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Implementation of intraoperative magnetic resonance imaging (iMRI) has been shown to optimize the extent of resection and safety of brain tumor surgery. In addition, iMRI can help account for the phenomenon of brain shift and can help to detect complications earlier than routine postoperative imaging, which can potentially improve patient outcome. The higher signal-to-noise ratio offered by 3 Tesla (T) iMRI compared with lower field strength systems is particularly advantageous. The purpose of this article is to review the imaging protocols, imaging findings, and technical considerations related to 3T iMRI. To maximize efficiency, iMRI sequences can be tailored to particular types of tumors and procedures, including nonenhancing brain tumor surgery, enhancing brain tumor surgery, transsphenoidal pituitary tumor surgery, and laser ablation. Unique imaging findings on iMRI include the presence of surgically induced enhancement, which can be a potential confounder for residual enhancing tumor, and hyperacute hemorrhage, which tends to have intermediate signal on T1-weighted sequences and high signal on T2-weighted sequences due to the presence of oxyhemoglobin. MR compatibility and radiofrequency shielding pose particularly stringent technical constraints at 3T and influence the design and usage of the surgical suite with iMRI.

Molecular analytical methods are increasingly needed for a quick and reliable analysis of tissue in an operating room to provide more information during operations. In this Trends article, we highlight the current state and the developments of optical spectroscopic methods as intra operative tools. The clinical problem and challenges are illustrated on the example of brain tumor surgery. While fluorescence microscopy is already used, vibrational spectroscopy techniques will complement the standard method for brain tissue diagnostics. New portable instruments are currently available and can be stationed in the operating room for quick evaluation of tissue. The promise and limitations of fluorescence and vibrational spectroscopy as intraoperative tools are surveyed in this report.

Background Leksell GammaPlan (LGP) and SurgiPlan (ELEKTA Instruments AB, Stockholm, Sweden) may be used effectively for the detailed evaluation of regional neuroanatomy before open neurosurgical procedures. We report our initial experience in the cases of cerebral gliomas. Methods LGP v.8.3 was used before the surgical resection of cerebral gliomas for (1) the delineation of subdural grid electrodes and a detailed evaluation of their position relatively to cortical structures, and (2) for the fusion of structural magnetic resonance imaging and diffusion tensor imaging (DTI) for a detailed visualization of the corticospinal tract (CST) and optic radiation. Results Delineation of the subdural grid within LGP in a patient with seizures caused by left parietal glioma permitted a detailed assessment of the location of electrodes relative to the cortical gyri and sulci and significantly facilitated interpretation of brain mapping before tumor resection. In another patient with parieto-occipital glioma, simultaneous three-dimensional visualization of the tumor, CST, and optic radiation with the use of LGP permitted us to perform tumor resection without postoperative neurologic complications. Finally, incorporation of DTI into SurgiPlan resulted in precise planning of stereotactic biopsy for bilateral thalamic glioma. Conclusion The possibility for detailed evaluation of regional neuroanatomy based on various images within LGP and SurgiPlan may facilitate effective and safe surgical management of intracranial gliomas.

Navigated repetitive transcranial magnetic stimulation (nrTMS) Q2 24 is a novel technology that, unlike the other non-invasive methods 25 used to map language, applies a methodology (“virtual lesions”) 26 that is identical to that of the gold standard direct electrical stimu27 lation (DES) during awake surgery [1]. 28 The induction of brain plasticity due to pathological conditions 29 is an established observation and has been studied extensively 30 in stroke [2]. In brain tumor surgery, a small number of reports 31 have demonstrated that brain plasticity can occur in slow-growing 32 lesions and may enable the resection of tumors that were pre33 viously deemed inoperable due to their infiltration of areas that 34 carry essential language or motor function [3]. This article reports 35 for the first time a subacute reshaping of the language network 36 within 7 months after surgery for a left fronto-opercular glioblas37 toma detected by nrTMS. 38

