Monday, December 2, 2013

Technical nuances in the management of tuberculum sellae and diaphragma sellae meningiomas

Technical nuances in the management of tuberculum sellae and diaphragma sellae meningiomas
Journal of Neurosurgery: Neurosurgical FOCUS: Table of Contents

Neurosurgical Focus, Volume 35, Issue 6, Page E7, December 2013.
Object Tuberculum sellae meningiomas (TSMs) and diaphragma sellae meningiomas (DSMs) are challenging lesions to treat due to their proximity to neurovascular structures. Methods The authors reviewed the medical records of patients who underwent surgical excision of TSMs and DSMs from 1990 to 2013. They also describe the technical strategies used to minimize injury to the optic apparatus, vascular structures, and pituitary stalk. Results Twenty-four patients with TSM and 6 patients with DSM were included in the study. Seventy percent of the tumors were large (≥ 5 cm). The pterional approach was employed in most cases. Optic canal involvement was observed in 4 patients. Twenty-one patients (70%) had visual dysfunction before surgery. At follow-up (median 18 months), visual improvement was noted in 10 (47.6%) of 21 patients. Gross-total excision was achieved in 22 patients (91.6%) with TSM and 5 (83.3%) with DSM. At last follow-up, 28 patients (93.3%) had a Glasgow Outcome Scale score of 5. There were no deaths in this series. Conclusions Tuberculum and diaphragma sellae meningiomas present a unique subset of tumors due to their location. They can be safely excised with minimal morbidity and mortality using microsurgical techniques. Attention to technical details during surgery leads to greater respectability and superior visual outcome.

Original Article: http://thejns.org/doi/abs/10.3171/2013.10.FOCUS13350?ai=rw&mi=3ba5z2&af=R
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A proposed grading system for standardizing tumor consistency of intracranial meningiomas

A proposed grading system for standardizing tumor consistency of intracranial meningiomas
Journal of Neurosurgery: Neurosurgical FOCUS: Table of Contents

Neurosurgical Focus, Volume 35, Issue 6, Page E1, December 2013.
Object Tumor consistency plays an important and underrecognized role in the surgeon's ability to resect meningiomas, especially with evolving trends toward minimally invasive and keyhole surgical approaches. Aside from descriptors such as "hard" or "soft," no objective criteria exist for grading, studying, and conveying the consistency of meningiomas. Methods The authors designed a practical 5-point scale for intraoperative grading of meningiomas based on the surgeon's ability to internally debulk the tumor and on the subsequent resistance to folding of the tumor capsule. Tumor consistency grades and features are as follows: 1) extremely soft tumor, internal debulking with suction only; 2) soft tumor, internal debulking mostly with suction, and remaining fibrous strands resected with easily folded capsule; 3) average consistency, tumor cannot be freely suctioned and requires mechanical debulking, and the capsule then folds with relative ease; 4) firm tumor, high degree of mechanical debulking required, and capsule remains difficult to fold; and 5) extremely firm, calcified tumor, approaches density of bone, and capsule does not fold. Additional grading categories included tumor heterogeneity (with minimum and maximum consistency scores) and a 3-point vascularity score. This grading system was prospectively assessed in 50 consecutive patients undergoing craniotomy for meningioma resection by 2 surgeons in an independent fashion. Grading scores were subjected to a linear weighted kappa analysis for interuser reliability. Results Fifty patients (100 scores) were included in the analysis. The mean maximal tumor diameter was 4.3 cm. The distribution of overall tumor consistency scores was as follows: Grade 1, 4%; Grade 2, 9%; Grade 3, 43%; Grade 4, 44%; and Grade 5, 0%. Regions of Grade 5 consistency were reported only focally in 14% of heterogeneous tumors. Tumors were designated as homogeneous in 68% and heterogeneous in 32% of grades. The kappa analysis score for overall tumor consistency grade was 0.87 (SE 0.06, 95% CI 0.76–0.99), with 90% user agreement. Kappa analysis scores for minimum and maximum grades of tumor regions were 0.69 (agreement 72%) and 0.75 (agreement 78%), respectively. The kappa analysis score for tumor vascularity grading was 0.56 (agreement 76%). Overall consistency did not correlate with patient age, tumor location, or tumor size. A higher tumor vascularity grade was associated with a larger tumor diameter (p = 0.045) and with skull base location (p = 0.02). Conclusions The proposed grading system provides a reliable, practical, and objective assessment of meningioma consistency and facilitates communication among providers. This system also accounts for heterogeneity in tumor consistency. With the proposed scale, meningioma consistency can be standardized as groundwork for future studies relating to surgical outcomes, predictability of consistency and vascularity using neuroimaging techniques, and effectiveness of various surgical instruments.

