This study was aimed at evaluating the screening accuracy of a population-based radiographic screening program for gastric cancer, conducted in longer examination intervals by using both the morbidity data of the Miyagi Cancer Registry and data of participants who underwent screening obtained from the Miyagi Cancer Society. At first, 4975 gastric cancer cases that were detected in the population-based radiographic screening for gastric cancer from the 2002-2016 fiscal year were analyzed. The cases with longer examination intervals showed a decreased detection rate of early gastric cancer that is suitable for endoscopic resection and an increased detection rate of advanced cancer, in comparison with the cases with annual examination. Then, the following participation trend in the gastric cancer screening program by 203,885 participants in the 2002 fiscal year was determined on the basis of the participants’ data from the Miyagi Cancer Society. The incidence of gastric cancer was determined on the basis of the data from the Miyagi Cancer Registry. The data indicated a significant increase in the incidence of interval cancer in the patients who did not undergo the examination in the second year as compared with the participants in the second-round screening (odds ratio [OR], 2.20; 95% confidence interval [CI], 1.59-3.04). The screening sensitivity of the annual screening program was 73.8%, whereas the value of the screening program conducted every other year was estimated to be 45.8%, with a significant difference (p < 0.001). Among the patients whose gastric cancers were detected in the screening examination in the third year, those who did not undergo the screening examination in the second year showed significantly lower survival rate than those who received the annual examination. This is because the former included more advanced cases than the latter. Thus, the accuracy of the gastric cancer screening program conducted at longer examination intervals might have deteriorated. Therefore, a biennial radiographic screening for gastric cancer should be carefully incorporated in the population-based program.

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Since 1999, Ota City has conducted individualized screening where the patient selects endoscopy or direct radiographic imaging as the screening modality. From 2008 to 2013, we performed ABC classification using Helicobacter pylori antibody and the serum pepsinogen method and found that the detection rate of stomach cancer was 0.53% (397/74,352 patients) and that in Group A was 0.19% (62/32,352); Group B, 0.51% (102/19,945); Group C, 1.03% (187/18,148); Group D, 1.17% (46/3,934). The discovery rates using H. pylori antibody and the serum pepsinogen method were 0.76% (289/38,093) and 1.06% (233/22,082), respectively. However, the incidence of cases missed with the H. pylori antibody and serum pepsinogen screening methods were 27.2% (108/397) and 41.3% (164/397), respectively, indicating that using H. pylori antibody fewer cases were overlooked; this method is thus suitable for screening. The H. pylori antibody level of a patient was measured during a medical checkup, and H. pylori screening was conducted to recommend endoscopic examination for antibody-positive patients. Screening of the subjects using only the ABC classification is thought to have a high risk of missed cases. Thus, an efficient endoscopic examination for H. pylori associated gastritis is necessary.

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We investigated whether the insertion time, withdrawal time, and number of images taken during colonoscopy are the indicators of the procedure quality. Among the 1591 cases of total colonoscopy performed by 13 different endoscopists as part of routine health examinations, the median insertion time, mean withdrawal time, and mean number of images taken by each endoscopist were calculated. We investigated the correlation between these indicators and the polyp detection rate. In addition, using logistic regression analysis, we analyzed the factors contributing to polyp detection. The Spearman’s rank correlation coefficient between each indicator and the polyp detection rate was 0.31 (P=0.30) for the insertion time, 0.67 (P=0.01) for the withdrawal time, and -0.36 (P=0.23) for the number of images documented. Only the withdrawal time was significantly correlated with polyp detection. Logistic regression analysis showed that male sex (odds ratio [OR], 1.65), a 1-year increase in age (OR, 1.02), and a withdrawal time of >=6.5 min (OR, 1.42) were significantly associated with polyp detection, while documentation of >=25 images (OR, 0.75) was associated with non-detection. The withdrawal time has been considered an indicator of the procedure quality. To determine the optimal image recording method, including the number of images documented, further research is necessary.

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Objective This study sought to evaluate and compare the radiation dose and image quality between ultra-low dose computed tomography colonography (CTC) with different levels of iterative reconstruction (Sinogram Affirmed Iterative Reconstruction, SAFIRE), and low dose CTC with filtered back projection (FBP).
Participants and Methods Following institutional ethics clearance, 80 participants who underwent screening with CTC were included. The participants were scanned using low dose protocol in a supine position with FBP, and ultra-low dose protocol in a prone position with iterative reconstruction. The effective dose and objective image quality were both evaluated.
Results The mean effective dose in low dose CTC was 1.28 mSv, compared to 0.61-0.82 mSv at four different ultra-low dose CTC (p<0.01). The mean effective dose was reduced by 46% in ultra-low dose protocol compared to low dose protocol (p<0.01). CTC image noise (standard deviation) was reduced by a maximum of 45% in CTC with iterative reconstruction compared to CTC reconstructed with SAFIRE (p<0.05).
Conclusions The radiation dose in ultra-low dose CTC with SAFIRE could be reduced by 46%, without decreasing image quality, compared to the radiation dose in low dose CTC with FBP.

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The category classification based on the Manual for Abdominal Ultrasound in Cancer Screening and Health Checkups (judgment manual) was announced in 2014. We investigated whether endoscopic ultrasonography (EUS) and contrast-enhanced endoscopic ultrasonography (CE-EUS) are efficient methods for performing a detailed examination of the pancreatic ductal carcinoma. We examined 183 cases of pancreatic ductal carcinomas diagnosed at our hospital between July 2008 and December 2015; furthermore, we used 28 cases of other pancreatic solid tumors as controls. When the judgment manual was applied to EUS, the sensitivity, specificity, and correct diagnosis rates for ultrasound (US) and EUS were 91% and 98%, 78% and 95%, and 89% and 98%, respectively. The category 5 was useful for diagnosis of the pancreatic ductal carcinoma via US, but EUS showed a better diagnostic performance than US. During CE-EUS examination using perflubutane, the contrast effect after the contrast peak was significantly reduced in pancreatic ductal carcinomas compared to the other pancreatic solid tumors. EUS and CE-EUS are useful and efficient methods for a detailed examination of the pancreatic ductal carcinoma.

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