@article {Nahmias744, author = {Claude Nahmias and Wahid T. Hanna and Lindi M. Wahl and Misty J. Long and Karl F. Hubner and David W. Townsend}, title = {Time Course of Early Response to Chemotherapy in Non{\textendash}Small Cell Lung Cancer Patients with 18F-FDG PET/CT}, volume = {48}, number = {5}, pages = {744--751}, year = {2007}, doi = {10.2967/jnumed.106.038513}, publisher = {Society of Nuclear Medicine}, abstract = {PET and 18F-FDG have the potential to follow the early metabolic response to chemotherapy in patients with non{\textendash}small cell lung cancer and to predict success or failure of the therapy. Methods: We studied 16 patients with non{\textendash}small cell lung cancer as they followed 2 courses of docetaxel and carboplatin. Each patient was studied weekly for 7 wk, and tissue activity was assessed by the amount of radioactivity retained 90 min after the intravenous injection of 18F-FDG. In a prospective analysis, the linear least-squares method was used to evaluate the time course of metabolic activity in tumor and liver, bone marrow, and unaffected lung tissues; a metabolic response was defined as a response in which the slope of the regression was negative and significantly different from zero. Our hypothesis was that patients who exhibited a tumor metabolic response would survive longer than those who did not. In a retrospective examination of our data, we grouped our patients into those who survived \<6 mo and those who survived longer and calculated the difference in the standardized uptake value (SUV) between day 7 and subsequent time points to determine the most appropriate timing of 2 PET studies in predicting response to therapy. Results: Fifteen of 16 patients completed the study. In the prospective study, 8 patients were classified as nonresponders as the slope of the regression of tumor SUV versus time was not different from zero; they all died within 35 wk of the end of their study. Seven patients were classified as responders; 5 survived and 2 died, one at 25 wk and the other at 76 wk. In the retrospective study, a decrease of 0.5 SUV between studies performed at 1 and 3 wk after the initiation of chemotherapy was predictive of those patients who survived \>6 mo and in whom chemotherapy was presumably successful. Conclusion: Patients with non{\textendash}small cell lung cancer who had a positive outcome, as exhibited by prolonged survival, were those who showed a tumor metabolic response assessed using weekly 18F-FDG PET studies. 18F-FDG PET studies performed at 1 and 3 wk after the initiation of chemotherapy allowed prediction of the response to therapy.}, issn = {0161-5505}, URL = {https://jnm.snmjournals.org/content/48/5/744}, eprint = {https://jnm.snmjournals.org/content/48/5/744.full.pdf}, journal = {Journal of Nuclear Medicine} }