Comparison between blinded and partially blinded detection of gastric cancer with multidetector CT using surgery and endoscopic submucosal dissection as reference standards

Abstract

ABSTRACT. The aim of this study is to compare blinded with partially blinded detection of gastric cancer with multidetector (MD) CT by using surgery and endoscopic submucosal dissection (ESD) as reference standards. 44 patients with gastric cancer underwent MDCT with air as an oral contrast agent. Surgery was performed on 37 patients, ESD on six and surgery after ESD on one. To provide comparison cases of blinded evaluation, 38 MDCT examinations were added for cases where no focal gastric lesion was seen on endoscopy. Two radiologists, blinded to the presence, number and location of the tumours, evaluated axial and axial plus multiplanar reformation (MPR) images of 82 MDCT examinations with or without gastric cancer. For partially blinded evaluation, the same radiologists, blinded to the location and number of tumours, evaluated axial and axial plus MPR images of 44 MDCT examinations of gastric cancer. Differences in assessment were resolved by consensus. 45 gastric cancers were found in surgical and ESD specimens. Detection rates of gastric cancer from axial and axial plus MPR images during blinded evaluation and from axial and axial plus MPR images during partially blinded evaluation were 62% (28/45), 64% (29/45), 64% (29/45) and 71% (32/45), respectively. There was no statistical significance for the comparison between blinded and partially blinded detection rates of gastric cancer. The detection rate of gastric cancer with MDCT during blinded evaluation showed no specific difference compared with the detection rate of gastric cancer with MDCT during partially blinded evaluation. . However, patients with early gastric cancer have 5-year survival rates of more than 85% [3,4]. Therefore, early detection of gastric cancer is essential for the improvement of patient survival and for the reduction of the overall use of medical resources. Although the use of endoscopy and a double-contrast barium study has a significant role in the detection of gastric cancer, the depth of tumour invasion and the presence or absence of metastasis cannot be determined by the use of these modalities. Multidetector CT (MDCT) is usually performed for pre-operative staging work-up of patients with gastric cancer. Accurate evaluation of the location and local extent of the gastric cancer (T stage) is important in the choice of the optimal therapeutic approach. However, if gastric cancer cannot be detected on MDCT, the modality cannot provide the information about the location and T stage of gastric cancer. Thus, lesion detection on MDCT is a prerequisite for gastric cancer staging on MDCT [5].Currently, some early gastric cancers may be treated with laparoscopic gastrectomy or endoscopic submucosal dissection (ESD) without laparotomy [6,7]. However, most studies on gastric cancer have confined the study population to patients who have received a laparotomy [5,[8][9][10][11]. This strict confinement of the study population may result in an overestimation of the detection rate of gastric cancer. Most results for the detection rate of gastr...

T and N Staging of Gastric Cancer Using Dual-Source Computed Tomography

“…Similar to this study, many other studies did not include patients without gastric cancer as the control group [3, 12, 15, 20]. Kim et al [21] and Park et al [22] used partially and completely blind methods in their gastric cancer studies and showed no difference in the two methods. Hence, the present study was not affected by the lack of a negative contrast group.…”

Gastric cancer detection using MDCT compared with 2D axial CT: diagnostic accuracy of three different reconstruction techniques

“…According to previous studies in which an MDCT scanner was used, the detection rate of gastric cancer on 2D axial CT and MPR was between 62% and 98%. However, the detection rate of EGC on 2D axial CT and MPR is generally low, i.e., between 41.2% and 71% [4][5][6][7].…”

“…previous reports, the detection rate of gastric cancer on 2D axial CT varies between 20% and 91% [3][4][5][6][7].…”