title: Computed tomography overestimation of esophageal tumor length: Implications for radiotherapy planning.
abstract: OBJECTIVE
  To assess the relationship between preoperative computed tomography (CT) and postoperative pathological measurements of esophageal tumor length and the prognostic significance of CT tumor length data.
  
  
  METHODS
  A retrospective study was carried out in 56 patients who underwent curative esophagogastrectomy. Tumor lengths were measured on the immediate preoperative CT and on the post-operative resection specimens. Inter- and intra-observer variations in CT measurements were assessed. Survival data were collected.
  
  
  RESULTS
  There was a weak correlation between CT and pathological tumor length (r = 0.30, P = 0.025). CT lengths were longer than pathological lengths in 68% (38/56) of patients with a mean difference of 1.67 cm (95% CI: 1.18-2.97). The mean difference in measurements by two radiologists was 0.39 cm (95% CI: -0.59-1.44). The mean difference between repeat CT measured tumor length (intra-observer variation) were 0.04 cm (95% CI: -0.59-0.66) and 0.47 cm (95% CI: -0.53-1.47). When stratified, patients not receiving neoadjuvant chemotherapy showed a strong correlation between CT and pathological tumor length (r = 0.69, P = 0.0014, n = 37) than patients that did (r = 0.13, P = 0.43, n = 19). Median survival with CT tumor length > 5.6 cm was poorer than with smaller tumors, but the difference was not statistically significant.
  
  
  CONCLUSIONS
  Esophageal tumor length assessed using CT does not reflect pathological tumor extent and should not be the only modality used for management decisions, particularly for planning radiotherapy.
authors.affiliation: Karim Sillah, Ian M Welch, Department of Gastrointestinal Surgery, University Hospital of South Manchester NHS Foundation Trust, Southmoor Road, Manchester M23 9LT, United Kingdom.
authors.forename: Karim
authors.initials: K
authors.lastname: Sillah
authors.forename: Luke R
authors.initials: LR
authors.lastname: Williams
authors.forename: Hans-Ulrich
authors.initials: HU
authors.lastname: Laasch
authors.forename: Azeem
authors.initials: A
authors.lastname: Saleem
authors.forename: Gillian
authors.initials: G
authors.lastname: Watkins
authors.forename: Susan A
authors.initials: SA
authors.lastname: Pritchard
authors.forename: Patricia M
authors.initials: PM
authors.lastname: Price
authors.forename: Catharine M
authors.initials: CM
authors.lastname: West
authors.forename: Ian M
authors.initials: IM
authors.lastname: Welch