[schoonder]

Dearjilly,
To get medication around the blood/brain barrier problem, a possible approach could be to administer the Herceptin directly into central nervous system via an intrathecal or lumbar puncture, if oncologist is willing to go that route.

Ronpaule, a member of this Board, has discussed this particular subject at some level of detail. A search for those posts or possibly even sending an e-mail may provide you with more knowledge about this procedure.