title: Does pre-operative estimation of oesophageal tumour metabolic length using 18F-fluorodeoxyglucose PET/CT images compare with surgical pathology length?
abstract: OBJECTIVE
  The aim of the study was to compare the pre-operative metabolic tumour length on FDG PET/CT with the resected pathological specimen in patients with oesophageal cancer.
  
  
  METHODS
  All patients diagnosed with oesophageal carcinoma who had undergone staging PET/CT imaging between the period of June 2002 and May 2008 who were then suitable for curative surgery, either with or without neo-adjuvant chemotherapy, were included in this study. Metabolic tumour length was assessed using both visual analysis and a maximum standardised uptake value (SUV(max)) cutoff of 2.5.
  
  
  RESULTS
  Thirty-nine patients proceeded directly to curative surgical resection, whereas 48 patients received neo-adjuvant chemotherapy, followed by curative surgery. The 95% limits of agreement in the surgical arm were more accurate when the metabolic tumour length was visually assessed with a mean difference of -0.05 cm (SD 2.16 cm) compared to a mean difference of +2.42 cm (SD 3.46 cm) when assessed with an SUV(max) cutoff of 2.5. In the neo-adjuvant group, the 95% limits of agreement were once again more accurate when assessed visually with a mean difference of -0.6 cm (SD 1.84 cm) compared to a mean difference of +1.58 cm (SD 3.1 cm) when assessed with an SUV(max) cutoff of 2.5.
  
  
  CONCLUSIONS
  This study confirms the high accuracy of PET/CT in measuring gross target volume (GTV) length. A visual method for GTV length measurement was demonstrated to be superior and more accurate than when using an SUV(max) cutoff of 2.5. This has the potential of reducing the planning target volume with dose escalation to the tumour with a corresponding reduction in normal tissue complication probability.
authors.affiliation: Regional Thoracic Surgical Unit, Royal Victoria Hospital, Grosvenor Road, Belfast, BT12 6BA, UK. reubenj@hotmail.com
authors.forename: Reubendra
authors.initials: R
authors.lastname: Jeganathan
authors.forename: James
authors.initials: J
authors.lastname: McGuigan
authors.forename: Frederick
authors.initials: F
authors.lastname: Campbell
authors.forename: Thomas
authors.initials: T
authors.lastname: Lynch
mesh_terms: D000328:Adult; D000368:Aged; D004938:Esophageal Neoplasms / Q000175:diagnosis* / Q000378:metabolism* / Q000473:pathology / Q000601:surgery; D005260:Female; D019788:Fluorodeoxyglucose F18; D006801:Humans; D008297:Male; D008875:Middle Aged; D020360:Neoadjuvant Therapy; D049268:Positron-Emission Tomography; D057234:Preoperative Period; D012189:Retrospective Studies; D014057:Tomography, X-Ray Computed; D047368:Tumor Burden
chemical_list: D019788:Fluorodeoxyglucose F18