title: Metabolic tumor volumes by [18F]-fluorodeoxyglucose PET/CT correlate with occult metastasis in oral squamous cell carcinoma of the tongue.
abstract: BACKGROUND
  To investigate the correlation between pretreatment metabolic tumor volume (MTV) as determined by [(18)F]-fluorodeoxyglucose positron emission tomography/computed tomography (PET/CT) and occult metastasis (OM) in oral squamous cell carcinoma (OSCC) of the tongue.
  
  
  METHODS
  Forty-three clinically node-negative (cN0) OSCC patients, diagnosed by preoperative workups (biopsy, physical examination, CT, and PET/CT) were enrolled. All patients had undergone primary tumor resections and elective neck dissections. MTVs were measured for tumors showing standardized uptake value (SUV) of >2.5 by an automated contouring program. Pretreatment variables (age, sex, clinical T stage, maximal SUV [SUV(max)] and MTV) and posttreatment variables (pathologic T stage, depth of invasion, lymphovascular invasion, pathologic tumor volume, and histological differentiation) were analyzed to identify their correlation with OM.
  
  
  RESULTS
  Twelve (27.9%) of 43 patients were found to have OM in pathologic specimen of neck dissections. A cutoff of 6.0 ml for the MTV was determined to be the most discriminative value for predicting OM. By univariate analysis, the patients with an MTV of >6.0 ml had significantly higher number of occult metastases than those with an MTV of <or=6.0 ml (57.1% vs. 13.7%, hazard ratio 8.33, 95% confidence interval, 1.95-35.6, P=0.009). Lymphovascular invasion and SUV(max) showed only trends toward significance (P=0.08 and 0.05, respectively). By multivariate analysis, only MTV had a significant correlation with OM (hazard ratio 54.66, 95% confidence interval, 1.05-2842.86, P=0.04).
  
  
  CONCLUSIONS
  MTV as determined by PET/CT demonstrated a statistically significant correlation with OM in patients with cN0 OSCC of the tongue.
authors.affiliation: Department of Otorhinolaryngology-Head and Neck Surgery, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea.
authors.forename: Man Ki
authors.initials: MK
authors.lastname: Chung
authors.forename: Han-Sin
authors.initials: HS
authors.lastname: Jeong
authors.forename: Young-Ik
authors.initials: YI
authors.lastname: Son
authors.forename: Yoon Kyoung
authors.initials: YK
authors.lastname: So
authors.forename: Ga Young
authors.initials: GY
authors.lastname: Park
authors.forename: Joon Young
authors.initials: JY
authors.lastname: Choi
authors.forename: Seung Hyup
authors.initials: SH
authors.lastname: Hyun
authors.forename: Hyung-Jin
authors.initials: HJ
authors.lastname: Kim
authors.forename: Young-Hyeh
authors.initials: YH
authors.lastname: Ko
authors.forename: Chung-Hwan
authors.initials: CH
authors.lastname: Baek
mesh_terms: D000328:Adult; D000368:Aged; D002294:Carcinoma, Squamous Cell / Q000175:diagnosis* / Q000556:secondary / Q000601:surgery; D005260:Female; D019788:Fluorodeoxyglucose F18; D006801:Humans; D008207:Lymphatic Metastasis; D008297:Male; D008875:Middle Aged; D009361:Neoplasm Invasiveness; D009364:Neoplasm Recurrence, Local / Q000175:diagnosis / Q000601:surgery; D009367:Neoplasm Staging; D049268:Positron-Emission Tomography; D011379:Prognosis; D019275:Radiopharmaceuticals; D015996:Survival Rate; D014057:Tomography, X-Ray Computed; D014062:Tongue Neoplasms / Q000175:diagnosis* / Q000601:surgery; D016896:Treatment Outcome; D047368:Tumor Burden; D055815:Young Adult
chemical_list: D019275:Radiopharmaceuticals; D019788:Fluorodeoxyglucose F18