Original Article: http://thejns.org/doi/abs/10.3171/2013.8.FOCUS13274?ai=rw&mi=3ba5z2&af=R
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Patterns of recurrence after stereotactic radiosurgery for treatment of meningiomas

Patterns of recurrence after stereotactic radiosurgery for treatment of meningiomas
Journal of Neurosurgery: Neurosurgical FOCUS: Table of Contents

Neurosurgical Focus, Volume 35, Issue 6, Page E14, December 2013.
Object The purpose of this study was to evaluate patterns of failure after stereotactic radiosurgery (SRS) for meningiomas and factors that may influence these outcomes. Methods Based on a retrospective chart review, 279 patients were treated with SRS for meningiomas between January 1999 and March 2011 at Wake Forest Baptist Health. Disease progression was determined using serial imaging, with a minimum follow-up of 6 months (median 34.2 months). Results The median margin dose was 12.0 Gy (range 8.8–20 Gy). Local control rates for WHO Grade I tumors were 96.6%, 84.4%, and 75.7% at 1, 3, and 5 years, respectively. WHO Grade II and III tumors had local control rates of 72.3%, 57.7%, and 52.9% at 1, 3, and 5 years, respectively. Tumors without pathological grading had local control rates of 98.7%, 97.6%, and 94.2% at 1, 3, and 5 years, respectively. Of the local recurrences, 63.1% were classified as marginal (within 2 cm of treatment field). The 1-, 3-, and 5-year rates of distant failure were 6.5%, 10.3%, and 16.6%, respectively, for Grade I tumors and 11.4%, 17.2%, and 22.4%, respectively, for Grade II/III tumors. Tumors without pathological grading had distant failure rates of 0.7%, 3.2%, and 6.5% at 1, 3, and 5 years, respectively. Wilcoxon analysis revealed that multifocal disease (p < 0.001) and high-grade histology (WHO Grade II or III; p < 0.001) were significant predictors of local recurrence. Additionally, male sex was a significant predictor of distant recurrence (p = 0.04). Multivariate analysis also showed that doses greater than or equal to 12 Gy were associated with improved local control (p = 0.015). Conclusions In this patient series, 12 Gy was the minimum sufficient margin dose for the treatment of meningiomas. Male sex is a risk factor for distant failure, whereas high-grade histology and multifocal disease are risk factors for local failure.

Original Article: http://thejns.org/doi/abs/10.3171/2013.8.FOCUS13283?ai=rw&mi=3ba5z2&af=R
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Controversies in the role of preoperative embolization in meningioma management

Controversies in the role of preoperative embolization in meningioma management
Journal of Neurosurgery: Neurosurgical FOCUS: Table of Contents

