title: Correlation between MR imaging-derived nasopharyngeal carcinoma tumor volume and TNM system.
abstract: OBJECTIVE
  To measure nasopharyngeal carcinoma tumor volume based on magnetic resonance images using a validated semiautomated measurement methodology and correlate tumor volume with TNM T classification.
  
  
  METHODS
  The study population consisted of 206 consecutive nasopharyngeal carcinoma patients who had magnetic resonance imaging staging scans. Tumor volume was measured using a semisupervised knowledge-based fuzzy clustering algorithm. Patients were divided into 4 groups according to TNM T classification. The difference in tumor volumes among the various TNM T-classification groups was examined.
  
  
  RESULTS
  The mean tumor volume in each T-classification group is as follows: T1, 8.6 mL +/- 5.0 (standard deviation [SD]); T2, 18.1 mL +/- 8.1 (SD); T3, 25.8 mL +/- 14.1 (SD); and T4, 36.2 mL +/- 18.9 (SD). The mean tumor volume increased significantly with advancing T classification (p < 0.0001). Tumor volume in a more advanced T group was significantly larger than that in an adjacent early T group (p < 0.01).
  
  
  CONCLUSIONS
  Validated magnetic resonance imaging-based tumor volume shows positive correlation between tumor volume and advancing T-classification groups. It may be possible to incorporate tumor volume as an additional prognostic factor into the existing TNM system.
authors.affiliation: Department of Diagnostic Radiology, Faculty of Medicine, National University of Singapore, Singapore, Singapore. dnrchv@nus.edu.sg
authors.forename: Vincent F H
authors.initials: VF
authors.lastname: Chong
authors.forename: Jia-Yin
authors.initials: JY
authors.lastname: Zhou
authors.forename: James B K
authors.initials: JB
authors.lastname: Khoo
authors.forename: Kap-Luk
authors.initials: KL
authors.lastname: Chan
authors.forename: Jing
authors.initials: J
authors.lastname: Huang
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000465:Algorithms; D002648:Child; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D009303:Nasopharyngeal Neoplasms / Q000473:pathology*; D009367:Neoplasm Staging / Q000379:methods; D012189:Retrospective Studies; D018709:Statistics, Nonparametric