Gamma knife radiosurgery for metastatic brain tumors

Sixty-three patients with metastatic brain tumors have had stereotactic radiosurgery 90 times with the Leksell Gamma Knife over a 29-month period. Initially, a single treatment of 35 to 45 Gy was delivered to the enhanced CT margin. This dose was found to be inadequate for tumor control. We then raised the marginal dose to 50 to 55 Gy, but even this radiosurgical dose did not appear to control tumor growth. However, we have found that metastatic brain tumors can be controlled successfully using enhanced MR scans and a peripheral dose of 60 Gy or even 65 Gy adjacent to the enhanced margins of the metastatic brain tumors, especially melanomas.