Awake craniotomy (AC) has seen an expanded role in brain tumor surgery over the past few decades. AC allows intraoperative cortical mapping and the continuous assessment of neurophysiological parameters, which are otherwise unattainable under general anesthesia (GA). The ability of AC to analyze eloquent brain areas makes it a powerful method for reducing the risks associated with tumor resection, especially in motor and language cortex. We present a review of the literature to examine the benefits and limits of using AC over GA.A literature search was performed using the Medline and PubMed databases from 1970 and 2012 that compared craniotomy for tumor resection under GA and AC. Data of interest included length of hospital stay, operating time, extent of resection, and neurological sequelae.A total of 8 studies with 951 patients (411 utilizing AC and 540 utilizing GA) were included in this review. Our interpretation of the literature suggests that AC (4 d, n=110) results in a shorter hospital stay than GA (9 d, n=116). Mean extent of resection was slightly less under awake conditions (41%, n=321) versus GA (44%, n=444), and postoperative deficits were less frequent under awake conditions (7%, n=411) versus GA (23%, n=520). Surgery time was slightly less in the AC group (165 min, n=324) versus GA (168 min, n=477).Given the effectiveness of AC for resection of eloquent tumors, the data suggests an expanded role for AC in brain tumor surgery regardless of tumor location.

Confocal laser endomicroscopy (CLE), although capable of obtaining images at cellular resolution during surgery of brain tumors in real time, creates as many non-diagnostic as diagnostic images. Non-useful images are often distorted due to relative motion between probe and brain or blood artifacts. Many images, however, simply lack diagnostic features immediately informative to the physician. Examining all the hundreds or thousands of images from a single case to discriminate diagnostic images from nondiagnostic ones can be tedious. Providing a real-time diagnostic value assessment of images (fast enough to be used during the surgical acquisition process and accurate enough for the pathologist to rely on) to automatically detect diagnostic frames would streamline the analysis of images and filter useful images for the pathologist/surgeon. We sought to automatically classify images as diagnostic or non-diagnostic. AlexNet, a deep-learning architecture, was used in a 4-fold cross validation manner. Our dataset includes 16,795 images (8572 nondiagnostic and 8223 diagnostic) from 74 CLE-aided brain tumor surgery patients. The ground truth for all the images is provided by the pathologist. Average model accuracy on test data was 91% overall (90.79 % accuracy, 90.94 % sensitivity and 90.87 % specificity). To evaluate the model reliability we also performed receiver operating characteristic (ROC) analysis yielding 0.958 average for the area under ROC curve (AUC). These results demonstrate that a deeply trained AlexNet network can achieve a model that reliably and quickly recognizes diagnostic CLE images., SPIE Medical Imaging: Computer-Aided Diagnosis 2017

Object Navigated transcranial magnetic stimulation (nTMS) combined with diffusion tensor imaging (DTI) is used preoperatively in patients with eloquent-located brain lesions and allows analyzing non-invasively the spatial relationship between the tumor and functional areas (e.g. the motor cortex and the corticospinal tract [CST]). In this study, we examined the diffusion parameters FA (fractional anisotropy) and ADC (apparent diffusion coefficient) within the CST in different locations and analyzed their interrater reliability and usefulness for predicting the patients' motor outcome with a precise approach of specific region of interest (ROI) seeding based on the color-coded FA-map. Methods Prospectively collected data of 30 patients undergoing bihemispheric nTMS mapping followed by nTMS-based DTI fiber tracking prior to surgery of motor eloquent high-grade gliomas were analyzed by 2 experienced and 1 unexperienced examiner. The following data were scrutinized for both hemispheres after tractography based on nTMS-motor positive cortical seeds and a 2nd region of interest in one layer of the caudal pons defined by the color-coded FA-map: the pre- and postoperative motor status (day of discharge und 3 months), the closest distance between the tracts and the tumor (TTD), the fractional anisotropy (FA) and the apparent diffusion coefficient (ADC). The latter as an average within the CST as well as specific values in different locations (peritumoral, mesencephal, pontine). Results Lower average FA-values within the affected CST as well as higher average ADC-values are significantly associated with deteriorated postoperative motor function (p = 0.006 and p = 0.026 respectively). Segmental analysis within the CST revealed that the diffusion parameters are especially disturbed on a peritumoral level and that the degree of their impairment correlates with motor deficits (FA p = 0.065, ADC p = 0.007). No significant segmental variation was seen in the healthy hemisphere. The interrater reliability showed perfect agreement for almost all analyzed parameters. Conclusions Adding diffusion weighted imaging derived information on the structural integrity of the nTMS-based tractography results improves the predictive power for postoperative motor outcome. Utilizing a second subcortical ROI which is specifically seeded based on the color-coded FA map increases the tracking quality of the CST independently of the examiner's experience. Further prospective studies are needed to validate the nTMS-based prediction of the patient's outcome., Highlights • ROI seeding based on nTMS-data and FA-maps improves DTI tractography of the CST. • Perfect interrater reliability for DTI tractography of the CST was observed. • The pattern of diffusivity disturbance predicts the postoperative motor outcome.

