title: Impact of the time interval between MDCT imaging and surgery on the accuracy of identifying metastatic disease in patients with pancreatic cancer.
abstract: OBJECTIVE
  Pancreatic adenocarcinoma is a rapidly progressive malignancy characterized by its tendency for early metastatic spread. MDCT is the primary diagnostic modality for the preoperative staging of patients with pancreatic cancer, with an accuracy established in multiple studies. However, for a variety of reasons, there is often a prolonged interval between staging MDCT and the surgical intervention. This study examines the relationship between the interval between imaging and surgery and the accuracy of MDCT in determining the presence or absence of metastatic disease at surgery in patients with pancreatic cancer.
  
  
  METHODS
  Patients were identified who had undergone surgery for pancreatic cancer at our institution with a dedicated preoperative pancreas-protocol MDCT performed in our department. Findings from the preoperative MDCT report were correlated with the operative findings, as well as the time between imaging and surgery.
  
  
  RESULTS
  Two hundred ninety-two MDCT scans were performed on 256 patients who underwent exploration for pancreatic adenocarcinoma. The patients had a median age of 67 years (range, 30-95 years), and 51.6% (132/256) were male. The median time between MDCT and surgical exploration was 15.5 days (range, 1-198 days). MDCT correctly predicted the absence of metastatic disease at surgery in 233 of 274 (85.0%) studies. MDCT was more accurate in predicting the absence of metastatic disease if the study was performed within 25 days of surgery than it was if the study was performed within more than 25 days of surgery (89.3% vs 77.0%; p = 0.0097). Furthermore, regression models showed that the negative predictive value of a given MDCT significantly decreased after approximately 4 weeks.
  
  
  CONCLUSIONS
  MDCT is an accurate method to stage patients with pancreatic cancer, but its accuracy in excluding distant metastatic disease depreciates over time. Patients should undergo a repeat MDCT within 25 days of any planned definitive operative intervention for pancreatic cancer to avoid unexpectedly finding metastatic disease at surgery.
authors.affiliation: 1 Department of Radiology, Johns Hopkins University School of Medicine, JHOC 3251, 601 N Caroline St, Baltimore, MD 21287.
authors.forename: Siva P
authors.initials: SP
authors.lastname: Raman
authors.forename: Sushanth
authors.initials: S
authors.lastname: Reddy
authors.forename: Matthew J
authors.initials: MJ
authors.lastname: Weiss
authors.forename: Lindsey L
authors.initials: LL
authors.lastname: Manos
authors.forename: John L
authors.initials: JL
authors.lastname: Cameron
authors.forename: Lei
authors.initials: L
authors.lastname: Zheng
authors.forename: Joseph M
authors.initials: JM
authors.lastname: Herman
authors.forename: Ralph H
authors.initials: RH
authors.lastname: Hruban
authors.forename: Elliot K
authors.initials: EK
authors.lastname: Fishman
authors.forename: Christopher L
authors.initials: CL
authors.lastname: Wolfgang
mesh_terms: D000236:Adenoma / Q000000981:diagnostic imaging* / Q000601:surgery; D000328:Adult; D000368:Aged; D042241:Early Diagnosis; D005260:Female; D006801:Humans; D007089:Image Enhancement / Q000379:methods*; D008207:Lymphatic Metastasis; D008297:Male; D008875:Middle Aged; D061330:Multidetector Computed Tomography / Q000379:methods*; D010190:Pancreatic Neoplasms / Q000000981:diagnostic imaging* / Q000556:secondary / Q000601:surgery; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D013997:Time Factors
keywords: MDCT; metastases; pancreatic adenocarcinoma; pancreatic cancer; staging