The use of adjuvant therapy is controversial in atypical meningiomas with gross total resection. Predictors of recurrence risk could be useful in selecting patients for additional treatments. The aim of this study was to investigate whether molecular features are associated with recurrence risk of atypical meningiomas. According to WHO classification, the diagnosis of atypical meningioma was based on the presence of one major criteria (mitotic activity, brain invasion) or three or more minor criteria. The molecular profile of 22 cases (eight mitotically active, eight brain-invasive, and six with minor criteria) was assessed exploring the mutational status and copy number variation of 409 genes using next generation sequencing. Of the 22 patients with a median follow up of 53.5 months, 13 had recurrence of disease within 68 months. NF2 mutation was the only recurrent alteration (11/22) and was unrelated to clinical-pathological features. Recurring meningiomas featured a significantly higher proportion of copy number losses than non-recurring ones (p = 0.027). Chromosome 18q heterozygous loss or CDKN2A/B homozygous deletion was significantly associated with shorter recurrence-free survival (p = 0.008; hazard ratio: 5.3). Atypical meningiomas could be tested routinely for these genetic alterations to identify cases for adjuvant treatment.

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.

BACKGROUND AND PURPOSE: Intra-arterial DSA has been traditionally used for confirmation of cure following gamma knife radiosurgery for AVMs. Our aim was to evaluate whether 4D arterial spin-labeling MRA and contrast-enhanced time-resolved MRA in combination can be an alternative to DSA for confirmation of AVM obliteration following gamma knife radiosurgery. MATERIALS AND METHODS: In this prospective study, 30 patients undergoing DSA for confirmation of obliteration following gamma knife radiosurgery for AVMs (criterion standard) also underwent MRA, including arterial spin-labeling MRA and contrast-enhanced time-resolved MRA. One dataset was technically unsatisfactory, and the case was excluded. The DSA and MRA datasets of 29 patients were independently and blindly evaluated by 2 observers regarding the presence/absence of residual AVMs. RESULTS: The mean time between gamma knife radiosurgery and follow-up DSA/MRA was 53 months (95% CI, 42–64 months; range, 22–168 months). MRA total scanning time was 9 minutes and 17 seconds. Residual AVMs were detected on DSA in 9 subjects (obliteration rate = 69%). All residual AVMs were detected on at least 1 MRA sequence. Arterial spin-labeling MRA and contrast-enhanced time-resolved MRA showed excellent specificity and positive predictive values individually (100%). However, their sensitivity and negative predictive values were suboptimal due to 1 false-negative with arterial spin-labeling MRA and 2 with contrast-enhanced time-resolved MRA (sensitivity = 88% and 77%, negative predictive values = 95% and 90%, respectively). Both sensitivity and negative predictive values increased to 100% if a composite assessment of both MRA sequences was performed. Diagnostic accuracy (receiver operating characteristic) and agreement (κ) are maximized using arterial spin-labeling MRA and contrast-enhanced time-resolved MRA in combination (area under receiver operating characteristic curve = 1, P < .001; κ = 1, P < .001, respectively). CONCLUSIONS: Combining arterial spin-labeling MRA with contrast-enhanced time-resolved MRA holds promise as an alternative to DSA for confirmation of obliteration following gamma knife radiosurgery for brain AVMs, having provided 100% sensitivity and specificity in the study. Their combined use also enables reliable characterization of residual lesions.

Cavernous sinus meningiomas (CSMs) remain a surgical challenge due to the intimate involvement of their contained nerves and blood vessels. Stereotactic radiosurgery (SRS) is a safe and effective minimally invasive alternative for the treatment of small- to medium-sized CSMs. Objective: To assess the medium- to long-term outcomes of SRS for CSMs with respect to tumour growth, prevention of further neurological deterioration and improvement of existing neurological deficits. This multicentric study included data from 15 European institutions. We performed a retrospective observational analysis of 1222 consecutive patients harbouring 1272 benign CSMs. All were treated with Gamma Knife stereotactic radiosurgery (SRS). Clinical and imaging data were retrieved from each centre and entered into a common database. All tumours with imaging follow-up of less than 24 months were excluded. Detailed results from 945 meningiomas (86%) were then analysed. Clinical neurological outcomes were available for 1042 patients (85%). Median imaging follow-up was 67 months (mean 73.4, range 24–233). Median tumour volume was 6.2 cc (+/−7), and the median marginal dose was 14 Gy (+/−3). The post-treatment tumour volume decreased in 549 (58.1%), remained stable in 336 (35.6%) and increased in only 60 lesions (6.3%), yielding a local tumour control rate of 93.7%. Only 27 (2.8%) of the 60 enlarging tumours required further treatment. Five- and ten-year actuarial progression-free survival (PFS) rates were 96.7% and 90.1%, respectively. Tumour control rates were higher for women than men (p = 0.0031), and also for solitary sporadic meningiomas (p = 0.0201). There was no statistically significant difference in outcome for imaging-defined meningiomas when compared with histologically proven WHO Grade-I meningiomas (p = 0.1212). Median clinical follow up was 61 months (mean 64, range 6–233). Permanent morbidity occurred in 5.9% of cases at last follow-up. Stereotactic radiosurgery is a safe and effective method for treating benign CSM in the medium term to long term.