This chapter reviews the diagnostic imaging findings of the brain during and after surgery, including intraoperative MRI, brain tumor surgery and treatment accessories, resection cavities, Ommaya reservoirs, chemotherapy wafers, brachytherapy, as well as neurodegenerative, neuropsychiatric, and epilepsy surgery

International audience; AbstractIntroductionAfter elective craniotomy for brain tumour surgery, patients are usually admitted to an intensive care unit (ICU) for monitoring. Our goal was to evaluate the incidence and timing of neurologic and non-neurologic postoperative complications after brain tumour surgery, to determine factors associated with neurologic events and to evaluate the timing and causes of ICU readmission.Patients and methodsThis prospective, observational and analytic study enrolled 188 patients admitted to the ICU after brain tumour surgery. All postoperative clinical events during the first 24 hours were noted and classified. Readmission causes and timing were also analysed.ResultsTwenty-one (11%) of the patients were kept sedated after surgery; the remaining 167 patients were studied. Thirty one percent of the patients presented at least one complication (25% with postoperative nausea and vomiting (PONV), 16% with neurologic complications). The occurrence of neurological complications was significantly associated with the absence of preoperative motor deficit and the presence of higher intraoperative bleeding. Seven patients (4%) were readmitted to the ICU after discharge; 43% (n = 3) of them had a posterior fossa surgery.ConclusionPostoperative complications, especially PONV, are frequent after brain tumour surgery. Moreover, 16% of patients presented a neurological complication, probably justifying the ICU postoperative stay for early detection. The absence of preoperative motor deficit and intraoperative bleeding seems to predict postoperative neurologic complications. Finally, patients may present complications after ICU discharge, especially patients with fossa posterior surgery, suggesting that ICU hospitalization may be longer in this type of surgery.

Extensive resective surgery plays a major role in prolonging survival of glioma patients. However, patient’s will is not to survive as long as possible, but rather to enjoy the longest possible «normal» life. Because glioma infiltrates functional tissue, it is necessary to define resection boundaries by functional maps rather than by tumoral imaging. In this perspective, advances in brain mapping have deeply improved the surgical management of glioma patients. In this chapter, we summarize the preoperative and intraoperative methods that allows to map the brain and we review the cortical and axonal mapping of the main cognitive functions.

Objective: VP Reveal (Vesalius Perfectus, Eindhoven, The Netherlands) is a commercially available “virtual reality” system designed to generate and review stereoscopic 3D models of any DICOM based CT, MRI, MRA, PET-scan within seconds. The system uses polarized 3D glasses and a 3D monitor.[for full text, please go to the a.m. URL], 67. Jahrestagung der Deutschen Gesellschaft für Neurochirurgie (DGNC), 1. Joint Meeting mit der Koreanischen Gesellschaft für Neurochirurgie (KNS)

