Resection Of Malignant Brain Tumors Research Articles

Tumor-Specific Alterations in Motor Cortex Excitability and Tractography of the Corticospinal Tract-A Navigated Transcranial Magnetic Stimulation Study.

Non-invasive brain mapping using navigated transcranial magnetic stimulation (nTMS) is a valuable tool prior to resection of malignant brain tumors. With nTMS motor mapping, it is additionally possible to analyze the function of the motor system and to evaluate tumor-induced neuroplasticity. Distinct changes in motor cortex excitability induced by certain malignant brain tumors are a focal point of research. A retrospective single-center study was conducted involving patients with malignant brain tumors. Clinical data, resting motor threshold (rMT), and nTMS-based tractography were evaluated. The interhemispheric rMT-ratio (rMTTumor/rMTControl) was calculated for each extremity and considered pathological if it was >110% or <90%. Distances between the corticospinal tract and the tumor (lesion-to-tract-distance - LTD) were measured. 49 patients were evaluated. 16 patients (32.7%) had a preoperative motor deficit. The cohort comprised 22 glioblastomas (44.9%), 5 gliomas of Classification of Tumors of the Central Nervous System (CNS WHO) grade 3 (10.2%), 6 gliomas of CNS WHO grade 2 (12.2%) and 16 cerebral metastases (32.7%). 26 (53.1%) had a pathological rMT-ratio for the upper extremity and 35 (71.4%) for the lower extremity. All patients with tumor-induced motor deficits had pathological interhemispheric rMT-ratios, and presence of tumor-induced motor deficits was associated with infiltration of the tumor to the nTMS-positive cortex (p = 0.04) and shorter LTDs (all p < 0.021). Pathological interhemispheric rMT-ratio for the upper extremity was associated with cerebral metastases, but not with gliomas (p = 0.002). Our study underlines the diagnostic potential of nTMS motor mapping to go beyond surgical risk stratification. Pathological alterations in motor cortex excitability can be measured with nTMS mapping. Pathological cortical excitability was more frequent in cerebral metastases than in gliomas.

295 High Volume Centers Provide Superior Value of Care in the Surgical Treatment of Malignant Brain Tumor

INTRODUCTION: Improved outcomes in surgical patients have been associated with increasing volume of cases. This has led to the development of centers that facilitate care for a specific patient population. METHODS: The 2016-2020 National Inpatient Sample (NIS) was queried for patients undergoing resection of malignant brain tumors. Teaching hospitals with high case load (greater than two standrad deviations above the mean, or &gt;140 cases) were categorized as high-volume centers (HVC). Value of care was computed by adding one point for each of the following variables: lower length of stay, lower total charges, discharge to home, and lack of major comorbidity or complication, as defined per DRG codes. RESULTS: A total of 118,390 patients underwent resection of malignant brain tumors in 3,009 hospitals. HVC criteria was met by 91 (3%) hospitals, which represented 20,230 (17.1%) of total cases. The Mid-Atlantic and South Atlantic regions had the highest percentage of cases (22.7% and 20.2%, respectively) and number of HVC (21 and 17, respectively). Value of care was higher at HVC (OR = 1.35 95%CI 1.31-1.39 p &lt; 0.01). After controlling for baseline risk factors and high risk admissions, HVC was associated with decreased complications of intracranial hemorrhage, deep venous thrombosis, aspiration pneumonitis, acute kidney injury, and external ventricular drain requirement (p &lt; 0.01 for all). HVC was also associated with decreased length of stay and increased rate of discharge to home (p &lt; 0.01 for both). CONCLUSIONS: Patients undergoing craniotomy for malignant brain neoplasms have superior outcomes in HVC. Trends of centralization are likely a reflection of the benefits of multidisciplinary treatment for these patients. Improvement of access to care at these institutions may improve the efficiency of the delivery of care for these patients.

