiologists. RESULTS A total of 43 lesions derived from 13 males and 7 females were included in the final analysis. The mean age was 65.5; mean number of pre-radiation treatments was 2.66; mean number of pre-surgical treatments was 2.7 and mean number of bevacizumab cycles was 22.7. All lesions showed a decrease or stabilization in growth rate compared to baseline. More specifically, 34 out of 43 lesions (79%) showed a negative growth rate value indicating decrease in tumor size. Comparison of treatment response using RANO criteria was not always in concordance with the 3DVGR measurement and showed inaccurate correlation with clinical outcome. CONCLUSIONS Although widely accepted for treatment response evaluation, RANO criteria are not an accurate technique for irregularly shaped lesions. As shown in our study, for atypical meningiomas, the 3DVGR measure seems to be more precise compared to RANO criteria. Furthermore, our results show great promise for treatment of refractory meningiomas with bevacizumab.

Semi-automated segmentation methods of SSTR PET for dosimetry prediction in refractory meningioma patients treated by SSTR-targeted peptide receptor radionuclide therapy.

Tumor dosimetry with somatostatin receptor-targeted peptide receptor radionuclide therapy (SSTR-targeted PRRT) by 177Lu-DOTATATE may contribute to improved treatment monitoring of refractory meningioma. Accurate dosimetry requires reliable and reproducible pretherapeutic PET tumor segmentation which is not currently available. This study aims to propose semi-automated segmentation methods to determine metabolic tumor volume with pretherapeutic 68Ga-DOTATOC PET and evaluate SUVmean-derived values as predictive factors for tumor-absorbed dose. Thirty-nine meningioma lesions from twenty patients were analyzed. The ground truth PET and SPECT volumes (VolGT-PET and VolGT-SPECT) were computed from manual segmentations by five experienced nuclear physicians. SUV-related indexes were extracted from VolGT-PET and the semi-automated PET volumes providing the best Dice index with VolGT-PET (Volopt) across several methods: SUV absolute-value (2.3)-threshold, adaptative methods (Jentzen, Otsu, Contrast-based method), advanced gradient-based technique, and multiple relative thresholds (% of tumor SUVmax, hypophysis SUVmean, and meninges SUVpeak) with optimal threshold optimized. Tumor-absorbed doses were obtained from the VolGT-SPECT, corrected for partial volume effect, performed on a 360° whole-body CZT-camera at 24, 96, and 168h after administration of 177Lu-DOTATATE. Volopt was obtained from 1.7-fold meninges SUVpeak (Dice index 0.85 ± 0.07). SUVmean and total lesion uptake (SUVmeanxlesion volume) showed better correlations with tumor-absorbed doses than SUVmax when determined with the VolGT (respective Pearson correlation coefficients of 0.78, 0.67, and 0.56) or Volopt (0.64, 0.66, and 0.56). Accurate definition of pretherapeutic PET volumes is justified since SUVmean-derived values provide the best tumor-absorbed dose predictions in refractory meningioma patients treated by 177Lu-DOTATATE. This study provides a semi-automated segmentation method of pretherapeutic 68Ga-DOTATOC PET volumes to achieve good reproducibility between physicians. SUVmean-derived values from pretherapeutic 68Ga-DOTATOC PET are predictive of tumor-absorbed doses in refractory meningiomas treated by 177Lu-DOTATATE, justifying to accurately define pretherapeutic PET volumes. This study provides a semi-automated segmentation of 68Ga-DOTATOC PET images easily applicable in routine. • SUVmean-derived values from pretherapeutic 68Ga-DOTATOC PET images provide the best predictive factors of tumor-absorbed doses related to 177Lu-DOTATATE PRRT in refractory meningioma. • A 1.7-fold meninges SUVpeak segmentation method used to determine metabolic tumor volume on pretherapeutic 68Ga-DOTATOC PET images of refractory meningioma treated by 177Lu-DOTATATE is as efficient as the currently routine manual segmentation method and limits inter- and intra-observer variabilities. • This semi-automated method for segmentation of refractory meningioma is easily applicable to routine practice and transferrable across PET centers.

The Role of Pharmacotherapy in Treatment of Meningioma: A Systematic Review.

