advice to stay on herceptin or not?

[sarah]

Hello,
I saw my onc and he said we should think about stopping herceptin in 6 months. Here in France it will be a mutual decision. I can stay on it for life if I want to. in fact he asked me if stopping worried me. The idea used to send me into a panic but i'm ok with the idea now.
my cancer has NEVER shown up on scans of any kind including a Petscan and MRI. the MRI showed some inflammation that was inconclusive. Only the biopsy showed that it had spread outside the breast.

so my questions:
1. Do I stay on herceptin - I have no ill effects from it
2. What are the best tests to see very small cancer? MRI, Petscan, Catscan. not clear on what each one does.
thanks
Sarah