High-Volume Centers Provide Superior Value of Care in the Surgical Treatment of Malignant Brain Tumor

Improved outcomes in surgical patients have been associated with increasing volume of cases. This has led to the development of centers that facilitate care for a specific patient population. To evaluate associations of outcomes with hospital characteristics in patients undergoing resection of malignant brain tumors. The 2016-2020 National Inpatient Sample (NIS) was queried for patients undergoing resection of malignant brain tumors. Teaching hospitals with case loads greater than two standard deviations above the mean (140 cases) were categorized as high-volume centers (HVC). Value of care (VoC) was evaluated by adding one point for each of the following: short length of stay, low total charges, favorable discharge disposition, and lack of major comorbidity or complication. A total of 118,390 patients underwent resection of malignant brain tumors in 3009 hospitals. HVC criteria was met by 91 (3%) hospitals. HVC were more likely to treat patients of younger age or higher socioeconomic status (p < 0.01 for all). The Mid-Atlantic and South Atlantic regions had the highest percentage of cases and number of HVC. VoC was higher at HVC (p < 0.01). HVC was associated with decreased complications (p < 0.01 for all) and improved patient outcomes (p < 0.01 for all). Patients undergoing craniotomy for malignant brain neoplasms have superior outcomes in HVC. Trends of centralization may be a reflection of the benefits of multidisciplinary treatment, geographic preferences, publicity, and cultural impact. Improvement of access to care is an important consideration as this trend continues.

Risk factors for postoperative thrombosis-related complications in patients undergoing malignant brain tumor resection: a retrospective cohort study.

Patients with malignant brain tumors frequently exhibit hypercoagulation and are at a high risk of postoperative thrombosis-related complications. However, the risk factors for postoperative thrombosis-related complications remain unclear. In this retrospective, observational study, we consecutively enrolled elective patients undergoing resection of malignant brain tumors from 26 November 2018 to 30 September 2021. The primary objective of the study was to identify risk factors for a composite of three major adverse events including postoperative lower limb deep venous thrombosis, pulmonary embolism, and cerebral ischemia. A total of 456 patients were enrolled in this study, where 112 (24.6%) patients had postoperative thrombosis-related complications, 84 (18.4%) with lower limb deep venous thrombosis, 0 (0.0%) with pulmonary embolism, and 42 (9.2%) with cerebral ischemia. In a multivariate model, age more than 60 years (OR: 3.98, 95% CI: 2.30-6.88, P < 0.001), preoperative abnormal APTT (OR: 2.81, 95% CI: 1.06-7.42, P = 0.037), operation duration longer than 5 h (OR: 2.36, 95% CI: 1.34-4.16, P = 0.003), and admission to ICU (OR: 2.49, 95% CI: 1.21-5.12, P = 0.013) were independent risk factors of the postoperative deep vein thrombosis. Intraoperative plasma transfusion (OR: 6.85, 95% CI: 2.73-17.18, P < 0.001) was associated with significantly increased odds of deep vein thrombosis. Patients with craniocerebral malignant tumors have a high incidence of postoperative thrombosis-related complications. There is an increase in the odds of postoperative lower limb deep venous thrombosis in patients; over 60 years old, with preoperative abnormal APTT, undergoing surgeries longer than 5-h, admission to ICU, or receiving intraoperative plasma infusion. Fresh frozen plasma infusion should be used more cautiously, especially in patients with a high risk of thrombosis.

Fluorescence-Guided Surgery: A Review on Timing and Use in Brain Tumor Surgery.

Fluorescence-guided surgery (FGS) allows surgeons to have improved visualization of tumor tissue in the operating room, enabling maximal safe resection of malignant brain tumors. Over the past two decades, multiple fluorescent agents have been studied for FGS, including 5-aminolevulinic acid (5-ALA), fluorescein sodium, and indocyanine green (ICG). Both non-targeted and targeted fluorescent agents are currently being used in clinical practice, as well as under investigation, for glioma visualization and resection. While the efficacy of intraoperative fluorescence in studied fluorophores has been well established in the literature, the effect of timing on fluorophore administration in glioma surgery has not been as well depicted. In the past year, recent studies of 5-ALA use have shown that intraoperative fluorescence may persist beyond the previously studied window used in prior multicenter trials. Additionally, the use of fluorophores for different brain tumor types is discussed in detail, including a discussion of choosing the right fluorophore based on tumor etiology. In the following review, the authors will describe the temporal nature of the various fluorophores used in glioma surgery, what remains uncertain in FGS, and provide a guide for using fluorescence as a surgical adjunct in brain tumor surgery.