The safety and efficacy of various pharmacotherapeutic regimens on refractory meningiomas have been the focus of investigations. We present a comprehensive review of the previous efforts and the current state of ongoing clinical trials. A PRISMA-compliant review of the MEDLINE and ClinicalTrial.gov databases of the National Library of Medicine were performed. The primary outcomes of interest for included articles were radiographic response, overall survival, progression-free survival, six-month progression-free survival, and adverse events. Overall, 34 completed trials and 27 ongoing clinical trials were eligible. Six-month progression-free survival was reported in 6-100% of patients in the completed studies. Hematological disorders were the most common adverse events. Of the ongoing clinical trials identified, nine studies are phase I clinical trials, eleven are phase II trials, two are phase I and II trials, one is phase II and III, and two trials do not have a designated phase. Currently, there is no effective chemotherapy for refractory or recurrent meningiomas. Several promising targeted agents have been developed and are currently being investigated in the hope of identifying novel therapeutic strategies for the treatment of this pathology.

Pharmacological Landscape of FDA-Approved Anticancer Drugs Reveals Sensitivities to Ixabepilone, Romidepsin, Omacetaxine, and Carfilzomib in Aggressive Meningiomas.

To date, there are no systemic treatment options for patients with recurrent or refractory meningioma. To identify effective drugs, we performed a large-scale drug screening using FDA-approved drugs on several meningioma cell lines. The impact of the top four compounds was assessed on cell viability, proliferation, colony formation, migration, and apoptosis. In addition, the antineoplastic effects of the selected drugs were validated in a heterotopic xenograft mouse model. Analyses of the viability of meningioma cells treated with 119 antineoplastic FDA-approved drugs resulted in categorization into sensitive and resistant drug-response groups based on the mean IC50 values and peak serum concentrations (Cmax) in patients. Eighty drugs, including 15 alkylating agents, 14 antimetabolites, and 13 tyrosine kinase inhibitors, were classified as resistant (IC50 > Cmax). The sensitive drug-response group (n = 29, IC50 < Cmax) included RNA/protein synthesis inhibitors, proteasome inhibitors, topoisomerase, tyrosine-kinase, and partial histone deacetylase and microtubule inhibitors. The IC50 value of the four most effective compounds (carfilzomib, omacetaxine, ixabepilone, and romidepsin) ranged from 0.12 to 9.5 nmol/L. Most of them caused cell-cycle arrest in the G2-M-phase and induced apoptosis. Furthermore, all drugs except romidepsin significantly inhibited tumor growth in vivo. The strongest antineoplastic effect was observed for ixabepilone, which reduced tumor volume by 86%. In summary, a large-scale drug screening provides a comprehensive insight into the anti-meningioma activities of FDA-approved drugs, and identified carfilzomib, omacetaxine, ixabepilone, and romidepsin as novel potent antineoplastic agents for the treatment of aggressive meningiomas. The most pronounced effects were observed with ixabepilone mandating for further clinical investigation.

Somatostatin Receptor Theranostics for Refractory Meningiomas.

Somatostatin receptor (SSTR)-targeted peptide receptor radionuclide therapy (PRRT) represents a promising approach for treatment-refractory meningiomas progressing after surgery and radiotherapy. The aim of this study was to provide outcomes of patients harboring refractory meningiomas treated by 177Lu-DOTATATE and an overall analysis of progression-free survival at 6 months (PFS-6) of the same relevant studies in the literature. Eight patients with recurrent and progressive WHO grade II meningiomas were treated after multimodal pretreatment with 177Lu-DOTATATE between 2019 and 2022. Primary and secondarily endpoints were progression-free survival at 6-months (PFS-6) and toxicity, respectively. PFS-6 analysis of our case series was compared with other similar relevant studies that included 86 patients treated with either 177Lu-DOTATATE or 90Y-DOTATOC. Our retrospective study showed a PFS-6 of 85.7% for WHO grade II progressive refractory meningiomas. Treatment was clinically and biologically well tolerated. The overall analysis of the previous relevant studies showed a PFS-6 of 89.7% for WHO grade I meningiomas (n = 29); 57.1% for WHO grade II (n = 21); and 0 % for WHO grade III (n = 12). For all grades (n = 86), including unknown grades, PFS-6 was 58.1%. SSTR-targeted PRRT allowed us to achieve prolonged PFS-6 in patients with WHO grade I and II progressive refractory meningiomas, except the most aggressive WHO grade II tumors. Large scale randomized trials are warranted for the better integration of PRRT in the treatment of refractory meningioma into clinical practice guidelines.

