Intralesional radioimmunotherapy in the treatment of malignant glioma: clinical and experimental findings.

In the last two decades radioimmunotherapy has been used as an additional treatment option for malignant glioma in several centers. More than 400 patients have been reported, who were treated in the framework of different studies. Most of them received labelled antibodies to tenascin, an extracellular matrix-glycoprotein, which is expressed in high amounts in malignant gliomas. We report side effects and survival time of 46 patients, treated after surgical resection and conventional radiotherapy with intralesionally injected labelled (131-Iodine) antibodies to tenascin. Despite the fact, that many treatments have been performed, little is known about the distribution properties of labelled antibodies after injection in the tumour cavity. For an optimal effect labelled antibodies should be able to reach tumour cells, which have migrated into the surrounding tissue. We investigated the propagation velocity and area of distribution of labelled antibodies and their considerably smaller fragments after the injection in C6-gliomas of Wistar rats. Propagation increased with time and was significantly greater after injection of labelled fragments than after injection of labelled antibodies. According to our results labelled fragments might be better able to reach distant tumour cells in the peritumoural tissue of malignant gliomas than labelled antibodies.