Scans or ways to evaluate cancer after chemo?

[gdavis]

My wife Deb has completed A/C cycles (4) and Taxol/Herceptin cycles (12 @ 1week intervals). She just started the Herceptin alone at 1/week for 40 weeks. She was diagnosed with DCIS, microinvasion, Her2+ (at some level or grade), ER+PR+, 1 node of 6 removed with cancer (stage 2...). They assumed the grade to be high but couldn't tell in from the biopsy.

My question is this; we asked the oncologist about doing some form of scan, PET or MRI or something to find out if there was any cancer elsewhere in her body after these initial chemo sessions were completed.

He told us that he doesn't recommend doing that since there are more problems with false positives than help in finding anything. He recommends waiting until a sympton arises.

But in reality, there were no symptons initially. So why should we wait for symptoms when it seems like that would be too late to do anything about it.

Does anyone know when and why scans of any type are performed????

thanks,