Clinical approach to fever in the neurosurgical intensive care unit: Focus on drug fever

Burke A. Cunha

Date of publication: 06-May-2013

Abstract

As fever is one of the cardinal signs of infection, the presence of fever in a patient in the neurosurgical intensive care unit (NSICU) raises the question of whether it is infectious in etiology. Infectious and noninfectious causes of fever in the NSICU may be determined based upon assessment of clinical signs and symptoms, the degree of temperature elevation, the relationship of the pulse to the fever (e.g., an infectious process resulting in hyperpyrexia and bradycardia), and when the fever occurs (e.g., related to the length of stay in the NSICU). There are many noninfectious disorders which contribute to temperatures >102°F in the NSICU; these include drug fevers, deep vein thrombosis, phlebitis/pulmonary embolism, acute myocardial infarction, atelectasis, dehydration, acute gout flare, malignancy, acute pancreatitis, transfusion associated hepatitis, and hemorrhage. Infectious rather than noninfectious disorders, however, are more typically associated with high-grade fevers (>102°F.) in the NSICU, and nosocomial pneumonia, (synonymous with ventilator-associated pneumonia [VAP]), is the leading culprit, followed by nosocomial infections and Clostridium difficile.

Introduction – Supplement on brain metastases

Daniel Silbergeld

Date of publication: 02-May-2013

Stereotactic radiosurgery and stereotactic radiotherapy for brain metastases

Lia M. Halasz, Jason K. Rockhill

Date of publication: 02-May-2013

Abstract

Stereotactic radiosurgery (SRS) and hypofractionated stereotactic radiotherapy (HFSRT) have become important treatment modalities for brain metastases. While effective, there are still areas of extensive debate on its appropriate use in patients with life-limiting diseases. This review provides an overview of the indications and challenges of SRS and HFSRT in the management of brain metastases.

Epidemiology and prognosis of brain metastases

Keith J. Stelzer

Date of publication: 02-May-2013

Abstract

A substantial, but uncertain, number of patients with cancer develop brain metastases. Risk of brain metastasis is recognized to vary with type of primary cancer. Within specific types of primary cancer, prognostic factors for development of brain metastases are being recognized. Recent data suggest that molecular biomarkers that relate to cellular function can predict risk of developing brain metastases. Such information could optimize surveillance standards and/or be used to select patients for preventive interventions. Though average survival for patients with brain metastases is typically less than 6 months, it is well-recognized that subgroups of patients have significant probability of longer survival. Multiple prognostic models have been proposed, validated, and compared without clearly demonstrating superiority of one model over another. However, some factors show consistency as predictive variables across models, and performance status is almost universally significant. Application of predictive models to specific treatments has been difficult. Tumor-specific prognostic models are evolving, and combinations of biological and clinical factors may be used to optimize models for particular primary tumor types.

Surgery for brain metastases

Kurt Andrew Yaeger, M. Nathan Nair

Date of publication: 02-May-2013

Abstract

The use of surgery in the treatment of brain metastases is controversial. Patients who present certain clinical characteristics may experience prolonged survival with resection compared with radiation therapy. Thus, for patients with a single metastatic lesion in the setting of well-controlled systemic cancer, surgery is highly indicated. Stereotactic radiosurgery (SRS) alone can provide a similar survival advantage, but when used as postoperative adjuvant therapy, patients experience extended survival times. Furthermore, surgery remains the only treatment option for patients with life-threatening neurological symptoms, who require immediate tumor debulking. Treatment of brain metastases requires a careful clinical assessment of individual patients, as different prognostic factors may indicate various modes or combinations of therapy. Since surgery is an effective method for achieving tumor management in particular cases, it remains an important consideration in the treatment algorithm for brain metastases.

Imaging of brain metastases

Kathleen R. Fink, James R. Fink

Date of publication: 02-May-2013

Abstract

Imaging plays a key role in the diagnosis of central nervous system (CNS) metastasis. Imaging is used to detect metastases in patients with known malignancies and new neurological signs or symptoms, as well as to screen for CNS involvement in patients with known cancer. Computed tomography (CT) and magnetic resonance imaging (MRI) are the key imaging modalities used in the diagnosis of brain metastases. In difficult cases, such as newly diagnosed solitary enhancing brain lesions in patients without known malignancy, advanced imaging techniques including proton magnetic resonance spectroscopy (MRS), contrast enhanced magnetic resonance perfusion (MRP), diffusion weighted imaging (DWI), and diffusion tensor imaging (DTI) may aid in arriving at the correct diagnosis. This image-rich review discusses the imaging evaluation of patients with suspected intracranial involvement and malignancy, describes typical imaging findings of parenchymal brain metastasis on CT and MRI, and provides clues to specific histological diagnoses such as the presence of hemorrhage. Additionally, the role of advanced imaging techniques is reviewed, specifically in the context of differentiating metastasis from high-grade glioma and other solitary enhancing brain lesions. Extra-axial CNS involvement by metastases, including pachymeningeal and leptomeningeal metastases is also briefly reviewed.

