Radiosurgical treatment of gliomas of the diencephalon

The results of Leksell Gamma Knife treatment of diencephalic gliomas are presented. Eight tumours in seven patients form the basis of this report. 7 patients, 4 males and 3 females. The age range was 7.5 to 33 years with a mean of 18 years. Mean follow-up was 21 +/- 12 months. In 4 patients the tumour had been reduced in volume by an open internal decompression procedure. The location of the tumour will determine the risks of treatment. With anterior lesions there is risk of endocrinological and visual pathway damage. With a pineal region lesion there is a risk of diplopia. In this series no tumour has increased in volume. Four have decreased and one has disappeared. Two patients suffered temporary diplopia. No visual disturbance has been observed to date. No hypothalamic disturbance has been observed yet. These tumours are dangerous not so much because of their biological nature as because of their location. However, the biological nature of the tumours, with the close concordance between the radiological and actual extent make them appropriate targets for radiosurgery as a primary treatment. The present study gives preliminary support to this line of treatment.