Introduction: The combination of stereotaxic techniques, advances in neuroimaging and the creation of continually improving software has permitted stereotaxic biopsy of cerebral lesions at the most varied sites. Improvement in the method of permanent interstitial radiation (brachytherapy) improves the precision with which the radioactive sources may be inserted, releasing a maximum dose of radiation to the tumour with minimum radiation to the surrounding tissue.
Patients and methods: We treated 237 patients (aged 1 to 78 years) with intracranial lesions, all included in the protocol of our centre. Stereotaxic systems of Leksell, Riechert-Mundinger, Micromar and Estereoflex were used. The procedure was in three stages: acquisition of the image, surgical planning and surgical operation. The imaging guide was the computerized axial tomography (CAT).
Results: Stereotaxic biopsy guided by CAT images was done in 153 patients. These were divided into three groups, taking the biopsy findings as the reference: group A (primary tumors, 128), group B (metastatic tumors, 15) and group C (non-malignant lesions, 10). Ninety six permanent implants of 192Ir were inserted, with a low dose of 4-7 cGy/h and a total dose of 80-120 Gy.
Conclusions: Stereotaxic biopsy is a very effective procedure with a significantly low range of complications. The permanent implant with a low dose rate, well situated and using a source of 192Ir is a safe, simple, effective method for the treatment of primary and recurrent glial tumours, and non-glial tumours which fulfil criteria for this type of brachytherapy.