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Purpose: The standard of care of patients with high-grademetastatic epidural compression is open decompression with or without stabilization. However, many patients are unwilling or unable to undergo open surgical decompression. This study investigated the outcomes of treating patients with high-grade (Ryu/ Rock radiographic grade IV and V, Spine Oncology Study Group Grade II and III) metastatic epidural spinal cord compression with spinal radiosurgery as first-line therapy in lieu of surgical decompression. Methods: Utilizing the Henry Ford Spinal Tumor Database, patients with metastatic lesions causing advanced radiographical grade (IV or V) epidural spinal cord compression who received stereotactic radiosurgery (SRS)with adequate clinical and radiological follow-up were identified from 2007-2011. These patients were retrospectively reviewed for clinical and radiological response to radiosurgery. Results: 33 patients with 35 metastatic lesions causing Ryu/Rock radiographical grade IV or V compression were identified with a median follow-up of 435 days. Of the 34 lesions in 32 patients who were ambulatory pre- SRS, 23 (67%) were ambulatory at last follow-up. 6/33 progressed early (less than 2 months) neurologically and an additional 5 patients developed late progressive neurologic deficit. The one patient who was initially non-ambulatory was able to regain ambulatory status. Radiologically, there was a significant epidural tumor response rate of 74%. Ultimately, 9 patients (27%) eventually required surgery for neurologic compromise or mechanical instability. There was one patient who received EBRT previously who experienced radiation myelopathy as a complication of SRS. Conclusion: Radiosurgery as an initial therapy for high-grade metastatic epidural compression appears to be a viable treatment paradigm for selected patients with close clinical and radiological follow-up. However, a significant minority will progress necessitating the need for rigorous monitoring. Further study is needed prospectively analyze the effectiveness of SRS with or without open surgical decompression. [ABSTRACT FROM AUTHOR]

Purpose Spine radiosurgery requires accurate image-guided stereotactic targeting and intensity-modulated radiation delivery. It can deliver a high radiation dose to spine and spinal cord tumors. The purpose of this study is to demonstrate the clinical effectiveness of radiosurgery for primary spine and cord tumors. Methods and Materials A total of 26 patients with 36 primary spine and cord tumors were treated with radiosurgery. There were 7 patients with spinal cord tumors, and 19 patients with primary spine tumors. Radiosurgery doses were single session of 12-18 Gy in 29 lesions, and fractionated in 6 lesions. Ten lesions were recurrent tumors after the initial therapy of combined surgery and radiation. Median follow-up was 12 months (range 2-42 months) with imaging studies and clinical examinations. Results The patients' symptoms and neurological status improved in 56%, and was stable in 28% after radiosurgery. One-year local tumor control rate was 94 %; complete response in 26%, partial response in 26%, and stable in 42%. There were no acute or long-term complications. Conclusion This study demonstrates that spine radiosurgery is an effective treatment for symptom improvement and tumor control of primary spine and spinal cord tumors. Spine radiosurgery can be a viable and non-invasive treatment option for primary spine tumors. [ABSTRACT FROM AUTHOR]

Introduction: Meningiomas are typically slow-growing lesions that, depending on the location, can be relatively benign. Knowing their exact rate of growth can be helpful in determining whether surgery is necessary. Methods: In this study we retrospectively reviewed the meningioma practices of the two senior authors (JR, MR). Our goal was to measure meningioma growth using a variety of methods (linear using diameters, and volumetric using the computer-aided perimeter and cross-sectional diameter methods) to compare rates of growth among the methods. Of 295 meningioma patients seen over an 8-year period, we identified a cohort of 31 patients with at least 30 months of follow-up. Volumes were calculated using medical imaging software with T1 post-contrast magnetic resonance imaging. Doubling times and growth rates were calculated. Results: Of the 31 patients, 26 (84%) were shown to have growing meningiomas. The perimeter methodology measured higher growth rates than the diameter method for both doubling times as well as percentage annual growth ( p < 0.01). The mean doubling time was 13.4 years (range, 2.1-72.8 years) and 17.9 years (range, 4-92.3 years) comparing perimeter and diameter methods, respectively. The mean percentage of annual growth was 15.2% (range, 1.8-61.7%) and 5.6% (range, 0.7-12.2%), comparing perimeter and diameter methods, respectively. Linear growth was calculated at 0.7 mm/year. Conclusion: Overall, we found that computer-aided perimeter methods showed a more accurate picture of tumor progression than traditional methods, which generally underestimated growth. [ABSTRACT FROM AUTHOR]

