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

• Main Authors: Huan Zhang, Weixing Dai, Caixia Fu, Xu Yan, Alto Stemmer, Tong Tong, Guoxiang Cai
• Format: Article
• Language: English
• Published: China Anti-Cancer Association 2018-06-01
• Series: Cancer Biology & Medicine
• Subjects: MRI; diffusion-weighted imaging; peritoneal cancer index; peritoneal metastases; colorectal malignancy
• Online Access: http://www.cancerbiomed.org/index.php/cocr/article/view/1131
• ISSN: 2095-3941; 2095-3941

<b>Objective: </b> 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.<b>Methods: </b> Twenty-seven patients underwent preoperative WB-MRI, followed by cytoreductive surgery for primary tumors of the appendix (<i>n</i> = 15), colorectum (<i>n</i> = 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.<b>Results: </b> No statistical difference was found between the WB-DWI PCI and surgical PCI (<i>P</i> = 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 &lt; 0.5 cm in diameter, WB-DWI demonstrated good sensitivity (69.4%).<b>Conclusions: </b> WB-DWI accurately predicted PCI before surgery in patients undergoing evaluation for cytoreductive surgery.