Brain Tumors

Abstract

This synthesis of the literature on radiotherapy for brain tumors, ie, cancer originating in the central nervous system (CNS), is based on 81 scientific articles, including 25 randomized studies, 13 prospective studies, and 25 retrospective studies. These studies involve 11 081 patients.

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Curative treatment is not available for patients with highly malignant glioma (grades III and IV).

Postoperative radiotherapy for highly malignant glioma extends patients' survival, with good quality of life, by several weeks to several months. Virtually all patients die from this disease. Although the clinical benefits from radiotherapy, measured as survival, appear to be modest, it is more effective than any chemotherapy tested thus far.

The clinical effects of radiotherapy for highly malignant glioma are improved only marginally by altering factors such as absorbed dose, fractionation, irradiated tissue volume, radiation quality, or by adding radiosensitizing substances.

Radiotherapy alone usually provides a clear but temporary improvement in patients with highly malignant glioma, hence it clearly has a palliative benefit.

Postoperative radiotherapy for low-grade malignant gliomas (grades I and II) may extend survival. It also reduces tumor volume. No evidence shows that radiotherapy alone or postoperatively can lead to cure.

In patients who have undergone subtotal meningioma resection, postoperative radiotherapy substantially reduces the risk for recurrence and extends life, and is thereby indicated. Radiotherapy is not indicated following macroscopic radical meningioma surgery.

Patients with brain metastases experience rapid neurological improvement following radiotherapy to the whole brain, and this palliative effect often remains throughout the remainder of the patient's life. Palliative radiotherapy, often to large volumes of the CNS, is therefore motivated in a large proportion of the patient groups.

In a smaller group of patients with solitary metastases, radiotherapy may be given postoperatively following radical neurosurgery. Life may be extended in this group, otherwise radiotherapy does not influence survival.

Stereotactic radiotherapy of solitary, mainly spherical metastases in the brain is often superior to other known methods with respect to palliation and survival. The number of patients is, however, relatively small.