Object Disturbance of the arcuate fasciculus in the dominant hemisphere is thought to be associated with language-processing disorders, including conduction aphasia. Although the arcuate fasciculus can be visualized in vivo with diffusion tensor imaging (DTI) tractography, its involvement in functional processes associated with language has not been shown dynamically using DTI tractography. In the present study, to clarify the participation of the arcuate fasciculus in language functions, postoperative changes in the arcuate fasciculus detected by DTI tractography were evaluated chronologically in relation to postoperative changes in language function after brain tumor surgery. Methods Preoperative and postoperative arcuate fasciculus area and language function were examined in 7 right-handed patients with a brain tumor in the left hemisphere located in proximity to part of the arcuate fasciculus. The arcuate fasciculus was depicted, and its area was calculated using DTI tractography. Language functions were measured using the Western Aphasia Battery (WAB). Results After tumor resection, visualization of the arcuate fasciculus was increased in 5 of the 7 patients, and the total WAB score improved in 6 of the 7 patients. The relative ratio of postoperative visualized area of the arcuate fasciculus to preoperative visualized area of the arcuate fasciculus was increased in association with an improvement in postoperative language function (p = 0.0039). Conclusions The role of the left arcuate fasciculus in language functions can be evaluated chronologically in vivo by DTI tractography after brain tumor surgery. Because increased postoperative visualization of the fasciculus was significantly associated with postoperative improvement in language functions, the arcuate fasciculus may play an important role in language function, as previously thought. In addition, postoperative changes in the arcuate fasciculus detected by DTI tractography could represent a predicting factor for postoperative language-dependent functional outcomes in patients with brain tumor.

Tractography: denition and application in brain tumor surgery Surgical treatment of brain tumors involves the maximum resection of the lesion, leading to a greater chance of tumor control and increase patient survival. On the other hand, surgical intervention should preserve eloquent areas and minimize the possible neurological de'cits resulting from the surgery. Currently, many tests are available to assist our surgical planning and strategy, aiming to achieve better results. In this article, we analyze the basic concepts of tractography and its applications in brain tumor surgeries.

The advanced imaging techniques outlined in this article are only slowly establishing their place in surgical practice. Even a low risk of false information is unacceptable in neurosurgery, thus decision-making is necessarily conservative. As more validation studies and greater experience accrue, surgeons are becoming more comfortable weighing the quality of information from functional imaging studies. Advanced imaging information is highly complementary to established surgical "good practice" such as anatomic planning, awake craniotomy, and electrocortical stimulation; its greatest impact is perhaps on how neurosurgery is planned and discussed before the patient is ever brought to the operating room. Access to functional magnetic resonance (MR) imaging, diffusion tractography, and intraoperative MR imaging can influence neurosurgical decisions before, during, and after surgery. However, the widespread adoption of these techniques in neurosurgical practice remains limited by the lack of standardized methods, the need for validation across institutions, and the unclear cost-effectiveness particularly for intraoperative MR imaging. Before advanced imaging results can be used therapeutically, it is incumbent on the neurosurgeon and neuroradiologist to develop a working understanding of each technique's strengths and weaknesses, positive and negative predictive values, and modes of failure. This content presents several imaging methods that are increasingly used in neurosurgical planning. As these techniques are progressively applied to surgery, radiologists, medical physicists, neuroscientists, and engineers will be necessary partners with the treating neurosurgeon to bridge the gap between the experimental and the therapeutic.

OBJECTIVE Transcranial magnetic stimulation (TMS) is a noninvasive method for analyzing cortical function. To utilize TMS for presurgical functional diagnostics, the magnetic impulse must be precisely targeted by stereotactically positioning the coil. The aim of this study was to evaluate the usefulness of TMS for operation planning when combined with a sensor-based electromagnetic navigation system (nTMS). METHODS Preoperative functional mapping with nTMS was performed in 10 patients with rolandic tumors. Intraoperative mapping was performed with the "gold standard" of direct cortical stimulation. Stimulation was performed in the same predefined 5-mm raster for both modalities, and the results were compared. RESULTS In regard to the 5-mm mapping raster, the centers of gravity of nTMS and direct cortical stimulation were located at the same spot in 4 cases and at neighboring spots in the remaining 6 cases. The mean distance between the tumor and the nearest motor response ("safety margin") was 7.9 mm (range, 5-15 mm; standard deviation, 3.2 mm) for nTMS and 6.6 mm (range, 0-12 mm; standard deviation, 3.4 mm) for direct cortical stimulation. CONCLUSION nTMS allowed for reliable, precise application of the magnetic impulse, and the peritumoral somatotopy corresponded well between the 2 modalities in all 10 cases. nTMS is a promising method for preoperative functional mapping in motor cortex tumor surgery.

