title: Accuracy of endoscopic ultrasonography in diagnosing ascites and predicting peritoneal metastases in gastric cancer patients.
abstract: BACKGROUND
  Preoperative diagnosis of peritoneal metastases (PM) is difficult in patients with gastric cancer (GC).
  
  
  OBJECTIVE
  To assess the accuracy of endoscopic ultrasonography (EUS) in diagnosing ascites and its predictability for the presence of PM in GC patients.
  
  
  METHODS
  Consecutive patients with newly diagnosed GC from 1998 to 2004 were studied.
  
  
  METHODS
  All patients underwent EUS, ultrasound (US), and computed tomography (CT) scan for preoperative staging and the presence of ascites. The results were compared with operative findings. The diagnosis of PM was confirmed by histopathology or peritoneal fluid cytology.
  
  
  RESULTS
  A total of 301 patients were recruited and in 250 patients the presence of ascites (n = 93) and PM (n = 71) were confirmed. EUS was more sensitive (87.1%) than combined US and CT scan examinations (16.1%) and operative findings (laparoscopy or laparotomy) (40.9%) in diagnosing ascites. Sensitivity, specificity, positive and negative predictive values, and accuracy for predicting the presence of PM were 73%, 84%, 64%, 89%, and 81% by EUS; 18%, 99%, 87%, 75%, and 76% by combining US and CT scan; and 77%, 94%, 83%, 91%, and 89% by operative findings, respectively. In multivariate logistic regression analysis, EUS detected ascites was the only significant independent predictor for the presence of PM (p<0.001; odds ratio 4.7 (95% confidence interval 2.0-11.2)).
  
  
  CONCLUSIONS
  EUS is a sensitive method for diagnosing ascites which is an important predictive factor for the presence of PM in GC patients.
authors.affiliation: Department of Medicine and Therapeutics, The Chinese University of Hong Kong, Prince of Wales Hospital, Shatin NT, Hong Kong, China. leeytong@cuhk.edu.hk
authors.forename: Y T
authors.initials: YT
authors.lastname: Lee
authors.forename: E K W
authors.initials: EK
authors.lastname: Ng
authors.forename: L C T
authors.initials: LC
authors.lastname: Hung
authors.forename: S C S
authors.initials: SC
authors.lastname: Chung
authors.forename: J Y L
authors.initials: JY
authors.lastname: Ching
authors.forename: W Y
authors.initials: WY
authors.lastname: Chan
authors.forename: W C
authors.initials: WC
authors.lastname: Chu
authors.forename: J J
authors.initials: JJ
authors.lastname: Sung
mesh_terms: D000230:Adenocarcinoma / Q000175:diagnosis / Q000000981:diagnostic imaging* / Q000556:secondary*; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001201:Ascites / Q000000981:diagnostic imaging; D019160:Endosonography; D004812:Epidemiologic Methods; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009367:Neoplasm Staging; D010534:Peritoneal Neoplasms / Q000175:diagnosis / Q000000981:diagnostic imaging* / Q000556:secondary*; D013274:Stomach Neoplasms / Q000473:pathology*; D014057:Tomography, X-Ray Computed