Gamma Knife radiosurgery for central neurocytoma: a quantitative systematic review and metanalysis.

Central neurocytomas (CN) are rare tumors within the central nervous system. Originating from the septum pellucidum and subependymal cells, they are typically found in the third and lateral ventricles. For this reason, they may lead to hydrocephalus and increased intracranial pressure. CNs are generally benign lesions that exhibit locally aggressive behavior and a high recurrence rate. Complete surgical resection is the preferred treatment; however, due to their anatomical location, this is often not feasible. Based on these findings, Gamma Knife radiosurgery (GKRS) has been introduced for managing both residual and recurrent tumors and as an initial therapy in selected cases. This study aimed to systematically review the available knowledge regarding GKRS for CN. A systematic investigation of the scientific literature was undertaken through an exhaustive search across prominent databases, including PubMed, Web of Science, and Google Scholar, by employing precise MeSH terms such as "Central neurocytoma," "Radiosurgery," "Gamma Knife," and "Stereotactic Radiosurgery." A comprehensive quantitative systematic review and meta-analysis were meticulously conducted, focusing on cases of CN treated with GKRS for a thorough evaluation of outcomes and efficacy. Seventeen articles, including 289 patients, met the inclusion criteria. Random effects meta-analysis estimates for disease control and local tumor control were 90% (95% CI 87-93%; I2 = 0%, p < 0.74) and 94% (95% CI 92-97%; I2 = 0%, p < 0.98), respectively. When considering only studies with at least 5 years of follow-up, progression-free survival was 89% (95% CI 85-94%; I2 = 0.03%, p < 0.74). The mean clinical control rate was 96%. This systematic review and meta-analysis confirmed the safety and efficacy of GKRS in managing CN.

Meningioma and Other Meningeal Tumors.

Meningiomas develop from meningothelial cells and approximately account for more than 30 percent of central nervous system (CNS) tumors. They can occur anywhere in the dura, most often intracranially and at dural reflection sites. Half of the cases are usually at parasagittal/falcine and convexity locations; other common sites are sphenoid ridge, suprasellar, posterior fossa, and olfactory groove. The female-to-male ratio is approximately 2 or 3-1, and the median age at diagnosis is 65 years. Meningiomas are generally extremely slow-growing tumors; many are asymptomatic or paucisymptomatic at diagnosis and are discovered incidentally. Clinical manifestations, when present, are influenced by the tumor site and by the time course over which it develops. Meningiomas are divided into three grades. Grade I represents the vast majority of cases; they are considered typical or benign, although their CNS location can still lead to severe morbidity or mortality, resulting in a reported ten-year net survival of over 80%. Atypical (WHO grade II) meningiomas are considered "intermediate grade" malignancies and represent 5-7% of cases. They show a tendency for recurrence and malignant degeneration with a relevant increase in tumor cell migration and surrounding tissue infiltration; ten-year net survival is reported over 60%. The anaplastic subtype (WHO III) represents only 1-3% of cases, and it is characterized by a poor prognosis (ten-year net survival of 15%). The treatment of choice for these tumors stands on complete microsurgical resection in case the subsequent morbidities are assumed minimal. On the other hand, and in case the tumor is located in critical regions such as the skull base, or the patient may have accompanied comorbidities, or it is aimed to avoid intensive treatment, some other approaches, including stereotactic radiosurgery and radiotherapy, were recommended as safe and effective choices to be considered as a primary treatment option or complementary to surgery. Adjuvant radiosurgery/radiotherapy should be considered in the case of atypical and anaplastic histology, especially when a residual tumor is identifiable in postoperative imaging. A "watchful waiting" strategy appears reasonable for extremely old individuals and those with substantial comorbidities or low-performance status, while there is a reduced threshold for therapeutic intervention for relatively healthy younger individuals due to the expectation that tumor progression will inevitably necessitate proactive treatment. To treat and manage meningioma efficiently, the assessments of both neurosurgeons and radiation oncologists are essential. The possibility of other rarer tumors, including hemangiopericytomas, solitary fibrous tumors, lymphomas, metastases, melanocytic tumors, and fibrous histiocytoma, must be considered when a meningeal lesion is diagnosed, especially because the ideal diagnostic and therapeutic approaches might differ significantly in every tumor type.