Fluorescein Sodium-Guided Neuroendoscopic Resection of Deep-Seated Malignant Brain Tumors: Preliminary Results of 18 Patients.

Deep-seated intracranial lesions are challenging to resect completely and safely. Fluorescence-guided surgery (FGS) promotes the resection of malignant brain tumors (MBTs). Classically, FGS is performed using microscope equipped with a special filter. Fluorescence-guided neuroendoscopic resection of deep-seated brain tumors has not been reported yet. To evaluate the feasibility, safety, and effectiveness of the fluorescence-guided neuroendoscopic surgery in deep-seated MBTs. A total of 18 patients with high-grade glioma (HGG) and metastatic tumor (MT) underwent fluorescein sodium (FS)-guided neuroendoscopic surgery. Tumor removal was carried out using bimanual microsurgical techniques under endoscopic view. The degree of fluorescence staining was classified as "helpful" and "unhelpful" based on surgical observation. Extent of resection was determined using magnetic resonance imaging (MRI). Karnofsky Performance Status (KPS) score was used for evaluation of general physical performances of patients. A total of 11 patients had HGG, and 7 had MT. No technical difficulty was encountered regarding the use of endoscopic technique. "Helpful" fluorescence staining was observed in 16 patients and fluorescent tissue was completely removed. Postoperative MRI confirmed gross total resection (88.9%). In 2 patients, FS enhancement was not helpful enough for tumor demarcation and postoperative MRI revealed near total resection (11.1%). No complication, adverse events, or side effects were encountered regarding the use of FS. KPS score of patients was improved at 3-mo follow-up. FS-guided endoscopic resection is a feasible technique for deep-seated MBTs. It is safe, effective, and allows for a high rate of resection. Future prospective randomized studies are needed to confirm these preliminary data.

Risk Factors for Hyponatremia and Perioperative Complications With Malignant Intracranial Tumor Resection in Adults: An Analysis of the Nationwide Inpatient Sample from 2012 to 2015

The present study aims to study the incidence and risk factors for developing hyponatremia and associated perioperative outcomes in adult patients admitted for malignant brain tumor resection. The 2012-2015 Nationwide Inpatient Sample was queried for all patients undergoing surgical resection of malignant brain tumors. These patients were then grouped by the presence of concurrent diagnosis of hyponatremia, and compared with respect to various clinical features, perioperative and postoperative complications, all-cause mortality, discharge disposition, length of stay, and hospitalization costs. Propensity score matching was utilized to control for appropriate baseline confounders and the influence of other endpoint variables. The search criteria identified 12,480 adult patients admitted for malignant brain tumor resection, of whom 1162 (9.3%) developed hyponatremia in the perioperative period. Patients with obstructive hydrocephalus (risk ratio [RR]= 1.23, P < 0.001), diabetes (RR= 1.14, P=0.014), hypertension (RR= 1.15, P < 0.001), and depression (RR= 1.24, P < 0.002) were more likely to develop hyponatremia. Tumor location was not associated with risk of developing hyponatremia. Patients with hyponatremia were more likely to require ventriculostomy (RR= 1.23, P < 0.001), ventriculoperitoneal shunt (RR=1.34, P < 0.001), and lumbar puncture (RR= 1.25, P <0.001), and were also more likely to be discharged to short-term hospital (RR= 1.25, P < 0.001) or rehabilitation (RR= 1.21, P < 0.001), as well as have longer hospital stay (P < 0.001) and increased hospital charges (P < 0.001). Patients with obstructive hydrocephalus, diabetes, hypertension, and depression were more likely to develop perioperative hyponatremia. Hyponatremia was associated with increased morbidity following malignant brain tumor resection.