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This paper addresses estimation of brain deformation during craniotomy using finite element modeling. Two mechanical models are optimized and compared for this purpose: linear solid-mechanic model and linear elastic model. Both models assume the realistic finite deformation of the brain after opening the skull. In this study, we use pre-operative and intra-operative magnetic resonance images (MRI) of five patients undergoing brain tumor surgery. Anatomical landmarks are identified by an expert radiologist on MRI and used for the method development and comparison studies. We use tetrahedral finite element meshes and optimize model parameters by minimizing the mean distance between the predicted locations of the anatomical landmarks using the pre-operative images and their actual locations on the intra-operative images. Evaluation of the objective function using a second set of landmarks not used in the optimization process suggests that accuracy of the solid mechanic model is higher than that of the elastic model for our application. Visual inspection of the results confirms this conclusion. The proposed method along with the location information of the surface landmarks measured in the operating room and marked on the pre-operative images can be used to estimate the brain deformations without needing intra-operative images. In this case, since the parameters of the brain tissue are not the same for different patients, the proposed optimization process is crucial for obtaining accurate results.

The goal of this study was to accomplish the cross-cultural adaptation of a quality of life instrument, specific for neurosurgical patients, called Innsbruck Health Dimensions Questionnaire for Neurosurgical Patients (IHD-NS). Thirty patients participated in this study, male and female, all having been submitted to brain tumor surgery more than twelve months before, and whose ages ranged from 26 to 66. After the process of translation/back translation and the elaboration of the Brazilian version of the instrument, the patients were assessed and reassessed within a one-month period. Statistical analyses evinced the preservation of the internal consistency, high agreement levels and highly significant intra-class correlation, allowing for the belief in the quality and reliability of the Portuguese version, named Questionário de Dimensões de Saúde para Pacientes Neurocirúrgicos de Innsbruck - DSI (NC).

3D medical images are important components of modern medicine. Their usefulness for the physician depends on their quality, though. Only high-quality images allow accurate and reproducible diagnosis and appropriate support during treatment. We have analyzed 202 MRI images for brain tumor surgery in a retrospective study. Both an experienced neurosurgeon and an experienced neuroradiologist rated each available image with respect to its role in the clinical workflow, its suitability for this specific role, various image quality characteristics, and imaging artifacts. Our results show that MRI data acquired for brain tumor surgery does not always fulfill the required quality standards and that there is a significant disagreement between the surgeon and the radiologist, with the surgeon being more critical. Noise, resolution, as well as the coverage of anatomical structures were the most important criteria for the surgeon, while the radiologist was mainly disturbed by motion artifacts.

Intraoperative ultrasound has been used for brain tumor surgery since more than 30 years now. In glioma surgery, taking into account the latest advances in ultrasound technology and its integration in a neuronavigation system intraoperative ultrasound is absolutely competitive with more recent imaging or visualization tools like 5-aminolevulinic acid fluorescence and intraoperative MRI. Intraoperative ultrasound allows for precise tumor depiction and intraoperative orientation in various indications. The actual chapter provides information about typical indications for intraoperative ultrasound in brain tumor surgery. It provides a guide for typical transducers and describes the depiction of intracranial lesions in B-mode ultrasound. During the course of resection, intraoperative ultrasound is prone to artifacts. Thus, a description of the most typical artifacts in intracranial surgery and a practical guide how optimize image quality and to avoid artifacts is given in this chapter.

It is now taken for granted that for certain cranial neurosurgical procedures, such as brain tumor surgery or cerebral abscesses, the use of navigation is the norm. Furthermore, should a complication arise during surgery where navigation was not used, and navigation may have helped to avoid such a complication, one would find this difficult to defend. Yet this was not the situation up until recently, and even in the last 10 years, a process has been underway to convince the remaining few skeptics that the extra time required during initial setup/registration, and the limitations with respect to accuracy that accompany all of the current navigation systems on the market are more than compensated by the advantages cranial navigation offers once surgery is underway.