Craniopharyngioma in Pediatrics and Adults.

Craniopharyngiomas are rare malignancies of dysembryogenic origin, involving the sellar and parasellar areas. These low-grade, epithelial tumors account for two main histological patterns (adamantinomatous craniopharyngioma and papillary craniopharyngioma), which differ in epidemiology, pathogenesis, and histomorphological appearance. Adamantinomatous craniopharyngiomas typically show a bimodal age distribution (5-15 years and 45-60 years), while papillary craniopharyngiomas are limited to adult patients, especially in the fifth and sixth decades of life. Recently, craniopharyngioma histological subtypes have been demonstrated to harbor distinct biomolecular signatures. Somatic mutations in CTNNB1 gene encoding ß-catenin have been exclusively detected in adamantinomatous craniopharyngiomas, which predominantly manifest as cystic lesions, while papillary craniopharyngiomas are driven by BRAF V600E mutations in up to 95% of cases and are typically solid masses. Despite the benign histological nature (grade I according to the World Health Organization classification), craniopharyngiomas may heavily affect long-term survival and quality of life, due to their growth pattern in a critical region for the presence of eloquent neurovascular structures and possible neurological sequelae following their treatment. Clinical manifestations are mostly related to the involvement of hypothalamic-pituitary axis, optic pathways, ventricular system, and major blood vessels of the circle of Willis. Symptoms and signs referable to intracranial hypertension, visual disturbance, and endocrine deficiencies should promptly raise the clinical suspicion for sellar and suprasellar pathologies, advocating further neuroimaging investigations, especially brain MRI. The optimal therapeutic management of craniopharyngiomas is still a matter of debate. Over the last decades, the surgical strategy for craniopharyngiomas, especially in younger patients, has shifted from the aggressive attempt of radical resection to a more conservative and individualized approach via a planned subtotal resection followed by adjuvant radiotherapy, aimed at preserving functional outcomes and minimizing surgery-related morbidity. Whenever gross total removal is not safely feasible, adjuvant radiotherapy (RT) and stereotactic radiosurgery (SRS) have gained an increasingly important role to manage tumor residual or recurrence. The role of intracavitary therapies, including antineoplastic drugs or sealed radioactive sources, is predominantly limited to monocystic craniopharyngiomas as secondary therapeutic option. Novel findings in genetic profiling of craniopharyngiomas have unfold new scenarios in the development of targeted therapies based on brand-new biomolecular markers, advancing the hypothesis of introducing neoadjuvant chemotherapy regimens in order to reduce tumor burden prior to resection. Indeed, the rarity of these neoplasms requires a multispecialty approach involving an expert team of endocrinologists, neurosurgeons, neuro-ophthalmologists, neuroradiologists, radiotherapists, and neuro-oncologists, in order to pursue a significant impact on postoperative outcomes and long-term prognosis.

Brain Tumors Affecting the Orbit Globe and Orbit Tumors Affecting the Brain.

Brain tumors affecting the orbit and orbital tumors affecting the brain are a heterogeneous group of lesions, with histological features, behaviors, diagnostic criteria, and treatments varying from each other. Dermoid cyst and cavernous hemangiomas are considered the most frequent benign lesions, while non-Hodgkin lymphoma is the most common malignant tumor in this region. Sharing the same anatomical region, clinical manifestations of orbital lesions may be often common to different types of lesions. Imaging studies are useful in the differential diagnosis of orbital lesions and the planning of their management. Lesions can be classified into ocular or extra-ocular ones: the latter can be further differentiated into extraconal or intraconal, based on the relationship with the extraocular muscles. Surgical therapy is the treatment of choice for most orbital lesions; however, based on the degree of removal, their histology and extension, other treatments, such as chemotherapy and radiotherapy, are indicated for the management of orbital lesions. In selected cases, chemotherapy and radiotherapy are the primary treatments. This chapter aimed to discuss the orbital anatomy, the clinical manifestations, the clinical testing and the imaging studies for orbital lesions, and the principal pathological entities affecting the orbit together with the principles of orbital surgery.

