Fractionated brain stereotactic irradiation using a non-invasive frame:Technique and preliminary results

In this study we report on the use of two non-invasive head frames in fractionated stereotactic irradiation for small benign or low grade brain tumors. Sixty-one patients were treated from April 1988 to December 1992 with external stereotactic irradiation: 12 presented with arteriovenous malformations (AVMs), 32 with benign tumors, and 17 with malignant tumors. Sire of the lesions ranged from 15 to 45 mm in diameter. Two immobilization devices were used: the Laitinen stereoadapter, until December 1992, and then the Beverly frame, specifically designed for radiotherapy. Treatment was given daily, 5 days/week, using 1 or 2 non-coplanar arcs, the dose per fraction ranging from 2 to 3 Gy. The study of the accuracy of the two frames showed an average discrepancy