Therapy Monitoring with Fluorine-18 FDG-PET and Fluorine-18 FDG-PET/CT

PET with the glucose analog [18F]-FDG is increasingly used to monitor tumor response in patients undergoing chemotherapy and chemoradiotherapy. The clinical value of FDG PET for differentiation of residual tumor and therapy-induced fibrosis has been documented for gastrointestinal cancer. Furthermore, quantitative assessment of therapy-induced changes in tumor [18F]-FDG uptake may allow the prediction of tumor response and patient outcome very early in the course of therapy. This suggests that FDG PET may be used to identify nonresponders early during neoadjuvant chemoradiotherapy, allowing for early modifications of the treatment protocol.