Biomedical subjects

Anthony L Asher

Publications and source records attributed to Anthony L Asher.

6 recordsLinked to original sources

PubMed2006

Self-assessment in neurological surgery: the SANS wired white paper.

OBJECTIVE: Periodic self-assessment is an important component of postgraduate medical education and certification. The Self-assessment in Neurological Surgery (SANS) examination has a history of usefulness for neurosurgical written and oral board examination preparation. The SANS Wired test represents a recreation of the original SANS test using an Internet-based platform. Advanced functionality and contemporary content have been added to meet the increasing requirements for demonstration of lifelong learning and self-assessment as part of the Maintenance of Certification (MOC) process. METHODS: A needs assessment was performed before the development of SANS Wired. Postexamination surveys for users obtaining continuing medical education credit were analyzed for user satisfaction with the platform and content. Test-item performance metrics were analyzed based on first-attempt responses. The economic value of SANS Wired as a component of the mandatory MOC process was evaluated. RESULTS: The needs assessment identified a deficiency of available content and mechanisms for neurosurgery-specific self-assessment. As of October 15, 2005, a total of 588 individuals had subscribed to SANS Wired (28 institutional licenses accounted for 229 users). Eighty-eight post-test surveys were analyzed for user satisfaction. Ninety-four percent of responses indicated that learning objectives had been met. Initial performance metrics show an average point-biserial discrimination index of +0.18 for all test items. CONCLUSION: The SANS Wired system seems to be an effective platform for neurosurgical self-assessment and is acceptable to users. The system satisfies, in part, two of the four required components of MOC, namely, periodic self-assessment and demonstration of cognitive expertise. It is endorsed by the American Board of Neurological Surgeons for MOC.

Certification↗

PubMed2006

Results of a phase II trial of the GliaSite radiation therapy system for the treatment of newly diagnosed, resected single brain metastases.

OBJECT: The aim of this study was to evaluate the effectiveness of brachytherapy using the GliaSite Radiation Therapy System in patients with a newly diagnosed resected single brain metastasis. The primary end point of the study was local tumor control. The secondary end points included patient survival, distant brain recurrence, quality of life, and treatment toxicity. METHODS: The authors conducted a prospective multiinstitutional phase II study of GliaSite brachytherapy prescribed at a 60-Gy dose administered to a 1-cm depth after resection of a single brain metastasis. No whole-brain radiation therapy was given. Patients were assessed at 1 and 3 months after brachytherapy and every 3 months thereafter for up to 2 years. Seventy-one patients were enrolled at 13 centers. A GliaSite balloon catheter was implanted in 62 patients. Fifty-four patients received brachytherapy. The median patient age was 60 years. The most common tumor (54%) was non-small cell lung cancer. Fifty-seven percent of patients had brain metastasis only, whereas 43% had extracranial metastasis. The median final administered dose was 60 Gy. The magnetic resonance imaging--determined local control rate, based on several different methods, was 82 to 87%. Both the median patient survival time and the median duration of functional independence were 40 weeks. Among the 35 patients who died, the cause of death was neurological in 11%. Thirteen patients underwent reoperation for suspected tumor recurrence or radiation necrosis, and histological diagnoses included radiation necrosis without tumor (nine patients), radiation necrosis mixed with tumor (two patients), and tumor only (two patients). Extracranial metastasis, tumor size, and radiation necrosis were significant factors affecting patient survival. CONCLUSIONS: In patients with a resected single brain metastasis, GliaSite brachytherapy leads to a local control rate, median patient survival time, and duration of functional independence similar to those achieved with resection plus whole-brain radiation therapy.

Adult↗

PubMed2005

Patterns of care for adults with newly diagnosed malignant glioma.