MIS removal of extraforaminal lumbar spine schwannoma using MAS-TLIF retractor: technical note.

BACKGROUND: To report the use of Nuvasive MAS-TLIF retractor for the removal of lumbar spine schwannomas. METHODS: A 47-year-old man with 1-year history of back pain with progressive left sciatica underwent surgical resection of a left extraforaminal lumbar schwannoma (type IV according to Eden's classification) using the MAS-TLIF retractor. RESULTS: The patient completely recovered from the preoperative symptoms and was discharged three days after surgery. The MRI acquired 6 months postoperatively showed complete tumour removal, with no signs of instability. The MAS-TLIF retractor allows for an optimal paraspinal tissues retraction, improving the area of exposure and the manoeuverability angle. Moreover, the stability of the retraction is guaranteed by the positioning of the two transpedicular screws. Spinal fusion is not necessary because the posterior tension band is not jeopardised. CONCLUSIONS: MAS-TLIF retractor allows for a minimally invasive and safe surgical removal of LSS maximising surgical exposure and avoiding spinal fusion.

Transcranial extradural subtemporal repair for sphenoid sinus lateral recess meningoencephalocele: technical note.

Cranial meningoencephalocele is a rare condition consisting of the herniation of meninges, CSF, and brain tissue through a cranial or skull base defect. Sphenoid sinus lateral recess meningoencephalocele is of particular interest due to the complex anatomy surrounding the bone defect and their demanding surgical management. In this technical note, we reported a step-by-step description of a rare case of sphenoid sinus lateral recess meningoencephalocele causing headache due to recurrent cerebrospinal fluid leak treated with a subtemporal craniotomy with extradural middle cranial fossa drilling and meningoencephalocele removal with multilayer reconstruction. The transcranial route is a safe and effective treatment for sphenoid sinus lateral recess meningoencephalocele repair. The subtemporal extradural approach allows for an optimal exposure of the relevant anatomy minimizing risks and improving the possibility to perform an effective multilayer skull base reconstruction.

Comparative Anatomical Study of Fronto-Orbito-Zygomatic and Fronto-Temporal Approach to the Central Skull Base.

ABSTRACT: Despite the advances in microsurgery and neuroanatomy, surgery of the central skull base still represents a challenge. Fronto-temporal approach has represented the mainstay of surgical approaches to this region. With advances in skull base surgery, orbital and zygomatic extensions were added to fronto-temporal approach to improve exposure minimizing brain retraction.The authors compared fronto-temporal and fronto-orbitozygomatic approaches to the central skull base by using the previously described operability score, to three different anatomical targets: the ipsilateral anterior clinoid process, the contralateral anterior clinoid process, and the ipsilateral posterior clinoid process.Based on the measurements taken, fronto-orbitozygomatic approache showed higher values at all 3 targets. The reported values were critically discussed.The operability score has been reported as an effective method to compare surgical approaches. The present study demonstrated the maximal possibility of exposure of the two approaches. Based on the strong variability of this anatomical region, especially because of the different pathologies, the authors suggest considering the operability score as a further tool to better define the best surgical approach to this anatomical region.

Surgical and Radiologic Prognostic Factors in Intramedullary Spinal Cord Lesions.

OBJECTIVE: The present study aimed to perform a comprehensive data analysis of 47 consecutive patients treated in 8 years and to observe how clinical, radiologic, and surgical factors affect early and long-term outcomes, recurrence rate, and survival. METHODS: Clinical, radiologic, and surgical data were collected retrospectively from the review of a prospectively collected database. The neurologic disability was evaluated according to the modified Rankin Scale (mRS). Radiologic data were obtained by direct measurement performed on magnetic resonance imaging (MRI). Univariate and multivariate statistical analysis was performed. RESULTS: From 2008 to 2016, 47 consecutive patients underwent microsurgical resection of intramedullary lesions (28 males and 19 females; mean age, 41.2 years). Ependymoma (53.2%), astrocytoma (14.9%), hemangioblastoma (14.9%), and cavernous angioma (6.4%) were the most frequent tumor histology. The mean follow-up duration was 69.3 months. Gross total tumor resection was performed in 80.8% of cases. Forty-two patients (89.4%) were alive at last follow-up. Five-year overall survival and recurrence-free survival were 92% and 82%, respectively. CONCLUSIONS: Among the examined variables, age seemed to strongly correlate with outcomes; better chances of recovery and a good postoperative outcome were observed in younger patients. Surfacing lesions had a better early functional outcome than did intramedullary located lesions. Patients' preoperative neurologic and functional status (mRS score ≤2) had a significant impact on late neurologic outcome. Progression-free survival correlated with the extent of tumor resection. Surgery should probably be performed before patients' neurologic decline, aiming to achieve maximal resection without compromising patients' quality of life.

