Published online Apr 15, 2020. doi: 10.4251/wjgo.v12.i4.435
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
The reliability of preoperative nodal diagnosis of advanced gastric cancer by multi-detector spiral computed tomography (MDCT) is still unclear.
To examine the diagnostic ability of MDCT more precisely by using data on intranodal pathological metastatic patterns.
A total of 108 patients with advanced gastric cancer who underwent MDCT and curative gastrectomy at Kanazawa Medical University Hospital 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.
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 was 91.4% and the specificity was 47.3% in the prospective phase. The large nodular and diffuse metastases were easy to diagnose because metastatic nodes with a large axis often exhibit these forms.
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. 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.
Core tip: The preoperative nodal diagnostic ability of multi-detector spiral computed tomography for advanced gastric cancer was examined more precisely using data from patients for whom precise one-to-one correspondence of lymph nodes could be performed between computed tomography and intranodal pathological metastatic patterns by using lymph node mapping. The number of dissected, metastatic, and detected nodes on computed tomography were 4241, 801, and 897, respectively. The sensitivity of multi-detector spiral computed tomography for nodal diagnosis was as good as 91% with the critical value of 7.6 mm for the long axis. The large nodular or diffuse metastases were easy to diagnose. However, the specificity was as low as 47%, because most of the metastatic nodes in gastric cancer were small nodes.