Future directions in treatment of brain metastases

Igor J. Barani, David A. Larson, Mitchel S. Berger

Date of publication: 02-May-2013

Background:Brain metastases affect up to 30% of patients with cancer. Management of brain metastases continues to evolve with ever increasing focus on cognitive preservation and quality of life. This manuscript reviews current state of brain metastases management and discusses various treatment controversies with focus on future clinical trials. Stereotactic radiosurgery (SRS) and whole-brain radiotherapy (WBRT) are discussed in context of multiple (4+ brain metastases) as well as new approaches combining radiation and targeted agents. A brief discussion of modified WBRT approaches, including hippocampal-avoidance WBRT (HA-WBRT) is included as well as a section on recently presented results of Radiation Therapy Oncology Group (RTOG) 0614, a randomized, double-blind, placebo-controlled trial of menantine for prevention of neurocognitive injury after WBRT.

Controversies in the management of brain metastases

Michael R. Levitt, Ralph Levitt, Daniel L. Silbergeld

Date of publication: 02-May-2013

Abstract

The multidisciplinary management of brain metastases has generated substantial controversy as treatment has diversified in recent years. Debate about the type, role, and timing of different diagnostic and therapeutic strategies has promoted rigorous scientific research into efficacy. However, much still remains unanswered in the treatment of this difficult disease process. This manuscript seeks to highlight some of the controversies identified in previous sections of this supplement, including prognosis, pathology, radiation and surgical treatment, neuroimaging, and the biochemical underpinnings of brain metastases. By recognizing what is yet unanswered, we hope to identify areas in which further research may yield promising results.

Whole brain radiotherapy for brain metastasis

Emory McTyre, Jacob Scott, Prakash Chinnaiyan

Date of publication: 02-May-2013

Abstract

Whole brain radiotherapy (WBRT) is a mainstay of treatment in patients with both identifiable brain metastases and prophylaxis for microscopic disease. The use of WBRT has decreased somewhat in recent years due to both advances in radiation technology, allowing for a more localized delivery of radiation, and growing concerns regarding the late toxicity profile associated with WBRT. This has prompted the development of several recent and ongoing prospective studies designed to provide Level I evidence to guide optimal treatment approaches for patients with intracranial metastases. In addition to defining the role of WBRT in patients with brain metastases, identifying methods to improve WBRT is an active area of investigation, and can be classified into two general categories: Those designed to decrease the morbidity of WBRT, primarily by reducing late toxicity, and those designed to improve the efficacy of WBRT. Both of these areas of research show diversity and promise, and it seems feasible that in the near future, the efficacy/toxicity ratio may be improved, allowing for a more diverse clinical application of WBRT.

Neuropathology of brain metastases

Melike Pekmezci, Arie Perry

Date of publication: 02-May-2013

Abstract

Metastatic tumors are the most common neoplasms encountered in the central nervous system (CNS), and continue to be major cause for mortality and morbidity. Macroscopic features and corresponding radiological findings can be diagnostic in majority of the cases, however, microscopic evaluation would be necessary when the differential diagnosis includes a primary CNS tumor, unknown primary tumor site, and when the resection of the tumor is either considered therapeutic or palliative. The first step in the diagnosis of a metastatic brain lesion is to exclude a primary CNS tumor, followed by verification or identification of the primary tumor and the site. Although general approach to a metastatic lesion from an unknown primary tumor is the same everywhere else, there are slight variations for the metastatic lesions in the CNS versus other regions. When morphological features are not enough to establish a definitive diagnosis, additional studies including immunohistochemical stains are applied. With the expending immunohistochemical armamentarium for pathologists, more accurate assessments are possible even in cases of unknown primary tumor. This review summarizes the diagnostic approach to CNS metastases, immunohistochemical assessment of neoplasm of unknown primary, and primary CNS lesions entering in the differential diagnosis of metastases.