Retrospective Study
Copyright ©The Author(s) 2020. Published by Baishideng Publishing Group Inc. All rights reserved.
World J Gastrointest Oncol. Apr 15, 2020; 12(4): 435-446
Published online Apr 15, 2020. doi: 10.4251/wjgo.v12.i4.435
Diagnostic ability of multi-detector spiral computed tomography for pathological lymph node metastasis of advanced gastric cancer
Zhi-Yong Jiang, Shinichi Kinami, Naohiko Nakamura, Takashi Miyata, Hideto Fujita, Hiroyuki Takamura, Nobuhiko Ueda, Takeo Kosaka
Zhi-Yong Jiang, Shinichi Kinami, Naohiko Nakamura, Takashi Miyata, Hideto Fujita, Hiroyuki Takamura, Nobuhiko Ueda, Takeo Kosaka, Department of Surgical Oncology, Kanazawa Medical University, 1-1 Daigaku, Uchinada-machi, Kahoku-gun, Ishikawa 920-0293, Japan
Author contributions: Jiang ZY was responsible for the scientific context and writing of the manuscript. Kinami S was responsible for instructing on the scientific research and writing of the manuscript. Nakamura N, Miyata T, Fujita H, Ueda N, Takamura H and Kosaka T contributed to the literature review; data analysis; drafting, editing, and critical revision of the manuscript; and approval of the final version of the manuscript.
Institutional review board statement: This study was reviewed and approved by the Ethics Committee of the Kanazawa Medical University Hospital.
Informed consent statement: Patients were not required to give informed consent to the study because the analysis used anonymous clinical data that were obtained after each patient agreed to treatment by written consent. Regarding data use in the retrospective study, the patients were given the opportunity to optout of the study at any time.
Conflict-of-interest statement: The authors declare no conflicts of interest related to the publication of the study.
Data sharing statement: No additional data are available.
Open-Access: This article is an open-access article that was selected by an in-house editor and fully peer-reviewed by external reviewers. It is distributed in accordance with the Creative Commons Attribution NonCommercial (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: http://creativecommons.org/licenses/by-nc/4.0/
Corresponding author: Shinichi Kinami, MD, PhD, Professor, Department of Surgical Oncology, Kanazawa Medical University, 1-1 Daigaku, Uchinada-machi, Kahoku-gun, Ishikawa 920-0293, Japan. kinami@kanazawa-med.ac.jp
Received: November 21, 2019
Peer-review started: November 21, 2019
First decision: December 12, 2019
Revised: February 12, 2020
Accepted: February 23, 2020
Article in press: February 23, 2020
Published online: April 15, 2020
Processing time: 146 Days and 1.2 Hours
ARTICLE HIGHLIGHTS
Research background

The reliability of preoperative diagnosis of nodal metastasis of advanced gastric cancer by multi-detector spiral computed tomography (MDCT) is still unclear. A preoperative nodal diagnosis by MDCT is made on the assumption that the size of the metastatic lymph node is large. However, pathological metastatic lymph nodes may not be necessarily large in size.

Research motivation

A one-to-one correspondence between lymph nodes confirmed on preoperative images and those assessed pathologically have not been reported to date. In our hospital, all dissected nodes are usually harvested by experienced surgeons and mapped individually. By measuring the size of the lymph node during harvest, pathological metastasis lymph nodes could be detected precisely by using preoperative MDCT.

Research objectives

The purpose of this study was to examine the preoperative nodal diagnostic ability of MDCT more precisely by using postoperative lymph node mapping and data on pathological metastatic patterns.

Research methods

A total of 108 patients with advanced gastric cancer who underwent MDCT and curative gastrectomy were enrolled in this study. The nodal sizes measured on computed tomography (CT) images were compared with the pathology results. A receiver-operating characteristic curve was constructed, from which the critical value (CV) was calculated by using the data of the first 69 patients retrospectively. By using the CV, sensitivity and specificity were calculated with prospectively collected data from 39 consecutive patients. This enabled a more precise one-to-one correspondence of lymph nodes between CT and pathological examination by using the size data of lymph node mapping. The intranodal pathological metastatic patterns were classified into the following four types: Small nodular, peripheral, large nodular, and diffuse.

Research results

Although all the cases were clinically suspected as having metastasis, 81 had lymph node metastasis and 27 had no metastasis. The number of dissected, detected on CT, and metastatic nodes were, 4241, 897, and 801, respectively. The CV obtained from the receiver-operating characteristic was 7.6 mm for the long axis. The sensitivity and specificity of the diagnostic ability of MDCT for nodal metastasis were respectively 86.8% and 80.1% in the retrospective phase. To verify the accuracy of the CV, diagnostic abilities were calculated using the data from prospective study phase. By referring to the sizes and serial numbers of the lymph nodes measured in the map, a one-to-one correspondence becomes possible between lymph nodes detected by MDCT and the pathological results in the prospective study. The sensitivity was 91.4% and the specificity was 47.3% in the prospective phase. Only 43.8% of the metastatic lymph nodes were larger than the critical values. The larger nodes were only 28.1% of all the peripheral type nodes and 52.7% of the large nodular or diffuse type nodes.

Research conclusions

The ability of MDCT to contribute to a nodal diagnosis of advanced gastric cancer was examined prospectively with precise size data from node mapping, using a CV of 7.6 mm for the long axis that was calculated from the retrospectively collected data. The sensitivity was as high as 91%, and would be improved when referring to the enhanced patterns. The nodal diagnosis of cases with the large nodular or diffuse pattern was slightly easier. However, its specificity was as low as 47%, because most of metastatic nodes in gastric cancer being small in size. The small nodular or peripheral type metastatic nodes were often small and considered difficult to diagnose.

Research perspectives

Obvious node-positive cases of advanced gastric cancer suitable for neoadjuvant chemotherapy can be identified using MDCT because the sensitivity for the nodal diagnosis was as high as 90% with the critical value of 7.6 mm for the long axis. However, the specificity was as low as 47%, so it seemed difficult to decide the omission of nodal dissection on the basis of the MDCT finding.