title: FDG PET/CT evaluation of treatment response in patients with recurrent colorectal cancer.
abstract: OBJECTIVE
  to evaluate the treatment response in patients with recurrent colorectal cancer (CRC) using FDG PET/CT.
  
  
  METHODS
  a total of 32 recurrent CRC patients (21 males, 11 females; mean age, 52.8 years) were included in this retrospective study. All patients underwent a baseline and follow-up FDG PET/CT scans after chemotherapy. Of 32 patients, 23 patients had follow-up carcinoembryonic antigen (CEA) levels.
  
  
  RESULTS
  on qualitative analysis of baseline and follow-up FDG PET/CT studies, there were 20 nonresponders and 12 were responders. On quantitative analysis, there were 19 nonresponders and 13 were responders. In responders, baseline and follow-up mean SUV(max) were 11.8 ± 10.1 and 3.7 ± 4.1, respectively (significant decrease, P = 0.001). Among nonresponders, baseline and follow-up mean SUV(max) were 8.1 ± 5.2 and 14.1 ± 9.0, respectively (significant increase, P = 0.003). There was no association between response and different factors like age, sex, diagnosis, extent of the lesions, and number of lesions.
  
  
  CONCLUSIONS
  FDG PET/CT appears to be useful modality in evaluating chemotherapy response and can differentiate responders from nonresponders in recurrent CRC patients.
authors.affiliation: Department of Nuclear Medicine, All India Institute of Medical Sciences, New Delhi, India.
authors.forename: Shamim Ahmed
authors.initials: SA
authors.lastname: Shamim
authors.forename: Rakesh
authors.initials: R
authors.lastname: Kumar
authors.forename: Varun
authors.initials: V
authors.lastname: Shandal
authors.forename: Dhanapathi
authors.initials: D
authors.lastname: Halanaik
authors.forename: Guresh
authors.initials: G
authors.lastname: Kumar
authors.forename: Chandra Shekhar
authors.initials: CS
authors.lastname: Bal
authors.forename: Arun
authors.initials: A
authors.lastname: Malhotra
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D015179:Colorectal Neoplasms / Q000000981:diagnostic imaging* / Q000188:drug therapy; D005260:Female; D019788:Fluorodeoxyglucose F18 / Q000493:pharmacokinetics; D006801:Humans; D008297:Male; D008875:Middle Aged; D049268:Positron-Emission Tomography; D012008:Recurrence; D014057:Tomography, X-Ray Computed; D016896:Treatment Outcome
chemical_list: D019788:Fluorodeoxyglucose F18