[Trastuzumab and blood-brain barrier].

Due to its large molecular weight trastuzumab is easily blocked by the intact blood brain-barrier or even when it's partly impaired in meningeal carcinomatosis or brain metastasis. Its penetration is facilitated by whole-brain-radiotherapy but trastuzumab only reaches rather low and most likely therapeutically inadequate levels in central nervous system after intravenous application. Further investigations with lapatinib are warrented.