Dose-Escalation Study of Carboplatin Administration Into the Brain for Glioblastoma Multiforme

High-grade gliomas are the commonest primary malignant brain tumours in adults, affecting approximately 5000 people per year in the UK. Standard treatment comprises a combination of surgery, radiotherapy and chemotherapy; however this condition remains incurable and the average survival is approximately 18 months from diagnosis. There are a number of reasons for this. Firstly these tumours are highly invasive and involve important areas of brain making it impossible to remove them surgically or cure them with radiotherapy. In the majority of cases the tumour recurs within 2 to 3cm of the original site of tumour removal. Secondly, due to the presence of a barrier between the bloodstream and the brain, when drugs designed to kill tumour cells (chemotherapy) are given intravenously or orally, they frequently do not reach the tumour at a sufficient dose to have a beneficial effect. As the chemotherapy dose has to be very high for a sufficient dose to reach the tumour, drug-related side-effects are common. Laboratory studies demonstrate that glioma tumour cells are sensitive to a number of different chemotherapies, including carboplatin. When given intravenously however, carboplatin does not reach a sufficient concentration in the tumour to have a beneficial effect. However, studies have shown that carboplatin can be infused directly into the brain at a concentration that is highly toxic to tumour cells, but not to normal brain tissue. Using very small tubes implanted around the tumour, the investigators are able to infuse carboplatin reliably and repeatedly into the area where tumours typical recur. In this study, the investigators intend to evaluate the safety of this approach and determine the optimal dose of carboplatin to administer. It is hoped that this study will also provide evidence of improved survival for patients with high-grade glioma.