The incidence of venous thromboembolism following surgical resection of intracranial and intraspinal meningioma. A systematic review and retrospective study.

INTRODUCTION: Historically, the development of venous thromboembolism (VTE) including deep venous thrombosis (DVT) and pulmonary thromboembolism (PE) was cited as a higher post-operative risk for patients harboring meningiomas. However, recent literature has suggested that there may be no elevated risk for VTE among these patients. The authors perform both a retrospective review of their own cases as well as a systematic review of the literature in order to determine the frequency of the VTE and rate of post-operative hemorrhage in this patient population. METHODOLOGY: Patients undergoing surgery for intracranial and spinal meningioma from 2012 to 2019 were retrospectively reviewed for patient demographics, clinical characteristics, and post-operative complications. Logistic regression was used to determine risk factors for the development of VTE. Additionally, a PubMed search was performed to identify patients addressing this topic. RESULTS: Our retrospective review included 189 patients who underwent 197 operations. The rate of VTE for patients receiving LMWH was 3.55 % vs. 4.06 % for those not receiving LMWH. There were no observed hemorrhages after initiation of LMWH. Multivariate analysis found tumor volume, history of DVT, and length of hospital stay as independent risk factors for VTE. In the systematic review, 11 papers describing 28,954 patients were included. The risk of developing a VTE with or without LMWH was 2.71 % versus 4.07 %, respectively. The hemorrhage risk was 2.23 % on LMWH versus 4.20 % not on LMWH. DISCUSSION: In several heterogeneous series of all types of neurosurgical procedures, the reported rate of VTE was 11.1 %. In our review of the literature, the VTE rate of 2.71 % was similar to our cohort's rate of 3.55 %, for patients administered LMWH postoperatively. Higher rates of VTE with meningiomas may not be the case as once thought. Regular use of LMWH appears to be a safe, but it also did not necessarily lower the rates of VTE in our cohort. The use of routine lower-extremity duplex ultrasound, mechanical prophylaxis, and early mobilization, may have contributed to these lower rates of VTEs in patients with meningiomas.

Evaluating the natural growth rate of metastatic cancer to the brain.

BACKGROUND: Brain metastases are becoming increasingly more prevalent as cancer patients survive longer with both improved local and systemic therapy. Little is known, however, of the natural growth rates of brain metastases. This investigation aims to ascertain this growth rate of these lesions before the initiation of any CNS- directed therapy. METHODS: A total of 700 patients were screened, identifying 18 cancer patients (13 breast and 5 lung) with 29 brain metastases that were serially imaged from 2011 to 2017 before treatment for their intracranial metastases. Growth rates were measured by contouring lesions serially across at least two MRI studies in iPlan software by independent raters. These values were then compared between primary (breast and lung) cancer cohorts. RESULTS: The mean age at diagnosis was 53 and 95% were female. The interval between primary cancer diagnosis and brain metastases was 4.6 years and 1.2 years in the breast and lung cancer groups, respectively. Of the breast and lung cancer patients, 23% and 40% were deceased, with respective 5.08 cm3 and 2.44 cm3 initial tumor volumes. The average growth rate of lung and breast tumors was 0.018 and 0.040 cm3/day, respectively, with deceased patients having larger and faster growing tumors. Breast and lung metastases grew 2.39% and 1.14% of their total volumes daily and doubling times were 86 and 139 days, respectively. CONCLUSION: This investigation provides a unique perspective into the biological growth of metastatic brain lesions. It is our hope that this study guides timing of treatment and informs both clinicians and patients of tumor growth kinetics before initiating treatment for intracranial metastases.

Laparoscope-Assisted Guidance to the Pineal Region.

Tumors arising in the pineal region present a number of challenges when planning for effective removal. This report describes the successful resection of a falcotentorial meningioma occurring in a 56-year-old female using a supracerebellar infratentorial approach. In order to excise the pineal region mass, a unique combination of instrumentation was used, including a microscope, endoscope, and abdominal laparoscope. This technique afforded us passage to the pineal region, which allowed for enhanced visualization and maneuverability and was more amenable to decreasing the physical stress of the operating surgeon. This article is the first to detail the use of an abdominal laparoscope to remove a pineal tumor of this size for near-total resection. The various surgical approaches and tools traditionally used to remove pineal tumors are discussed, and the particular advantages and disadvantages of our hybrid approach are reviewed.

Glioblastoma multiforme presenting with an open ring pattern of enhancement on MR imaging.

