Meningioma of the skull base: long-term outcome after image-guided stereotactic radiotherapy

Stereotactic intensity-modulated radiotherapy for skull base meningioma using the HybridArc with Novalis STx system

Background

Skull base meningiomas are often difficult to remove completely with preserved nerve function and may require radiation therapy. However, the Gamma Knife is unsuitable for large tumor volume or the optic nerve, which is difficult to identify on imaging. We report the results of stereotactic radiotherapy with HybridArc using Novalis STx for skull base meningiomas.

Methods

We retrospectively examined 28 patients with skull base meningioma who underwent stereotactic radiotherapy (54 Gy/30 fractions) with HybridArc.

Results

The 28 patients, nine males and 19 females, were aged 31-83 years (mean 58.4 years), and the tumor volume was 2.6-97.1 mL (mean 29.7 mL). HybridArc irradiation was performed with D95 54 Gy/30 fractions for all patients with a median follow-up period of 36.0 months (range: 12-78 months). Tumor control rates at 1, 2, and 5 years after radiotherapy were 92.6%, 89.1%, and 82.8%, respectively. Only one non-atypical meningioma remained uncontrolled; thus, the tumor control rate for non-atypical meningioma at 1, 2, and 5 years was 94.1%. Tumor control rates for atypical meningioma at 1, 2, and 5 years were 85.7%, 71.4%, and 53.6%, respectively, significantly worse than for non-atypical meningiomas (P = 0.0395). Radiation injury was observed in two cases (7.1%). Visual field defects were observed in 16 patients, and diplopia in 6. Visual field and diplopia improvements were achieved in 5 and 2 patients, respectively (with overlap).

Conclusion

Stereotactic radiotherapy (54 Gy/30 fractions) with HybridArc using Novalis STx is a safe and effective approach for relatively large skull base meningiomas.

Prospective Assessment of Early Proton Therapy-Induced Optic Neuropathy in Patients With Intracranial, Orbital or Sinonasal Tumors: Impact of A Standardized Ophthalmological Follow Up

PURPOSE

Proton therapy (PT) can be a good option to achieve tumor control while reducing the probability of radiation induced toxicities compared to X-ray-based radiotherapy. However, there are still uncertainties about the effects of PT on the organs in direct contact with the irradiated volume. The aim of this prospective series was to report 6-month follow-up of clinical and functional optic neuropathy rates of patients treated by proton therapy using a standardized comprehensive optic examination.

METHODS AND MATERIALS

Standardized ophthalmological examinations were performed to analyze subclinical anomalies in a systematic way before treatment and 6 months after the end of proton therapy with: Automatic visual field, Visual evoked potential (VEP) and optic coherence of tomography (OCT).

RESULTS

From October 2018 to July 2020 we analyzed 81 eyes. No significant differences were found in the analysis of the clinical examination of visual functions by the radiation oncologist. However, considering VEP, the impairment was statistically significant for both fibers explored at 30'angle (p:0.007) and 60'angle (p <0.001). In patients with toxicity, the distance of the target volume from the optical pathways was more important with a p-value for 30'VEP at 0.035 and for 60'VEP at 0.039.

CONCLUSIONS

These results confirm uncertainties concerning relative biological effectiveness of proton therapy, linear energy transfer appears to be more inhomogeneous especially in areas close to the target volumes. The follow-up of patients after proton therapy is not an easy process to set up but it is necessary to improve our knowledges about the biological effects of proton therapy in real life. Our study which will continue during the coming years, suggests that follow-up with in-depth examinations such as VEP as a biomarker could improve the detection of early abnormalities.

