Hi Maureen.
I can't judge what an ideal time interval for checking is but in my case, my oncologist has just moved me to a 16-week interval now that I am almost 4 years post treatment. Before that, it was at a 3 month schedule and for the first year, it was even a monthly one as my doctor told me that my chance of recurrence was pretty high due to the advanced stage. Like Brian, my scans are now given annually and I only had PET/CT scan once last year when my blood tumor marker showed some abnormal reading. Other than that, I just have MRI,ultrasound to the neck and the abdomen and chest x-ray. At most doctor visits, I also had a nose scope which took only a few minutes. I shall have my next appointment in October and I won't expect anything abnormal.

Karen