BACKGROUND: Intracerebral ring enhancing lesions can be the presentation of a variety of pathologies, including neoplasia, inflammation, and autoimmune demyelination. Use of a precise diagnostic algorithm is imperative in correctly treating these lesions and minimizing potential adverse treatment effects. CASE DESCRIPTION: A 55-year-old patient presented to the hospital with complaints of a post-concussive syndrome and a non-focal neurologic exam. Imaging revealed a lesion with an open ring enhancement pattern, minimal surrounding vasogenic edema, and minimal mass effect. Given the minimal mass effect, small size of the lesion, and nonfocal neurological exam, we elected to pursue a comprehensive noninvasive neurologic workup because our differential ranged from inflammatory/infectious to neoplasm. Over the next 8 weeks, the patient's condition worsened, and repeat imaging showed marked enlargement of the lesion with a now closed ring pattern of enhancement with satellite lesions and a magnetic resonance (MR) spectroscopy and perfusion signature suggestive of neoplasm. The patient was taken to surgery for biopsy and debulking of the lesion. Surgical neuropathology examination revealed glioblastoma multiforme. CONCLUSION: The unique open ring enhancement pattern of this lesion on initial imaging is highly specific for a demyelinating process, however, high-grade glial neoplasms can also present with complex and irregular ring enhancement including an open ring sign. Therefore, other imaging modalities should be used, and close follow-up is warranted when the open ring sign is encountered.

Radiolucent Skull Clamps for Intra-Operative Imaging: A Technical Note.

Conventionally, surgery and procedural-based radiology are performed on different premises. With advances in imaging technology, the operating room is rapidly being transformed into an intraoperative imaging suite. Diagnostic imaging in conjunction with surgery has great utility and by all accounts has great future potential. During the last decade, cone beam computed tomography (CT) scanners have been introduced and have made intraoperative imaging more feasible because these scanners can be made less bulky. The current usefulness of intraoperative magnetic resonance imaging (MRI) or CT for neurosurgery, however, is impaired by the lack of completely radiolucent skull clamps, causing image artifacts. Metal artifacts are particularly problematic, given that they lead to a considerably higher image quality degradation factor for cone beam CT scanners than for conventional CT scanners. Here, we describe our experience with near-radiolucent skull clamps and their associated problems and discuss future improvements to facilitate high-quality image guidance in the field of neurosurgery.

Fractionated stereotactic radiation therapy for brain metastases: a systematic review with tumour control probability modelling.

OBJECTIVE: Fractionated stereotactic radiotherapy (FSRT) is a relatively new option for the treatment of brain metastases. We performed a quantitative systematic review to determine if local control (LC) following is affected by FSRT dosing regimen. METHODS: We reviewed articles describing LC following FSRT for brain metastases. LC data from each study were extracted from actuarial survival curves and aggregated to form a single data set. LC curves were generated using the Kaplan-Meier method. Log-rank testing and Cox proportional hazards modelling were utilized to test for associations between the biologically effective dose (BED) and LC. Tumour control probability modelling was performed to illustrate the relationship between the BED and the likelihood of LC after FSRT. RESULTS: 10 studies (720 metastases) met inclusion criteria. Prescription doses ranged from 18 to 42 Gy, delivered in 3-12 fractions (BED range: 29-100 Gy10). 1- and 2-year actuarial LC rates were 80% and 69%, respectively. Increasing BED was associated with improved LC (HR = 0.77 per increase of 10 Gy10, p = 0.009). Tumour control probability models demonstrated that the BEDs of 40, 50 and 60 Gy10 yield predicted 1-year LC rates of 73%, 78% and 84%, respectively. The BEDs of 40, 50 and 60 Gy10 yield 2-year LC rates of 62%, 69% and 81%, respectively. CONCLUSION: FSRT provides high rates of LC for patients with brain metastases. We found evidence for a dose-response relationship that should be explored in prospective trials. Advances in knowledge: This review identified a dose-response relationship for LC in patients treated with FSRT for brain metastases.

ILAE type 3 hippocampal sclerosis in patients with anti-GAD-related epilepsy.

OBJECTIVE: To describe the neuropathologic findings and clinical course of 2 patients who underwent temporal lobectomy for medically refractive epilepsy and were later found to have high anti-glutamic acid decarboxylase (GAD) concentrations. METHODS: Small case series. RESULTS: Neuropathologic examination of both patients revealed International League Against Epilepsy (ILAE) type 3 hippocampal sclerosis. Following surgery, both developed signs and symptoms of stiff person syndrome and later cerebellar ataxia. Laboratory studies demonstrated high concentrations of anti-GAD antibodies in both patients. CONCLUSIONS: These cases suggest that ILAE type 3 hippocampal sclerosis may be immunologically related to and may exist as part of a broader anti-GAD-related neurologic syndrome in some instances.

Endoscopic Endonasal Transsphenoidal Resection for Pituitary Apoplexy during the Third Trimester of Pregnancy.

Pituitary apoplexy is an uncommon phenomenon typically characterized by vascular insufficiency or acute hemorrhage into a pituitary adenoma. The overall incidence of pituitary apoplexy ranges between 1 and 25% of all pituitary adenomas. With the widespread use of MRI technology, the diagnosis of asymptomatic intratumoral hemorrhage is closer to 10%. The authors report a case of a 27-year-old female in her 36th week of pregnancy who presented with severe onset headache and acute left-sided vision loss. MRI of the brain revealed a large hemorrhagic mass occupying the sella turcica. The patient underwent an emergent endoscopic endonasal transsphenoidal resection for pituitary apoplexy. Postoperatively, the patient's neurologic deficit resolved. Minimally invasive endoscopic endonasal transsphenoidal resection of pituitary apoplexy can be safely utilized in third trimester pregnant women presenting with acute severe neurologic deficits.

