title: Clinical implications of initial FDG-PET/CT in locally advanced rectal cancer treated with neoadjuvant chemoradiotherapy.
abstract: OBJECTIVE
  The present study evaluated the predictive and prognostic impact of initial fluorine-18-fluorodeoxyglucose-positron emission tomography/computed tomography (FDG-PET/CT) in patients with locally advanced rectal cancer treated with neoadjuvant concurrent chemoradiotherapy (CCRT).
  
  
  METHODS
  Eighty-one consecutive patients with locally advanced rectal cancer (cT3-T4 N-/N+) treated with neoadjuvant CCRT were enrolled. The FDG-PET/CT parameters, including the SUVmax, metabolic tumor volume (MTV, 50 % of SUVmax), and multiplication of the SUVmean and MTV (total lesion glycolysis, TLG), were analyzed in relation to the pathologic response and disease recurrence.
  
  
  RESULTS
  Five patients (6.2 %) achieved a pathologic complete response (pCR) after CCRT followed by surgery. None of the FDG-PET/CT parameters was identified as a predictive factor for pCR. After a median follow-up period of 26.7 (range 10.9-63.3) months, 19 patients (23.5 %) presented a local and/or distant recurrence. In a multivariate analysis including the clinicopathologic parameters, the TLG of the primary tumor was associated with a worse disease-free survival after neoadjuvant CCRT (HR 20.035, 95 % CI 1.726-232.559; P = 00.017).
  
  
  CONCLUSIONS
  The TLG of the primary tumor in the initial FDG-PET/CT can be considered as a prognostic factor for patients with locally advanced rectal cancer treated with neoadjuvant CCRT.
authors: Department of Oncology/Hematology, Kyungpook National University Medical Center, Kyungpook National University School of Medicine, 807 Hogukno Buk-gu, Daegu 702-210, South Korea.
authors: Soo Jung
authors: SJ
authors: Lee
authors: Jong Gwang
authors: JG
authors: Kim
authors: Sang-Woo
authors: SW
authors: Lee
authors: Yee Soo
authors: YS
authors: Chae
authors: Byung Woog
authors: BW
authors: Kang
authors: Yoo Jin
authors: YJ
authors: Lee
authors: Jun Seok
authors: JS
authors: Park
authors: Gyu Seog
authors: GS
authors: Choi
mesh_terms: D000328:Adult; D000368:Aged; D059248:Chemoradiotherapy / Q000379:methods; D018572:Disease-Free Survival; D005260:Female; D019788:Fluorodeoxyglucose F18; D005500:Follow-Up Studies; D006019:Glycolysis; D006801:Humans; D008297:Male; D008875:Middle Aged; D064847:Multimodal Imaging / Q000379:methods*; D015999:Multivariate Analysis; D020360:Neoadjuvant Therapy / Q000379:methods; D009364:Neoplasm Recurrence, Local; D049268:Positron-Emission Tomography; D011379:Prognosis; D019275:Radiopharmaceuticals; D012004:Rectal Neoplasms / Q000000981:diagnostic imaging / Q000473:pathology / Q000628:therapy*; D014057:Tomography, X-Ray Computed; D016896:Treatment Outcome
chemical_list: D019275:Radiopharmaceuticals; D019788:Fluorodeoxyglucose F18