Stereotactic interstitial radiotherapy for brain tumors.

The narrow margin between tumor 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 tumor control. So far, interstitial radiotherapy using low activity permanent or temporary implants has been carried out in 179 patients with differentiated gliomas (132 cases) and other tumors-anaplastic gliomas and glioblastomas (16 cases), ependymomas and papillomas (4 cases) and a variety of other mostly extracerebral tumors (27 cases)-in functionally critical cortical or deep-seated location. Brachytherapy with I-125 implants is recommended for slowly proliferating, differentiated non-resectable tumors in functionally critical areas. It enables the surgeon to achieve a radiosurgical tumor removal while carefully avoiding radiation and operative damage to healthy brain. Experimental and clinical data make an individualized treatment for each patient desirable.