Background Chronic stimulation of the human subthalamic nucleus (STN) is gradually becoming accepted as a long-term therapeutic option for patients with advanced Parkinson disease (PD). 3Tesla (T) magnetic resonance imaging (MRI) improves contrast resolution in basal ganglia nuclei containing high levels of iron, because of magnetic susceptibility effects that increase significantly as the magnetic field gets higher. This phenomenon can be used for better visualization of the STN and may reduce the time necessary for detailed microrecording (MER) mapping, increasing surgery efficacy and lowering morbidity. Objective The objective of this retrospective study is to analyze a population of 20 deep brain stimulation (DBS) electrode implanted patients with PD divided into two groups in which different targeting methods were used. Methods Mean age was 56 years (range 37 to 69 years). Mean disease duration was 11.6 years. Mean follow-up was 12 months (range 6 to 36 months). Patients were divided into two groups: Group A contained 6 patients who underwent STN targeting using 1T stereotactic (T1w + T2w) MRI plus STN indirect atlas derived targeting. Group B consisted of 14 patients who underwent STN targeting using 3T nonstereotactic (T2w) MRI fused with 1T T1w stereotactic MRI and STN direct targeting. For statistical analysis, we compared (five different parameters in both (matched) groups: Unified Parkinson's disease rating scale (UPDRS) score reduction (medication off before surgery against stimulation on/medication off after surgery), postoperative drug reduction, duration of surgery, the “central preoperative track” chosen as final implantation track during surgery, and correspondence between the targeted STN and the intraoperative neurophysiologic data. Results Mean UPDRS III score reduction (medication off/stimulation on versus preoperative medication off) was 69% in Group A and 74% in Group B (p = 0.015, log-rank test) respectively. Postoperatively, antiparkinsonian treatment was reduced by 66% in Group A and 75% in Group B (p = 0.006, log-rank test). The preoperative “central” track (which corresponds to ideal STN targeting) proved to be the most clinically effective in 2/12 leads for Group A versus 21/28 for Group B (p < 0.001). Neurophysiologic data confirmed these results; the hypothetical target was confirmed by MER data in 76% of tracks in Group A, and in 75% of tracks in Group B (p < 0.001, univariate and multivariate analysis). Conclusion 3T MRI appears to be a useful tool in STN-DBS preoperative targeting. Neurophysiologic testing remains fundamental to determine lead deepness (and prevent clinical side effects.

During the past decades, in small-to-medium size vestibular schwannomas, Gamma Knife surgery (GKS) has become a reliable therapeutic option because of either excellent local tumor control or minimal morbidity, with cranial neuropathy becoming increasingly rare. Although still insufficiently analyzed in larger cohorts of patients with long-term follow-ups, adequate chances of hearing preservation and vestibular sparing seem clinically guaranteed. However, deeper investigations are needed in this regard, expanding the number of cases and the follow-up period. A small group of patients with vestibular schwannomas (74 patients, including 41 men and 33 women) treated between 2003 and 2009 using GKS at the authors' institution were analyzed—both before and after GKS—with computerized static stabilometry and electronystagmography for balance disorders, vertigo, and ataxia on 1 side and pure tone average, vocal speech discrimination score, auditory brainstem response, and so forth for hearing impairment and tinnitus on the other side. Eligibility criteria for this prospective study included previously untreated unilateral lesions and a Gardner-Robertson hearing class of I–III. Dosimetry plans had been programmed at the lower effective dosages for these tumors (median surface dose 12.4 Gy, range 10–13 Gy), carefully avoiding even minimal toxic dosages on the most vulnerable targets: the cochlea (never > 6 Gy) and the vestibular canals (< 7.5 Gy). To date, tumor growth control rates remain satisfactory; at a mean follow-up of 50 months, the rate was 96%. The overall level of hearing preservation was 72%, with 81% having Gardner-Robertson Class I hearing. Tinnitus decreased, from 52% to 28% of patients (p < 0.01). Significant improvements were also observed in vestibular symptoms, with computerized static stabilometry abnormalities decreasing from 62% to 32% (p < 0.001) and electronystagmography abnormalities reducing from 48% to 14% (p < 0.001). Using appropriate radiodosimetry planning, GKS seems to guarantee not only adequate tumor growth control rates, but also better levels of hearing preservation, with a documented, long-lasting improvement in vestibular functions.