[en] Linac-based stereotactic irradiation (STI) with high quality assurance, a new therapeutic modality for intracranial tumors, was introduced to the Jichi Medical School Hospital in 1997. Initial clinical results of 32 patients with 64 metastatic lesions treated with STI between October 1997 and December 1999 were analyzed. Problems and prospects of STI were further discussed in this communication. The fifty percent survival time of all the subjects was 9.7 months. The survival rate at 6 and 12 months was 71.2% and 41.2%, respectively. The initial local control rate assessed by MR images was 96.6% at 3 months in the 33 lesions managed with STI alone, excluding 3 cases of suspected radionecrosis. The rate of those free from progression of tumors was 53.3% at 6 months and 47.9% at 12 months. The number of brain metastases, as one of the main targets of STI, has been increasing with the recent advances of therapy for cancer patients. Those patients who have single or, at most, four brain metastases with less than 3.5 cm in diameter and with no active extracranial diseases are good candidates for STI. STI may be included in a choice of treatment modalities for brain metastases because it has high local control rate and preserves good quality of life in cancer patients. (author)