Diagnostic performance of linked color imaging for gastric cancer by Helicobacter pylori infection status: A subanalysis of the large-scale, multicenter randomized controlled trial LCI-FIND.

BACKGROUND: Linked color imaging (LCI) is a new image enhancement technology that facilitates the recognition of subtle differences in mucosal color. In the large-scale, multicenter randomized controlled trial LCI-FIND, LCI demonstrated good diagnostic performance for the detection of tumor lesions in the upper gastrointestinal tract. The aim of the present study was to exploratively evaluate the diagnostic performance of LCI according to H. pylori infection status as a subanalysis of LCI-FIND trial. METHODS: The patients were randomly allocated to receive white light imaging (WLI) first, followed by LCI (WLI group), or vice versa (LCI group), and the two groups were compared for the detection of tumors. Data from this trial were analyzed by the presence/absence of H. pylori infection and further analyzed by successful or unsuccessful eradication in the H. pylori infection group. RESULTS: The 752 patients in the WLI group and 750 patients in the LCI group who had participated in the LCI-FIND trial were included. In the successful eradication group, more gastric lesions were detected by primary mode in the LCI group than in the WLI group, indicating that more lesions were missed by WLI. Fisher's exact probability test for the comparison of the WLI and LCI groups yielded a p-value of 0.0068, with missed gastric lesions being detected 0.136 times (95% confidence interval: 0.020-0.923), significantly less with LCI than with WLI. CONCLUSION: The current study suggests that LCI should be used for gastric cancer screening, particularly in patients with successful H. pylori eradication.

Rates and risk factors of bleeding after gastric endoscopic submucosal dissection with continuous warfarin or 1-day withdrawal of direct oral anticoagulants.

BACKGROUND AND AIM: The 2017 Japanese guidelines recommend continuing warfarin therapy during the perioperative period or discontinuing direct oral anticoagulants (DOACs) only on the day of endoscopic submucosal dissection for early gastric cancer. However, their safety has not been sufficiently explored. This study aimed to validate this management method. METHODS: This retrospective, multicenter study analyzed the characteristics and outcomes of patients who underwent gastric endoscopic submucosal dissection between July 2017 and June 2019. The patients were categorized according to the use of warfarin or DOACs. RESULTS: Among the 62 eligible patients, 53 (85%) were male (median age, 76 years). Warfarin was used in 10 patients (16%) and DOACs in 52 patients (84%). Fourteen patients taking DOACs (27%) used concomitant antiplatelet agents, with seven patients (13%) continuing treatment at the time of the endoscopic procedure. No postprocedural bleeding occurred in patients receiving warfarin (0%), whereas 10 cases (19%) of bleeding occurred in patients receiving DOACs: rivaroxaban, 0% (0/22); dabigatran, 0% (0/2); edoxaban, 43% (6/14); and apixaban, 29% (4/14). The type of anticoagulant (P < 0.01) and continuation of antiplatelet therapy (P = 0.02) were risk factors for postprocedural bleeding in patients receiving DOACs. Intraprocedural bleeding requiring transfusion or symptomatic thromboembolic events were not reported. CONCLUSIONS: Continuous warfarin therapy is preferred. DOAC withdrawal 1 day before a procedure is associated with a high bleeding rate, which may differ for different types of anticoagulants. The continuation of antiplatelet medications in patients receiving DOACs carries a high risk of bleeding and is a future challenge.

Linked color imaging provides enhanced visibility with a high color difference in upper gastrointestinal neoplasms.

