ISSN:1040-8746    

出版商:OVID    

年代:1999

数据来源: OVID

摘要:

Despite the advent of new technologies available for the imaging of brain tumors and the evolution of methods to deliver more focused radiation therapy, most malignant gliomas recur locally. Therapies aimed at increasing local control of gliomas will set the stage for improved survival in a disease with a dismal overall prognosis. This review focuses on several radiotherapeutic approaches to dose escalation that may help improve local control.

ISSN:1040-8746    

出版商:OVID    

年代:1999

数据来源: OVID

摘要:

Despite significant advances in medical imaging techniques and their routine preoperative use, real-time intraoperative information regarding anatomy remains of indisputable importance to neurosurgeons. Intraoperative displacement of the brain tissue caused by surgical retraction or the resection cavity itself, as well as shift caused by cerebrospinal fluid leakage, may result in alteration of the surgical anatomy of the lesion and surrounding structures. Neurosurgical navigation methods are beneficial in providing accurate intraoperative information regarding the anatomy of the surgical field. Furthermore, interactive image guidance may decrease incision lengths, operating times, and postoperative morbidity. This review focuses on recent developments in neurosurgical navigational techniques that enable real-time anatomic visualization during brain tumor surgery.

ISSN:1040-8746    

出版商:OVID    

年代:1999

数据来源: OVID

摘要:

Chemotherapy remains part of the treatment triad that includes surgery and radiation therapy for the management of malignant gliomas. In recent years there has been an increased understanding of the molecular pathways of malignant transformation. Based on this research, new drugs have been evaluated, with specific cellular targets in mind that can be modified or inhibited. Many of these agents are now being tested in phase I and II clinical trials and have shown some promising results. Clearly, not all patients with malignant gliomas respond equally to chemotherapy. Recent evidence suggests that certain molecular markers may predict chemosensitivity in some tumor types, particularly anaplastic oligodendroglioma. This article reviews recent trends in the use of chemotherapy and clinical trials of new therapies for adults with malignant gliomas.

ISSN:1040-8746    

出版商:OVID    

年代:1999

数据来源: OVID

摘要:

De novoglioblastomas develop in older patients without prior clinical history of less malignant tumors. Progressive glioblastomas are common among younger patients and arise through progression from lower-grade astrocytomas.CDKN2Adeletions,PTENalterations, andEGFRamplification are more prevalent amongde novoglioblastomas, whereas p53 mutations are more common among progressive glioblastomas. Loss of heterozygosity (LOH) for chromosome 10 is seen uniformly among bothde novoand progressive high-grade astrocytomas. The inactivation of thePTENgene is found in approximately 30% to 40% of astrocytomas with chromosome 10 loss, and LOH pattern in the remaining astrocytomas strongly supports the presence of another yet unidentified tumor suppressor gene telomeric toPTEN.More than 80% of oligodendrogliomas exhibit LOH for 1p and 19q alleles. Oligoastrocytomas with 1p/19q LOH are related to oligodendrogliomas, and those with p53 mutations are related to astrocytomas.

ISSN:1040-8746    

出版商:OVID    

年代:1999

数据来源: OVID

摘要:

Although early clinical gene therapy trials for recurrent central nervous system neoplasms showed the proof-of-principle, they did not fulfill the high expectations suggested by the preclinical experimental data. Insufficient distribution of vectors in human brain tumors and very low transduction efficiency require that we reevaluate gene transfer concepts for brain tumor treatment. Major steps to improve gene transfer into the central nervous system and the efficacy of gene therapy for malignant brain tumors include: 1) the design of more effective vector systems; 2) the development of new or improved prodrug/suicide systems, gene replacement approaches, or strategies targeting the immune response or tumor angiogenesis; 3) the study of new techniques to enhance delivery of genetic vectors into brain tumors and for monitoring gene delivery into tumors; and 4) assessment of the role of gene therapy as part of a combined treatment approach.

ISSN:1040-8746    

出版商:OVID    

年代:1999

数据来源: OVID

ISSN:1040-8746    

出版商:OVID    

年代:1999

数据来源: OVID

摘要:

Both clinical and laboratory evidence indicates that local control rates for many experimental and clinical human tumors decrease with protraction of the overall duration of radiation therapy and that a likely basis for this decrease is tumor cell repopulation during treatment. Such observations have stimulated interest in tumor kinetics, and a number of techniques have been developed that increase the potential for meaningful clinical study of the proliferative behavior of tumors. This review discusses the clinical and experimental evidence for proliferation during treatment, describes two potential approaches—accelerated fractionation and concurrent chemotherapy and radiotherapy—that can be employed to counteract such intratreatment proliferation, explores methods available for measuring tumor cell kinetics, and discusses how kinetics information may be used in the future to tailor therapy to a tumor’s individual characteristics.

ISSN:1040-8746    

出版商:OVID    

年代:1999

数据来源: OVID

摘要:

Combinations of paclitaxel and radiation therapy or paclitaxel with other chemotherapy agents and radiation have been tested with variable results in patient populations. To date, three phase I trials have been conducted using paclitaxel alone in combination with radiotherapy for the treatment of patients with head and neck cancer. Dose-limiting toxicity in the 1-hour infusion was mucositis, whereas in the 24-h/wk infusion, fever was the dose-limiting toxicity. In the long-term infusion (24 h/d, 7 d/wk), no dose-limiting toxicity was seen at the doses of paclitaxel given. In two of the protocols in which biopsies were obtained, a G2/M block was observed. A phase I protocol using paclitaxel in combination with fluorouracil and hydroxyurea with radiation and a phase II protocol using paclitaxel with cisplatin in operable head and neck cancers have been reported. Preliminary results suggest that paclitaxel in combination with radiotherapy is a reasonable experimental treatment that deserves further study in patients with stage III and IV squamous cell carcinomas of the head and neck.

ISSN:1040-8746    

出版商:OVID    

年代:1999

数据来源: OVID

摘要:

The overall survival of patients with squamous cell cancer of the head and neck has not significantly improved over the past 2 decades. Preclinical studies suggest that combining a monoclonal antibody to the epidermal growth factor receptor with irradiation or chemotherapy agents active in squamous cell cancer of the head and neck could increase treatment efficacy. Completed phase I studies have shown these combinations to be both feasible and tolerable. Phase III studies are now beginning to establish firmly the efficacy of this innovative new approach.

ISSN:1040-8746    

出版商:OVID    

年代:1999

数据来源: OVID