Fractionated Stereotactic Radiotherapy Compared to Stereotactic Radiosurgery for Vestibular Schwannoma in Patients with Type 2 Neurofibromatosis.

BACKGROUND: The use of radiotherapy (RT) for the treatment of vestibulocochlear schwannomas is standard in patients with type 2 neurofibromatosis (NF2). In the general population, fractionated RT (FRT) can achieve good results compared to single-dose radiosurgery (SRS). We aimed to assess whether this is true for NF2 patients as well. METHODS: This retrospective cohort study included 34 patients and 54 lesions treated between 2010 and 2023 in a single university hospital. RESULTS: Thirty-four patient charts were assessed. The median follow-up was 62.6 months (range, 7.1-135.8 months). Lesion size (median larger diameter, 2.5 cm) was correlated with the use of FRT (P > 0.001). Younger age also was correlated with FRT (P = 0.006). Median overall survival and progression-free survival (PFS) were not reached. The overall control rate was 76.5%, and the mean PFS was 49.8 months, compared with . 90.5% and 57.2 months, respectively, for SRS and 66.7% and 44.9 months, respectively, for FRT. There were no differences between the 2 groups in hearing loss, tinnitus, and facial palsy. CONCLUSIONS: In the NF2 population, FRT may yield worse control rates than SRS. Whenever possible, it is preferable to not fractionate treatment for these patients. Nevertheless, the FRT results were still good. More and larger prospective trials are warranted.

Stereotactic Radiosurgery or Fractionated Stereotactic Radiotherapy for Arteriovenous Malformation.

BACKGROUND: The best management for AVM, particularly high-grade ones and those that have been ruptured before, is still unknown. Data from prospective data lacks support for the best approach. METHODS: We retrospectively review patients with AVM at a single institution that were treated with radiation or a combination of radiation and embolization. These patients were divided into two groups based on radiation fractionation: SRS and fSRS. RESULTS: One-hundred and thirty-five (135) patients were first assessed and 121 met study criteria. Mean age at treatment was 30.5 years, and most patients were male. The groups were otherwise balanced, except for nidus size. SRS group had smaller lesions (P > 0.005). SRS correlates to better chance of nidus occlusion and lesser chance of retreatment. Complications such as radionecrosis (5%) and bleeding after nidus occlusion (1 patient) were rare. CONCLUSIONS: Stereotactic radiosurgery plays an important role on the treatment of AVM. Whenever possible, SRS should be preferred. Data from prospective trials about larger and previously ruptured lesions are needed.

Spheno-orbital meningiomas: Is orbit reconstruction mandatory? Long-term outcomes and exophthalmos improvement.

Background: Meningiomas correspond to one-third of all primary central nervous system tumors. Approximately 9% of them are spheno-orbital meningiomas (SOMs), presenting significant clinical symptoms as visual impairment and orbital esthetics. This article aims to evaluate exophthalmos' improvement in a surgical series without orbital reconstruction. Methods: We consecutively included all patients diagnosed with SOM, admitted to a single institution for 10 years. Surgical resection was the standard of care, associated or not with adjuvant radiation therapy. The radiological investigation included preoperative and postoperative head CT or MRI. We quantified proptosis through imaging. Results: Forty patients composed this series, 87.5% were female. Proptosis was the most common presentation (90%), followed by decreased visual acuity (65%), motility deficit (20%), and headache (20%). Gross total resection was achieved in 65% of the procedures. In late outcomes, 78% of the patients maintained or improved visual acuity and 85% maintained or improved headache. Proptosis significantly improved after surgery and along with the follow-up (P < 0.001). Ten patients were submitted to adjuvant RT, six of them after a subtotal resection. All patients of this subgroup had proptosis. It was observed a higher frequency of worse in visual acuity in patients submitted to RT (71% vs. 28%, P = 0.038). Conclusion: Resection of SOM was sufficient to stop the evolution of visual deficit and allowed the improvement of proptosis. Orbital reconstruction does not seem to be an essential step in reducing enophthalmos.

Place of Gamma Knife Stereotactic Radiosurgery in Grade 4 Vestibular Schwannoma Based on Case Series of 86 Patients with Long-Term Follow-Up.

INTRODUCTION: Grade IV vestibular schwannoma (Koos classification) is generally considered to be an indication for microsurgical resection or combined radiosurgery-microsurgery. However, the place of Gamma Knife stereotactic surgery (GK-SRS), either as first-line treatment or when progression of residual tumor compresses the brainstem, has not been clearly evaluated. This article reports the results of a large case series of patients with grade 4 vestibular schwannoma treated by GK-SRS. MATERIAL AND METHOD: All consecutive patients with grade IV vestibular schwannoma treated by GK-SRS in our department between 1996 and 2011 with a minimum follow-up of 3 years were included in this study. RESULTS: 86 patients were treated by GK-SRS with a minimum follow-up of 3 years. Mean follow-up was 6.2 years (3-16 years). The mean age of the patients at the time of GK-SRS was 54.6 years (range: 23-84) and the sex ratio was 0.6. At the time of radiosurgery, no patient presented brainstem dysfunction prior to GK-SRS. 38 patients had functional hearing before treatment. One patient presented mild trigeminal neuralgia before GK-SRS. Tumor control with no clinical deterioration was obtained in 78 patients (90.7%). No radiation-induced brainstem or cranial nerve toxicity was observed in any of these patients. Functional hearing was maintained in 25 patients. 8 (9.3%) patients presented tumor growth and required microsurgical resection in 7 cases and ventricular shunt in 1 case. CONCLUSION: On the basis of this large series, GK-SRS appears to be a safe and effective treatment option for grade IV vestibular schwannoma for patients with no signs of brainstem dysfunction.

Frontal Lobe Decortication (Frontal Lobectomy with Ventricular Preservation) in Epilepsy-Part 1: Anatomic Landmarks and Surgical Technique.

BACKGROUND: An extensive frontal resection is a frequently performed neurosurgical procedure, especially for treating brain tumor and refractory epilepsy. However, there is a paucity of reports available regarding its surgical anatomy and technique. OBJECTIVES: We sought to present the anatomic landmarks and surgical technique of the frontal lobe decortication (FLD) in epilepsy. The goals were to maximize the gray matter removal, spare primary and supplementary motor areas, and preserve the frontal horn. MATERIAL AND METHODS: The anatomic study was based on dissections performed in 15 formalin-fixed adult cadaveric heads. The clinical experience with 15 patients is summarized. RESULT: FLD consists of 5 steps: 1) coagulation and section of arterial branches of lateral surface; 2) paramedian subpial resection 3 cm ahead of the precentral sulcus to reach the genu of corpus callosum; 3) resection of gray matter of lateral surface, preserving the frontal horn; 4) removal of gray matter of basal surface preserving olfactory tract; 5) removal of gray matter of the medial surface under the rostrum of corpus callosum. The frontal horn was preserved in all 15 patients; 12 patients (80%) had no complications; 2 patients presented temporary hemiparesis; and 1 Rasmussen syndrome patient developed postoperative fever. The best seizure control was in cases with focal magnetic resonance imaging abnormalities limited to the frontal lobe. CONCLUSION: FLD is an anatomy-based surgical technique for extensive frontal lobe resection. It presents reliable anatomic landmarks, selective gray matter removal, preservation of frontal horn, and low complication rate in our series. It can be an alternative option to the classical frontal lobectomy.