Diagnostic value of whole-body MRI with diffusion-weighted sequence for detection of peritoneal metastases in colorectal malignancy

Abstract

Objective:To assess the diagnostic accuracy of whole-body MRI using diffusion-weighted sequence (WB-DWI) to determine the peritoneal cancer index (PCI) in correlation with surgical and histopathological findings.Methods:Twenty-seven patients underwent preoperative WB-MRI, followed by cytoreductive surgery for primary tumors of the appendix (n = 15), colorectum (n = 12), and associated peritoneal disease. A total of 351 regions were retrospectively reviewed. The sensitivity, specificity, and accuracy were calculated at 13 anatomical sites. The WB-DWI PCI and PCI type were compared with surgical and histopathological findings. Results:No statistical difference was found between the WB-DWI PCI and surgical PCI (P = 0.574). WB-DWI correctly predicted the PCI type in 24 of 27 patients with high accuracy (88.9%), including 10 of 10 patients with small-volume tumor, 12 of 14 with moderate-volume tumor, and 2 of 3 with large-volume tumor. WB-DWI correctly depicted tumors in 163 of 203 regions, with 40 false-negative and 23 false-positive regions. The overall sensitivity, specificity, and accuracy of WB-DWI for the detection of peritoneal tumors were 80.3%, 84.5%, and 82.1%, respectively. For lesions < 0.5 cm in diameter, WB-DWI demonstrated good sensitivity (69.4%). Conclusions:WB-DWI accurately predicted PCI before surgery in patients undergoing evaluation for cytoreductive surgery.

Diagnostic value of diffusion-weighted imaging/magnetic resonance imaging for peritoneal metastasis from malignant tumor

“…When considering only the retrospective studies, [ 7 , 20 , 21 , 23 – 25 ] the pooled sensitivity of DWI for PMs was 85% (95% CI: 81%–89%). Heterogeneity was observed ( P = .03, I 2 = 60.3%).…”

Dedicated MRI staging versus surgical staging of peritoneal metastases in colorectal cancer patients considered for CRS-HIPEC; the DISCO randomized multicenter trial

“…PPVs for predicting complete cytoreduction have been reported of 0.63–0.97 with DLS [ 6 , 8 – 10 , 30 ]. Sensitivities and specificities of 0.80–0.98 and 0.85–0.93 have been reported with use of MRI at region-wise analysis in two cohort studies of 27 and 60 patients [ 17 , 18 ], from with a PPV of 0.90 could be achieved for predicting an operable extent of disease [ 17 ]. This was in concordance with the findings of Van’t Sant and colleagues who reported a PPV of 0.89 finding an operable extent of disease in a cohort study of 49 patients [ 15 ].…”

“…CT is the preferred first-line imaging tool for the detection of peritoneal metastases but falls short when used to assess the total peritoneal tumor burden [ 12 – 16 ]. Magnetic resonance imaging (MRI), with diffusion-weighted imaging (DWI), has shown to predict the extent of disease accurately (sensitivity of 0.80–0.98 and a specificity 0.85–0.93% [ 17 , 18 ]) and to be a valuable adjunct to decide whether complete cytoreduction can be achieved [ 13 , 15 , 17 ]. DWI-MRI had also shown to be superior for detecting liver metastases [ 19 , 20 ].…”

Peritoneal Metastasis: A Dilemma and Challenge in the Treatment of Metastatic Colorectal Cancer

“…Even very small lesions (2-3 mm) can show a significantly high signal on DWI-MRI images [67], while ascites and intestinal contents show a low signal. In a Chinese study, the sensitivity, specificity, and accuracy of DWI-MRI in assessing CRC-PM were 80.3%, 84.5%, and 82.1%, respectively [68]. In another study, the sensitivity and specificity of DWI-MRI in detecting peritoneal dissemination of gynecologic malignancies were up to 90.0% and 95.5%, respectively [69].…”