Efficacy of Gamma Knife radiosurgery in the management of multiple sclerosis-related trigeminal neuralgia: a systematic review and meta-analysis.

Trigeminal neuralgia (TN) is the most frequent craniofacial pain condition, which commonly affects patients suffering from multiple sclerosis (MS). Stereotactic radiosurgery, especially Gamma Knife radiosurgery (GKRS), represents a safe and effective treatment for TN, and it has been adopted also for MS-TN, with a lower success rate. Therefore, we aimed to analyze the outcome of GKRS for MS-TN. PubMed, Web of Science, and Google Scholar and the reference list of relevant articles were searched for GKRS in MS-TN. Two investigators independently identified the articles, assessed the study quality, and extracted the data. Endpoints of interest were initial pain responders, successful treatments at the end of follow-up, and factors influencing the outcome. Data analyses were performed using R software. Twelve articles involving 646 patients met our inclusion criteria. Pooled proportion of patients who experienced an initial response to GKRS treatment was 83% (CI 74-90%). The cumulative proportion of successful treatments at the end of follow-up was 47% (CI 33-60%). No variables were found to have a significant contribution to heterogeneity regarding the initial response outcome. The only variable significantly explaining the heterogeneity found in the proportion of successful treatments was the length of the follow-up, with a negative b coefficient (- 0.0051, p value = 0.0047). Regarding the efficacy of GKRS in MS-TN, the initial pain response rate was 83%, which dramatically decreases to 47% during follow-up. GKRS still represents a valuable option for MS-TN; however, its long-term efficacy should be always considered.

Comparative anatomical study on the role of zygomatic osteotomy in the extradural subtemporal approach to the clival region, when less is more.

PURPOSE: A great concern in performing the extradural subtemporal approach (ESTA) is the evaluation of the actual advantage provided by zygomatic osteotomy (ZO). Complications related to zygomatic dissection have been widely reported in the literature, making it of paramount importance to balance the actual need to perform it, against the risk of maneuver-related morbidity. Authors comparatively analyze the putative advantage provided by ZO in the ESTA in terms of anatomic exposure and surgical operability. Technical limits and potentials are critically revised and discussed. METHODS: A comparative microanatomical laboratory investigation was conducted. The operability score (OS) was applied for quantitative analysis of surgical operability. RESULTS: ZO was found to provide a weakly significant improvement in the surgical angle of attack (p value 0.01) (mean increase 3°). Maneuverability arch (MAC) increase related to ZO did not reach statistical significance (p value 0.09) (mean increase 2°). The variations provided by MAC increase on the conizing effect (CE) did not lead to an actual advantage in the real surgical scenario, modifying the vision area (VA) in terms of reduction of central vision area (CA) in favor of an increase of peripheral vision area (PA) only in the most caudal part of the surgical field. Ultimately, ZO did not influence the overall OS, scoring both ESTA-ZO+ and ESTA-ZO- 2 out of 3. CONCLUSION: In the ESTA, ZO does not provide an actual significant advantage in terms of surgical operability on clival and paraclival areas.

Temporal Galeofascial Flap for Reconstruction After Transmaxillary Approaches to the Clival Region.