A multi-institutional phase II trial of bevacizumab for recurrent and refractory meningioma.

BackgroundSystemic therapies for refractory meningiomas are limited with no FDA-approved therapeutics. Vascular endothelial growth factor (VEGF) is a signaling protein associated with neovascularization, peritumoral edema, and meningioma tumorigenesis.MethodsThis phase II study investigates the efficacy of bevacizumab (BEV), a VEGF binding monoclonal antibody, in patients with progressive Grade I (G1M), Grade II (G2M), Grade III (G3M) meningioma, and other non-parenchymal tumors including vestibular schwannoma (n = 4) and hemangiopericytoma (n = 4) with the primary endpoint of progression-free survival rate at 6-months (PFS-6). Non-meningiomas were included with the respective meningioma grade in the analysis. Secondary endpoints include median overall survival (mOS) and response rate.ResultsFifty Patients (26 women; median age 54 years; range 23–81), 42 with progressive meningioma were treated: 10 G1M, 20 G2M, and 12 G3M. Prior treatments include surgical resection (41 patients), radiosurgery (24 patients), external beam radiotherapy (28 patients), and chemotherapy (14 patients). Median infusions administered were 16 (range, 2–68). Response was graded using the Macdonald’s criteria. PFS-6, median PFS, and mOS were 87%, 22 months, 35 months for G1M; 77%, 23 months, 41 months for G2M; and 46%, 8 months, 12 months for G3M. Best radiographic responses include stable disease (G1M: 100%; G2M: 85%; G3M: 82%); partial response (G1M: 0%; G2M: 5%; G3M: 0%) and progressive disease (G1M: 0%; G2M: 10%; G3M:18%). The most common toxicities were hypertension (n = 19, 42.2%), proteinuria (n = 16, 35.6%), and fatigue (n = 14, 31.1%).ConclusionThis study showed BEV is well tolerated and appears to be a promising systemic treatment option for patients with recurrent and refractory meningiomas.

The Potential of Personalized/Precision Medicine for Meningiomas

Meningiomas are one of the most common primary brain tumors. The majority of patients with meningiomas can undergo curative resection or remain asymptomatic for a lifetime, but a minority of them have tumors with cumbersome clinicopathological features causing life-threatening disease. Although several cytotoxic agents and hormonal therapies have been tried for refractory and unresectable meningiomas, there are no effective drugs available for meningiomas so far. In the last decade, due to the rapid progress in comprehensive genomic research for individual tumors, novel somatic and recurrent mutations were discovered in meningiomas. The discovered somatic mutations were mostly mutually exclusive with NF2 gene alterations, and importantly, several of these mutations, such as AKT1 and SMO, are potentially actionable mutations for precision/personalized medicine. In addition, immunotherapy is another attractive treatment option for refractory meningiomas due to the development of immune checkpoint inhibitors. Herein, we describe the possibility of precision medicine for meningiomas according to each molecular aberrancy and present the currently ongoing clinical trials including hormonal therapy, targeted kinase inhibitors, and immunotherapy.

RADT-28. RECURRENT MENINGIOMA WITH 1p/22q SOMATIC MUTATION OF GNAS: A CASE REPORT

Abstract OBJECTIVE Refractory meningioma faces the problems of low total resection rate, high recurrence rate and high disability rate. Here we report a patient with recurrent refractory meningioma who was benefited from precision treatment plan based on molecular diagnosis. METHODS Molecular diagnosis by next generation sequencing (NGS) test was used to test the hybridized captured DNA in the tumor tissue of the patient. RESULTS The 53-year-old female diagnosed with meningioma was admitted to our hospital after tumor progression was observed for 3 weeks. She had received 4 operations for the tumor previously. The first three times of postoperative pathology indicated WHO Ⅰ grade meningioma. The fourth postoperative pathology showed excessive meningioma, with active growth of tumor cells in some areas and small focal necrosis, WHO Ⅰ- fair grade. Somatic mutation GNAS p.F309VFS *25 and deletion of the short arm of chromosome 1 / long arm of chromosome 22 were also found (1P / 22Q) by NGS test. The second recurrent foci showed partial amplification of 17q and 19, except for 1p/22q deletions, compared with the first. Meningiomas with 1p/22q deletion are type C meningiomas (more than half are grade WHO Ⅰ). Meningiomas have been shown to be highly vascularized neoplasms, with a 2-fold increase in VEGF expression in atypical meningiomas and a 10-fold increase in malignant meningiomas. According to the molecular diagnosis results, the precise treatment plan was determined: concurrent chemoradiotherapy, followed by anti-VEGF-targeted drugs combined with temozolomide for 2 months. The residual lesions were significantly reduced after treatment. CONCLUSION This case is the first to report a meningioma with pituitary tumor driver gene GNAS mutation, which is more prone to recurrence due to the combination of 1P / 22Q chromosome mutation. Molecular diagnosis can guide precise treatment to benefit patients.