Intraoperative Photodiagnosis for Malignant Glioma Using Photosensitizer Talaporfin Sodium.

Objective: The aim of this study was to demonstrate the clinical feasibility of intraoperative photodiagnosis (PD) of malignant brain tumor using talaporfin sodium (TPS), which is an agent used in photodynamic therapy (PDT) for cancers.Methods: Forty-seven patients diagnosed with malignant gliomas by preoperative imaging (42 patients with gliomas and 5 patients with other brain tumors) received an intravenous injection of TPS at 40 mg/m2 24 h before resection. During surgery, these patients were irradiated with diode laser light at 664 nm, and tumor fluorescence was observed. The fluorescence intensity was visually rated on a 3-point rating scale [strong fluorescence, weak fluorescence and no fluorescence]. TPS concentrations in 124 samples from 47 cases were measured by HPLC (High performance liquid chromatography).Results: The fluorescence intensity was confirmed to be weak in all patients with Grade II gliomas and strong in almost all patients with Grade III or IV gliomas, reflecting the histological grade of malignancy. In patients with non-glioma brain tumors except for 1 patient with a metastatic brain tumor, the fluorescence intensity was strong. The mean TPS concentration in tissues was 1.62 μg/g for strong fluorescence areas, 0.67 μg/g for weak fluorescence areas and 0.19 μg/g for no fluorescence areas.Conclusions: Establishment of an appropriate fluorescence observation system enabled fluorescence-guided resection of malignant brain tumors using TPS, and the fluorescence intensity of tumors correlated with the TPS concentrations in tissues. These results suggest that TPS is a useful photosensitizer for both intraoperative fluorescence diagnosis and photodynamic therapy.

Fluorescein-Guided Surgery for Pediatric Brainstem Gliomas: Preliminary Study and Technical Notes

Introduction Brainstem gliomas (BsG) account for 10 to 15% of pediatric brain tumors. Surgery is the preferred treatment for focal and exophytic lesions. Sodium fluorescein has been proven safe and effective in resection of malignant brain tumors. Objective The objective was to o analyze the safety and effectiveness of this approach, to evaluate intraoperative fluorescein imaging, and to measure the safety of chosen dose for pediatric patients. Methods Twelve cases were enrolled between March 2014 and September 2016 in Beijing Tiantan Hospital. All of the patients received 2.5 mg/kg of sodium fluorescein before opening the dura; the intraoperative fluorescence enhancement was observed, and the degree of satisfaction and consistency with the neuronavigation were evaluated. Results With a mean age of 7.5 years, there were eight cases located within the pontine, three in the medullary oblongata, and one in the tectal plate. Histological results were astrocytoma, glioblastoma, oligodendroglioma, and pilocytic astrocytoma. Under the fluorescein module of the microscope, the tumors were recognizable enough to help surgeons to discriminate the lesion from non-fluorescent tissue, with a consistency of 83% with the neuronavigation. Total removal was accomplished in nine cases, while the mean percentage of resection of the other cases was 93.7%. The Karnofsky performance score (KPS) showed no significant differences between pre-operation and discharge, but there was a difference between pre-operation and 6-month follow-up. Conclusion The fluorescein-guided surgery is useful for demarcating the tumor margin and works well with other navigation and monitoring devices. A safe dose of sodium fluorescein (2.5 mg/kg) was proven effective for children.

Preoperative steroid use and the incidence of perioperative complications in patients undergoing craniotomy for definitive resection of a malignant brain tumor