Contains fulltext : 171797.pdf (Publisher’s version ) (Open Access) In brain tumor surgery, recognition of tumor boundaries is key. However, intraoperative assessment of tumor boundaries by the neurosurgeon is difficult. Therefore, there is an urgent need for tools that provide the neurosurgeon with pathological information during the operation. We show that third harmonic generation (THG) microscopy provides label-free, real-time images of histopathological quality; increased cellularity, nuclear pleomorphism, and rarefaction of neuropil in fresh, unstained human brain tissue could be clearly recognized. We further demonstrate THG images taken with a GRIN objective, as a step toward in situ THG microendoscopy of tumor boundaries. THG imaging is thus a promising tool for optical biopsies.

Image guidance and visualization play an important role in modern surgery to help surgeons perform their surgical procedures. Here, the focus is on neurosurgery applications, in particular brain tumor surgery where a craniotomy (opening of the skull) is performed to access directly the brain region to be treated. In this type of surgery, once the skull is opened the brain can change its shape, and this deformation is known as brain shift. Moreover, the boundaries of many types of tumors are difficult to identify by the naked eye from healthy tissue. The main goal of this work was to study and develop image guidance and visualization methods for tumor surgery in order to overcome the problems faced in this type of surgery. Due to brain shift the magnetic resonance dataset acquired before the operation (preoperatively) no longer corresponds to the anatomy of the patient during the operation (intraoperatively). For this reason, in this work methods were studied and developed to compensate for this deformation. To guide the deformation methods, information of the superficial vessel centerlines of the brain was used. A method for accurate (approximately 1 mm) reconstruction of the vessel centerlines using a multiview camera system was developed. It uses geometrical constraints, relaxation labeling, thin plate spline filtering and finally mean shift to find the correct correspondences between the camera images. A complete non-rigid deformation pipeline was initially proposed and evaluated with an animal model. From these experiments it was observed that although the traditional non-rigid registration methods (in our case coherent point drift) were able to produce satisfactory vessel correspondences between preoperative and intraoperative vessels, in some specific areas the results were suboptimal. For this reason a new method was proposed that combined the coherent point drift and thin plate spline semilandmarks. This combination resulted in an accurate (below 1 mm) non-rigid registration method, evaluated with simulated data where artificial deformations were performed. Besides the non-rigid registration methods, a new rigid registration method to obtain the rigid transformation between the magnetic resonance dataset and the neuronavigation coordinate systems was also developed. Once the rigid transformation and the vessel correspondences are known, the thin plate spline can be used to perform the brain shift deformation. To do so, we have used two approaches: a direct and an indirect. With the direct approach, an image is created that represents the deformed data, and with the indirect approach, a new volume is first constructed and only after that can the deformed image be created. A comparison of these two approaches, implemented for the graphics processing units, in terms of performance and image quality, was performed. The indirect method was superior in terms of performance if the sampling along the ray is high, in comparison to the voxel grid, while the direct was superior otherwise. The image quality analysis seemed to indicate that the direct method is superior. Furthermore, visualization studies were performed to understand how different rendering methods and parameters influence the perception of the spatial position of enclosed objects (typical situation of a tumor enclosed in the brain). To test these methods a new single-monitor-mirror stereoscopic display was constructed. Using this display, stereo images simulating a tumor inside the brain were presented to the users with two rendering methods (illustrative rendering and simple alpha blending) and different levels of opacity. For the simple alpha blending method an optimal opacity level was found, while for the illustrative rendering method all the opacity levels used seemed to perform similarly. In conclusion, this work developed and evaluated 3D reconstruction, registration (rigid and non-rigid) and deformation methods with the purpose of minimizing the brain shift problem. Stereoscopic perception of the spatial position of enclosed objects was also studied using different rendering methods and parameter values.