Neurosurgical Focus, Volume 35, Issue 6, Page E17, December 2013.
The role of preoperative embolization in meningioma management remains controversial, even though 4 decades have passed since it was first described. It has been shown to offer benefits such as decreased blood loss and "softening of the tumor" during subsequent resection. However, the actual benefits remain unclear, and the potential harm of an additional procedure along with the cost of embolization have limited its use to a small proportion of the meningiomas treated. In this article the authors retrospectively reviewed their experience with preoperative embolization of meningiomas over the previous 6 years (March 2007–March 2013). In addition, they performed a MEDLINE search using a combination of the terms "meningioma," "preoperative," and "embolization" to analyze the indications, embolizing agents, timing, and complications reported during preoperative embolization of meningiomas. In this retrospective review, 18 cases (female/male ratio 12:6) were identified in which endovascular embolization was used prior to resection of an intracranial meningioma. Craniotomy for tumor resection was performed within 4 days after endovascular embolization in all cases, with an average time to surgery of 1.9 days. The average duration of surgery was 4 hours and 18 minutes, and the average blood loss was 574 ml, with a range of 300–1000 ml. Complications following endovascular therapy were identified in 3 (16.7%) of 18 cases, including one each of transient hemiparesis, permanent hemiparesis, and tumor swelling. The literature review returned 15 articles consisting of a study population greater than 25 patients. No randomized controlled study was found. The use of small polyvinyl alcohol particles (45–150 μm) is more effective in preoperative devascularization than larger particles (150–250 μm), but is criticized due to the higher risk of complications such as cranial nerve palsies and postprocedural hemorrhage. Time to surgery after embolization is inconsistently reported across the articles, and conclusions on the appropriate timing of surgery could not be drawn. The overall complication rate reported after treatment with preoperative meningioma embolization ranges from as high as 21% in some of the older literature to approximately 6% in recent literature describing treatment with newer embolization techniques. The evidence in the literature supporting the use of preoperative meningioma embolization is mainly from case series, and represents Level III evidence. Due to the lack of randomized controlled clinical trials, it is difficult to draw any significant conclusions on the overall usefulness of preoperative embolization during the management of meningiomas to consider it a standard practice.

Original Article: http://thejns.org/doi/abs/10.3171/2013.9.FOCUS13351?ai=rw&mi=3ba5z2&af=R
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Atypical meningiomas: is postoperative radiotherapy indicated?

Atypical meningiomas: is postoperative radiotherapy indicated?
Journal of Neurosurgery: Neurosurgical FOCUS: Table of Contents

Neurosurgical Focus, Volume 35, Issue 6, Page E15, December 2013.
Object The role of postoperative radiation therapy after surgery for atypical meningiomas remains controversial. In this retrospective cohort study, the authors examine the recurrence rates for atypical meningiomas after resection (with or without adjuvant radiotherapy) and identify which factors were associated with recurrence. Methods Of 90 patients with atypical meningiomas who underwent surgery between 1999 and 2009, 71 (79%) underwent gross-total resection (GTR) and 19 (21%) underwent subtotal resection (STR); 31 patients received adjuvant radiotherapy. All tumors were pathology-confirmed WHO Grade II atypical meningiomas. Univariate and multivariate analyses were performed to identify factors associated with recurrence-free survival. Results Among 90 patients, 17 developed tumor recurrence (81% recurrence-free survival at 5 years). In the overall group, adjuvant radiotherapy reduced the recurrence rate to 9% from 19% at 5 years (p = 0.048). After STR, adjuvant radiotherapy significantly reduced recurrence from 91% to 20% (p = 0.0016). However, after GTR, adjuvant radiotherapy did not significantly reduce the recurrence rate (16.7% without radiation therapy vs 11.8% with radiation therapy) (p = 1.00). Five factors independently predictive of tumor recurrence included mitotic index, sheeting, necrosis, nonuse of radiation therapy, and STR. Further recursive partitioning analysis showed significant increases in risk for patients older than 55 years with mitoses and sheeting. Conclusions Adjuvant radiotherapy was effective at lowering recurrence rates in patients after STR but delivered no significant improvement in patients after GTR. Given that rates after GTR were similar with or without adjuvant radiotherapy, close observation without postoperative radiation therapy may be a viable option for these patients. Patients older than 55 years and those with mitoses noted during pathological examination had a significant risk of recurrence after GTR; for these patients, postoperative radiotherapy is recommended.

