LINAC-BASED SMALL-FIELD RADIOTHERAPY FOR BRAIN-TUMORS

Small-field radiotherapy based on a 6-MeV linac and a conventional hea d mold is investigated as an alternative to radiosurgery with stereota ctic frames. The system requires no additional device and allows fract ionated treatment. The dose distributions obtained are comparable to t hose reported with a Gamma Unit. Overall positioning errors are within 2 mm. Using this approach, seven patients with brain tumors who could not have been treated otherwise, underwent fractionated radiotherapy with total accumulated doses ranging from 70 to 108 Gy. The treatment was tolerated well with no acute toxicity or adverse effect encountere d during the follow-up period of 8-14 months. All of the patients rema ined free from disease progression in the treated volumes. Although th e follow-up is brief, the preliminary results suggest that this is a s imple and inexpensive but effective system for the treatment of small intracranial malignancies.