Case Report: Identification of a Novel GNAS Mutation and 1p/22q Co-Deletion in a Patient With Multiple Recurrent Meningiomas Sensitive to Sunitinib.

BackgroundAlthough surgical resection can cure the majority of meningiomas, there are still approximately 20% of patients suffering from an aggressive course with recurrence or progression. In this study, we reported a novel GNAS mutation and 1p/22q co-deletion responding to sunitinib in a patient with multiple recurrent meningiomas.Case PresentationA 53-year-old woman with meningioma was hospitalized due to postoperative tumor progression for 3 weeks. WHO grade I meningioma was pathologically diagnosed after the first three surgeries, but the second recurrence occurred approximately 3 years following the third surgery. Next-generation sequencing was performed on the first two recurrent samples. GNAS mutations and 1p/22q co-deletion were both identified, and amplification at 17q and chromosome 19 was also found in the second recurrent sample, based on which WHO grade II/III meningioma was diagnosed. The lesion in the left cerebellopontine angle area enlarged after use of radiotherapy combined with temozolomide chemotherapy for 2 months. When sunitinib was added, the residual lesions began to lessen and continuously reduced.ConclusionThis typical case suggested that timely molecular diagnosis for refractory meningiomas contributed to guiding the molecular classification and clinicians to make more reasonable individualized therapeutic regimens, consequently benefiting the patients. This case report also highlighted the potential role of sunitinib in the treatment of refractory meningiomas.

Les méningiomes : mise au point sur les connaissances actuelles

Meningiomas are the most frequent among intracranial tumors, and represent more than 30% of primitive central nervous system neoplasms. Arising from the meninges, they are generally benign lesions and can be treated by either radio-clinical follow-up or surgical resection with excellent outcome. However, more than 20% of meningiomas harbor atypical or malignant features and represent challenges for both prognostic evaluation and therapeutic strategy. The discovery of the genetic and epigenetic landscapes of meningiomas enabled the identification of new prognostic markers and potential therapeutic targets for refractory meningiomas. This review summarizes current epidemiology, histological and molecular characteristics, diagnosis and treatments for meningiomas, and highlights the close relationship between the development of meningiomas and hormonal intake, as illustrated by recent recommendations of the “Agence Nationale de Securité du Medicament”, the French national drug safety agency.

A Retrospective Interventional Cohort Study to Assess the Safety and Efficacy of Sandostatin LAR for Treatment of Recurrent and/or Refractory Meningiomas.

Background: Meningiomas are the most common adult primary intracranial tumors in the United States. Despite high recurrence rate of atypical and malignant subtypes, there is no approved drug indicated specifically for meningioma. Since the majority of meningiomas exhibit high density of somatostatin receptors subtypes, somatostatin analogs have been under close investigation. The aim of this study was to evaluate efficacy and safety of Sandostatin LAR (octreotide) in patients with progressive, and/or recurrent meningioma, and identify subset of patients who were more likely to benefit from this treatment.Methods: A total of 43 patients ≥ 18 years old were included in the retrospective chart review. The patients underwent treatment with Sandostatin LAR (octreotide) from 01.01.2010 to 06.01.2017 at the University of California, Irvine after confirmation of the diagnosis. Six months progression free survival (PFS6) was defined as a primary endpoint, and the overall survival (OS), safety, and toxicity were identified as secondary endpoints.Results: The OS for 6 months, 1, and 3 years for all WHO grades was 94.8, 88.1, and 67.0%, respectively. The PFS6 for WHO I, II, III, and all was 89.4, 89, 33.3, and 80% respectively. For patients with no prior surgeries, chemotherapy or radiation, the PFS6 was 88.9, 84.8, and 94.8%, respectively. Interestingly, the PFS6 was 90.5% for skull-based and 80% for 3–6 cm tumors. Patients with tumors in parasagittal location had PFS6 of 83.3% compared to PFS6 of 50.0% for patients with convexity tumors. Evaluation of PFS6 based on the effect of estrogen and progesterone on meningioma identified that ER-PR+ tumors had PFS6 of 87.8% while patients with ER-PR- meningiomas had PFS6 of 62.5%. Median TTP for WHO grade I, II, and III was 3.1, 2.40, and 0.26 years, respectively. Subgroup analysis showed that median TTP was 3.1 years for <3 cm tumors, 3.22 years for skull-based tumors, 2.37 years for patients with prior surgeries and 3.10 years for patients with no history of chemotherapy. History of radiation had no effect on median TTP. Sandostatin LAR (octreotide) was well-tolerated.Conclusions:This is one of the largest retrospective analysis of meningioma patients treated with Sandostatin LAR (octreotide) suggesting that this treatment has minimal to no adverse events and could prolong overall survival, and progression free survival especially for patients with ER-PR+ tumors who underwent surgeries for small skull-based tumors.