BACKGROUND: A paramount concern after transmaxillary approaches has been skull base reconstruction. Regional pedicled flaps represent the best reconstructive option. We have described a technique to harvest a lateral-based multilayered vascularized flap for skull base reconstruction after resection of large tumors using the transmaxillary transpterygoid approach (TMTPA). METHODS: We performed a cadaver study using the TMTPA to harvest the combined temporal galeofascial flap (CTGF). The first layer, with major sealing capabilities, is composed by a temporoparietal galeal-pericranial flap. The second layer is composed by temporal muscle fascia to provide mechanical support for flap dural engrafting. RESULTS: The CTGF provides excellent coverage of both the clival dural lining and the ipsilateral pterygopalatine fossa structures (×1.6). The CTGF is pliable and easy to harvest. It offers great flexibility in flap content and design, providing a large quantity of vascularized tissue. The vascular pedicle derives from the superficial temporal vessels, which can ensure flap trophism. CONCLUSIONS: CTGF represents an effective option as a regional multilayered pedicled flap for skull base reconstruction after resection of clival tumors using the TMTPA. The flap pedicle, owing to its anatomical location, will often be preserved even after repeated microsurgical or endoscopic procedures, providing a technical alternative for reconstruction even in patients who have undergone multiple surgeries with low residual availability of regional flaps.

Endonasal Endoscopic and Transoral Approaches to the Craniovertebral Junction and the Clival Region: A Comparative Anatomical Study.

OBJECTIVE: Anterior craniovertebral junction (CVJ) surgery has continued to be one of the most debated neurosurgical topics. The transoral approach (TOA) has been considered the choice for this region. However, it has some limitations and a not negligible degree of surgery-related morbidity. With the advent of endoscopy, the endoscopic endonasal approach (EEA) was developed, which minimized morbidity and improved exposure. To the best of our knowledge, despite the extensive reported data, a comparative anatomical study has not been performed and no definitive consensus has been reached on the indications for both approaches. METHODS: We compared the TOA and EEA to the CVJ using the previously described operability score (OS), calculated at 4 different targets: the C1 tubercle (C1), the lowest exposed point of the odontoid process (C2), the basion (BS) and the middle clivus (MC). The higher the OS for the selected targets, the more favorable the approach. RESULTS: The TOA had higher OSs at the MC, C1, and C2 targets, and the EEA showed greater OSs at MC and C1. The TOA and EEA had similar OSs at the BS. These results have shown that the OS is more favorable at C1-C2 using the TOA and the OSs at the MC and BS were similar. CONCLUSIONS: The OS is an effective method to compare surgical approaches. The present study demonstrated the maximal exposure capability of the 2 approaches. The TOA seemed to be superior for lower targets and the EEA for upper targets. Because of the strong variability in the CVJ anatomy and pathological features, we suggest considering the OS as a further tool to better define the best surgical approach.

The Role of Surgery in Meningiomas.

PURPOSE OF REVIEW: This review presents the most recent evidences and recommendations in the pre-, intra-, and post-surgical management of patients harboring meningiomas. Due to the increasing relevance of multimodal approaches, in order to preserve patients' neurological function and quality of life (QoL), the role of observation and radiation treatments (as either primary or adjuvant therapy) has also been discussed. RECENT FINDINGS: Multiple advances in neurosurgery, including the use of the microscope and endoscope, improved preoperative neuroimaging, intraoperative image-guided approaches, and intraoperative neurophysiological monitoring, have extended the neurosurgeon's ability to remove lesions that were previously considered only partially resectable or unresectable, while minimizing morbidity. On the other hand, the preservation of patients' neurological integrity and QoL are increasingly important issues, more than complete tumor resection, for both patients and neurosurgeons. In this setting, stereotactic radiosurgery (SRS) and radiotherapy (RT) may be considered safe and effective alternatives for asymptomatic small- to moderate-sized tumors that demonstrate growth on serial imaging, or in combination with planned subtotal resection (STR) for tumors in critical locations. Data supporting the use of pharmacotherapy in meningiomas are, to date, weak, but the strength of the evidence might improve in the next future with the identification of targetable mutations. Complete microsurgical resection remains the standard of care if it can be achieved with minimal or no morbidity. However, many studies have reported SRS/RT as safe and effective treatments, either as primary approach or as complementary to surgery, especially when dealing with critically located meningiomas (e.g., cranial base) or in patients with comorbidity or wishing to avoid invasive treatments. The management of meningiomas is a field of complementary disciplines: neurosurgeon needs to work closely with radiation oncologists while tailoring the optimal treatment for these patients in order to achieve the best results.