LIPOSOMAL DISTRIBUTION IN MALIGNANT GLIOMA - POSSIBILITIES FOR THERAPY

We investigated the potential of In-111-labelled liposomes to specific ally target recurrent high-grade glioma in eight patients, all of whom had clinical and radiological evidence of relapse following prior tre atment With surgery and radiotherapy. The phospholipid liposomes were labelled with 74 MBq In-111 and injected intravenously. The distributi on of radioactive material in the brain was imaged using a dedicated n euro-SPET imager. Images were taken 1 h post-injection and repeated at 24, 48 and 72 h. In addition, whole-body images were performed with a gamma camera and blood taken for radioactivity determination. At 72 h post-injection, excellent tumour demarcation could be seen in seven o f eight patients. The images obtained correlated well with the corresp onding computed tomography images. Blood radioactivity levels graduall y declined over the 72 h. Tumour uptake continued to rise throughout t his time and, together with the steady fall in normal brain tissue, th e tumour-to-brain contrast gradually increased (maximum 7:5). Whole-bo dy images indicate that the Liver is the major organ of uptake with up to 50% of the injected dose. No toxicity could be attributed to the i njected liposomes. Although the total percentage uptake was low (1.1%) , the tumour-to-brain contrast ratios, together with the SPET images, suggest the potential for tumour-specific targeting.