Positron Emission Tomography Imaging of Lung Cancer

This article reviews the role of 18F-2-deoxy-d-glucose (FDG) positron emission tomography (PET) imaging in staging, radiation therapy planning, and determination of prognosis and therapeutic response in patients with nonsmall cell lung cancer. In addition, radiotracers that interrogate different metabolic pathways, receptors, and targets to overcome the potential limitations of FDG-PET in staging, as well as early response evaluation and monitoring of response to targeted therapies, are reviewed. 18F-2-deoxy-D-glucose (FDG) positron emission tomography (18FDG-PET) imaging has a key role in staging, radiation therapy planning, and determination of prognosis and therapeutic response in patients with non-small cell lung cancer. FDG-PET-CT is not optimal in determination of T descriptors (additional small lung nodules, locoregional invasion, etc.) as respiratory motion and or low-radiation-dose imaging degrade image quality. Radiotracers interrogate different metabolic pathways, receptors, and targets to overcome the potential limitations of FDG-PET in staging, as well as perform early response evaluation and monitoring of response to targeted therapies. A PET-CT-defined tumor target is usually smaller than that defined by CT, and incorporation of PET-CT into radiotherapy planning can allow radiation-dose escalation without increasing side effects. FDG is the only Medicare-approved PET-CT tracer for evaluation of cancer. Novel PET radiotracers that interrogate different metabolic pathways beyond glycolysis, receptors, and targets are being evaluated in staging, response evaluation, and targeted therapy assessment.