There are few guidelines on how best to follow patients in complete remission after chemotherapy for lymphoma. Most experts agree that routine visits to the doctor are worthwhile. The question of routine imaging, however, is less clear. Historically, routine chest x-rays were replaced by CT scans under the assumption that more information was better. We are facing a similar shift in paradigm as many patients now undergo routine PET/CT imaging.
A recent study published in the journal Leukemia & Lymphoma found that only 21% of positive surveillance PET/CT scans represented actual relapse; i.e., 79% of patients with scans that were read as positive had not relapsed. Patients with false-positive scans therefore underwent additional scanning and invasive biopsies with no benefit. Moreover, the scans added over $8000 per patient to the cost of follow up. A related study performed at Weill Cornell Medical College found that routine scanning was associated with significant anxiety and even post-traumatic stress disorder.
Until there is better evidence to guide decisions regarding routine surveillance, it is important to talk with your doctor. Ask about the pros and cons as they apply to you personally. Try to agree on a plan that is acceptable to both of you.
New Developments in Lymphoma 
Dr. Martin:
I had a false positive experience and it led to all the things discussed above. PET/CT scans have had a positive place in my treatment; however, they are simply a tool and not a diagnosis. If I learned anything in my experience, it has been to trust my own instincts. I have known before any test or exam that something was developing.
Thank you for the update.
Peg Gould