title: 18F-FLT-PET for detection of rectal cancer.
abstract: OBJECTIVE
  This pilot study was undertaken to examine the ability of (18)F-3'-fluoro-3'-deoxy-l-thymidine positron emission tomography ((18)F-FLT-PET)to detect rectal cancer, to identify pathologic lymph nodes and to determine the accuracy of tumour length estimation in comparison with computer tomography (CT).
  
  
  METHODS
  Nine patients with biopsy proven rectal cancer underwent CT and (18)F-FLT-PET scanning prior to short-term pre-operative radiotherapy (5×5Gy). Within 10 days after the start of radiotherapy a surgical resection was performed. Tumour lengths and regional lymph node visualisation on both imaging modalities were compared with pathology findings.
  
  
  RESULTS
  All tumours were visible on CT. (18)F-FLT-PET visualised 7 out of 9 tumours (78%). The pathology-based tumours lengths correlated better with CT as compared to FLT-PET(r=0.91, p<0.01). (18)F-FLT-PET was not able to visualise pathologic lymph nodes. However, CT identified all patients with pathologic lymph nodes.
  
  
  CONCLUSIONS
  Primary rectal cancer can be visualised by (18)F-FLT-PET in the majority of cases but not in all. However, (18)F-FLT-PET was not able to identify pathologic lymph nodes. Therefore, we conclude that (18)F-FLT-PET has limited value for the detection of pathologic lymph nodes and tumour delineation in rectal cancer.
authors.affiliation: Department of Radiation Oncology, University Medical Center Groningen, The Netherlands. c.t.muijs@rt.umcg.nl
authors.forename: Christina T
authors.initials: CT
authors.lastname: Muijs
authors.forename: Jannet C
authors.initials: JC
authors.lastname: Beukema
authors.forename: Joachim
authors.initials: J
authors.lastname: Widder
authors.forename: Alphons C M
authors.initials: AC
authors.lastname: van den Bergh
authors.forename: Klaas
authors.initials: K
authors.lastname: Havenga
authors.forename: Jan
authors.initials: J
authors.lastname: Pruim
authors.forename: Johannes A
authors.initials: JA
authors.lastname: Langendijk
mesh_terms: D000368:Aged; D005260:Female; D019788:Fluorodeoxyglucose F18; D006801:Humans; D008198:Lymph Nodes / Q000473:pathology; D008297:Male; D008875:Middle Aged; D010865:Pilot Projects; D049268:Positron-Emission Tomography / Q000592:standards; D012004:Rectal Neoplasms / Q000175:diagnosis*; D012680:Sensitivity and Specificity; D014057:Tomography, X-Ray Computed / Q000592:standards; D047368:Tumor Burden
chemical_list: D019788:Fluorodeoxyglucose F18