BACKGROUND AND AIM: The aim of this post-hoc analysis in a randomized, controlled, multicenter trial was to evaluate the visibility of upper gastrointestinal (UGI) neoplasms detected using linked color imaging (LCI) compared with those detected using white light imaging (WLI). METHODS: The visibility of the detected UGI neoplasm images obtained using both WLI and LCI was subjectively reviewed, and the median color difference (ΔE) between each lesion and the surrounding mucosa according to the CIE L*a*b* color space was evaluated objectively. Multivariate logistic regression analysis was performed to identify factors associated with neoplasms that were missed under WLI and detected under LCI. RESULTS: A total of 120 neoplasms, including 10, 32, and 78 neoplasms in the pharynx, esophagus, and stomach, respectively, were analyzed in this study. LCI enhanced the visibility 80.9% and 93.6% of neoplasms in pharynx/esophagus and stomach compared with WLI, respectively. LCI also achieved a higher ΔE of enhanced neoplasms compared with WLI in the pharynx/esophagus and stomach. The median WLI ΔE values for gastric neoplasms missed under WLI and later detected under LCI were significantly lower than those for gastric neoplasms detected under WLI (8.2 vs 9.6, respectively). Furthermore, low levels of WLI ΔE (odds ratio [OR], 7.215) and high levels of LCI ΔE (OR, 22.202) were significantly associated with gastric neoplasms missed under WLI and later detected under LCI. CONCLUSION: Color differences were independently associated with missing gastric neoplasms under WLI, suggesting that LCI has an obvious advantage over WLI in enhancing neoplastic visibility.

Current prognostic factors of advanced gastric cancer patients treated with chemotherapy: real world data from a Japanese 12 institutions.

BACKGROUND: Understanding the prognostic factors of advanced gastric cancer before starting chemotherapy is important to determine personalized treatment strategies. However, the details of chemotherapy and the prognosis of advanced gastric cancer patients have changed with the time and environment. The aim of this study was to understand the current reality of chemotherapy and to estimate the prognostic factors of advanced gastric cancer patients before starting chemotherapy at multiple centers. This includes specialized cancer hospitals and community hospitals, with the latest data under the Japanese insurance system. METHODS: We evaluated the clinical parameters and treatment details of 1025 patients who received systemic chemotherapy for unresectable advanced gastric cancer from 2012 to 2018 at 12 institutions in Japan. Prognostic factors were analyzed using the Cox proportional hazards regression model. RESULTS: As of April 2021, 953 (93%) patients had died, while 72 (7%) patients survived. The median overall survival and progression-free survival of first-line chemotherapy was 11.8 months (95% confidence interval, 10.8-12.3 months) and 6.3 months (95% confidence interval, 5.9-6.9 months), respectively. Multivariate analysis revealed eight prognostic factors: age < 40 years, performance status ≥2, no gastrectomy, diffuse histological type, albumin <3.6, alkaline phosphatase ≥300, creatinine ≥1.0 and neutrophil-to-lymphocyte ratio > 3.0. Patients using trastuzumab showed better survival than patients without (16.1 months vs. 11.1 months; P = 0.0005). CONCLUSIONS: We identified eight prognostic factors for patients with advanced gastric cancer undergoing Japanese standard chemotherapy. Our results will help clinicians develop treatment strategies for every patient.

Scattered Tiny Whitish Protrusions in the Stomach Are a Clue to the Diagnosis of Autoimmune Gastritis.

Herein, we report two patients with autoimmune gastritis who had undergone multiple esophagogastroduodenoscopy procedures for 17 and 9 years, respectively, before their diagnosis. Instead, they had been diagnosed with and treated for Helicobacter pylori-associated gastritis. The correct diagnosis was made when scatterings of tiny whitish protrusions in the gastric mucosa were detected on esophagogastroduodenoscopy. Our findings suggest that scattered tiny whitish bumps may be a clue to the diagnosis of autoimmune gastritis.

Endocrinological Changes after Anamorelin Administration in Patients with Gastrointestinal Cancer.

