PT - JOURNAL ARTICLE AU - Lale Kostakoglu AU - Stanley J. Goldsmith TI - <sup>18</sup>F-FDG PET Evaluation of the Response to Therapy for Lymphoma and for Breast, Lung, and Colorectal Carcinoma DP - 2003 Feb 01 TA - Journal of Nuclear Medicine PG - 224--239 VI - 44 IP - 2 4099 - http://jnm.snmjournals.org/content/44/2/224.short 4100 - http://jnm.snmjournals.org/content/44/2/224.full SO - J Nucl Med2003 Feb 01; 44 AB - PET is a unique form of diagnostic imaging that observes in vivo biologic changes using radiopharmaceuticals that closely mimic endogenous molecules. 18F-FDG, which allows the evaluation of glucose metabolism, is the most commonly used tracer in oncology because of the practical half-life of 18F (110 min), compared with other short-lived positron emitters. 18F-FDG uptake in tumors is proportional to the glycolytic metabolic rate of viable tumor cells indicating the increased metabolic demand of tumors for glucose. 18F-FDG PET significantly improves the accuracy of imaging tumors in initial staging, management of recurrent cancer, and monitoring of therapy response. The information provided by this technique is more sensitive and specific than that provided by anatomic imaging modalities. 18F-FDG PET is particularly superior to CT or MRI in the ability to evaluate the effectiveness of various treatment regimens early during therapy or after therapy. In this review, we discuss the role of 18F-FDG PET in evaluating the response to therapy and the impact of this information on patient management.