We studied the impact of preoperative steroids on 30day morbidity and mortality of craniotomy for definitive resection of malignant brain tumors. Glucocorticoids are used to treat peritumoral edema in patients with malignant brain tumors, however, prolonged (⩾10days) use of preoperative steroids as a risk factor for perioperative complications following resection of brain tumors has not been studied comprehensively. Therefore, we identified 4407 patients who underwent craniotomy to resect a malignant brain tumor between 2007 and 2012, who were reported in the National Surgical Quality Improvement Program, a prospectively collected clinical database. Metastatic brain tumors constituted 37.5% (n=1611) and primary malignant gliomas 62.5% (n=2796) of the study population. We used logistic regression to assess the association between preoperative steroid use and perioperative complications before and after 1:1 propensity score matching. Patients who received steroids constituted 22.8% of the population (n=1009). In the unmatched cohort, steroid use was associated with decreased length of hospitalization (odds ratio [OR] 0.7; 95% confidence interval [CI] 0.6–0.8), however, the risk for readmission (OR 1.5; 95% CI 1.2–1.8) was increased. In the propensity score matched cohort (n=465), steroid use was not statistically associated with any adverse outcomes. Patients who received steroids were less likely to stay hospitalized for a protracted period of time, but were more likely to be readmitted after discharge following craniotomy. As an independent risk factor, preoperative steroid use was not associated with any observed perioperative complications. The findings of this study suggest that preoperative steroids do not independently compromise the short term outcome of craniotomy for resection of malignant brain tumors.

Confocal Laser Endomicroscopy for Diagnosis and Histomorphologic Imaging of Brain Tumors In Vivo

Early detection and evaluation of brain tumors during surgery is crucial for accurate resection. Currently cryosections during surgery are regularly performed. Confocal laser endomicroscopy (CLE) is a novel technique permitting in vivo histologic imaging with miniaturized endoscopic probes at excellent resolution. Aim of the current study was to evaluate CLE for in vivo diagnosis in different types and models of intracranial neoplasia. In vivo histomorphology of healthy brains and two different C6 glioma cell line allografts was evaluated in rats. One cell line expressed EYFP, the other cell line was used for staining with fluorescent dyes (fluorescein, acriflavine, FITC-dextran and Indocyanine green). To evaluate future application in patients, fresh surgical resection specimen of human intracranial tumors (n = 15) were examined (glioblastoma multiforme, meningioma, craniopharyngioma, acoustic neurinoma, brain metastasis, medulloblastoma, epidermoid tumor). Healthy brain tissue adjacent to the samples served as control. CLE yielded high-quality histomorphology of normal brain tissue and tumors. Different fluorescent agents revealed distinct aspects of tissue and cell structure (nuclear pattern, axonal pathways, hemorrhages). CLE discrimination of neoplastic from healthy brain tissue was easy to perform based on tissue and cellular architecture and resemblance with histopathology was excellent. Confocal laser endomicroscopy allows immediate in vivo imaging of normal and neoplastic brain tissue at high resolution. The technology might be transferred to scientific and clinical application in neurosurgery and neuropathology. It may become helpful to screen for tumor free margins and to improve the surgical resection of malignant brain tumors, and opens the door to in vivo molecular imaging of tumors and other neurologic disorders.

Enhanced expression of coproporphyrinogen oxidase in malignant brain tumors: CPOX expression and 5-ALA-induced fluorescence

In photodynamic diagnosis, 5-aminolevulinic acid (5-ALA) is widely used for the fluorescence-guided resection of malignant brain tumors, where 5-ALA is converted to protoporphyrin IX, which exhibits strong fluorescence. Little is known, however, about the detailed molecular mechanisms underlying 5-ALA-induced fluorescence. To resolve this issue, we analyzed transcriptome profiles for the genes encoding enzymes, transporters, and a transcription factor involved in the porphyrin-biosynthesis pathway. By quantitative real-time (qRT)-PCR, we measured the mRNA levels of those genes in a total of 20 tumor samples that had been surgically resected from brain tumor patients at the Department of Neurosurgery of Osaka Medical College from 2008 to 2009. We selected 10 tumor samples with no 5-ALA-induced fluorescence, among which 2 were glioblastomas and 8 were metastatic brain tumors. Another 10 tumor samples were selected with strong fluorescence, among which 7 were glioblastomas and 3 were metastatic brain tumors. The qRT-PCR analysis study of these latter 10 samples revealed predominantly high levels of the mRNA of the coproporphyrinogen oxidase (CPOX) gene. The high mRNA level of CPOX expression was significantly well correlated with the phenotype of strong 5-ALA-induced fluorescence (P = .0003). These findings were further confirmed by immunohistochemical studies with a CPOX-specific antibody. It is concluded that induction of CPOX gene expression is one of the key molecular mechanisms underlying the 5-ALA-induced fluorescence of malignant brain tumors. The induction mechanism for the CPOX gene in brain tumors remains to be elucidated.

