title: Diffusion-weighted imaging of nasopharyngeal carcinoma to predict distant metastases.
abstract: Our study aimed to identify diffusion-weighted imaging (DWI) parameters obtained from primary nasopharyngeal carcinoma (NPC) at initial presentation, that can predict patients at risk of distant metastases. One hundred and sixty-four patients underwent pretreatment magnetic resonance imaging and DWI. The apparent diffusion coefficient (ADC)mean, ADCskewness, and ADCkurtosiswere obtained by histogram analysis. Univariate and multivariate analyses of these ADC parameters together with primary volume (PV), nodal volume (NV), T stage, N stage and presence of locoregional relapse (LRR) were compared between patients with distant metastases (DM+) and patients without distant metastases (DM-) at 5 years using logistic regression. Twenty-eight out of 164 patients (17.1 %) were DM+ (2.5-60 months) and 136/164 patients were DM- (61.2-119.4 months). Compared to DM- patients, the primary tumour of DM+ patients showed significantly lower ADCskewness(ADC values with the greatest frequency were higher) (p = 0.041), and higher PV (p = 0.022), NV (p < 0.01), T stage (p = 0.023), N stage (p < 0.01) and LRR (p < 0.01). On multivariate analysis the ADCskewnesswas no longer significant (p = 0.120) and only NV and LRR were independent predictors for DM+ (p = 0.023 and 0.021, respectively). DWI showed that compared to DM- patients, DM+ patients had a significantly lower primary tumour ADCskewness, but at initial presentation NV was the only independent predictor of DM.
authors.affiliation: Department of Imaging and Interventional Radiology, Faculty of Medicine, Prince of Wales Hospital, The Chinese University of Hong Kong, 30-32 Ngan Shing Street, Shatin, New Territories, Hong Kong S.A.R, China.
authors.forename: Qi-Yong
authors.initials: QY
authors.lastname: Ai
authors.affiliation: Department of Imaging and Interventional Radiology, Faculty of Medicine, Prince of Wales Hospital, The Chinese University of Hong Kong, 30-32 Ngan Shing Street, Shatin, New Territories, Hong Kong S.A.R, China. king2015@cuhk.edu.hk.
authors.forename: Ann D
authors.initials: AD
authors.lastname: King
authors.affiliation: Department of Imaging and Interventional Radiology, Faculty of Medicine, Prince of Wales Hospital, The Chinese University of Hong Kong, 30-32 Ngan Shing Street, Shatin, New Territories, Hong Kong S.A.R, China.
authors.forename: Benjamin King Hong
authors.initials: BK
authors.lastname: Law
authors.affiliation: State Key Laboratory in Oncology in South China, Sir Y.K. Pao Center for Cancer, Department of Clinical Oncology, Hong Kong Cancer Institute and Prince of Wales Hospital, The Chinese University of Hong Kong, Hong Kong S.A.R, China.
authors.forename: David Ka-Wai
authors.initials: DK
authors.lastname: Yeung
authors.affiliation: Department of Imaging and Interventional Radiology, Faculty of Medicine, Prince of Wales Hospital, The Chinese University of Hong Kong, 30-32 Ngan Shing Street, Shatin, New Territories, Hong Kong S.A.R, China.
authors.forename: Kunwar S
authors.initials: KS
authors.lastname: Bhatia
authors.affiliation: Medical Physics and Research Department, Hong Kong Sanatorium and Hospital, Hong Kong S.A.R, China.
authors.forename: Jing
authors.initials: J
authors.lastname: Yuan
authors.affiliation: Department of Imaging and Interventional Radiology, Faculty of Medicine, Prince of Wales Hospital, The Chinese University of Hong Kong, 30-32 Ngan Shing Street, Shatin, New Territories, Hong Kong S.A.R, China.
authors.forename: Anil T
authors.initials: AT
authors.lastname: Ahuja
authors.affiliation: Department of Imaging and Interventional Radiology, Faculty of Medicine, Prince of Wales Hospital, The Chinese University of Hong Kong, 30-32 Ngan Shing Street, Shatin, New Territories, Hong Kong S.A.R, China.
authors.forename: Lok Yiu Sheila
authors.initials: LY
authors.lastname: Wong
authors.affiliation: State Key Laboratory in Oncology in South China, Sir Y.K. Pao Center for Cancer, Department of Clinical Oncology, Hong Kong Cancer Institute and Prince of Wales Hospital, The Chinese University of Hong Kong, Hong Kong S.A.R, China.
authors.forename: Brigette B
authors.initials: BB
authors.lastname: Ma
authors.affiliation: State Key Laboratory in Oncology in South China, Sir Y.K. Pao Center for Cancer, Department of Clinical Oncology, Hong Kong Cancer Institute and Prince of Wales Hospital, The Chinese University of Hong Kong, Hong Kong S.A.R, China.
authors.forename: Frankie Kwok Fai
authors.initials: FK
authors.lastname: Mo
authors.affiliation: State Key Laboratory in Oncology in South China, Sir Y.K. Pao Center for Cancer, Department of Clinical Oncology, Hong Kong Cancer Institute and Prince of Wales Hospital, The Chinese University of Hong Kong, Hong Kong S.A.R, China.
authors.forename: Michael K M
authors.initials: MK
authors.lastname: Kam
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002277:Carcinoma; D038524:Diffusion Magnetic Resonance Imaging / Q000379:methods*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D000077274:Nasopharyngeal Carcinoma; D009303:Nasopharyngeal Neoplasms / Q000175:diagnosis* / Q000556:secondary*; D009305:Nasopharynx / Q000000981:diagnostic imaging*; D009362:Neoplasm Metastasis; D009367:Neoplasm Staging / Q000379:methods*; D011237:Predictive Value of Tests
keywords: Diffusion-weighted imaging; Distant metastases; Magnetic resonance imaging; Nasopharyngeal carcinoma