Role of positron emission tomography in the early prediction of response to chemotherapy in patients with non--small-cell lung cancer.

In recent years, molecular imaging with [(18)F]fluorodeoxyglucose-positron-emission tomography, [(18)F]FDG-PET, has become part of the standard of care in initial staging of patients with non-small-cell lung cancer. Currently, there is an increasing interest in the role of [(18)F]FDG-PET in the evaluation of biological characteristics of the tumor and the prediction of response to anticancer therapies at an early phase of treatment. According to the existing data, quantitative assessment of therapy-induced changes in tumor [(18)F]FDG uptake may allow the prediction of tumor response and patient outcome very early in the course of therapy. Treatment may be adjusted according to the chemosensitivity of the tumor tissue in an individual patient. Thus, [(18)F]FDG-PET has the potential to reduce the side effects and costs of ineffective therapy. This review provides an update on recent studies that evaluate the role of [(18)F]FDG-PET in the early prediction of response to chemotherapy and prognosis in patients with non-small-cell lung cancer. In addition, it discusses the application of [(18)F]FDG-PET to the monitoring of new targeted forms of anticancer therapy and particularly of epidermal growth factor receptor tyrosine kinase inhibitors. Finally, it evaluates the usefulness of [(18)F]fluorothymidine, a PET tracer for imaging tumor proliferation, in predicting response to therapy in patients with lung cancer.