Changes in hormone levels in patients with cancer cachexia after anamorelin administration have not been fully investigated. This study aimed to determine how anamorelin affects the endocrine system in patients with gastrointestinal cancer and cachexia. We prospectively enrolled 13 patients and comprehensively investigated their body weight and levels of serum albumin, hemoglobin A1c (HbA1c), and hormones before (week 0) and 3 and 12 weeks after anamorelin administration. The variables were evaluated at week 3 in 9 patients and at week 12 in 5 patients. At week 3, anamorelin administration resulted in body weight gain and increased the levels of growth hormone and HbA1c, as well as insulin-like growth factor-1 standard deviation scores (IGF-1 SD scores). At the same time, negative correlations were observed between ΔIGF-1 SD score and Δthyroidstimulating hormone (TSH) and between ΔIGF-1 SD score and Δfree testosterone. ΔBody weight and ΔIGF-1 SD score correlated positively at week 12. These results suggest that TSH and free testosterone levels can be affected 3 weeks after anamorelin administration; however, those variables tend to return to a state of equilibrium, and anabolic effects of anamorelin appear in long-term (≥ 12 weeks) users.

Characterization of Gastric Tissue-Resident T Cells in Autoimmune and Helicobacter pylori-Associated Gastritis.

Data regarding the in-depth surface marker profiles of gastric tissue-resident lymphocytes in autoimmune and Helicobacter pylori-associated gastritis are lacking. In this study, we investigated potential differences in lymphocyte composition between these profiles. We enrolled patients with autoimmune (n = 14), active (current infection of H. pylori in the stomach; n = 10), and inactive gastritis (post-eradication of H. pylori; n = 20). Lymphocytes were isolated from the greater curvature of the stomach and lesser curvature of the body and analyzed using flow cytometry. The CD8+/CD3+ and CD4+/CD3+ ratios differed between the samples. Body CD4+/antrum CD4+, which is calculated by dividing the CD4+/CD3+ ratio in the body by that in the antrum, was significantly higher in autoimmune gastritis (3.54 ± 3.13) than in active (1.47 ± 0.41) and inactive gastritis (1.42 ± 0.77). Antrum CD8+/CD4+ in autoimmune gastritis (7.86 ± 7.23) was also higher than that in active (1.49 ± 0.58) and inactive gastritis (2.84 ± 2.17). The area under the receiver operating characteristic curve of antrum CD8+/CD4+ was 0.842, and the corresponding optimal cutoff point was 4.0, with a sensitivity of 71.4% and a specificity of 93.3%. We propose that an antrum CD8+/CD4+ ratio > 4.0 is a potential diagnostic marker for autoimmune gastritis.

Microsatellite Instability Analysis and Its Prognostic Value in Invasive Nonampullary Duodenal Adenocarcinoma.

PURPOSE: Nonampullary duodenal adenocarcinoma (NADA) is a rare disease. Although several prognostic factors have been reported for this disease, they remain controversial due to their rarity. In this study, we retrospectively analyzed 54 cases of invasive NADA, focusing on the microsatellite instability (MSI) phenotype, programmed cell death-ligand 1 (PD-L1) expression, and prognostic factors. METHODS: Expression of the PD-L1 protein and cell differentiation markers in tumors was detected by immunohistochemistry. Microsatellite markers (NR-21, NR-22, NR-24, BAT-25, and BAT-26) were amplified for MSI assessment by PCR. RESULTS: The incidence of MSI in invasive NADA was 35.2%. No significant correlation between the MSI phenotype and clinicopathological factors was observed. Positive expression of PD-L1 by immune cells was common in advanced-stage disease (p = 0.054), and positive expression of PD-L1 in cancer cells correlated significantly with the histologically undifferentiated type (p = 0.016). Kaplan-Meier survival analysis demonstrated a significantly better overall survival (OS) in patients with MSI (p = 0.013) and at early-stage disease (p = 0.000) than in those with microsatellite-stable or at late tumor stages. Univariate and multivariate analyses showed that MSI (hazard ratio [HR]: 0.282, 95% confidence interval [CI]: 0.106-0.751, p = 0.011) and early tumor stage (stage I-II) (HR: 8.81, 95% CI: 2.545-30.500, p = 0.001) were independent better prognostic factors of OS. CONCLUSIONS: MSI and early tumor stage (stage I-II) were independent better prognostic factors of OS. A high proportion of MSI phenotypes and positive PD-L1 expression may be helpful for identifying immune checkpoint inhibitors as a novel therapeutic strategy.