International audience; OBJECTIVE:Awake craniotomy (AC) in brain lesions has allowed an improvement of both oncologic and functional results. However, intraoperative seizures (IOSs) were reported as a cause of failure of AC. Here, we analyze the incidence, risk factors, and consequences of IOSs in a prospective cohort of 374 ACs without electrocorticography (ECoG).METHODS:We performed a prospective study including all patients who underwent AC for an intra-axial supratentorial cerebral lesion from 2009-2014 in our department. Occurrence of IOS was analyzed with respect to medical and epilepsy history, tumor characteristics, operative technique, and postoperative outcomes.RESULTS:The study comprised 374 patients with a major incidence of low-grade glioma (86%). Most of the patients (83%) had epilepsy history before surgery (20% had intractable seizures). Preoperative mean Karnofsky performance scale (KPS) score was 91. IOSs occurred in 13 patients (3.4%). All IOSs were partial seizures, which quickly resolved by irrigation with cold Ringer lactate. No procedure failed because of IOS, and the rate of aborted AC whatever the cause was nil. Mean stimulation current intensity for cortical and subcortical mapping was 2.25 ± 0.6 mA. Presurgical refractory epilepsy was not associated with a higher incidence of IOS. Three months after surgery, no patients had severe or disabling permanent worsening, even within the IOS group (mean KPS score of 93.7).CONCLUSIONS:AC for intra-axial brain lesion can be safely and reproducibly achieved without ECoG, with a low rate of IOS and excellent functional results, even in patients with preoperative intractable epilepsy.

Some tumor-specific near-infrared (NIR) fluorescent dyes such as indocyanine green (ICG), IDRye800CW, and 5-aminolevulinic acid have been used clinically for detecting tumor margins or micro-cancer lesions. In this study, we evaluated the physicochemical properties of liposomally formulated phospholipid-conjugated ICG, denoted by LP-iDOPE, as a clinically translatable NIR imaging nanoparticle for brain tumors. We also confirmed its brain-tumor-specific biodistribution and its characteristics as the intra-operative NIR imaging nanoparticles for brain tumor surgery. These properties of LP-iDOPE may enable neurosurgeons to achieve more accurate identification and more complete resection of brain tumor.

OBJECT The Agency for Healthcare Research and Quality patient safety indicators (PSIs) and the Centers for Medicare and Medicaid Services hospital-acquired conditions (HACs) are administrative data-based metrics. The use of these outcomes as standard performance measures has been discussed in previous studies. With the objective of determining the applicability of these events as performance metrics among patients undergoing brain tumor surgery, this study had 2 aims: 1) to evaluate the association between PSIs, HACs, and in-hospital mortality rates; and 2) to determine a correlation between hospital volume, PSIs, and HACs. METHODS Patients with brain tumors treated between 1998 and 2009 were captured in the Nationwide Inpatient Sample database. Hospitals were categorized into groups according to surgical volume. Associations between PSIs, HACs, and in-hospital mortality rates were studied. Factors associated with a PSI, HAC, and mortality were evaluated in a multivariate setting. RESULTS A total of 444,751 patients with brain tumors underwent surgery in 1311 hospitals nationwide. Of these, 7.4% of patients experienced a PSI, 0.4% an HAC, and 1.9% died during their hospitalization. The occurrence of a PSI was strongly associated with mortality. Patients were 7.6 times more likely to die (adjusted odds ratio [aOR] 7.6, CI 6.7–8.7) with the occurrence of a PSI in a multivariate analysis. Moderate to strong associations were found between HACs, PSIs, and hospital volume. Patients treated at the highest-volume hospitals compared with the lowest-volume ones had reduced odds of a PSI (aOR 0.9, CI 0.8–1.0) and HAC (aOR 0.5, CI 0.5–0.08). CONCLUSIONS Patient safety-related adverse events were strongly associated with in-hospital mortality. Moderate to strong correlations were found between PSIs, HACs, and hospital procedural volume. Patients treated at the highest-volume hospitals had consistently lower rates of mortality, PSIs, and HACs compared with those treated at the lowest-volume facilities.

Brain tumor surgery is one of the key factors in prolonging survival in patients with low- and high-grade gliomas. However, resections of these infiltrative lesions have historically been limited by the inability to accurately detect tumor margins. New methods in microscopy and dye injection have enabled more complete resections, but continue to lack biochemical specificity or high-resolution image acquisition. Stimulated Raman scattering microscopy represents an improvement over past techniques in the ability to differentiate intraparenchymal tissues on the basis of biochemical attributes, and is available for use in real-time, a feature that facilitates its translation to the surgical setting.

Hemostatic options available to the surgeon in the late 19th and early 20th centuries were limited. The surgical ligature was limited in value to the neurological surgeon because of the unique structural composition of brain tissue as well as the approaches and operating angles used in this type of surgery. In this manuscript the authors review the options available and the evolution of surgical hemostatic techniques and electrosurgery in the late 19th and early 20th centuries and the impact of these methods on the surgical management of tumors of the brain and its coverings.