Purpose: During image-guided radiosurgery, it is common to account only for translational shifts while leaving rotational deviations uncorrected. The aim of this study is to investigate the rotational setup deviations and estimate the dosimetric impact in spinal radiosurgery. Materials and methods: Stereoscopic image registrations of 711 spine radiosurgery procedures (546 patients) were retrospectively reviewed and classified to cervical (C), thoracic (T), and lumbar (L) spines. The probability of rotational deviations were estimated in three orthogonal axis. In order to investigate the dosimetric impact, the original simulation CT images were rotated in the range of ±5 deg in each axis. Then, the dosimetric changes were recorded; including the coverage (V90) and minimum dose (Dmin) to the target, and the dose of 10% volume (D10) and maximum dose (Dmax) to the spinal cord. Results: Target rotations of >5 deg and >3 deg occurred respectively in 1% and 8% of cases. The mean rotations were small (|µ|<0.6 deg) with no axis and site dependent trends. The standard deviations (σ) of different sites and axes ranged from 1.4 to 2.0 deg (mean σ=1.7 deg). The overall dosimetric changes of the target coverage(V90) and cord D10 were small. Five degree rotation resulted in a target V90 decrease of 1±1%, 2±2% and 3±1%, respectively in the lateral, vertical, and longitudinal axes. The corresponding cord D10 increased by 3±6%, 2±2%, and 6±5%. The changes in cord Dmax ranged from 92% to 138% of the original reference spinal cord. Corresponding changes in target Dmin were 59~106%. Conclusion: Large target rotations occurred in a small percentage of patients. The overall dosimetric impact on target coverage and cord D10 was small. However larger effects were observed on the target Dmin and cord Dmax. Special care must be taken for targets of elongated shapes involving multiple vertebrae. [ABSTRACT FROM AUTHOR]

Rationale and Objectives: The purpose of this study was to correlate the status of magnetic resonance contrast enhancement with immunohistologic vascular parameters such as microvascular cellular proliferation (MVCP), microvascular density (MVD), vascular endothelial growth factor receptor-2 (VEGFR-2) expression, and World Health Organization (WHO) grade obtained from image-guided biopsy specimens. We also compared perfusion computed tomography (PCT) parameters such as cerebral blood volume (CBV), cerebral blood flow (CBF), and permeability surface area-product (PS) with the presence or absence of contrast enhancement. Materials and Methods: A total of 26 image-guided biopsy specimens in 16 patients with treatment naive gliomas were obtained from contrast-enhancing (CE) and nonenhancing (NE) regions of the glioma. Contrast enhancement status was correlated with MVD, MVCP, VEGFR-2 expression, and WHO grade obtained from the biopsy specimen as well as with the PCT parameters. Results: Contrast enhancement showed statistically significant correlation with MVCP (P = .003) and PS (P = .007) when compared with various immunohistologic and perfusion vascular parameters. WHO grade of the biopsy specimen showed statistically significant correlation with contrast enhancement (P = .002), MVCP (P < .001), and PS values (P = .028). Conclusion: Contrast enhancement in gliomas is primarily from a break in blood-brain barrier as evidenced by its correlation with PS and MVCP, whereas it was not statistically correlated with CBV and MVD even though it showed a positive trend. Contrast enhancement also showed significant correlation with WHO grade suggesting a biopsy from CE region in a heterogeneous glioma probably will still yield the most aggressive part of the glioma is also shown by its association with MVCP and PS estimates. [ABSTRACT FROM AUTHOR]

Spine stereotactic radiosurgery (SSRS) is proving to be one of the most significant advances in the treatment of both metastatic and primary spine tumors. High-dose hypofractionated and single fraction radiation appear to convey better local tumor control than conventional radiation for tumors considered radioresistant, such as renal cell carcinoma and melanoma. Multiple series have demonstrated control rates greater than 85% which appears to be histology independent. The markedly improved local control rates compared to conventional radiation techniques are beginning to change the treatment paradigms for spine tumors. Recent evidence in the literature reflects the integration of SSRS in the treatment of metastatic and primary malignant and benign spine tumors as the principle treatment or as a neoadjuvant or postoperative adjuvant therapy. For instance, as confidence grows with the use of SSRS as a postoperative adjuvant, surgical resection of metastatic disease has become less aggressive with the expectation that radiation can control residual disease. Despite high dose radiation delivery within millimeters of the spinal cord, toxicity has been limited with rare cases of radiation-induced myelopathy. The establishment of spinal cord and other critical structure tolerances is essential to the continued evolution of SSRS, as radiation oncologists begin to use this modality to treat spinal cord compression. This paper reviews the neurosurgical integration of SRS into spine practice. [ABSTRACT FROM AUTHOR]

