Clinical Aspects of Detection and Imaging of Brain Tumors

Abstract

Intracranial tumours comprise about 9% of all primary tumours. About 30% of them are benign, 40% are infiltrating, 5% are of congenital origin and 25% of them are metastatic. A thorough general examination and a recent chest X-ray are a necessary part of investigation of any patient suspected of having a brain tumour [1]. The clinical triad of headache, vomiting and papilloedema is often absent. At admission, one-third of patients with a tumour in the brain have no significant headache and approximately half have no papilloedema. Vomiting occurs in more advanced stages of tumour or if the tumour is within the posterior fossa. With infiltrating tumours, 10 years may elapse between the first fit and the onset of features which prove that a tumour in the brain is the underlying cause. With meningiomas this interval rarely exceeds 5 years [1]. Gliomas are the commonest of brain tumours (about 25%). These comprise of astrocytomas, oligodendrogliomas, ependimomas and medulloblastomas (common in children). Meningiomas occur in about 20% of all brain tumours. Less common tumours include the craniopharyngiomas, pituitary adenomas, neuromas, penealomas, cordoma and the glomus tumour. Cerebral metastases occur relatively frequently and from a variety of primary sources. Parietal and occipital and cerebellar single deposits are often seen, whilst the diagnosis is clear cut when multiple deposits are seen. From the point of view of this review, I will discuss below the role of radionuclide imaging in neoplasms of the brain as far as its detection and its monitoring is concerned.