Efficacy and Safety of Intrathecal Administration of Thiotepa in Combination With Methotrexate in Breast Cancer With Leptomeningeal Metastasis

This study is testing whether injecting two chemotherapy drugs — thiotepa and methotrexate — directly into the fluid around the brain (intrathecal route) can help women with breast cancer that has spread to the membranes surrounding the brain and spinal cord (leptomeningeal metastasis). **You may be eligible if...** - You are a woman aged 18–75 with confirmed breast cancer - Your cancer has spread to the membranes surrounding the brain/spinal cord - You can have or already have an Ommaya reservoir (a small device implanted under the scalp for drug delivery) - You have at least one measurable lesion - Your blood counts and organ function meet the required thresholds **You may NOT be eligible if...** - Your general health is severely declined - You have significant active brain bleeding or uncontrolled infection - You cannot tolerate the required procedures Talk to your doctor to see if this trial is right for you.