Advances in Multidisciplinary Management of Skull Base Meningiomas

The surgical management of Skull Base Meningiomas (SBMs) has radically changed over the last two decades. Extensive surgery for patients with SBMs represents the mainstream treatment; however, it is often challenging due to narrow surgical corridors and proximity to critical neurovascular structures. Novel surgical technologies, including three-dimensional (3D) preoperative imaging, neuromonitoring, and surgical instruments, have gradually facilitated the surgical resectability of SBMs, reducing postoperative morbidity. Total removal is not always feasible considering a risky tumor location and invasion of surrounding structures and brain parenchyma. In recent years, the use of primary or adjuvant stereotactic radiosurgery (SRS) has progressively increased due to its safety and efficacy in the control of grade I and II meningiomas, especially for small to moderate size lesions. Patients with WHO grade SBMs receiving subtotal surgery can be monitored over time with surveillance imaging. Postoperative management remains highly controversial for grade II meningiomas, and depends on the presence of residual disease, with optional upfront adjuvant radiation therapy or close surveillance imaging in cases with total resection. Adjuvant radiation is strongly recommended in patients with grade III tumors. Although the currently available chemotherapy or targeted therapies available have a low efficacy, the molecular profiling of SBMs has shown genetic alterations that could be potentially targeted with novel tailored treatments. This multidisciplinary review provides an update on the advances in surgical technology, postoperative management and molecular profile of SBMs.

Short diameter may be a useful simple indicator of the tumor response in skull base meningiomas after conventionally fractionated stereotactic radiotherapy

OBJECTIVES

The purpose of this study was to assess the radiological change patterns in skull base meningiomas after conventionally fractionated stereotactic radiotherapy (CFSRT) to determine a simple and valid method to assess the tumor response.

MATERIALS AND METHODS

Forty-one patients with a benign skull base meningioma treated by CFSRT from March 2007 to August 2015 were retrospectively evaluated. We measured tumor volume (TV), long-axis diameter (LD), and short-axis diameter (SD) on both pre-treatment images and follow-up images of 1, 3, and 5 years after CFSRT, respectively. The paired t test was used to detect differences in the LD and SD change rates. Spearman's correlation coefficients were calculated to evaluate relationships between the TV and the diameters changes.

RESULTS

The number of available follow-up MRIs that was performed at 1, 3, and 5 years after the CFSRT was 41 (100%), 34 (83%), and 23 (56%), respectively. The change rates of SD were significantly higher than those of LD at every time point and more strongly correlated with the change rates of tumor volume at 3 and 5 years after CFSRT.

CONCLUSIONS

SD may be useful as a simple indicator of the tumor response for skull base meningioma after CFSRT.

KEY POINTS

• The change rate in short-axis diameter is a useful and simple indicator of the response of skull base meningioma to conventionally fractionated stereotactic radiotherapy. • Conventionally fractionated stereotactic radiotherapy for skull base meningioma achieved excellent 5-year local control.

Normofractionated stereotactic radiotherapy versus CyberKnife-based hypofractionation in skull base meningioma: a German and Italian pooled cohort analysis

Background

This retrospective German and Italian multicenter analysis aimed to compare the role of normofractionated stereotactic radiotherapy (nFSRT) to CyberKnife-based hypofractionated stereotactic radiotherapy (CK-hFSRT) for skull base meningiomas.

Methods

Overall, 341 patients across three centers were treated with either nFSRT or CK-hFSRT for skull base meningioma. Treatment planning was based on computed tomography (CT) and magnetic resonance imaging (MRI) following institutional guidelines. Most nFSRT patients received 33 × 1.8 Gy, and most CK-hFSRT patients received 5 × 5 Gy. The median follow-up time was 36 months (range: 1–232 months).

Results

In the CK-hFSRT group, the 1-, 3-, and 10-year local control (LC) rates were 99.4, 96.8, and 80.3%, respectively. In the nFSRT group, the 1-, 3-, and 10-year LC rates were 100, 99, and 79.1%, respectively. There were no significant differences in LC rates between the nFSRT and CK-hFSRT groups (p = 0.56, hazard ratio = 0.76, 95% confidence interval, 0.3–1.9). In the CK-hFSRT group, only one case (0.49%) of severe toxicity (CTCAE 4.0 ≥ 3) was observed. In the nFSRT group, three cases (2.1%) of grade III toxicity were observed.

