title: Tumor size on abdominal MRI versus pathologic specimen in resected pancreatic adenocarcinoma: implications for radiation treatment planning.
abstract: OBJECTIVE
  We assessed the accuracy of abdominal magnetic resonance imaging (MRI) for determining tumor size by comparing the preoperative contrast-enhanced T1-weighted gradient echo (3-dimensional [3D] volumetric interpolated breath-hold [VIBE]) MRI tumor size with pathologic specimen size.
  
  
  METHODS
  The records of 92 patients who had both preoperative contrast-enhanced 3D VIBE MRI images and detailed pathologic specimen measurements were available for review. Primary tumor size from the MRI was independently measured by a single diagnostic radiologist (P.M.) who was blinded to the pathology reports. Pathologic tumor measurements from gross specimens were obtained from the pathology reports. The maximum dimensions of tumor measured in any plane on the MRI and the gross specimen were compared. The median difference between the pathology sample and the MRI measurements was calculated. A paired t test was conducted to test for differences between the MRI and pathology measurements. The Pearson correlation coefficient was used to measure the association of disparity between the MRI and pathology sizes with the pathology size. Disparities relative to pathology size were also examined and tested for significance using a 1-sample t test.
  
  
  RESULTS
  The median patient age was 64.5 years. The primary site was pancreatic head in 81 patients, body in 4, and tail in 7. Three patients were American Joint Commission on Cancer stage IA, 7 stage IB, 21 stage IIA, 58 stage IIB, and 3 stage III. The 3D VIBE MRI underestimated tumor size by a median difference of 4 mm (range, -34-22 mm). The median largest tumor dimensions on MRI and pathology specimen were 2.65 cm (range, 1.5-9.5 cm) and 3.2 cm (range, 1.3-10 cm), respectively.
  
  
  CONCLUSIONS
  Contrast-enhanced 3D VIBE MRI underestimates tumor size by 4 mm when compared with pathologic specimen. Advanced abdominal MRI sequences warrant further investigation for radiation therapy planning in pancreatic adenocarcinoma before routine integration into the treatment planning process.
authors.affiliation: Department of Radiation Oncology, Emory University, Atlanta, Georgia, USA. whall4@emory.edu
authors.forename: William A
authors.initials: WA
authors.lastname: Hall
authors.forename: John L
authors.initials: JL
authors.lastname: Mikell
authors.forename: Pardeep
authors.initials: P
authors.lastname: Mittal
authors.forename: Lauren
authors.initials: L
authors.lastname: Colbert
authors.forename: Roshan S
authors.initials: RS
authors.lastname: Prabhu
authors.forename: David A
authors.initials: DA
authors.lastname: Kooby
authors.forename: Dana
authors.initials: D
authors.lastname: Nickleach
authors.forename: Krisztina
authors.initials: K
authors.lastname: Hanley
authors.forename: Juan M
authors.initials: JM
authors.lastname: Sarmiento
authors.forename: Arif N
authors.initials: AN
authors.lastname: Ali
authors.forename: Jerome C
authors.initials: JC
authors.lastname: Landry
mesh_terms: D000230:Adenocarcinoma / Q000473:pathology*; D000368:Aged; D003287:Contrast Media; D003951:Diagnostic Errors; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008875:Middle Aged; D009367:Neoplasm Staging; D010190:Pancreatic Neoplasms / Q000473:pathology*; D047368:Tumor Burden
chemical_list: D003287:Contrast Media