Permanent low-activity iodine-125 implants for cerebral metastases.

Beginning in 1987, selected patients with metastatic brain tumors were treated with permanent implants of low-activity radioactive iodine-125(125I) seeds. These patients underwent craniotomy, gross total resection of the metastatic lesion, and placement of the seeds. In general, criteria for treatment included the presence of a recurrent tumor with a volume too large to permit radiosurgery, and a Karnofsky Performance Score of 70 or higher. Thirteen patients underwent 14 implant procedures; all received external whole-brain radiotherapy. Implant dose ranged from 43 Gy to 132 Gy, with a mean of 83 Gy. Survival after implantation ranged from 2 weeks to almost 9 years, with a median of 9 months. Clinical and radiographic local control was obtained in 9 patients. Two patients died of acute, postoperative complications within a month of implantation, so no information regarding tumor control is available for them. Late complications included a bone flap infection in one patient and a CSF leak in another; both were treated without further sequelae. These results demonstrate that permanent 125I implants can results in good survival and quality of life, and occasionally can yield long-term survival. Potentially, it is a cost-effective treatment in that a separate procedure for stereotactic implantation or radiosurgery is not needed, as is the case with the use of temporary high-activity seeds. The permanent implantation itself adds less than 10 minutes to the craniotomy, and the risk of symptomatic radiation necrosis is low. We recommend consideration of this procedure in patients harboring large, recurrent metastatic tumors that require further surgery.