title: Prognostic value of metabolic tumor volume as measured by fluorine-18-fluorodeoxyglucose positron emission tomography/computed tomography in nasopharyngeal carcinoma.
abstract: BACKGROUND
  The prognostic value of the tumor burden characterized by the metabolic tumor volume (MTV) remains under investigation in nasopharyngeal carcinoma (NPC). The purpose of this study was to evaluate the prognostic value of the maximum standardized uptake value (SUVmax ) and MTV according to metabolic volume threshold as measured by positron emission tomography (PET)/computed tomography (CT), and other clinical factors, in patients with NPC.
  
  
  METHODS
  This study was a retrospective chart review. We evaluated the association of SUVmax , MTV2.5 , MTV3.0 , and other clinical factors with overall survival (OS) using Kaplan-Meier and Cox regression models. (MTV2.5 and MTV3.0 are the volume of hypermetabolic tissue within the regions of gross tumor volumes with a SUV value greater than the threshold values of 2.5 and 3.0, respectively.)
  
  
  RESULTS
  Higher MTV2.5 of 31.45 cm(3) and MTV3.0 of 23.01 cm(3) were associated with an increased risk of death (hazard ratio [HR] = 5.028; p = 0.029), although no significant relationship was found between SUVmax and OS. Interestingly, MTV3.0 was associated with OS in both the differentiated and undifferentiated groups, although MTV2.5 was only associated with OS in the undifferentiated group. Among the clinical parameters, only radiotherapy was associated with longer OS (HR = 12.124; p < 0.001).
  
  
  CONCLUSIONS
  The MTV and radiotherapy could be prognostic values associated with OS. Particularly, MTV2.5 and MTV3.0 might be valuable metabolic parameters for predicting long-term survival in patients with NPC. Furthermore, MTV3.0 may be more useful because it can be applied irrespective of pathologic subtype.
authors.affiliation: Department of Otorhinolaryngology and Biomedical Research Institute, Pusan National University School of Medicine, Pusan National University Hospital, Busan, South Korea.
authors.forename: Young-Ho
authors.initials: YH
authors.lastname: Yoon
authors.forename: Seok-Hwan
authors.initials: SH
authors.lastname: Lee
authors.forename: Sung-Lyong
authors.initials: SL
authors.lastname: Hong
authors.forename: Seong-Jang
authors.initials: SJ
authors.lastname: Kim
authors.forename: Hwan-Jung
authors.initials: HJ
authors.lastname: Roh
authors.forename: Kyu-Sup
authors.initials: KS
authors.lastname: Cho
mesh_terms: D000328:Adult; D000368:Aged; D002277:Carcinoma; D005260:Female; D019788:Fluorodeoxyglucose F18; D006801:Humans; D008297:Male; D008875:Middle Aged; D000077274:Nasopharyngeal Carcinoma; D009303:Nasopharyngeal Neoplasms / Q000000981:diagnostic imaging / Q000473:pathology*; D049268:Positron-Emission Tomography / Q000379:methods*; D011379:Prognosis; D019275:Radiopharmaceuticals; D012189:Retrospective Studies; D016019:Survival Analysis; D014057:Tomography, X-Ray Computed / Q000379:methods*; D047368:Tumor Burden; D055815:Young Adult
chemical_list: D019275:Radiopharmaceuticals; D019788:Fluorodeoxyglucose F18
keywords: computed tomography; nasopharyngeal neoplasms; positron-emission tomography; prognosis; radiotherapy; tumor burden