Fluorescence spectroscopy measurements in ultrasonic navigated resection of malignant brain tumors

Glioblastoma multiforme is a highly malignant primary brain tumor. It has no border but at best a marginal zone, however, invisible to the surgeon. An optical touch pointer (OTP) enabling differentiation of healthy and tumor tissue by means of fiber-optic fluorescence spectroscopy has been developed. In combination with an ultrasonic navigation system, the OTP may be used for demarcation of resectable tumor tissue. The aim of the study was to evaluate the clinical performance of OTP during surgery of malignant brain tumors. Nine patients were operated on with the standard surgical procedure, including white light microscopy and navigation. A total of 5 mg/kg bodyweight of 5-amino-levulin acid was orally administrated before surgery. The OTP was calibrated into the ultrasound-based navigation system and measurements were performed in tumor core and along the tumor border. The ratio between the protoporphyrin IX fluorescence at 635 nm and the autofluorescence was used for quantifications of data. Biopsies (n = 20), ultrasound images (n = 30), and visual inspection (n = 180) were compared to the fluorescence ratio. Healthy and tumor tissue could be identified and differentiated with the OTP (P < 0.001). The fluorescence ratio in average was 0 outside the tumor and low in the gliotic edema zone around the tumor. It increased in the marginal zone and was highest in the solid tumor tissue. In the necrotic tissue, in the center of the tumor, the ratio in average was 0. The OTP can be used in combination with ultrasound-based navigation and may help to determine whether to resect otherwise not identifiable tissue.

Skin shift and its effect on navigation accuracy in image-guided neurosurgery

Neuronavigation systems have been developed for image-guided neurosurgery to aid in the accurate resection of malignant brain tumors. Therefore, the accuracy of the neuronavigation is important. However, many factors can reduce the navigation accuracy during surgery. Before craniotomy, the patient's head is secured to a head frame with head pins; this fixation may cause displacement of fiducial markers and reduce the accuracy. We term this phenomenon skin shift. In this study, the extent of skin shift and its effect on navigation accuracy were determined by use of both preoperative magnetic resonance imaging (MRI) scans acquired before fixation and intraoperative MRI scans acquired after fixation. We measured the displacement of the fiducial markers by using fusion images obtained by integrating preoperative and intraoperative MRI scans. We also evaluated the navigation accuracy of registration based on preoperative and on intraoperative MRI. The mean (± SD) extent of skin shift was 5.34 (± 2.65) mm. The navigation accuracy of registration based on preoperative MRI was 4.06 (± 2.25) mm, and that of registration based on intraoperative MRI was 2.51 (± 1.32) mm. No significant correlation was observed between the extent of skin shift and the distance between the head pins and fiducial markers (p > 0.05). The navigation accuracy of registration based on intraoperative MRI was significantly higher than that of registration based on preoperative MRI (p < 0.001). The results indicated that skin shift was caused by the fixation, and that this shift reduced the navigation accuracy. Intraoperative MRI can correct the effect of skin shift.

Quantification of in vivo fluorescence decoupled from the effects of tissue optical properties using fiber-optic spectroscopy measurements

We present a method for tissue fluorescence quantification in situ using a handheld fiber optic probe that measures both the fluorescence and diffuse reflectance spectra. A simplified method to decouple the fluorescence spectrum from distorting effects of the tissue optical absorption and scattering is developed, with the objective of accurately quantifying the fluorescence in absolute units. The primary motivation is measurement of 5-aminolevulinic acid-induced protoporphyrin IX (ALA-PpIX) concentration in tissue during fluorescence-guided resection of malignant brain tumors. This technique is validated in phantoms and ex vivo mouse tissues, and tested in vivo in a rabbit brain tumor model using ALA-PpIX fluorescence contrast.