The purpose of this study was to determine the usefulness of perfusion CT (PCT) parameters particularly blood volume and neovascular permeability estimates (permeability surface area-product, PS) in the evaluation of oligodendrogliomas (OG), correlation with genetic subtypes of OGs (with or without loss of heterozygosity/LOH on 1p/19q) as well as comparison of perfusion parameters of OGs with astroglial tumors. Pre-operative PCT done in 21 patients with OGs was retrospectively correlated with our previously published PCT data for 32 patients with astroglial neoplasms (Jain R et al., AJNR Am J Neuroradiol 29:694-700, 2008). All OGs were also analyzed for genetic subtypes of with or without LOH. PCT parameters PS and cerebral blood volume (CBV) were obtained for the entire lesion and a statistical analysis done to correlate various histopathological variants. Low grade OGs ( n = 13) showed slightly lower CBV (1.42 vs. 1.72 ml/100 g; P value 0.391) and PS (0.56 vs. 0.95 ml/100 g/min; P value 0.099) as compared to high grade OGs ( n = 8), though not statistically significant. LOH positive OGs ( n = 13) showed higher mean CBV (1.59 vs. 1.45; P value 0.712) and slightly lower PS (0.68 vs. 0.75; P value 0.718) as compared to LOH negative OGs ( n = 8), although not statistically significant. Low grade OGs ( n = 13) showed higher mean CBV 1.42 ml/100 g as compared to low grade astroglial tumors ( n = 8) 0.95 ml/100 g ( P value = 0.08), however no statistically significant difference was noted for PS (0.56 vs. 0.52 ml/100 g/min, P value 0.695). Statistically significant differences were observed in CBV and PS values of high grade OGs and high grade astroglial tumors with the high grade glial tumors showing higher mean CBV (2.79 vs. 1.72; P value 0.03) as well as higher PS (2.37 vs. 0.95; P value < 0.01), however this difference was not significant if only comparing grade III OGs with grade III astroglial tumors. PCT perfusion parameters including PS values do not help grade OGs despite showing a trend for higher CBV and PS in higher grade OGs. Similarly LOH positive OGs also showed slightly higher CBV, but again failed to reach any statistically significant level. Low grade OGs showed slightly higher CBV as compared to low grade astroglial tumors, whereas higher grade OGs showed significantly lower PS values as compared to higher grade astroglial tumors despite showing high CBV. [ABSTRACT FROM AUTHOR]

Brain tumor patients undergo various combinations therapies, leading to very complex and confusing imaging appearances on follow up MR imaging and hence, differentiating recurrent or progressing tumors from treatment induced necrosis or effects has always been a challenge in neuro-oncologic imaging. This particular topic has become more relevant these days because of the advent of newer anti-angiogenic and anti-neoplastic chemotherapeutic agents as well as use of salvage radiation therapy. Various clinically available functional imaging modalities can provide additional physiologic and metabolic information about the tumors which could be useful in identifying viable tumor from treatment induced necrosis and hence, can guide treatment planning. In this review we will discuss various functional neuro-imaging modalities, their advantages and limitations and also their utility in treatment planning. [ABSTRACT FROM AUTHOR]

Stereotactic Radiotherapy (SRT) is more commonly used for skull base tumors in conjunction with the technical development of radiation intensity modulation. Purpose of this study is to correlate clinical and radiographic characteristics of delayed radiation injury (RI) occurring around central skull base following SRT with SRT dosimetric data. Total of six patients were identified to have developed RI in the vicinity of SRT target volume out of 141 patients who received SRT in he center or near-center of the skull base. The images and medical records were retrospectively reviewed. The analysis was performed for RI location, time of development, imaging and clinical characteristics and evolution of RI and correlated with SRT dosimetric analysis using image fusion with follow-up MRI scans. Mean follow-up time was 24 ± 9 months. During the follow-up period, twelve sites of RI were found in 6 patients. They were clinically symptomatic in 4/6 patients (66.6%) at median 12.5 months after SRT. Mean time interval between SRT and detection of RI was 9 ± 3, 18.5 ± 5, and 13.5 months for brainstem, temporal lobe, and cerebellum/labyrinth lesions, respectively. All RI lesions were included in the region of high SRT doses. After steroid and symptomatic treatment, 50% of RI lesions showed complete response, and 40% showed partial response. RI can occur around the skull base because of irregular shape of target tumor, its close proximity to normal brain parenchyma, and inhomogeneity of dose distribution. Brainstem lesions occurred earlier than temporal lobe RI. The majority of the RI lesions, not mixed with the tumor in this study, showed radiographic and clinical improvement with steroid and symptomatic treatments. [ABSTRACT FROM AUTHOR]

