title: Prognostic value of the primary lesion apparent diffusion coefficient (ADC) in nasopharyngeal carcinoma: a retrospective study of 541 cases.
abstract: The prognostic value of the primary lesion pretreatment apparent diffusion coefficient (ADC), which is obtained by diffusion-weighted magnetic resonance imaging (MR-DWI), remains unknown in nasopharyngeal carcinoma (NPC). Thus, to investigate whether the pretreatment ADC value as measured from the primary site on MR-DWI is an independent prognostic factor in NPC, we retrospectively reviewed a cohort of 541 patients with histologically-proven stage I-IVB NPC. All patients underwent MRI using a 3-Tesla system (Trio Tim; Siemens, Erlangen Germany). To calculate ADC, the primary lesion was designated on the ADC map at the level of the largest tumor diameter to cover most of the lesion, avoiding cystic or necrotic components. Median and mean (±SD) pretreatment ADC were 0.713 and 0.716 ± 0.079 × 10(-3) mm(2)/s, respectively. Univariate and multivariate analysis confirmed high pretreatment ADC was a good prognostic factor for poor local relapse-free survival and disease-free survival. Furthermore, the area under the ROC curve for prediction of local failure significantly increased when pretreatment ADC was combined with T classification (P = 0.004). Thus, pretreatment ADC might provide useful information for predicting outcome and selecting high-risk patients appropriate for more aggressive therapy. Further studies are warranted to investigate the biological basis of this observation.
authors.affiliation: Department of Radiation Oncology, Sun Yat-sen University Cancer Center, State Key Laboratory of Oncology in South China, Collaborative Innovation Center for Cancer Medicine, Canton, Guangdong Province, People's Republic of China.
authors.forename: Yuan
authors.initials: Y
authors.lastname: Zhang
authors.affiliation: Department of Radiation Oncology, Sun Yat-sen University Cancer Center, State Key Laboratory of Oncology in South China, Collaborative Innovation Center for Cancer Medicine, Canton, Guangdong Province, People's Republic of China.
authors.forename: Xu
authors.initials: X
authors.lastname: Liu
authors.affiliation: Imaging Diagnosis and Interventional Center, Sun Yat-sen University Cancer Center, State Key Laboratory of Oncology in South China, Collaborative Innovation Center for Cancer Medicine, Canton, Guangdong Province, People's Republic of China.
authors.forename: Yun
authors.initials: Y
authors.lastname: Zhang
authors.affiliation: Department of Radiation Oncology, Sun Yat-sen University Cancer Center, State Key Laboratory of Oncology in South China, Collaborative Innovation Center for Cancer Medicine, Canton, Guangdong Province, People's Republic of China.
authors.forename: Wen-Fei
authors.initials: WF
authors.lastname: Li
authors.affiliation: Department of Radiation Oncology, Sun Yat-sen University Cancer Center, State Key Laboratory of Oncology in South China, Collaborative Innovation Center for Cancer Medicine, Canton, Guangdong Province, People's Republic of China.
authors.forename: Lei
authors.initials: L
authors.lastname: Chen
authors.affiliation: Department of Radiation Oncology, Sun Yat-sen University Cancer Center, State Key Laboratory of Oncology in South China, Collaborative Innovation Center for Cancer Medicine, Canton, Guangdong Province, People's Republic of China.
authors.forename: Yan-Ping
authors.initials: YP
authors.lastname: Mao
authors.affiliation: Imaging Diagnosis and Interventional Center, Sun Yat-sen University Cancer Center, State Key Laboratory of Oncology in South China, Collaborative Innovation Center for Cancer Medicine, Canton, Guangdong Province, People's Republic of China.
authors.forename: Jing-Xian
authors.initials: JX
authors.lastname: Shen
authors.affiliation: Department of Radiation Oncology, Sun Yat-sen University Cancer Center, State Key Laboratory of Oncology in South China, Collaborative Innovation Center for Cancer Medicine, Canton, Guangdong Province, People's Republic of China.
authors.forename: Fan
authors.initials: F
authors.lastname: Zhang
authors.affiliation: Department of Radiation Oncology, Sun Yat-sen University Cancer Center, State Key Laboratory of Oncology in South China, Collaborative Innovation Center for Cancer Medicine, Canton, Guangdong Province, People's Republic of China.
authors.forename: Hao
authors.initials: H
authors.lastname: Peng
authors.affiliation: Department of Medical Statistics and Epidemiology, School of Public Health, Sun Yat-sen University, Canton, People's Republic of China.
authors.forename: Qing
authors.initials: Q
authors.lastname: Liu
authors.affiliation: Department of Radiation Oncology, Sun Yat-sen University Cancer Center, State Key Laboratory of Oncology in South China, Collaborative Innovation Center for Cancer Medicine, Canton, Guangdong Province, People's Republic of China.
authors.forename: Ying
authors.initials: Y
authors.lastname: Sun
authors.affiliation: Department of Radiation Oncology, Sun Yat-sen University Cancer Center, State Key Laboratory of Oncology in South China, Collaborative Innovation Center for Cancer Medicine, Canton, Guangdong Province, People's Republic of China.
authors.forename: Jun
authors.initials: J
authors.lastname: Ma
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D002277:Carcinoma; D015331:Cohort Studies; D038524:Diffusion Magnetic Resonance Imaging; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D053208:Kaplan-Meier Estimate; D008297:Male; D008875:Middle Aged; D000077274:Nasopharyngeal Carcinoma; D009303:Nasopharyngeal Neoplasms / Q000175:diagnosis* / Q000401:mortality* / Q000628:therapy; D009367:Neoplasm Staging; D049268:Positron-Emission Tomography; D011379:Prognosis; D012372:ROC Curve; D012189:Retrospective Studies; D014057:Tomography, X-Ray Computed; D017211:Treatment Failure; D016896:Treatment Outcome; D055815:Young Adult