Experience of micromultileaf collimator linear accelerator based single fraction stereotactic radiosurgery: tumor dose inhomogeneity, conformity, and dose fall off.

PURPOSE: Sharp dose fall off outside a tumor is essential for high dose single fraction stereotactic radiosurgery (SRS) plans. This study explores the relationship among tumor dose inhomogeneity, conformity, and dose fall off in normal tissues for micromultileaf collimator (mMLC) linear accelerator (LINAC) based cranial SRS plans. METHODS: Between January 2007 and July 2009, 65 patients with single cranial lesions were treated with LINAC-based SRS. Among them, tumors had maximum diameters < or = 20 mm: 31; between 20 and 30 mm: 21; and > 30 mm: 13. All patients were treated with 6 MV photons on a Trilogy linear accelerator (Varian Medical Systems, Palo Alto, CA) with a tertiary m3 high-resolution mMLC (Brainlab, Feldkirchen, Germany), using either noncoplanar conformal fixed fields or dynamic conformal arcs. The authors also created retrospective study plans with identical beam arrangement as the treated plan but with different tumor dose inhomogeneity by varying the beam margins around the planning target volume (PTV). All retrospective study plans were normalized so that the minimum PTV dose was the prescription dose (PD). Isocenter dose, mean PTV dose, RTOG conformity index (CI), RTOG homogeneity index (HI), dose gradient index R50-R100 (defined as the difference between equivalent sphere radius of 50% isodose volume and prescription isodose volume), and normal tissue volume (as a ratio to PTV volume) receiving 50% prescription dose (NTV50) were calculated. RESULTS: HI was inversely related to the beam margins around the PTV. CI had a "V" shaped relationship with HI, reaching a minimum when HI was approximately 1.3. Isocenter dose and mean PTV dose (as percentage of PD) increased linearly with HI. R50-R100 and NTV50 initially declined with HI and then reached a plateau when HI was approximately 1.3. These trends also held when tumors were grouped according to their maximum diameters. The smallest tumor group (maximum diameters < or = 20 mm) had the most HI dependence for dose fall off. For treated plans, CI averaged 2.55 +/- 0.79 with HI 1.23 +/- 0.06; the average R50-R100 was 0.41 +/- 0.08, 0.55 +/- 0.10, and 0.65 +/- 0.09 cm, respectively, for tumors < or = 20 mm, between 20 and 30 mm, and > 30 mm. CONCLUSIONS: Tumor dose inhomogeneity can be used as an important and convenient parameter to evaluate mMLC LINAC-based SRS plans. Sharp dose fall off in the normal tissue is achieved with sufficiently high tumor dose inhomogeneity. By adjusting beam margins, a homogeneity index of approximately 1.3 would provide best conformity for the authors' SRS system.

Dynamic perfusion MRI characteristics of dural metastases and meningiomas: a pilot study characterizing the first-pass wash-in phase beyond relative cerebral blood volume.

OBJECTIVE: Dural metastases and meningiomas are extraaxial lesions that may be difficult to distinguish using conventional imaging methods. This distinction, however, is clinically important. Perfusion MRI may play a role in preoperative assessment. The aim of this study was to evaluate the utility of perfusion parameters in differentiating between these two entities. In particular, we evaluated two new metrics that reflect the first-pass wash-in characteristics of perfusion. MATERIALS AND METHODS: Patients with intracranial extraaxial masses who underwent perfusion MRI were included. Region-of-interest analysis was performed and several perfusion metrics were calculated including relative cerebral blood volume (rCBV), mean transit time and time to peak (TTP) enhancement from initial bolus enhancement (T0), calculated as TTP-T(0). Two new metrics characterizing first pass wash-in enhancement were also measured: relative wash-in time and wash-in slope. Lesions were divided into two groups: meningioma and metastasis. Comparisons between the two groups were made using Wilcoxon rank sum and Fisher exact tests. RESULTS: Twenty lesions were studied (12 meningioma and 8 metastases). Compared with meningiomas, relative wash-in time was statistically lower in metastases (p < 0.05). No other statistically significant differences were observed. Specifically, there was no difference between the two study groups in rCBV. CONCLUSION: First-pass wash-in characteristics of dural lesions may be useful for evaluating and characterizing lesions. In particular, a metric describing the wash-in phase of perfusion-that is, relative wash-in time-was found to be lower in metastases compared with meningiomas. Contrary to a prior report, we found rCBV to be limited in the evaluation of extraaxial lesions.

Two cases of spinal meningeal melanocytoma.

Meningeal melanocytoma is a rare pigmented tumor originating from the melanocytes that generally occurs in the posterior fossa and the spinal cord. Although it is known as a relatively benign tumor, some recurrences have been reported. We report two cases of spinal meningeal melanocytoma with immunohistochemical and ultrastructural studies. In addition, we include a summary of published cases since the first case of Limas and Tio in 1972.