[Computer tomographically guided stereotactic interstitial therapy of brain tumors using temporary or permanent 125iodine seed implantation].

Therapy resistance of inoperable malignant gliomas is an unsolved problem for radiotherapy. A combination of interstitial therapy and percutaneous high voltage therapy is described which should improve the prognosis of brain tumours when it has been perfected. For all tumours of low malignancy we recommend the permanent implantation of 125iodine seeds of low activity (10-60 mCi 125I, DO = 6-10 rad/h.) as the primary form of treatment, possibly supplemented by high voltage therapy. For tumours of higher malignancy, temporary implantation of high activity 125I is indicated (more than 200 mCi, DO = 25-100 rad/h.) as local boost before or after total volume irradiation of brain. Our experience of 30 patients up to date is encouraging.