Introduction

There is increasing interest in outcome measurement associated with the management of patients with tumours affecting the central nervous system. This interest is largely the result of the significant costs of diagnosis and therapy, and also relates to the nature and extent of neurological disabilities which have a tremendous impact on both public health and economic productivity.

Brain tumours rank second in relative incidence of tumours of childhood and from sixth to eighth among tumours of adults, depending upon whether pituitary tumours and tumours metastic to the brain are included (Berens et al. 1990, Black 1990, Walker et al. 1985). The most common primary brain tumours are the gliomas. These include the astrocytoma which appears in benign and malignant forms, the glioblastoma which is a highly malignant astrocytoma and the oligodendroglioma. The gliomas comprise approximately 40–60% of primary brain tumours, and of these about half fall into a relatively benign category and half into a rapidly progressive, more malignant, classification. Other tissues within the brain also give rise to tumours and these include the ependyma and the choroid plexus. Primitive developmental tumours such as the primitive neuroectodermal tumour (PNET), medulloblastoma, ependymoblastoma and the pineoblastoma may occur, usually appearing in infancy and childhood.

The second most common type of intracranial tumour is the meningioma (Barbaro et al. 1987) that arises from the lining of the skull and produces symptoms by external pressure on the brain. These tumours are considered ‘extra-axial’ lesions and occur more commonly in women and in older patients.