CONTEXT: Patients with malignant glioma (grade III or IV) face a poor prognosis, and few evidence-based treatment guidelines are available. There is a dearth of prospective data on patterns of care for these patients. OBJECTIVE: To provide benchmark data to enable comparison of individual practice patterns and outcomes. DESIGN, SETTING, AND PATIENTS: The Glioma Outcomes (GO) Project enrolled 788 patients at 52 clinical sites, both academic and community practices, between December 1997 and July 2000. The enrollment criteria included adult patients with primary grade III or IV glioma undergoing a first or second operation for diagnosis or treatment. The data collection instruments included questionnaire forms given at enrollment, during the perioperative period, and at follow-up intervals of 3 months until death or a maximum of 24 months. Of the patients recorded in the GO database, 565 patients with newly diagnosed tumors were used for this analysis. MAIN OUTCOME MEASURES: Patterns of care (surgical management, perioperative care, postoperative management). RESULTS: Most patients underwent magnetic resonance imaging (n = 518; 92%) and an attempt at tumor resection (n = 425; 75%). Cortical mapping (n = 107; 19%) and intraoperative image guidance (n = 161; 29%) were uncommon. Most received perioperative corticosteroids (n = 535; 99%) and antiepileptic medications (n = 497; 88%), but few received antidepressants (n = 38; 8%) or prophylactic heparin (n = 42; 7%). Most received adjuvant radiation therapy (n = 479; 87%), but fewer received chemotherapy (n = 300; 54%). Practice patterns varied significantly between academic and community settings. CONCLUSIONS: Reliance on magnetic resonance imaging, surgery, and radiation is generally accepted; however, relatively infrequent chemotherapy use may conflict with published literature, and frequent use of prophylactic antiepileptic medications contradicts established practice guidelines. Other practice patterns involving surgical adjuncts, prophylactic heparin, and antidepressants require further investigation to clarify appropriateness. Establishing further clinical guidelines may help reduce variability in practice patterns.

Adult↗

PubMed2005

Safety and feasibility of convection-enhanced delivery of Cotara for the treatment of malignant glioma: initial experience in 51 patients.

OBJECTIVE: We report the safety and feasibility of using convection-enhanced delivery to administer Cotara (Peregrine Pharmaceuticals, Inc., Tustin, CA), a novel radioimmunotherapeutic agent, to patients with malignant glioma. METHODS: Between April 1998 and November 2002, 51 patients with histologically confirmed malignant glioma received Cotara by convection-enhanced delivery. Most patients (88%) were treated with Cotara targeting tumor volume-dependent, single or multiple administrations of activity ranging from 0.5 to 3.0 mCi/cm3 of baseline clinical target volume. Two weeks after infusion, single-photon emission computed tomographic imaging determined the spatial distribution of Cotara. Patients were followed for as long as 41 months (average follow-up, 5 mo). Safety was evaluated on the basis of incidence of procedure-related, neurological, and systemic adverse events. Feasibility was evaluated in a subset of patients on the basis of the correlation between the prescribed activity and the actual activity administered to the targeted region. RESULTS: Fifty-one patients, 37 with recurrent glioblastoma multiforme, 8 with newly diagnosed glioblastoma multiforme, and 6 with recurrent anaplastic astrocytomas, were treated. Average tumor volume was 36 +/- 27.6 cm3 (range, 5-168 cm3). Of the 67 infusions, 13 (19%), 52 (78%), and 2 (3%) delivered less than 90%, 100 +/- 10%, and more than 110%, respectively, of the prescribed administered activity to the targeted region. Treatment-emergent, drug-related central nervous system adverse events included brain edema (16%), hemiparesis (14%), and headache (14%). Systemic adverse events were mild. Several patients had objective responses to Cotara. CONCLUSION: The majority of Cotara infusions delivered between 90 and 110% of the prescribed administered activity to the targeted region. This method of administration has an acceptable safety profile compared with literature reports of other therapeutics delivered by convection-enhanced delivery.

Adolescent↗

PubMed2004

Brain metastases.

Explore the source record for details and available documents.

Antineoplastic Agents↗

PubMed2003

Convection-enhanced delivery in clinical trials.

The poor prognosis associated with the current management of malignant gliomas has led investigators to develop alternative treatments such as targeted toxin therapy. The optimal method for administering these agents is under development but appears to be convection-enhanced delivery (CED). The direct intratumoral infusion of targeted toxins was first performed in nude mouse flank tumor models of human malignant glioma. After the demonstration of in vivo efficacy, these potent cytotoxic compounds were tested in Phase I and Phase II clinical trials. Using a high-flow microinfusion technique, volumes of up to 180 ml were infused by CED through catheters placed directly into brain tumors. Minor systemic toxicity was seen in the form of hepatic enzyme elevation. Neural toxicity manifested as seizure activity and hemiparesis resulted from peritumoral edema that followed the completion of the infusion. Peritumoral toxicity was believed to be more related to the concentration of the infused immunotoxin than to the infusion volume. In approximately half of patients treated with CED a stable disease course, a partial response, or a complete response was demonstrated in some clinical trials. Targeted toxin therapy has clinical efficacy in patients with malignant gliomas. Convection-enhanced delivery appears to represent an effective method for administering these agents in patients with malignant brain tumors.

Adolescent↗