[Interstitial stereotactic radiotherapy of brain tumors]

The narrow margin between tumour sensitivity and healthy brain sensitivity to radiation considerably limits conventional radiation therapy (teletherapy). Interstitial radiotherapy (brachytherapy) with iodine-125 permanent implants is effective for local tumour control. So far, interstitial radiotherapy using low activity permanent implants has been carried out in 72 patients with differentiated gliomas (55 cases) and other tumours in functionally critical cortical or deep-seated location. The overall response rate was 64%. In 15 patients, local radiotherapy did not halt clinical deterioration. Brachytherapy with I-125 permanent implants is recommended for slowly proliferating, differentiated, non-resectable tumours in functionally critical areas. It enables the surgeon to achieve radiosurgical tumour removal while carefully avoiding radiation and operative damage to the healthy brain. On the basis of biological, experimental and clinical data, individualized treatment for each patient is desirable.