Pitfalls in FDG PET-CT

Abstract

Since FDG-PET is rapidly gaining a crucial role in therapeutic decision-making and management of cancer patients, it is important to clarify the incidence and causes of potential pitfalls. The most important issue to remember is that ¹⁸F-FDG is not a tumor-specific tracer since inflammatory conditions and some benign processes may cause areas of increased FDG uptake. Several examples of potentially misleading inflammatory processes causing false positive results are reported in the literature. Most common sources of such misinterpretations include nonspecific inflammation, abscess, sarcoidosis and other granulomatous diseases, post-radiation inflammatory processes, gastritis and colitis. Although the degree of inflammatory process uptake is usually less than the uptake within the neoplastic tissues, there is clearly an overlap between the two conditions and, in some cases, the uptake could even exceed the neoplastic uptake.