Cyberknife Radiosurgery and Concurrent Intrathecal Chemotherapy for Leptomeningeal Metastases: Case Report of Prolonged Survival of a HER-2+ Breast Cancer Patient Status-Post Craniospinal Irradiation.

Leptomeningeal disease (LMD) from breast cancer is usually a rapidly fatal condition, with median overall survival reported to be 15 weeks. Conventional treatment for LMD includes craniospinal irradiation and intrathecal (IT) methotrexate. However, the role of stereotactic radiation for leptomeningeal disease remains poorly defined. This case report describes our experience using Cyberknife radiosurgery to treat a 49-year-old female with HER-2+ breast cancer and focal/nodular leptomeningeal metastases that were refractory to craniospinal irradiation and concurrent IT chemotherapy. This combined approach--i.e., craniospinal irradiation, IT chemotherapy, and Cyberknife Radiosurgery for local, recurrent metastases--resulted in survival of 46 months with controlled disease. Based on our experience with this patient, we believe further consideration of radiosurgery for LMD is warranted.