title: Does the interval from imaging to operation affect the rate of unanticipated metastasis encountered during operation for pancreatic adenocarcinoma?
abstract: BACKGROUND
  Pancreatic ductal adenocarcinoma (PDAC) is an aggressive malignancy with a propensity for early metastasis that is often encountered unexpectedly at operation. Our objective was to examine the effect of the time interval between preoperative imaging and attempted resection and the venue in which imaging was performed on the frequency of unanticipated metastasis (UM) encountered at operation. We hypothesize that imaging obtained locally at our hospital and within 4 weeks of operation will result in a lesser frequency of UM encountered at operation.
  
  
  METHODS
  Between January 2004 and December 2009, records of patients undergoing planned pancreatic resection for PDAC at a high volume pancreatic surgery center were compiled. Exclusion criteria included neoadjuvant therapy, prior pancreatic resection, or evidence of metastasis on imaging. Review and analysis of clinical, radiographic, operative, and pathologic data were undertaken. Frequency of UM and outcome of resection was compared with the interval between most recent cross-sectional imaging (dual-phase contrast-enhanced CT or MRI) and operation defined as imaging-to-operation interval (IOI).
  
  
  RESULTS
  Four-hundred eighty-seven patients met eligibility requirements for the study: 431 (88%) proximal and 56 (12%) distal PDAC. 202 (41%) patients had their most recent imaging performed at an outside institution, and no difference in the rates of UM was observed whether imaging was conducted at our institution or at an outside institution (P > .05). Of 329 with complete imaging information for analysis, UM were discovered in 60 (18%): 52 (18%) of 293 proximal PDAC and 8 (22%) of 36 distal PDAC. In proximal PDAC, there was a linear relationship in the frequency of UM as a function of the weekly IOI (R(2) = .99; P = .006). For distal PDAC, no significant difference in the frequency of UM as a function of IOI was observed.
  
  
  CONCLUSIONS
  For proximally located PDAC, the frequency of UM increases with greater imaging-to-operation interval. Performing imaging at a high volume, pancreatic surgery center compared with elsewhere was not associated with a decrease in the rate of UM. Obtaining timely diagnostic imaging for proximal PDAC may improve the accuracy of preoperative staging, and thereby reduce the number of operations not producing oncologic benefit.
authors: Indiana University School of Medicine, Department of Surgery, Indianapolis, IN, USA.
authors: Jeffrey A
authors: JA
authors: Glant
authors: Joshua A
authors: JA
authors: Waters
authors: Michael G
authors: MG
authors: House
authors: Nicholas J
authors: NJ
authors: Zyromski
authors: Atilla
authors: A
authors: Nakeeb
authors: Henry A
authors: HA
authors: Pitt
authors: Keith D
authors: KD
authors: Lillemoe
authors: C Max
authors: CM
authors: Schmidt
mesh_terms: D000368:Aged; D021441:Carcinoma, Pancreatic Ductal / Q000175:diagnosis / Q000473:pathology / Q000556:secondary* / Q000601:surgery*; D005188:False Negative Reactions; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D009362:Neoplasm Metastasis / Q000175:diagnosis; D009367:Neoplasm Staging; D010190:Pancreatic Neoplasms / Q000175:diagnosis / Q000473:pathology / Q000601:surgery*; D011446:Prospective Studies; D013997:Time Factors; D014057:Tomography, X-Ray Computed