Tumefactive demyelinating lesions (TDLs) can mimic a neoplasm on conventional imaging and may necessitate biopsy for diagnosis. The purpose of this study was to differentiate TDLs from high grade gliomas based on physiologic (permeability) and hemodynamic (blood volume) parameters using perfusion CT. Five patients who presented with tumefactive enhancing lesions on initial MRI that mimicked a neoplasm underwent perfusion CT. We compared the perfusion CT parameters of these patients with those of 24 patients with high grade gliomas. TDLs showed lower permeability surface area product (PS) (0.8 ± 0.2 vs 2.4 ± 1.4 ml/100 g/min, P-value 0.014) and lower cerebral blood volume (CBV) (1.0 ± 0.2 vs 2.8 ± 1.2 ml/100 g, P-value 0.006) as compared to high grade gliomas. TDLs show lower PS and CBV as compared to high grade gliomas, to which they can mimic on conventional MR imaging, due to lack of neoangiogenesis and vascular endothelial proliferation and hence perfusion CT can be used to differentiate the two entities. [ABSTRACT FROM AUTHOR]

Background Cerebral radiation necrosis is a serious complication of radiation treatment for brain tumors. Therapeutic options include corticosteroids, anticoagulation and hyperbaric oxygen with limited efficacy. Bevacizumab, an antibody against VEGF had been reported to reduce edema in patients with suspected radiation necrosis. We retrospectively reviewed 6 patients with biopsy proven cerebral radiation necrosis treated with bevacizumab between 2006 and 2008. Results Interval MRI follow-up demonstrated radiographic response in all patients with an average reduction of 79% for the post gadolinium studies and 49% for the FLAIR images. The initial partial radiographic response was noted for up to a mean follow-up time of 5.9 months (6 weeks to 18 months). Conclusion Bevacizumab appears to produce radiographic response and clinical benefits in the treatment of patients with cerebral radionecrosis. [ABSTRACT FROM AUTHOR]

Radiosurgery delivers highly focused radiation beams to the defined target with high precision and accuracy. It has been demonstrated that spine radiosurgery can be safely used for treatment of spine metastasis with rapid and durable pain control, but without detrimental effects to the spinal cord. This study was carried out to determine the role of single fraction radiosurgery for epidural spinal cord compression due to multiple myeloma. A total of 31 lesions in 24 patients with multiple myeloma, who presented with epidural spinal cord compression, were treated with spine radiosurgery. Single fraction radiation dose of 10-18 Gy (median of 16 Gy) was administered to the involved spine including the epidural or paraspinal tumor. Patients were followed up with clinical exams and imaging studies. Median follow-up was 11.2 months (range 1-55). Primary endpoints of this study were pain control, neurological improvement, and radiographic tumor control. Overall pain control rate was 86%; complete relief in 54%, and partial relief in 32% of the patients. Seven patients presented with neurological deficits. Five patients neurologically improved or became normal after radiosurgery. Complete radiographic response of the epidural tumor was noted in 81% at 3 months after radiosurgery. During the follow-up time, there was no radiographic or neurological progression at the treated spine. The treatment was non-invasive and well tolerated. Single fraction radiosurgery achieved an excellent clinical and radiographic response of myeloma epidural spinal cord compression. Radiosurgery can be a viable treatment option for myeloma epidural compression. [ABSTRACT FROM AUTHOR]

Purpose: The Novalis system has been demonstrated to achieve accurate target localization on anthropomorphic phantoms. However, other factors, such as rotational deviation, patient intrafraction motion, and image fusion uncertainty due to patient body deformation, could contribute additional position uncertainty for actual patients. This study evaluates such position uncertainty for spinal radiosurgery patients. Materials and Methods: Fifty-two consecutive spinal radiosurgery patients were included in the study. Rotational deviation was evaluated from 6-deg of freedom (6D) fusion results for all patients. The combined uncertainty of patient motion and image fusion was determined from fusion results of additional kV x-ray images acquired before, during, and after treatment for 25 of the 52 patients. The uncertainty of image fusion was also evaluated by performing 6D fusion ten different times with various regions of interest in the images selected for fusion. This was performed for two patients with L3 and T2 lesions, respectively, for comparison. Results: The mean rotational deviation was 0.7±1.8, 0.7±1.5, and 0.7±1.6 deg along the yaw, roll, and pitch directions, respectively. The combined uncertainty from patient motion and image fusion was 0.1±0.9, 0.2±1.2, and 0.2±1.0 mm in the anteroposterior (AP), longitudinal, and lateral directions, respectively. The uncertainty (standard deviation) due to image fusion was less than 0.28 mm in any direction for the L3 lesion and 0.8 mm in the AP direction for the T2 lesion. Conclusion: Overall position uncertainty for spinal radiosurgery patients has been evaluated. Rotational deviation and patient motion were the main factors contributed to position uncertainty for actual patient treatment. [ABSTRACT FROM AUTHOR]