Linked Color Imaging (LCI) Emphasizes the Color Changes in the Gastric Mucosa After Helicobacter pylori Eradication.

BACKGROUND: Diffuse redness is a characteristic endoscopic finding that indicates current infection of Helicobacter pylori, which is reduced after successful eradication. Linked color imaging (LCI) has been reported to improve the visibility of diffuse redness compared to white light imaging (WLI); however, quantitative evaluation has not been reported. AIMS: This study aimed to objectively evaluate the color change of the gastric mucosa after H. pylori eradication. METHODS: Images of the greater curvature of the antrum and corpus were captured, and the sites were biopsied during esophagogastroduodenoscopy (EGD) before and 1 year after eradication. The region of interest (ROI) was set around the biopsied area on the images. The color difference (ΔE) before and after eradication was calculated using the CIE L*a*b* color space. The association between the histological evaluation and the color value of the corresponding ROI was determined. RESULTS: At the antrum, there was no significant color change with either mode. At the corpus, the a* value, which reflected redness, decreased significantly after eradication with both modes (WLI: 41.2 to 36.0, LCI: 37.5 to 25.5); the b* value, reflecting yellowish, decreased with WLI, but increased significantly with LCI (WLI: 44.6 to 41.6, LCI: 23.9 to 29.2). The ΔE was significantly larger with LCI than with WLI (16.5 vs. 8.6). The a* values at the corpus were generally associated with histological neutrophil infiltration. CONCLUSIONS: Quantitative evaluation revealed that LCI emphasizes the change in color of the gastric mucosa due to the reduction in diffuse redness.

A prospective multicenter study of the magnifying endoscopic evaluation of the invasion depth of superficial esophageal cancers.

BACKGROUND: Treatment strategies for superficial esophageal squamous cell carcinoma (SESCC) are determined mainly on the basis of the invasion depth. The Japan Esophageal Society (JES) developed a simplified magnifying endoscopic classification for estimating the invasion depth of SESCC. We aimed to evaluate its accuracy. METHODS: We prospectively applied the JES classification for estimating the invasion depth of SESCC to 204 consecutive lesions from 6 hospitals in Japan between April 2016 and October 2018. We analyzed the accuracy of the endoscopic diagnosis by adding the following two categories to the JES classification: ≥ 7 mm lesion in B2 vessels (defined as B2 ≥ 7 mm) and B2 vessels with inflammation (defined as B2i). RESULTS: After applying the exclusion criteria, 201 lesions remained in the analysis. The diagnostic value of type B1, B2, B3 vessels were as follows: sensitivity, 93.9%, 68.0%, 25.0%; specificity, 81.1%, 89.2%, 99.4%; positive predictive value (PPV), 95.6%, 47.2%, 75.0%; negative predictive value (NPV), 75.0%, 95.1%, 95.4%; and accuracy, 91.5%, 86.5%, 95.0%, respectively. A retrospective analysis showed that the diagnostic accuracy was higher in type B2 vessels (86.5% to 92.0%). An avascular area (AVA) was found in 55 (27%) of the 201 lesions, which tended to be associated with a deeper pathological diagnosis of each Type B vessel. In an additional analysis, B2 ≥ 7 mm and B2i improved the diagnostic accuracy of type B2 vessels from 86.5% to 92.0%. CONCLUSIONS: The JES classification is useful for estimating the invasion depth of SESCC. The diagnostic accuracy for type B2 vessels was low, which may be improved by using B2 ≥ 7 mm and B2i.

Linked Color Imaging Focused on Neoplasm Detection in the Upper Gastrointestinal Tract : A Randomized Trial.

