Potential clinical utility of dual time point FDG-PET for distinguishing benign from malignant lesions: implications for oncological imaging Posible utilidad clínica del estudio FDG-PET en dos tiempos para distinguir las lesiones benignas de las malignas: implicaciones para la imagen oncológica

The utility of 18F-fl uorodeoxyglucose (FDG)-positron emission tomography (PET) is widely recognized for the management of patients with cancer encompassing several aspects including diagnosis, staging, and monitoring therapeutic intervention1. However, FDG not only accumulates within malignant tumor sites but also in the infl ammatory lesions. As a result, the clinical utility of FDG-PET is also being investigated for detection, characterization, and monitoring of patients with infectious and non-infectious infl ammatory processes in several centres across the world. Functional imaging, in certain settings, has superior diagnostic performance characteristics compared with those of structural imaging techniques such as computed tomography (CT) and magnetic resonance imaging (MRI). For example, FDG-PET has been shown to be highly sensitive in the detection of chronic osteomyelitis, infection of implanted prostheses, the source of fever of unknown origin, vasculitis, infl ammatory bowel disease, and atherosclerosis2. However, non-specifi c accumulation of FDG in benign processes such as infl ammation and infection can make it diffi cult at times to distinguish malignant neoplastic lesions from the benign ones. Fortunately, dual time point and delayed FDG-PET imaging allows for distinction between these two distinct pathological categories, as the pattern and rate of FDG uptake over time vary considerably between malignant and benign processes. Hence, dual time point FDG-PET has gained considerable interest in the recent literature as an important diagnostic approach to improve the overall sensitivity, specifi city, and accuracy of FDG-PET3