ABSTRACT Glioblastoma multiforme is a highly infiltrative tumor that typically has a central region of necrosis surrounded by contrast-enhancing proliferative tumor cells surrounded by diffuse isolated tumor cells that migrate into the brain. The goal of surgery is often directed toward the central necrotic region and the imaging-defined enhancing margin. To limit morbidity from removing functional brain tissue, the infiltrative tumor cells found in surrounding brain are generally not considered part of the surgical target. This is also the site where tumors recur after treatment. It is well accepted by most surgeons and neuro-oncologists that, when possible, aggressive resection of malignant gliomas is the preferred initial step in management. Although there are limited randomized prospective studies that address extent of resection and survival, the benefit of aggressive surgical resection will not be debated in this report. Tumor resection to the maximum extent that is safely possible can decrease tumor burden and thereby enhance the effects of adjuvant therapies, improve symptoms from mass effect, reduce the frequency of seizures, and provide tissue for pathological and genomic studies to better identify and test novel therapy.Surgery for glioblastoma is highly dependent on imaging. Magnetic resonance imaging can provide an anatomic definition of the lesion and functional capacity of critical cortical regions and allow for precise localization within the brain. The common use of stereotactic guidance, intraoperative imaging, functional magnetic resonance imaging, and physiologic monitoring have enhanced the surgeon's ability to achieve aggressive tumor removal while protecting the patient from neurologic impairment. This review will address the use of these techniques as an important first step in managing patients with glioblastoma.
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ABSTRACT: Although temozolomide (TMZ) replaced nitrosoureas as the standard initial chemotherapy for glioblastoma (GBM), no studies have compared TMZ with nimustine (ACNU), a nitrosourea agent widely used in central Europe and most Asian regions. One hundred thirty-five patients with GBM who underwent extensive tumor resection in our institution received both radiation and chemotherapy as initial treatment, 34 received TMZ and 101 ACNU-based (ACNU plus teniposide or cisplatin) chemotherapy. Efficacy analysis included overall survival (OS) and progression-free survival (PFS). The following prognostic factors were taken into account: age, performance status, extent of resection, and O(6)-methylguanine-DNA-methyltransferase (MGMT) gene status. The median OS was superior in the TMZ versus the ACNU group (p = 0.011), although MGMT gene silencing, which is associated with a striking survival benefit from alkylating agents, was more frequent in the ACNU group. In multivariate Cox analysis adjusting for the common prognostic factors, TMZ chemotherapy independently predicted a favorable outcome (p = 0.002 for OS, hazard ratio [HR], 0.45; p = 0.011 for PFS, HR, 0.56). Given that >40 % of patients in ACNU group did not receive the intensive chemotherapy cycles because of severe hematological and nonhematological toxicity, we performed a further subanalysis for patients who received at least 4 cycles of chemotherapy. Although a modest improvement in survival occurred in this ACNU subgroup, the efficacy was still inferior to that in the TMZ cohort. Our data suggest that the survival benefit of TMZ therapy is superior to that of an ACNU-based regimen in patients with extensive tumor resection, also shows greater tolerability.Neurosurgical Review 08/2013; · 1.86 Impact Factor
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ABSTRACT: Objective Intraoperative MRI is considered the gold standard among all intraoperative imaging technologies currently available. Its main indication is in the intraoperative detection of residual disease during tumour resections. We present our initial experience with the first intraoperative low-field MRI in a Spanish hospital of the public healthcare system. We evaluate its usefulness and accuracy to detect residual tumours and compare its intraoperative results with images obtained postoperatively using conventional high-field devices.Material and methodsWe retrospectively reviewed the first 21 patients operated on the aid of this technology. Maximal safe resection was the surgical goal in all cases. Surgeries were performed using conventional instrumentation and the required assistance in each case.ResultsThe mean number of intraoperative studies was 2.3 per procedure (range: 2 to 4). Intraoperative studies proved that the surgical goal had been achieved in 15 patients (71.4%), and detected residual tumour in 6 cases (28.5%). After comparing the last intraoperative image and the postoperative study, 2 cases (9.5%) were considered as “false negatives”.Conclusions Intraoperative MRI is a safe, reliable and useful tool for guided resection of brain tumours. Low-field devices provide images of sufficient quality at a lower cost; therefore their universalisation seems feasible.Neurocirugia (Asturias, Spain) 01/2013; 24(1):11–21. · 0.32 Impact Factor
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ABSTRACT: Despite recent advances in the treatment of solid tumors, there are few effective treatments for malignant gliomas due to the infiltrative nature, and the protective shield of blood-brain barrier or blood-tumor barriers that restrict the passage of chemotherapy drugs into the brain. Imaging techniques, such as PET and MRI, have allowed the assessment of tumor function in vivo, but they are indirect measures of activity and do not easily allow continuous repeated evaluations. Because the biology of glioma on a cellular and molecular level is fairly unknown, especially in relation to various treatments, the development of novel therapeutic approaches to this devastating condition requires a strong need for a deeper understanding of the tumor's pathophysiology and biochemistry. Cerebral microdialysis, a probe-based sampling technique, allows a discrete volume of the brain to be sampled for neurochemical analysis of neurotransmitters, metabolites, biomarkers, and chemotherapy drugs, which has been employed in studying brain tumors, and is significant for improving the treatment of glioma. In this review, the current concepts of cerebral microdialysis for glioma are elucidated, with a special emphasis on its application to neurochemistry and pharmacokinetic studies.Journal of pharmaceutical and biomedical analysis 03/2014; 96C:77-89. · 2.45 Impact Factor