PET scans are great, but...
A positron emission tomography (PET) scan is an important imaging test that is commonly used in follow-up of the lymphoma patient to assess the response to therapy. Recurrent lymphoma tumor causes the image on the scan to be abnormal. (Additionally, PET scans are also used in evaluation of other diseases, e.g., heart disease.)
What I wish to bring to your attention is that the PET scan is very important, indeed, very valuable, but is so sensitive that it can produce a "false positive" result. False positive means that the PET scan image is abnormal, but there is NO lymphoma tumor present. A false positive image may be the result of an insignificant infection (or, at times, a more important infection).
The "bottom line"---if you have a PET scan report that is considered abnormal, do not become immediately alarmed, but rather, speak with your physician whether the scan report might be a false positive finding.
Mort