Increased Her2 serum marker

[Julie2]

I have been on Herceptin and Tykerb since 4 months. My Her2 ELISA numbers were constantly decreasing or stable during these 4 months but the recent one jumped up by 4 points to 12.4. I know from past experience that means trouble. I am kind of worried and figuring out the options. I have been having mets in mediastinal lymph nodes since Aug 07. I have already used Navelbine. It takes me to NED and when I stop, it comes back. Anybody used cyberknife for their mediastinal lymph nodes? How effective it is for multiple lymph nodes?

Thanks,
Julie