Surgical resection of malignant brain tumors with stereotaxic guidance

Los autores reportan un estudio clínico de fase I sobre una técnica quirúrgica para resecar tumores gliales ubicados en o cerca de estructuras motoras cerebrales (área cortical motora o cápsula interna). La resección quirúrgica en estas regiones siempre conlleva un alto riesgo de lesión de la función motora. Para reducir este riesgo se ha preconizado el uso de abordajes guiados por estereotaxia computarizada (“neuronavegación”), ultrasonografía intraoperatoria, resonancia magnética (RM) intraoperatoria o registro cortical intraoperatorio. No obstante, estos artefactos tecnológicos son muy costosos o requieren de una especial experiencia para poder aplicarlas masivamente. En este trabajo se describe una manera más sencilla de resecar tumores gliales de bordes definidos por las neuroimágenes, colocando con guía estereotáxica marcas de algodón (Cotonoides®, de Codman®) embebidas en azul de tripano. Las marcas se colocan: una en el centro volumétrico y/o en el fondo del tumor y otras 3 ó 4 marcas en los bordes contiguos a la(s) estructura(s) motora(s) que se desea preservar. Luego se realiza la craneotomía y corticotomía de la manera convencional. En el abordaje se sigue el hilo de la marca central o del fondo. Una vez llegado al tumor, la resección prosigue de manera usual deteniéndola cada vez que se encuentre alguna marca de los bordes. En aquellos bordes donde no se colocó marca alguna la resección termina según el criterio del cirujano. Esta serie consta de 12 casos de gliomas de diversos grados ubicados cerca del área cortical motora o de la cápsula interna. La función motora y la calidad de vida fueron evaluadas clínicamente utilizando las escalas de fuerza muscular y de Karnofsky, respectivamente. La extensión de la resección se apreció comparando las imágenes por resonancia magnética (RM) pre y posoperatoria. Se logró la resección macroscópica completa del tumor en todos los casos. En 2 de los 12 pacientes la fuerza muscular empeoró de manera transitoria y en 4 pacientes (incluyendo los dos primeros) disminuyó el puntaje en la escala de Karnofsky. Se concluye que se justifica continuar este trabajo con un estudio clínico de fase II pues se pudo obtener la resección completa sin mayor morbilidad.

Factors related to surgical complications and their impact on the functional status in 236 open surgeries for malignant tumors in a Latinoamerican hospital

Background There are not many studies that address the selection of patients harboring malignant brain tumors for open surgery. It is necessary, especially in developing countries, to establish the standards because of their impact not only on the efficacy but also on the cost-effectiveness of surgery. With the concern to add information that may help in future studies about the decision making, we proposed to analyze factors associated with surgical complications and evaluate their influence on the functional status at 30 days after surgery. Methods A consecutive series of 236 surgeries performed between June 1999 and June 2005 were retrospectively analyzed (168 gliomas, 65 metastases, 3 others). Variables evaluated were age, sex, pre- and postoperative KPS, ASA status, anatomic localization, extent of tumor resection, tumor histology, and number of surgeries. Results The incidence of complicated craniotomies was 15.68% and mortality was 2.97%. Postoperatively, 92% of the patients improved or maintained the functional status, whereas 8% worsened. In multivariate analysis, only preoperative KPS ( P = .009), ASA status ( P = .02), and histology type ( P = .03) showed significant association with postoperative complications. Conclusions We found that the neurologic and clinical preoperative condition and grade III gliomas were factors related to postoperative complications, whereas age, extent of resection, and number of surgeries were not risk factors. We believe that these conclusions provide an additional benchmark for future multicentric studies that focus on the selection criteria for resection of malignant brain tumors.

