title: Diffusion-weighted MRI versus 18F-FDG PET/CT: performance as predictors of tumor treatment response and patient survival in patients with non-small cell lung cancer receiving chemoradiotherapy.
abstract: OBJECTIVE
  The purpose of this study was to compare the predictive capabilities of diffusion-weighted MRI (DWI) and 18F-FDG PET/CT for tumor response to therapy and survival in patients with non-small cell lung cancer (NSCLC) receiving chemoradiotherapy.
  
  
  METHODS
  The study included 64 patients with NSCLC diagnosed as stage III who underwent pretherapeutic DWI and FDG PET/CT and were treated with chemoradiotherapy. For quantitative prediction, apparent diffusion coefficient (ADC) for DWI and maximum standardized uptake value (SUVmax) for PET/CT were measured at all targeted lesions and averaged to obtain final values for each patient. To evaluate the predictive capability of either index for distinguishing partial response and nonresponse (stable or progressive disease) groups, receiver operating characteristic analysis was performed, and sensitivity, specificity, and accuracy of the two modalities were compared using the McNemar test. Finally, overall and progression-free survival curves divided by the corresponding threshold value were compared by means of the log-rank test.
  
  
  RESULTS
  The area under the curve (Az) for ADC (Az=0.84) was significantly larger than that for SUVmax (Az=0.64, p<0.05). The application of feasible threshold values resulted in specificity (44.4%) and accuracy (76.6%) of DWI becoming significantly higher than those of PET/CT (specificity, 11.1%; p<0.05 and accuracy, 67.2%, p<0.05). In addition, only overall survival and progression-free survival of the two groups divided by ADC at 2.1×10(-3) mm2/s and SUVmax at 10 showed a significant difference (p<0.05).
  
  
  CONCLUSIONS
  DWI may have better potential than FDG PET/CT for prediction of tumor response to therapy in NSCLC patients before chemoradiotherapy.
authors.affiliation: Department of Radiology, Kobe University Graduate School of Medicine, and Kobe University Hospital, 7-5-2 Kusunoki-cho, Chuo-ku, Kobe 650-0017, Japan. yosirad@kobe-u.ac.jp
authors.forename: Yoshiharu
authors.initials: Y
authors.lastname: Ohno
authors.forename: Hisanobu
authors.initials: H
authors.lastname: Koyama
authors.forename: Takeshi
authors.initials: T
authors.lastname: Yoshikawa
authors.forename: Keiko
authors.initials: K
authors.lastname: Matsumoto
authors.forename: Nobukazu
authors.initials: N
authors.lastname: Aoyama
authors.forename: Yumiko
authors.initials: Y
authors.lastname: Onishi
authors.forename: Kazuro
authors.initials: K
authors.lastname: Sugimura
mesh_terms: D000328:Adult; D000368:Aged; D001706:Biopsy; D002289:Carcinoma, Non-Small-Cell Lung / Q000000981:diagnostic imaging* / Q000628:therapy*; D059248:Chemoradiotherapy; D003287:Contrast Media; D038524:Diffusion Magnetic Resonance Imaging / Q000379:methods*; D005260:Female; D019788:Fluorodeoxyglucose F18; D006801:Humans; D007090:Image Interpretation, Computer-Assisted; D008175:Lung Neoplasms / Q000000981:diagnostic imaging / Q000473:pathology* / Q000628:therapy*; D008297:Male; D008875:Middle Aged; D064847:Multimodal Imaging / Q000379:methods*; D009367:Neoplasm Staging; D049268:Positron-Emission Tomography; D011237:Predictive Value of Tests; D011446:Prospective Studies; D012372:ROC Curve; D019275:Radiopharmaceuticals; D012680:Sensitivity and Specificity; D016019:Survival Analysis; D014057:Tomography, X-Ray Computed; D016896:Treatment Outcome
chemical_list: D003287:Contrast Media; D019275:Radiopharmaceuticals; D019788:Fluorodeoxyglucose F18