摘要:Background: Carcinomatous Meningitis (CM) refers to the multifocal seeding of the leptomeninges by malignant cells. CM occurs in approximately 5% of patients with breast cancer. Herein, we suggest that Intrathecal (IT) can use in treatment of breast cancer patients with CM before of any treatment until can prevent of going patient to debilitating phase of this disease. Patients and Methods: Three patients with high risk breast cancer with CM: A 62 year-old Kurdish woman with a history of lung tuberculosis. Her cerebrospinal fluid was positive for malignant cells. She treated with IT chemotherapy and died 3 months after diagnosis of CM. A 48 year-old woman in premenopausal states had a left axillary mass for last 4 months. After one year of followed up she complaints with refractory headache. In cerebrospinal fluid (CSF) analysis with diagnosis of CM treated with brain irradiation and multiple courses of IT chemotherapy. After six months she is well still and in follow up with previous drug list and monthly IT chemotherapy. A 63 year-old woman was presented at the emergency department of our hospital. After 4 months of her treatment she complained from decrease of consciousness and in CSF analysis with positive cytology. She treated with IT chemotherapy and She died about 2 weeks ago with exacerbation of brain tumor. Conclusion: According to the poor prognosis of this disease it is better that in high risk breast cancer patients like Non-Hodgkin lymphoma (NHL) high risk patients. IT prophylaxis was done for these high risk patients because by this way, we can prevent of going patient to debilitating phase of this disease.