Histological Examination of False Positive Tissue Resection Using 5-Aminolevulinic Acid-Induced Fluorescence Guidance

Intraoperative 5-aminolevulinic acid (5-ALA)-induced fluorescence guidance for resection of malignant brain tumors was correlated with histological examination to investigate false positive findings in 42 patients with malignant glioma and six patients with metastatic brain tumor. Patients received a single 1 g oral dose of 5-ALA 2 hours before surgery. The tumor site was illuminated with a laser with a peak wavelength of 405 +/- 1 nm and output of 40 mW. Samples with strong fluorescence were obtained from the tumor bulk and samples with weak fluorescence from the tumor cavity. Fluorescence was observed in 36 of the 42 malignant gliomas and four of the six metastatic brain tumors. No tumor cells were found in fluorescent samples from six of the 36 malignant gliomas and all four metastatic brain tumors. Five of the six malignant gliomas were recurrent cases. Fluorescence was found in areas of peritumoral edema or inflammatory cell and reactive astrocyte infiltration. Intraoperative 5-ALA-induced fluorescence guidance is useful for the resection of initial malignant glioma since false positive results are rare, but only non-eloquent weak positive areas should be resected. In contrast, all weak positive areas of recurrent malignant gliomas must be resected. Weak positive areas of the peritumoral edema surrounding metastatic brain tumors should be removed carefully as false positive results are common.

Correlation of factors predicting intraoperative brain shift with successful resection of malignant brain tumors using image-guided techniques

Background Intraoperative brain shift may cause inaccuracy of stereotactic image guidance on the basis of preoperatively acquired imaging data. The purpose of our study was to determine whether factors predicting brain shift affect the success of image-guided resection of malignant brain tumors. Methods We retrospectively studied 54 patients who underwent image-guided resections of histopathologically confirmed malignant brain tumors (9 metastases, 45 high-grade gliomas). Precautions were taken during surgery to minimize brain shift, but intraoperative imaging was not performed. The following factors predictive of intraoperative brain shift were assessed: tumor size, periventricular location, patient age, prior surgery or radiation therapy, patient positioning, use of mannitol, and length of operative time. Postoperative magnetic resonance imaging was obtained in all cases within 48 hours of surgery to assess extent of resection. Results Perioperative mortality was 0% in our series; perioperative morbidity was 3 of 54 patients (5.5%); 1 patient required reoperation for a hematoma, and 2 had transient neurological deficits. Successful resection was accomplished in 93% of tumors less than 30 cm 3 compared with 63.6% of tumors greater than 30 cm 3 ( P = .026, Fisher exact test). This difference was more pronounced for patients with malignant gliomas. However, other factors predictive of intraoperative brain shift were not associated with unsuccessful resection. Conclusions Intraoperative brain shift does not significantly affect the likelihood of successful resection of malignant brain tumors smaller than 30 cm 3. Larger tumors are less likely to be successfully resected, although factors other than brain shift can contribute to unsuccessful resection.

Central nervous system (CNS) penetration of homoharringtonine (HHT).

Generally tritiated homoharringtonine ([3H]HHT, 150 microCi, 430 micrograms) was administered intravenously to seven patients at varying times before surgical resection of malignant brain tumor. Plasma, urine, cerebrospinal fluid (CSF), and tumor specimens were obtained during surgery, and the concentrations of HHT, its major metabolite, and [3H]HHT equivalent were determined chromatographically and radiochemically. For [3H]HHT equivalent, the concentration in tumor ranged from 0.6 to 4.3 ng/g and the ratio of tumor to plasma concentration from 0.5 to 1.8. In one patient who had CSF available for drug determination, the CSF to plasma ratio of total [3H]HHT was 0.3 at 45 minutes after drug administration and less than 0.2 ng/ml was unchanged HHT. For unchanged HHT, drug concentration in tumor ranged from undetectable (4 patients) to 1.8 ng/g. A major metabolite of HHT was detectable in the tumor specimens of all the patients. These results indicate that homoharringtonine can penetrate into brain tumors; in 3 patients with brain tumors, the ratios of HHT concentration in the tumor to that in the concurrent plasma were greater than one.