Conclusion

This analysis of pooled data from three centers showed excellent LC and low side effect rates for patients treated with CK-hFSRT or nFSRT. The efficacy, safety, and convenience of a shortened treatment period provide a compelling case for the use of CK-hFSRT in patients with moderate size skull base meningioma and provided that OAR constraints are met.

Lower doses to hippocampi and other brain structures for skull-base meningiomas with intensity modulated proton therapy compared to photon therapy

BACKGROUND AND PURPOSE

Radiotherapy of skull-base meningiomas is challenging due to the close proximity of multiple sensitive organs at risk (OARs). This study systematically compared intensity modulated proton therapy (IMPT), non-coplanar volumetric modulated arc therapy (VMAT) and intensity modulated radiotherapy (IMRT) based on automated treatment planning. Differences in OARs sparing, with specific focus on the hippocampi, and low-dose delivery were quantified.

MATERIALS AND METHODS

Twenty patients, target diameter >3 cm, were included. Automated plan generation was used to calculate a VMAT plan with three non-coplanar arcs, an IMRT plan with nine non-coplanar beams with optimized gantry and couch angles, and an IMPT plan with three patient-specific selected non-coplanar beams. A prescription dose of 50.4 GyRBE in 28 fractions was used. The same set of constraints and prioritized objectives was used. All plans were rescaled to the same target coverage. Repeated measures ANOVA was used to assess the statistical significance of differences in OAR dose parameters between planning techniques.

RESULTS

Compared to VMAT and IMRT, IMPT significantly improved dose conformity to the target volume. Consequently, large dose reductions in OARs were observed. With respect to VMAT, the mean dose and D_40% in the bilateral hippocampus were on average reduced by 48% and 74%, respectively (p ≤ 0.005). With IMPT, the mean dose in the normal brain and volumes receiving 20-30 Gy were up to 47% lower (p ≤ 0.01). When comparing IMPT and IMRT, even larger dose differences in those OARs were observed.

CONCLUSION

For skull-base meningiomas IMPT allows for a considerable dose reduction in the hippocampi, normal brain and other OARs compared to both non-coplanar VMAT and IMRT, which may lead to a clinically relevant reduction of late neurocognitive side effects.

Prevalence and correlates of fatigue in patients with meningioma before and after surgery

Background

Fatigue is a common symptom in patients with brain tumors, but comprehensive studies on fatigue in patients with meningioma specifically are lacking. This study examined the prevalence and correlates of fatigue in meningioma patients.

Methods

Patients with grade I meningioma completed the Multidimensional Fatigue Inventory (MFI-20) before and 1 year after neurosurgery. The MFI consists of 5 subscales: General Fatigue, Physical Fatigue, Mental Fatigue, Reduced Motivation, and Reduced Activity. Patients’ scores were compared with normative data. Preoperative fatigue was compared with postoperative fatigue. Correlations with sex, age, education, tumor hemisphere, preoperative tumor volume, antiepileptic drugs (AEDs), symptoms of anxiety/depression, and self-reported cognitive complaints were explored.

Results

Questionnaires were completed by 65 patients preoperatively, and 53 patients postoperatively. Of 34 patients, data from both time points were available. Patients had significantly higher fatigue levels on all subscales compared to normative values at both time points. Mean scores on General Fatigue, Physical Fatigue, and Mental Fatigue remained stable over time and improvements were observed on Reduced Motivation and Reduced Activity. Preoperatively, the prevalence of high fatigue (Z-score ≥ 1.3) varied between 34% for Reduced Motivation and 43% for General Fatigue/Mental Fatigue. The postoperative prevalence ranged from 19% for Reduced Activity to 49% on Mental Fatigue. Fatigue was associated with cognitive complaints, anxiety and depression, but not with education, tumor lateralization, tumor volume, or AEDs.

Conclusion

Fatigue is a common and persistent symptom in patients with meningioma undergoing neurosurgery. Findings emphasize the need for more research and appropriate care targeting fatigue for meningioma patients.