Original Article: http://thejns.org/doi/abs/10.3171/2013.9.FOCUS13325?ai=rw&mi=3ba5z2&af=R
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Improvement of therapeutic index for brain tumors with daily image guidance

Improvement of therapeutic index for brain tumors with daily image guidance
Radiation Oncology

Background: Image-guidance maximizes the therapeutic index of brain irradiation by decreasing setup uncertainty. As dose-volume data emerge defining the tolerance of critical normal structures responsible for neuroendocrine function and neurocognition, minimizing clinical target volume (CTV) to planning target volume (PTV) expansion of targets near these structures potentially lessens long-term toxicity. Methods: We reviewed the treatment records of 29 patients with brain tumors, with a total of 517 fractions analyzed. The CTV was uniformly expanded by 3 mm to create the PTV for all cases. We determined the effect of patient specific factors (prescribed medications, weight gain, tumor location) and image-guidance technique on setup uncertainty and plotted the mean +/- standard deviation for each factor. ANOVA was used to determine significance between these factors on setup uncertainty. We determined the impact of applying the initial three fraction variation as custom PTV-expansion on dose to normal structures. Results: The initial 3 mm margin encompassed 88% of all measured shifts from daily imaging for all fractions. There was no difference (p = n.s.) in average setup uncertainty between CBCT or kV imaging for all patients. Vertical, lateral, longitudinal, and 3D shifts were similar (p = n.s.) between days 1, 2, and 3 imaging and later fractions. Patients prescribed sedatives experienced increased setup uncertainty (p < 0.05), while weight gain, corticosteroid administration, and anti-seizure medication did not associate with increased setup uncertainty. Patients with targets near OAR with individualized margins led to decreased OAR dose. No reductions to targets occurred with individualized PTVs. Conclusions: Daily imaging allows application of individualized CTV expansion to reduce dose to OAR responsible for neurocognition, learning, and neuroendocrine function below doses shown to correlate with long-term morbidity. The demonstrated reduction in dose to OAR in this study has implications for quality of life and provides the motivation to pursue custom PTV expansion.

Original Article: http://www.ro-journal.com/content/8/1/283
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Management of meningiomas involving the transverse or sigmoid sinus

Management of meningiomas involving the transverse or sigmoid sinus
Journal of Neurosurgery: Neurosurgical FOCUS: Table of Contents

Neurosurgical Focus, Volume 35, Issue 6, Page E9, December 2013.
Meningiomas that invade the transverse or sigmoid sinuses are uncommon tumors that are challenging to treat surgically. Although the risk of recurrence is associated with the extent of resection, complete removal of meningiomas in these locations must be balanced with avoidance of venous outflow obstruction, which could cause venous infarction and significant neurological consequences. When a meningioma occludes a venous sinus completely, gross-total resection of the intravascular portion is commonly performed. When the tumor invades but does not completely obliterate a major venous sinus, however, opinions differ on whether to accept a subtotal resection or to open the sinus, perform a complete resection, and reconstruct the venous outflow tract. In this paper, the authors review the different strategies used to treat these lesions and provide illustrative case examples.

Original Article: http://thejns.org/doi/abs/10.3171/2013.8.FOCUS13340?ai=rw&mi=3ba5z2&af=R
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Current standing and frontiers of gene therapy for meningiomas

Current standing and frontiers of gene therapy for meningiomas
Journal of Neurosurgery: Neurosurgical FOCUS: Table of Contents

Neurosurgical Focus, Volume 35, Issue 6, Page E4, December 2013.
Meningiomas are among the most common intracranial tumors. The treatment of choice for these lesions is complete resection, but in 50% of cases it is not achieved due to tumor location and/or surgical morbidities. Moreover, benign meningiomas have high recurrence rates of up to 32% in long-term follow-up. Molecular analyses have begun to uncover the genetics behind meningiomas, giving rise to potential genetics-based treatments, including gene therapy. The authors performed a literature review on the most relevant genes associated with meningiomas and both current and potential gene therapy strategies to treat these tumors. Wild-type NF2 gene insertion, oncolytic viruses, and transfer of silencing RNA have all shown promising results both in vitro and in mice. These strategies have decreased meningioma cell growth, proliferation, and angiogenesis. However, no clinical trial has been done to date. Future research and trials in gene insertion, selective inhibition of oncogenes, and the use of oncolytic viruses, among other potential treatment approaches, may shape the future of meningioma management.

Original Article: http://thejns.org/doi/abs/10.3171/2013.8.FOCUS13305?ai=rw&mi=3ba5z2&af=R
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Sunday, December 1, 2013

Epilepsy App



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