Just found this phase one trial for Her2+ brain mets at Duke:

Intrathecal Pertuzumab and Trastuzumab in Patients With New Untreated Asymptomatic or Low Symptomatic Brain Metastasis in HER2 Positive Breast Cancer

https://clinicaltrials.gov/ct2/show/NCT02598427

"Intrathecal administration of pertuzumab and trastuzumab will occur via lumbar puncture (spinal tap) under fluoroscopic guidance by interventional radiology at Duke University Medical Center. The spinal needle will be inserted into the spinal column and 7 mL of cerebrospinal fluid (CSF) will be collected. Once the CSF is removed, the intrathecal pertuzumab and trastuzumab will be administered using aseptic technique."