title: Hepatic metastases in patients with colorectal cancer: relationship between size of metastases, standard of reference, and detection rates.
abstract: OBJECTIVE
  To determine the relationship between the size of hepatic metastases, the standard of reference, and the reported detection rate in patients with colorectal cancer.
  
  
  METHODS
  With use of a MEDLINE search (January 1994 to January 2001), articles were selected that contained original results on detection of hepatic metastases of colorectal cancer, categorized for size in at least two categories, with use of helical computed tomography (CT), helical CT at arterial portography, or magnetic resonance imaging. Results were compared with the size distribution of hepatic metastases in 47 consecutive patients with colorectal carcinoma, which were detected by using a combination of intraoperative ultrasonography (US) and palpation.
  
  
  RESULTS
  Seven studies met all predefined criteria. Four studies involved intraoperative US in all patients and demonstrated a significant negative correlation (-0.988) between detection rate and fraction of small metastases. These studies had a higher fraction and lower detection rate of small metastases and a lower overall detection rate. A majority (58% [145 of 252]) of metastases in the study population were smaller than 20 mm.
  
  
  CONCLUSIONS
  Few articles adequately describe the standard of reference and size distribution of hepatic lesions. Hepatic metastases of colorectal cancer are frequently smaller than 20 mm. When the standard of reference is suboptimal, many small metastases are excluded from analysis, and detection rates are therefore inflated.
authors.affiliation: Department of Radiology, Leiden University Medical Center, Albinusdreef 2, PO Box 9600, 2300 RC Leiden, The Netherlands. a.r.van_erkel@lumc.nl
authors.forename: Arian R
authors.initials: AR
authors.lastname: van Erkel
authors.forename: Milan E J
authors.initials: ME
authors.lastname: Pijl
authors.forename: Annette A
authors.initials: AA
authors.lastname: van den Berg-Huysmans
authors.forename: Martin N J M
authors.initials: MN
authors.lastname: Wasser
authors.forename: Cornelis J H
authors.initials: CJ
authors.lastname: van de Velde
authors.forename: Johan L
authors.initials: JL
authors.lastname: Bloem
mesh_terms: D002277:Carcinoma / Q000175:diagnosis* / Q000000981:diagnostic imaging / Q000473:pathology / Q000556:secondary*; D015179:Colorectal Neoplasms / Q000473:pathology* / Q000601:surgery; D006801:Humans; D007432:Intraoperative Period; D008113:Liver Neoplasms / Q000175:diagnosis* / Q000000981:diagnostic imaging / Q000473:pathology / Q000556:secondary*; D010173:Palpation; D014463:Ultrasonography