Whole-body diffusion-weighted MRI for operability assessment in patients with colorectal cancer and peritoneal metastases

Cancer Imaging. 2019 Jan 7;19(1):1. doi: 10.1186/s40644-018-0187-z.


Background: Correct staging of patients with colorectal cancer is of utmost importance for the prediction of operability. Although computed tomography (CT) has a good overall performance, estimation of peritoneal cancer spread is a known weakness, a problem that cannot always be overcome by Fluorine-18 fluorodeoxyglucose positron emission tomography/computed tomography (18F-FDG-PET/CT); especially in infiltrative and miliary disease spread. Due to its high spatial and contrast resolution magnetic resonance imaging (MRI) with diffusion-weighted imaging (DWI) might have a better performance. Our aim was to evaluate the added value of whole-body diffusion-weighted MRI (WB-DWI/MRI) to CT for prediction of peritoneal cancer spread and operability assessment in colorectal cancer patients with clinically suspected peritoneal carcinomatosis (PC).

Methods: This institutional review board approved retrospective study included sixty colorectal cancer patients who underwent WB-DWI/MRI in addition to CT for clinically suspected peritoneal metastases. WB-DWI/MRI and CT were assessed for detecting PC following the peritoneal cancer index (PCI), determination of PCI-score categorized as PC < 12, PCI = 12-15 and PCI > 15, detection of nodal and distant metastases and estimation of overall operability. Histopathology after surgery and biopsy and/or 6 months follow-up were used as reference standard.

Results: For detection of PC, CT had 43.2% sensitivity, 95.6% specificity, 84.5% positive predictive value (PPV) and 75.2% negative predictive value (NPV). WB-DWI/MRI had 97.8% sensitivity, 93.2% specificity, 88.9% PPV and 98.7% NPV. WB-DWI/MRI enabled better detection of inoperable distant metastases (all 12 patients) than CT (2/12 patients) and significantly improved prediction of PCI category [WB-DWI/MRI PCI < 12: 37/39 patients (94.9%); PCI = 12-15: 4/4 patients (100%); PCI > 15: 16/17 patients (94.1%) versus CT PCI < 12: 38/39 patients (97.4%); PCI = 12-15: 0/4 patients (0%); PCI > 15: 2/17 patients (11.8%); p < 0.0001)]. WB-DWI/MRI improved prediction of inoperability over CT with 90.6% sensitivity compared to 25% (p < 0.0001).

Conclusions: WB-DWI/MRI significantly outperformed CT for estimation of spread of PC, overall staging and prediction of operability. Pending validation in larger prospective trials, WB-DWI/MRI could be used to guide surgical planning and minimize unnecessary exploratory laparotomies.

Keywords: CRS-HIPEC; CT; Colorectal peritoneal carcinomatosis; FDG-PET/CT; Metastases; Operability assessment; PCI; WB-DWI/MRI.

Publication types

  • Evaluation Study

MeSH terms

  • Adult
  • Aged
  • Carcinoma / diagnostic imaging*
  • Carcinoma / pathology
  • Carcinoma / surgery
  • Colorectal Neoplasms / diagnostic imaging*
  • Colorectal Neoplasms / pathology
  • Colorectal Neoplasms / surgery
  • Contrast Media
  • Diffusion Magnetic Resonance Imaging*
  • Female
  • Humans
  • Male
  • Middle Aged
  • Peritoneal Neoplasms / diagnostic imaging*
  • Peritoneal Neoplasms / secondary
  • Peritoneal Neoplasms / surgery
  • Preoperative Period


  • Contrast Media