title: Early assessment of induction chemotherapy response of nasopharyngeal carcinoma by pretreatment diffusion-weighted magnetic resonance imaging.
abstract: OBJECTIVE
  This study aimed to evaluate the feasibility of pretreatment diffusion-weighted imaging in predicting response after induction chemotherapy (IC) in nasopharyngeal carcinoma (NPC).
  
  
  METHODS
  Fifty-four patients with stage III and IV NPC underwent MRI examination at baseline, after 2 cycles of chemotherapy, and at the end of chemoradiotherapy. Apparent diffusion coefficient (ADC) values were compared between effective and ineffective subjects after IC.
  
  
  RESULTS
  Mean ADC in effective groups was significantly (P < 0.05) higher than that in the ineffective group. Average and minimum ADCs demonstrated higher sensitivity than maximum ADC for predicting IC response, with 68.4%, 71.1%, and 50.0%, respectively, at an equivalent 68.7% specificity. We observed negative correlations between pretreatment ADC and tumor regression after chemotherapy (γ = - 0.425, P = 0.001) and after chemoradiotherapy (γ = - 0.418, P = 0.003).
  
  
  CONCLUSIONS
  Pretreatment ADC was a valuable biomarker for predicting IC response of NPC. Noninvasive diffusion-weighted imaging provides additional indicator in guiding optical therapeutic options for patients with NPC.
authors.affiliation: From the Departments of *Radiology, and †Radiation Oncology, Fujian Provincial Cancer Hospital and Institute, Fuzhou, Fujian, People's Republic of China.
authors.forename: Dechun
authors.initials: D
authors.lastname: Zheng
authors.forename: Yunbin
authors.initials: Y
authors.lastname: Chen
authors.forename: Ying
authors.initials: Y
authors.lastname: Chen
authors.forename: Luying
authors.initials: L
authors.lastname: Xu
authors.forename: Fengjie
authors.initials: F
authors.lastname: Lin
authors.forename: Jin
authors.initials: J
authors.lastname: Lin
authors.forename: Chaobin
authors.initials: C
authors.lastname: Huang
authors.forename: Jianji
authors.initials: J
authors.lastname: Pan
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D002277:Carcinoma; D059248:Chemoradiotherapy / Q000379:methods*; D038524:Diffusion Magnetic Resonance Imaging / Q000379:methods*; D042241:Early Diagnosis; D005240:Feasibility Studies; D005260:Female; D006801:Humans; D060828:Induction Chemotherapy / Q000379:methods*; D008297:Male; D008875:Middle Aged; D000077274:Nasopharyngeal Carcinoma; D009303:Nasopharyngeal Neoplasms / Q000175:diagnosis* / Q000628:therapy*; D011379:Prognosis; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D016896:Treatment Outcome; D055815:Young Adult