title: Time course of early response to chemotherapy in non-small cell lung cancer patients with 18F-FDG PET/CT.
abstract: PET and (18)F-FDG have the potential to follow the early metabolic response to chemotherapy in patients with non-small cell lung cancer and to predict success or failure of the therapy.
  
  
  METHODS
  We studied 16 patients with non-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 (18)F-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.
  
  
  CONCLUSIONS
  Patients with non-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 (18)F-FDG PET studies. (18)F-FDG PET studies performed at 1 and 3 wk after the initiation of chemotherapy allowed prediction of the response to therapy.
authors.affiliation: Department of Medicine, University of Tennessee, Knoxville, TN 37920-6999, USA. CNahmias@mc.utmck.edu
authors.forename: Claude
authors.initials: C
authors.lastname: Nahmias
authors.forename: Wahid T
authors.initials: WT
authors.lastname: Hanna
authors.forename: Lindi M
authors.initials: LM
authors.lastname: Wahl
authors.forename: Misty J
authors.initials: MJ
authors.lastname: Long
authors.forename: Karl F
authors.initials: KF
authors.lastname: Hubner
authors.forename: David W
authors.initials: DW
authors.lastname: Townsend
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D005260:Female; D006801:Humans; D008297:Male; D000970:Antineoplastic Agents / Q000008:administration & dosage; D016190:Carboplatin / Q000008:administration & dosage; D002289:Carcinoma, Non-Small-Cell Lung / Q000175:diagnosis / Q000000981:diagnostic imaging / Q000188:drug therapy; D000077143:Docetaxel; D019788:Fluorodeoxyglucose F18; D008175:Lung Neoplasms / Q000175:diagnosis / Q000188:drug therapy; D049268:Positron-Emission Tomography / Q000379:methods; D011379:Prognosis; D019275:Radiopharmaceuticals; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D043823:Taxoids / Q000008:administration & dosage; D013997:Time Factors; D014057:Tomography, X-Ray Computed / Q000379:methods; D016896:Treatment Outcome
chemical_list: D000970:Antineoplastic Agents; D016190:Carboplatin; D000077143:Docetaxel; D019788:Fluorodeoxyglucose F18; D019275:Radiopharmaceuticals; D043823:Taxoids