Tumor Treating Fields for the Treatment of Leptomeningeal Metastases of the Spine in Patients With Breast or Lung Cancer

This study is testing a wearable device that delivers low-level electrical fields (called Tumor Treating Fields) to the spine in patients with breast or lung cancer that has spread to the lining of the spinal cord (called leptomeningeal metastases), a very serious and difficult-to-treat complication. **You may be eligible if...** - You are 18 or older - You have a prior diagnosis of breast cancer or lung cancer - Your cancer has spread to the lining of the spinal cord, confirmed by spinal MRI and spinal fluid testing - You are willing to wear the device for at least 18 hours per day - Your general health level meets the study criteria (ECOG 0–3) - You have adequate blood counts and organ function **You may NOT be eligible if...** - Your cancer spread to the spinal lining has not been confirmed with both imaging and fluid testing - Your body shape does not allow the device to be properly fitted - You are unable to attend scheduled follow-up visits - You have another serious condition that would interfere with safety assessments Talk to your doctor to see if this trial is right for you.