We evaluated the reliability and usefulness of preoperative brain functional mapping and intraoperative brain monitoring in surgery of the brain tumor located around the sensorimotor region. Combinations with the preoperative identification of central sulcus by magnetoencephalography and the intraoperative motor-evoked potential monitoring assisted in designing the surgical strategy and provided important information during the surgery to minimize postoperative neurological deficit. Especially, decreases of MEPs in amplitude reliably predict impaired motor function during operation.

O mapeamento com estimulação direta do córtex cerebral foi utilizado quando o tumor estava próximo ou infiltrava o lobo central. OBJETIVO: Avaliar interferências na técnica de estimulação eletrica direta do córtex e substância branca, sob anestesia geral, durante cirurgia para tumor cerebral relacionado ao lobo central. MÉTODO: Foram estudados 42 pacientes operados de junho de 2000 a junho de 2003. Os fatores que modificaram a intensidade da estimulação necessaria para localizar a área motora durante a cirurgia foram estudados. RESULTADOS: A intensidade necessária do estimulo foi maior entre os pacientes com déficit motor antes da cirurgia (p=0,425), edema na ressonância magnetica (p=0,468) e anestesia com proporfol contínuo (p=0,001). CONCLUSÃO: O mapeamento funcional do lobo central durante a cirurgia foi prejudicado pelo deficit motor acentuado, edema cerebral e anestesia com propofol contínuo. Brain mapping with direct electrical stimulation is usefull when the tumor is located near or has infiltrated the central lobe. OBJETIVE: To analize the surgical findings with direct electrical stimulation of the cortex and white matter under general anesthesia during surgery for brain tumors related to the central lobe. METHOD: We studied 42 patients operated on from June 2000 to June 2003. We analyzed surgical findings and details of brain mapping. RESULTS: The mean value of the intensity of the stimulus was greater among those who presented motor deficit prior to surgery (p = 0.0425) and edema on MRI (p= 0.0468) or during anesthesia with continuous propofol (p=0.001). CONCLUSION: The functional mapping of the central lobe may be influenced by severe motor deficit, edema on MRI and propofol's anesthesia.

It is just over a century since successful brain tumor resection. Since then the diagnosis, imaging, and management of brain tumors have improved, in large part due to technological advances. Similarly, the operating room (OR) for brain tumor surgery has increased in complexity and specificity with multiple forms of equipment now considered necessary as technical adjuncts. It is evident that the theme of minimalism in combination with advanced image-guidance techniques and a cohort of sophisticated technologies (e.g., robotics and nanotechnology) will drive changes in the current OR environment for the foreseeable future. In this report we describe what may be regarded today as standard essentials in an operating room for the surgical management of brain tumors and what we believe to be the current 'state-of-the-art' brain tumor OR. Also, we speculate on the additional capabilities of the brain tumor OR of the near future.

We present a new method for visualizing 3D volumetric diffusion tensor MR images. We distinguish between linear anisotropy and planar anisotropy and represent values in the two regimes using streamtubes and streamsurfaces, respectively. Streamtubes represent structures with primarily linear diffusion, typically fiber tracts; streamtube direction correlates with tract orientation. The cross-sectional shape and color of each streamtube represent additional information from the diffusion tensor at each point. Streamsurfaces represent structures in which diffusion is primarily planar. Our algorithm chooses a very small representative subset of the streamtubes and streamsurfaces for display. We describe the set of metrics used for the culling process, which reduces visual clutter and improves interactivity. We also generate anatomical landmarks to identify the locations of such structures as the eyes, skull surface, and ventricles. The final models are complex surface geometries that can be imported into many interactive graphics software environments. We describe a virtual environment to interact with these models. Expert feedback from doctors studying changes in white-matter structures after gamma-knife capsulotomy and preoperative planning for brain tumor surgery shows that streamtubes correlate well with major neural structures, the 2D section and geometric landmarks are important in understanding the visualization, and the stereo and interactivity from the virtual environment aid in understanding the complex geometric models.