Retrospective Cohort Study
Copyright ©The Author(s) 2016. Published by Baishideng Publishing Group Inc. All rights reserved.
World J Gastroenterol. May 28, 2016; 22(20): 4891-4900
Published online May 28, 2016. doi: 10.3748/wjg.v22.i20.4891
Rectal cancer staging: Multidetector-row computed tomography diagnostic accuracy in assessment of mesorectal fascia invasion
Davide Ippolito, Silvia Girolama Drago, Cammillo Talei Franzesi, Davide Fior, Sandro Sironi
Davide Ippolito, Silvia Girolama Drago, Cammillo Talei Franzesi, Davide Fior, Sandro Sironi, School of Medicine, University of Milano-Bicocca, Milan, 20900 Monza (MB), Italy
Davide Ippolito, Silvia Girolama Drago, Cammillo Talei Franzesi, Davide Fior, Sandro Sironi, Department of Diagnostic Radiology, H. San Gerardo Hospital, Milan, 20900 Monza (MB), Italy
Author contributions: Ippolito D was guarantor of integrity of entire study and conception the study; Ippolito D and Drago SG contributed to study design, acquisition, data analysis/interpretation and statistical analysis; Ippolito D, Drago SG and Franzesi CT contributed to study design, and clinical studies; Franzesi CT and Fior D contributed to literature research; Drago SG contributed to manuscript preparation; Ippolito D and Sironi S contributed to manuscript definition of intellectual content; Ippolito D and Franzesi CT contributed to manuscript editing; all authors contributed to manuscript revision/review; Ippolito D made manuscript final version approval.
Institutional review board statement: The study was reviewed and approved by the H. San Gerardo Institutional Review Board.
Informed consent statement: Every patient gave his informed consent, as required by our Institution.
Conflict-of-interest statement: All the authors are aware of the content of the manuscript and have no conflict of interest.
Data sharing statement: No additional data are available.
Open-Access: This article is an open-access article which was selected by an in-house editor and fully peer-reviewed by external reviewers. It is distributed in accordance with the Creative Commons Attribution Non Commercial (CC BY-NC 4.0) license, which permits others to distribute, remix, adapt, build upon this work non-commercially, and license their derivative works on different terms, provided the original work is properly cited and the use is non-commercial. See:
Correspondence to: Davide Ippolito, MD, Department of Diagnostic Radiology, H. San Gerardo Hospital, Via Pergolesi 33, Milan, 20900 Monza (MB), Italy.
Telephone: +39-02-64488265 Fax: +39-02-64488299
Received: January 28, 2016
Peer-review started: January 30, 2016
First decision: March 7, 2016
Revised: March 24, 2016
Accepted: April 7, 2016
Article in press: April 7, 2016
Published online: May 28, 2016

AIM: To assess the diagnostic accuracy of multidetector-row computed tomography (MDCT) as compared with conventional magnetic resonance imaging (MRI), in identifying mesorectal fascia (MRF) invasion in rectal cancer patients.

METHODS: Ninety-one patients with biopsy proven rectal adenocarcinoma referred for thoracic and abdominal CT staging were enrolled in this study. The contrast-enhanced MDCT scans were performed on a 256 row scanner (ICT, Philips) with the following acquisition parameters: tube voltage 120 KV, tube current 150-300 mAs. Imaging data were reviewed as axial and as multiplanar reconstructions (MPRs) images along the rectal tumor axis. MRI study, performed on 1.5 T with dedicated phased array multicoil, included multiplanar T2 and axial T1 sequences and diffusion weighted images (DWI). Axial and MPR CT images independently were compared to MRI and MRF involvement was determined. Diagnostic accuracy of both modalities was compared and statistically analyzed.

RESULTS: According to MRI, the MRF was involved in 51 patients and not involved in 40 patients. DWI allowed to recognize the tumor as a focal mass with high signal intensity on high b-value images, compared with the signal of the normal adjacent rectal wall or with the lower tissue signal intensity background. The number of patients correctly staged by the native axial CT images was 71 out of 91 (41 with involved MRF; 30 with not involved MRF), while by using the MPR 80 patients were correctly staged (45 with involved MRF; 35 with not involved MRF). Local tumor staging suggested by MDCT agreed with those of MRI, obtaining for CT axial images sensitivity and specificity of 80.4% and 75%, positive predictive value (PPV) 80.4%, negative predictive value (NPV) 75% and accuracy 78%; while performing MPR the sensitivity and specificity increased to 88% and 87.5%, PPV was 90%, NPV 85.36% and accuracy 88%. MPR images showed higher diagnostic accuracy, in terms of MRF involvement, than native axial images, as compared to the reference magnetic resonance images. The difference in accuracy was statistically significant (P = 0.02).

CONCLUSION: New generation CT scanner, using high resolution MPR images, represents a reliable diagnostic tool in assessment of loco-regional and whole body staging of advanced rectal cancer, especially in patients with MRI contraindications.

Keywords: Magnetic resonance, Multi detector computed tomography, Rectal cancer, Mesorectal fascia, Multiplanar reconstructions

Core tip: The introduction of new generation of multidetector-row computed tomography (MDCT) scanner allowed thin-collimation scanning and high spatial resolution, resulting in improved multiplanar reconstructions (MPRs) and could be potentially useful, in a single examination, for local staging and distant metastases evaluation in rectal cancer patients. On these basis in our study we assessed the accuracy of high row number MDCT for the prediction of tumor invasion of the mesorectal fascia, being MRI findings as reference standard, and whether the addition of high-resolution MPR images can provide greater accuracy.