title: Predictive value of volumetric parameters measured by F-18 FDG PET/CT for lymph node status in patients with surgically resected rectal cancer.
abstract: OBJECTIVE
  The objective of this study was to investigate the predictive role of volumetric parameters such as metabolic tumor volume (MTV) and total lesion glycolysis (TLG) measured by F-18 FDG PET/CT for regional lymph node (rLN) metastasis in rectal cancer patients.
  
  
  METHODS
  Retrospectively, 74 rectal cancer patients were enrolled. All patients received surgical treatment and F-18 FDG PET/CT at diagnosis. The F-18 FDG PET/CT findings of primary cancer and rLN involvement were compared with the pathologic diagnosis within 5 weeks after operation. Univariate and multivariate analyses were used to analyze the associations among the pathologic LN status and age, sex, T stage, AJCC stage, SUVmax, lymphatic invasion, venous invasion, neural invasion, and volumetric parameters.
  
  
  RESULTS
  The LN (+) group showed statistically significant higher values of MTV2.5 (p < 0.0001), MTV3 (p < 0.0001), MTV3.5 (p = 0.0001), TLG2.5 (p = 0.0007), TLG3 (p = 0.0011), and TLG3.5 (p = 0.0024). In univariate analysis, T stage, AJCC stage, neural invasion, and volumetric parameters were factors significantly associated with pathologic LN involvement. However, in multivariate analysis, advanced T stage, high AJCC stage, MTV2.5, and TLG2.5 were associated with pathologic LN involvement in rectal cancer.
  
  
  CONCLUSIONS
  This study showed that, not only T stage and AJCC stage, but also volumetric parameters such as MTV2.5 and TLG2.5 are useful factors for the prediction of pathologic LN status in rectal cancer patients.
authors.affiliation: Department of General Surgery, Pusan National University School of Medicine, Busan, Korea.
authors.forename: Hong Jae
authors.initials: HJ
authors.lastname: Jo
authors.forename: Seong-Jang
authors.initials: SJ
authors.lastname: Kim
authors.forename: In Joo
authors.initials: IJ
authors.lastname: Kim
authors.forename: Sojung
authors.initials: S
authors.lastname: Kim
mesh_terms: D000328:Adult; D000368:Aged; D005260:Female; D019788:Fluorodeoxyglucose F18; D006801:Humans; D008207:Lymphatic Metastasis; D008297:Male; D008875:Middle Aged; D064847:Multimodal Imaging; D049268:Positron-Emission Tomography; D011237:Predictive Value of Tests; D012004:Rectal Neoplasms / Q000175:diagnosis* / Q000473:pathology* / Q000601:surgery; D012189:Retrospective Studies; D014057:Tomography, X-Ray Computed; D047368:Tumor Burden
chemical_list: D019788:Fluorodeoxyglucose F18