Boron Neutron Capture Therapy for High-Grade Skull-Base Meningioma

Objectives  Boron neutron capture therapy (BNCT) is a nuclear reaction-based tumor cell-selective particle irradiation that occurs when nonradioactive Boron-10 is irradiated with low-energy neutrons to produce high-energy α particles (10B [ n , α] 7Li). Possible complications associated with extended surgical resection render high-grade meningioma (HGM) a challenging pathology and skull-base meningiomas (SBMs) even more challenging. Lately, we have been trying to control HGMs using BNCT. This study aims to elucidate whether the recurrence and outcome of HGMs and SBMs differ based on their location. Design  Retrospective review. Setting  Osaka Medical College Hospital and Kyoto University Research Reactor Institute. Participants  Between 2005 and 2014, 31 patients with recurrent HGM (7 SBMs) were treated with BNCT. Main Outcome Measures  Overall survival and the subgroup analysis by the anatomical tumor location. Results  Positron emission tomography revealed that HGMs exhibited 3.8 times higher boron accumulation than the normal brain. Although tumors displayed transient increases in size in several cases, all lesions were found to decrease during observation. Furthermore, the median survival time of patients with SBMs post-BNCT and after being diagnosed as high-grade were 24.6 and 67.5 months, respectively (vs non-SBMs: 40.4 and 47.5 months). Conclusions  BNCT could be a robust and beneficial therapeutic modality for patients with high-grade SBMs.

Cranial nerve outcomes after primary stereotactic radiosurgery for symptomatic skull base meningiomas

OBJECTIVE

To evaluate cranial nerve (CN) outcomes after primary stereotactic radiosurgery (SRS) for petroclival, cavernous sinus, and cerebellopontine angle meningiomas.

METHODS

From our prospectively maintained database of 2022 meningioma patients who underwent Leksell stereotactic radiosurgery (SRS) during a 30-year interval, we found 98 patients with petroclival, 242 with cavernous sinus, and 55 patients with cerebellopontine angle meningiomas. Primary radiosurgery was performed in 245 patients. Patients included in this report had at least one CN deficit at the time of initial presentation and a minimum of 12 month follow up. Median age at the time of SRS was 58 years. Median follow up was 58 months (range 12-300 months), Median tumor volume treated with SRS was 5.9 cm³ (range 0.5-37.5 cm³), and median margin dose was 13 Gy (range 9-20Gy).

RESULTS

Tumor control was achieved in 229 patients (93.5%) at a median follow up of 58 months. Progression free survival rate (PFS) after SRS was 98.7% at 1 year, 96.4% at 3 years, 93.7% at 5 years, and 86.4% at 10 years Overall, 114 of the 245 patients (46.5%) reported improvement of CN function. Patients with CP angle meningiomas demonstrated lower rates of CN improvement compared to petroclival and cavernous sinus meningioma patients. Deterioration of CN function after SRS developed in 24 patients (10%). The rate of deterioration was 2.8% at 1 year, 5.2% at 3 years, and 8% at 10 years.

CONCLUSION

Primary SRS provides effective tumor control and favorable rate of improvement of preexisting CN deficit.

Clinical outcome after particle therapy for meningiomas of the skull base: toxicity and local control in patients treated with active rasterscanning

BACKGROUND

Meningiomas of the skull base account for 25-30% of all meningiomas. Due to the complex structure of the cranial base and its close proximity to critical structures, surgery is often associated with substantial morbidity. Treatment options include observation, aggressive surgical intervention, stereotactic or conventional radiotherapy. In this analysis we evaluate the outcome of 110 patients with meningiomas of the skull base treated with particle therapy. It was performed within the framework of the "clinical research group heavy ion therapy" and supported by the German Research Council (DFG, KFO 214).

METHODS

Between May 2010 and November 2014, 110 Patients with skull base meningioma were treated with particle radiotherapy at the Heidelberg Ion Therapy Center (HIT). Primary localizations included the sphenoid wing (n = 42), petroclival region (n = 23), cavernous sinus (n = 4), sella (n = 10) and olfactory nerve (n = 4). Sixty meningiomas were benign (WHO °I); whereas 8 were high-risk (WHO °II (n = 7) and °III (n = 1)). In 42 cases histology was not examined, since no surgery was performed. Proton (n = 104) or carbon ion (n = 6) radiotherapy was applied at Heidelberg Ion Therapy Center (HIT) using raster-scanning technique for active beam delivery. Fifty one patients (46.4%) received radiotherapy due to tumor progression, 17 (15.5%) after surgical resection and 42 (38.2%) as primary treatment.

