Treatment of brain and spinal tumours
Post-operative management of high grade gliomas comprises a six week course of radiotherapy involving attendance at hospital for 5 days a week for that period. X-ray beams are directed on the tumour with a margin of safety – the small daily radiation doses being better tolerated by the surrounding normal brain (which inevitably receives a high radiation dose in the immediate environs of the tumour).
The addition of a tablet chemotherapy agent (temozolomide) to the radiotherapy has improved the outlook for patients with this potentially dangerous tumour type in recent years. Overall, such treatment is well tolerated.
Low grade glioma patients may move straight to post-operative radiotherapy (usually not chemotherapy - although a case can be argued for this in one type of tumour, the oligodendroglioma). It is not always necessary to proceed to radiotherapy immediately. It does not necessarily prejudice the long term survival chance to employ ‘watchful waiting’ (which implies an MRI scan every six months or so) and employing radiotherapy only if the scan shows tumour progression.
The same principles apply to spinal gliomas, although it is usually more difficult to achieve good debulking of a spinal glioma as the surrounding tissue is so vital.
Benign (non-cancerous) tumours include meningiomas and pituitary adenomas. Surgical therapy is usually curative for typical meningiomas. Any residual core tissue that is difficult to remove can be definitively eliminated by focal radiation therapy – radiosurgery (Gamma Knife or X-knife options being the most common forms). Prolactinoma pituitary adenomas shrink well on dopamine agonist therapy, whilst surgery, radiosurgery (usually Gamma Knife) or conventional radiotherapy all have roles in the management of most others.
Acoustic neuromas are a further form of benign tumour and these in particular can be successfully treated by radiosurgery. A recent group of patients treated at our unit using the Gamma Knife clearly demonstrate the advantages of removing these tumours by this less invasive procedure than conventional surgery. In addition these patients are more likely to retain their hearing, hearing loss being a risk of conventional surgical techniques. Radiosurgery has eclipsed surgery for most acoustic neuromas in recent years and is undoubtedly the most important for curative treatment of brain arteriovenous malformations (AVM). Our team at St. Bartholomew’s Hospital introduced radiosurgery to London in 1989 and has both Gamma Knife and X-knife options available for therapy. The exact treatment method chosen is based on each individual patient’s situation.
The use of radiosurgery for cerebral metastases has to be considered alongside the possibility of conventional surgery and radiotherapy. Conventional open surgery may be the initial therapy of choice for a patient suffering a lot of intracranial pressure caused by a large metastatic tumour on the surface of the brain. Such surgery decompresses the problem and radiotherapy then follows. Radiosurgery may be useful for deep single metastases where conventional radiotherapy has failed or is not perceived to be likely to eliminate the problem. Once again, the decision on the most appropriate treatment option is based on the individual’s problems.
Medical treatment can be highly effective too. Chemotherapy can cure primary brain germ cell tumours and lymphomas, backed up by good radiotherapy. Gliomas respond to temozolmide and nitrosourea based chemotherapy regimens; others are being trialled. Dopamine agonists shrink prolactinomas and reduce growth hormone secretion in acromegaly.
Our long experience with tumours of the brain and spinal cord, and the expert surgeons and histopathologists, who form an integral part of the team, all have helped improve the outlook for patients with brain and spine tumours considerably in the last decade.
Further information on brain tumours is available on the Cancer Advice web site.