Intracavitary Carrier-embedded Cs131 Brachytherapy for Recurrent Brain Metastases: a Randomized Phase II Study

This study tests whether placing a small radioactive implant (Cs-131 brachytherapy seeds embedded in a collagen carrier) inside the cavity left after brain surgery can reduce the chance that a previously irradiated brain metastasis comes back again. It is a randomized Phase II study. **You may be eligible if...** - You are 18 or older and can give informed consent - You are having planned surgery (craniotomy) to remove a brain metastasis that was previously treated with radiation and is suspected of still being alive (viable) - Your expected extent of removal is at least 95% of the tumor - Your functional status is adequate (Karnofsky ≥ 70) - You can undergo MRI with contrast dye **You may NOT be eligible if...** - You cannot tolerate MRI or CT - You are pregnant (negative test required within 30 days of surgery) - You are breastfeeding and unwilling to pause - Your cancer has spread along the brain lining (leptomeningeal disease) or you have more than 5 additional active brain tumors Talk to your doctor to see if this trial is right for you.