[Rich66]

Intracranial Lesions Mimicking Neoplasms

Accepted July 25, 2008

http://arpa.allenpress.com/arpaonlin...2165-133.1.101


In this review, we have compiled a unique series of cases that presented both clinically and radiologically as intracranial mass lesions. Tumor was initially considered in each of the cases. However, pathology revealed a variety of nonneoplastic etiologies, including demyelinating disease, vascular disease, inflammation, and infection, as well as posttreatment effects. Although tumor is often the most likely diagnostic consideration in a patient presenting with a contrast-enhancing mass lesion within the brain parenchyma with surrounding edema and mass effect, that is not always the case. Not uncommonly, there can be significant overlap in the radiologic presentation between neoplastic and nonneoplastic diseases. Both neoplastic and nonneoplastic diseases can produce abnormal contrast enhancement, mass effect, and perilesional edema on both computed tomography (CT) and magnetic resonance imaging (MRI). Occasionally, some of these nonneoplastic etiologies may produce signs and symptoms mimicking tumoral disease clinically.¹ As such, these situations may offer a diagnostic challenge to both the clinician and radiologist, and often these patients undergo biopsy. In most cases, the pathologist can readily differentiate between neoplasia and nonneoplastic imitators. However, because the benign nature of some pseudoneoplastic lesions may not be immediately apparent on pathologic examination, it behooves the pathologist to be aware of their existence. The purpose of this case series is to alert pathologists, radiologists, and other clinicians involved in the care of neurooncologic patients to consider nonneoplastic etiologies in the differential diagnosis of both intra-axial and extra-axial mass lesions.
Tumor-mimicking conditions from several etiologic categories are presented in tabular form, including infection and inflammation, demyelinating disease, vascular disease, and post treatment conditions, with accompanying illustrations and discussion of the current and pertinent literature. Case examples of each condition discussed are described in the Table .




Int J Radiat Oncol Biol Phys. 2010 Feb 1;76(2):504-512.
Intracranial Metastatic Disease Spares the Limbic Circuit: A Review of 697 Metastatic Lesions in 107 Patients.
Marsh JC, Herskovic AM, Gielda BT, Hughes FF, Hoeppner T, Turian J, Abrams RA.

Department of Radiation Oncology, Rush University Medical Center, Chicago, Illinois.
PURPOSE: We report the incidence of metastatic involvement of the limbic circuit in a retrospective review of patients treated at our institution. This review was performed to assess the feasibility of selectively sparing the limbic system during whole-brain radiotherapy and prophylactic cranial irradiation. METHODS AND MATERIALS: We identified 697 intracranial metastases in 107 patients after reviewing contrast-enhanced CT and/or MR image sets for each patient. Lesions were localized to the limbic circuit or to the rest of the brain/brain stem. Patients were categorized by tumor histology (e.g., non-small-cell lung cancer, small-cell lung cancer, breast cancer, and other) and by total number of intracranial metastases (1-3, oligometastatic; 4 or more, nonoligometastatic). RESULTS: Thirty-six limbic metastases (5.2% of all metastases) were identified in 22 patients who had a median of 16.5 metastases/patient (limbic metastases accounted for 9.9% of their lesions). Sixteen metastases (2.29%) involved the hippocampus, and 20 (2.86%) involved the rest of the limbic circuit; 86.2% of limbic metastases occurred in nonoligometastatic patients, and 13.8% occurred in oligometastatic patients. The incidence of limbic metastases by histologic subtype was similar. The incidence of limbic metastases in oligometastatic patients was 4.9% (5/103): 0.97%, hippocampus; 3.9%, remainder of the limbic circuit. One of 53 oligometastatic patients (1.9%) had hippocampal metastases, while 4/53 (7.5%) had other limbic metastases. CONCLUSIONS: Metastatic involvement of the limbic circuit is uncommon and limited primarily to patients with nonoligometastatic disease, supporting our hypothesis that it is reasonable to selectively exclude or reduce the dose to the limbic circuit when treating patients with prophylactic cranial irradiation or whole-brain radiotherapy for oligometastatic disease not involving these structures. Copyright © 2010 Elsevier Inc. All rights reserved.

PMID: 20117288 [PubMed - as supplied by publisher]

The limbic system performs a number of vital functions including acquisition and consolidation of memory, regulation of emotional and autonomic responses to external stimuli, psychomotor activation, concentration/ attention span, executive planning, and visual-spatial orientation. Based on many years of clinical experience in treating intracranial metastases, we have noted a very low incidence of involvement of the limbic circuit in metastatic disease. We postulate that it may be reasonable and safe to exclude and/or reduce the dose to these structures when treating patients with either whole-brain radiation therapy (WBRT) or prophylactic cranial irradiation (PCI). In order to confirm this hypothesis, we performed this study.

The NovoTTF-100A delivers low intensity alternating electric fields to the patient’s tumor site (SCIENCE).
LINK

The Device
The NovoTTF-100A is a non-invasive device, consisting of four sets of insulated electrodes attached to an electronic box. The electrodes are placed on the outside of the shaved scalp. The electrodes generally resemble bandages with wires attached. The electrodes connect to a portable TTField-generating box running off a battery or plugged into a wall supply. The device is lightweight (approximately 6 lbs) and fits neatly into a dedicated carrying case that will be provided to the patient.

The Device and Treatment
The NovoTTF-100A is a portable, investigational device for cancer treatment using TTFields – Tumor Treating Fields (SCIENCE). The device is intended for continuous home use by patients (TREATMENT) with a newly diagnosed GBM tumor (ELIGIBILITY). Results from a pilot study of the device suggest that the investigational treatment may increase the length of time before disease progression and increase median overall survival newly diagnosed GBM patients. These results were from a small study and have not yet been validated. The device has not yet been proven to be safe and effective for any indication. (CLINICAL EXPERIENCE).

Electrical Device for Cancer Treatment Polarizes Audiences

Toxicity advantage over chemotherapy

LINK

December 2, 2010 (Montreal, Quebec) — An investigational glioblastoma treatment that delivers alternating electric fields through scalp electrodes might also have application in other cancers, particularly nonsmall-cell lung cancer (NSCLC), according to an Israeli presenter here at the Society for Neuro-Oncology 15th Annual Scientific Meeting.

"We do this to all our patients; we intoxicate them," said Dr. Ram about the adverse effects of chemotherapy. "Even if NovoTTF did not extend survival, if it was equivalent to chemotherapy [for survival], then it may still improve quality of life."
Dr. Ram did not know the median length of time that the NovoTTF cohort wore the device, but an earlier phase 2 study followed some of them for 59 months. "Seventy percent are still alive — that's unheard of," he remarked.
"There were concerns that patients might have more headaches or seizures, but there were none," he said.
Dr. Ram reported that the rate of adverse events related to the central nervous system (CNS) was similar for NovoTTF and chemotherapy (66% vs 67%), as were serious CNS adverse events (21% vs 22%), seizures (15% vs 12%), and headaches (18% vs 13%).
"There are no real concerns that this does anything hazardous to the brain," he said.

Trial: http://clinicaltrials.gov/ct2/show/NCT00916409