Super-selective Intra-arterial Cerebral Infusion of Trastuzumab for the Treatment of Cerebral Metastases of HER2/Neu Positive Breast Cancer

The purpose of this study is to evaluate the safety of administering a single dose of trastuzumab into the artery for the treatment of brain metastasis(es) from HER2/neu positive breast cancer. This study will try to determine the best tolerated single dosage of trastuzumab administered into arteries by gradually increasing the dosage given to participants as the study progresses. Early participants will receive a dosage of 1 mg/kg. As more participants enroll into the study, this single dosage will be increased at designated levels up to 8 mg/kg, if it's determined to be safe to increase. Trastuzumab is a type of antibody, which is a protein used by the body's immune system to fight against pathogens such as bacteria and viruses. This antibody binds to cell receptors known as the HER2/neu tyrosine kinase receptor. These receptors are expressed in certain cancer subtypes such as breast cancer. By blocking signaling through this HER2/neu receptor, trastuzumab can slow down or stop the over-expression of the HER2/neu protein. Over-expression of HER2/neu has been shown to play a role in the development and progression of certain types of breast cancer. Therefore, by slowing down or stopping the expression of HER2/neu, investigators hope to slow down or stop the growth of metastasis(es) and increase the responsiveness to therapy.