Objectively examine the effect of 3D-Augmented Reality anatomic review on craniotomy planning among neurosurgical residents as it pertains to craniotomy size, skull positioning, and knowledge of significant anatomic relationships. Postgraduate year 1-7 neurosurgery residents were instructed to review standard 2D radiographs, pin a skull, and tailor a craniotomy for 6 different lesions and case vignettes. Participants then reviewed the lesion in a 3D-augmented reality (AR) environment, followed by repeating the craniotomy station for a variety of lesion types and locations (superficial, subcortical, deep, skull base). Quiz with case-specific anatomic and surgical questions followed by an exit survey for qualitative impressions. Eleven of thirteen eligible residents participated. Skull position significantly changed in 5 out of 6 cases after 3D-AR view (P < 0.05, 20° angular adjustment). No significant change in incision length or craniotomy size. Subgroup analysis of junior versus senior residents revealed that craniotomy size was significantly altered in 2 out of 6 cases. Qualitative testimonials (Likert scale 5 = strongly agree) reported a change in craniotomy approach after 3D-review (3.5), improved appreciation of anatomy (4.2), increased confidence in surgical approach (4.33 junior residents, 3.5 senior residents), smaller incision (3.5 junior residents, 1.75 senior residents), better appreciation of white matter tracts (4.6). The augmented reality platform offers a medium to examine surgical planning skills. Residents uniformly appreciated 3D-AR as a valuable tool for improving appreciation of critical anatomic structures and their relationship to lesional pathology. 3D-AR review significantly altered skull positioning for various lesions and craniotomy approaches, particularly among junior residents. [ABSTRACT FROM AUTHOR]

Augmented reality (AR) is an emerging technology in neurosurgery with the potential to become a strategic tool in the delivery of care and education for trainees. Advances in technology have demonstrated promising use for improving visualization and spatial awareness of critical neuroanatomic structures. In this report, we employ a novel AR registration system for the visualization and targeting of skull landmarks. A markerless AR system was used to register 3-dimensional reconstructions of suture lines onto the head via a head-mounted display. Participants were required to identify craniometric points with and without AR assistance. Targeting error was measured as the Euclidian distance between the user-defined location and the true craniometric point on the subjects' heads. All participants successfully registered 3-dimensional reconstructions onto the subjects' heads. Targeting accuracy was significantly improved with AR (3.59 ± 1.29 mm). Across all target points, AR increased accuracy by an average of 19.96 ± 3.80 mm. Posttest surveys revealed that participants felt the technology increased their confidence in identifying landmarks (4.6/5) and that the technology will be useful for clinical care (4.2/5). While several areas of improvement and innovation can further enhance the use of AR in neurosurgery, this report demonstrates the feasibility of a markerless headset-based AR system for visualizing craniometric points on the skull. As the technology continues to advance, AR is expected to play an increasingly significant role in neurosurgery, transforming how surgeries are performed and improving patient care. [ABSTRACT FROM AUTHOR]

This article, published in the Journal of Neurological Surgery, discusses a case study of a 65-year-old man with a recurrent clival chordoma. Despite previous surgery and radiotherapy, the tumor had progressed significantly. The article presents a video demonstrating the use of an expanded endoscopic transpterygoid transcavernous approach for tumor resection. Skull base reconstruction was performed using a temporoparietal fascia flap. The article provides valuable insights for researchers and medical professionals studying chordoma treatment options. [Extracted from the article]

This article discusses the use of bedside skull X-rays and high fraction inspired oxygen (FIO2) therapy for monitoring and treating postoperative pneumocephalus in patients undergoing expanded endoscopic endonasal surgery (EEA) for skull base tumors. The study found that bedside skull X-rays were effective in monitoring pneumocephalus and identifying cases of worsening pneumocephalus due to over drainage. Additionally, high FIO2 therapy was shown to accelerate the resorption of trapped air in the intracranial cavity. The use of bedside X-rays reduced the need for CT scans, resulting in cost savings and reduced radiation exposure. [Extracted from the article]