RESULTS

Median follow-up in this analysis was 46,8 months (95% CI 39,9-53,7; Q1-Q3 34,3-61,7). Particle radiotherapy could be performed safely without toxicity-related interruptions. No grade IV or V toxicities according to CTCAE v4.0 were observed. Particle RT offered excellent overall local control rates with 100% progression-free survival (PFS) after 36 months and 96.6% after 60 months. Median PFS was not reached due to the small number of events. Histology significantly impacted PFS with superior PFS after 5 years for low-risk tumors (96.6% vs. 75.0%, p = 0,02). Overall survival was 96.2% after 60 months and 92.0% after 72 months from therapy. Of six documented deaths, five were definitely not and the sixth probably not meningioma-related.

CONCLUSION

Particle radiotherapy is an excellent treatment option for patients with meningiomas of the skull base and can lead to long-term tumor control with minimal side effects. Other prospective studies with longer follow-up will be necessary to further confirm the role of particle radiotherapy in skull base meningioma.

Degree of Vascular Encasement in Sphenoid Wing Meningiomas Predicts Postoperative Ischemic Complications

BACKGROUND

Sphenoid wing meningiomas (SWMs) can encase arteries of the circle of Willis, increasing their susceptibility to intraoperative vascular injury and severe ischemic complications.

OBJECTIVE

To demonstrate the effect of circumferential vascular encasement in SWM on postoperative ischemia.

METHODS

A retrospective review of 75 patients surgically treated for SWM from 2009 to 2015 was undertaken to determine the degree of circumferential vascular encasement (0°-360°) as assessed by preoperative magnetic resonance imaging (MRI). A novel grading system describing "maximum" and "total" arterial encasement scores was created. Postoperative MRIs were reviewed for total ischemia volume measured on sequential diffusion-weighted images.

RESULTS

Of the 75 patients, 89.3% had some degree of vascular involvement with a median maximum encasement score of 3.0 (2.0-3.0) in the internal carotid artery (ICA), M1, M2, and A1 segments; 76% of patients had some degree of ischemia with median infarct volume of 3.75 cm 3 (0.81-9.3 cm 3 ). Univariate analysis determined risk factors associated with larger infarction volume, which were encasement of the supraclinoid ICA ( P < .001), M1 segment ( P < .001), A1 segment ( P = .015), and diabetes ( P = .019). As the maximum encasement score increased from 1 to 5 in each of the significant arterial segments, so did mean and median infarction volume ( P < .001). Risk for devastating ischemic injury >62 cm 3 was found when the ICA, M1, and A1 vessels all had ≥360° involvement ( P = .001). Residual tumor was associated with smaller infarct volumes ( P = .022). As infarction volume increased, so did modified Rankin Score at discharge ( P = .025).

CONCLUSION

Subtotal resection should be considered in SWM with significant vascular encasement of proximal arteries to limit postoperative ischemic complications.

Health-related quality of life of cranial WHO grade I meningioma patients: are current questionnaires relevant?

Background

The clinical relevance of Health-Related Quality of Life (HRQoL) in meningioma patients has been increasingly acknowledged in recent years. Various questionnaires have been used. However, almost none of these questionnaires has been particularly developed for and/or validated in this patient group. Therefore, the aim of this study was to assess the relevance and comprehensiveness of existing HRQoL questionnaires used in meningioma research and to assess the agreement between patients and health care professionals (HCPs) on the most relevant and important HRQoL issues.

Methods

A systematic literature search, following the PRISMA statement, was conducted to identify all HRQoL questionnaires used in meningioma research. Semi-structured interviews were organized with patients and HCPs to (1) assess the relevance of all issues covered by the questionnaires (score 0–3: not relevant–highly relevant), (2) assess the ten most important issues, and (3) identify new relevant HRQoL issues.