A look ahead: future directions of SSR-directed imaging and therapy in meningioma

Background Meningiomas, which are the most common of CNS tumours in adults, show a high expression of the somatostatin receptor subtype 2 (SSR). Visualization of these receptors with specific PET ligands augments contrast-enhanced MRI and CT of the brain in resolving several clinical issues related to differential diagnosis, evaluation of meningioma extent, and therapy planning or follow-up. Moreover, SSR-directed radioligands labeled with beta-emitters serve for radiopeptide therapy (RPT) in patients with recurrent or refractory meningioma. In the light of recent developments in radiochemistry, neuropathology/molecular genetics, and emerging systemic treatments, we present our perspective on future directions of SSR-directed imaging and therapy in meningioma.

Current status of SSR-directed imaging and therapy in meningioma

Meningiomas are the most common tumours of the central nervous system in adults. In clinical routine, their diagnostic workup prior to subsequent therapies such as resection and radiotherapy usually consists of contrast-enhanced MRI and CT of the brain. However, there are several diagnostic uncertainties in the clinical workup, which standard morphological imaging fails to resolve. Molecular imaging has an emerging role for the diagnosis of meningiomas, which characteristically show high expression of the somatostatin receptor subtype 2 (SSR). PET imaging with selective ligands can visualize and quantify this expression against low background signal in healthy brain. Moreover, SSR-directed radioligands labeled with beta-emitters can be effective for radiopeptide therapy (RPT) in patients with recurrent or refractory meningioma. A literature search on the PubMed literature database was conducted using the terms “meningioma”, “PET”, “somatostatin receptor”, “SS(T)R”, “DOTATATE”, “DOTATOC”, “Radiopeptide therapy”, “imaging”, “therapy” alone and in combination, extending until February 2019. The search results were augmented by the authors’ own literature files. We summarize the current state of SSR-directed imaging in patients with meningioma regarding the distinct clinical applications for initial diagnosis, differential diagnosis, surgery and radiotherapy planning. Our review also summarizes SSR imaging for the differentiation of recurrent meningioma tissue from post-therapeutic changes within the individual follow-up. Moreover, we discuss the clinical value and place of SSR-directed RPT in patients with refractory or recurrent meningioma. Molecular imaging with SSR-directed radioligands contributes to the diagnostic work-up of meningioma patients by providing information that is absent from structural MR or CT imaging. Targeted SSR RPT offers well-tolerated treatment options in patients with refractory or recurrent meningioma.

Multimodality Therapy of Patients with Refractory Meningiomas.

Recurrent and refractory meningiomas are a clinical challenge and treatment at the time of recurrence is not well delineated. Treatment with surgery and/or radiation remain the mainstay, but each has their limitations and risks. The search for an adjuvant systemic therapy continues and as many of the initially promising approaches have not had reproducible responses. Bevacizumab has shown some efficacy in controlling recurrent disease and could be useful in disease that is multifocal or in close proximity to critical structures. Other targeted therapies, as well as immunotherapy, are being studied and trials are in development. Though we are hopeful that these novel therapies will benefit patients with refractory meningiomas, we approach them with some trepidation. This is due to prior failures of immunotherapy and targeted therapy in central nervous system disease. In addition, there is known difficulty in developing trials and assessing response with these slow-growing tumors.