Question for the ladies who had positive IM node

[Brenda_D]

At my last Pet/CT scan, last Oct, a positive IM node that was on my first Pet/CT, no longer lit up. I was told that the chemo and rads had knocked it out.
Fast forward to today, and almost 1 year after that last scan, how will I know that it's still negative in the IM node chain? Should I request a new Pet/CT in October?
I see my onc for a 3 month follow up next week.
I intend to ask him about that and also what my chances are for re-occurence. At this time I'm NED. Just finished Herceptin in May.
I'm a little afraid he may say "no scans unless you have symptoms", and I never had symptoms of the a positive IM node even back then. We only found it because I had the pet/ct scan.