Results

Fourteen different questionnaires were found in the literature, comprising 140 unique issues. Interviews were conducted with 20 patients (median age 57, 71% female) and 10 HCPs (4 neurosurgeons, 2 neurologists, 2 radiotherapists, 1 rehabilitation specialist, 1 neuropsychologist; median experience 13 years). Meningioma patients rated 17–80% of the issues in each of the questionnaires as relevant, HCPs 90–100%. Patients and HCPs agreed on the relevance of only 49 issues (35%, Cohen’s kappa: 0.027). Both patients and HCPs considered lack of energy the most important issue. Patients and HCPs suggested five additional relevant issues not covered by current HRQoL questionnaires.

Conclusions

Existing HRQoL questionnaires currently used in meningioma patients do not fully cover all relevant issues to these patients. Agreement between patients and HCPs on the relevance of issues was poor. Both findings support the need to develop and validate a meningioma-specific HRQoL questionnaire.

Electronic supplementary material

The online version of this article (10.1007/s00701-017-3332-8) contains supplementary material, which is available to authorized users.

A neuro-oncologic challenge: the case of a large, aggressive, malignant meningioma of the skull base with paranasal sinus involvement

BACKGROUND

Malignant meningiomas, rare tumors that account for approximately 1%-3% of all meningioma, have high recurrence, morbidity, and mortality rate and a particularly poor outcome. Surgical excision followed by adjuvant radiotherapy is the current approach for the treatment of these tumors.

METHODS

In the case reported, the disease, characterized by a high proliferative index (Ki67 60%-70%), was treated with endoscopic surgery limited to the extracranial portion; then the patient underwent radiotherapy, on the residual tumor volume, to a total dose of 66 Gy delivered in 33 fractions (2 Gy/fraction) by helical intensity-modulated radiation therapy with image-guided radiotherapy daily checks (tomotherapy).

RESULTS

Two and a half years after the treatment, the patient is alive and a partial response is maintained. The patient is healthy overall with grade I fatigue and grade II hearing loss as late toxicity (Common Terminology Criteria for Adverse Events 4.1).

CONCLUSIONS

Within a multidisciplinary approach, new radiotherapy techniques confirm their effectiveness and reliability for the treatment of malignant meningioma.

Endoscopic transnasal surgery for planum and tuberculum sella meningiomas: decision-making, technique and outcomes

Tuberculum sella and planum sphenoidale meningiomas pose a management challenge given their intimate relationship to surrounding critical neurovascular structures. The development and advancement of expanded endoscopic transnasal surgery has provided a good surgical option that in well-selected cases, may provide several advantages over a transcranial route. These include early devascularization, complete dura and bone removal, elimination of brain retraction and enhanced visualization of the optic apparatus perforating vessels. The authors review the endoscopic transnasal approach to these tumors and discuss surgical decision-making and case selection, surgical technique and outcomes. We also discuss the expanding role of stereotactic radiosurgery and fractionated stereotactic radiotherapy for these challenging lesions.

Review of photon and proton radiotherapy for skull base tumours

An extremely large variety of benign and malignant tumours occur at skull base; these tumour lesions are in the proximity to structures deputed to relevant physiologic functions, limiting extensive surgical approaches to this body district. Most recent progresses of surgery and radiotherapy have allowed to improve local control with acceptable rates of side effects. Various photon radiotherapy techniques are employed, including 3-dimensional conformal radiotherapy, intensity modulated radiotherapy (IMRT), stereotactic radiotherapy (SRT) and brachytherapy that is manly limited to the treatment of primary or recurrent nasopharyngeal carcinoma. Proton beam radiotherapy is also extensively used thanks to its physical characteristics. Our review, focusing in particular on meningioma, chordoma, and chondrosarcoma, suggests that proton therapy plays a major role in the treatment of malignant tumours whereas photon therapy still plays a relevant role in the treatment of benign tumour lesions.