BACKGROUND: Linked color imaging (LCI) is a new image-enhanced endoscopy technique that allows users to recognize slight differences in mucosal color. OBJECTIVE: To compare the performance of LCI with white light imaging (WLI) in detecting neoplastic lesions in the upper gastrointestinal tract. DESIGN: A controlled, multicenter trial with randomization using minimization. (University Hospital Medical Information Network Clinical Trials Registry: UMIN000023863). SETTING: 16 university hospitals and 3 tertiary care hospitals in Japan. PATIENTS: 1502 patients with known previous or current cancer of the gastrointestinal tract and undergoing surveillance for gastrointestinal cancer. INTERVENTION: WLI followed by LCI examination (WLI group) or LCI followed by WLI examination (LCI group). MEASUREMENTS: Diagnosis of 1 or more neoplastic lesions in the pharynx, esophagus, or stomach in the first examination (primary outcome) and 1 or more neoplastic lesions overlooked in the first examination (secondary outcome). RESULTS: 752 patients were assigned to the WLI group and 750 to the LCI group. The percentage of patients with 1 or more neoplastic lesions diagnosed in the first examination was higher with LCI than with WLI (60 of 750 patients or 8.0% [95% CI, 6.2% to 10.2%] vs. 36 of 752 patients or 4.8% [CI, 3.4% to 6.6%]; risk ratio, 1.67 [CI, 1.12 to 2.50; P = 0.011]). The proportion with overlooked neoplasms was lower in the LCI group than in the WLI group (5 of 750 patients or 0.67% [CI, 0.2% to 1.6%] vs. 26 of 752 patients or 3.5% [CI, 2.3% to 5.0%]; risk ratio, 0.19 [CI, 0.07 to 0.50]). LIMITATION: Endoscopists were not blinded. CONCLUSION: LCI is more effective than WLI for detecting neoplastic lesions in the pharynx, esophagus, and stomach. PRIMARY FUNDING SOURCE: Fujifilm Corporation.

[Zinc acetate-associated gastric lesions:a case report].

An 82-year-old Japanese man underwent esophagogastroduodenoscopy for postprandial epigastric discomfort. The patient was diagnosed with hypozincemia with a serum zinc level of 63µg/dL (normal range:80-130µg/dL), and he had commenced oral intake of zinc acetate 1 month before the esophagogastroduodenoscopy. Endoscopy showed erosions with white-coated mucosa surface adhesions and erythema on the lesser curvature of the gastric body. Moderately differentiated tubular adenocarcinoma was suspected based on the biopsy examination findings;therefore, he was referred to our hospital for further examination and treatment. A repeat endoscopy showed two erosions with white-coated mucosa surface adhesion and erythema on the lesser curvature of the gastric body. However, the lesion location was different from that detected in the initial endoscopy. The biopsy showed no neoplastic changes. Therefore, based on the endoscopic findings and history of oral zinc acetate administration, we diagnosed the gastric mucosal injury as zinc acetate-associated gastric lesions. The cessation of zinc acetate intake resulted in the resolution of gastric lesions. Reassessment of the biopsy specimen from the initial endoscopy revealed erosions, epithelial cells showing infarct-like necrosis, degenerative atypical cells, and necrotic substances, which were misdiagnosed as neoplastic changes. This case highlights the importance of recognizing the typical endoscopic features of a zinc acetate-associated gastric lesion to enable its prompt diagnosis during esophagogastroduodenoscopy.

Early gastric cancer detection in high-risk patients: a multicentre randomised controlled trial on the effect of second-generation narrow band imaging.

OBJECTIVE: Early detection of gastric cancer has been the topic of major efforts in high prevalence areas. Whether advanced imaging methods, such as second-generation narrow band imaging (2G-NBI) can improve early detection, is unknown. DESIGN: This open-label, randomised, controlled tandem trial was conducted in 13 hospitals. Patients at increased risk for gastric cancer were randomly assigned to primary white light imaging (WLI) followed by secondary 2G-NBI (WLI group: n=2258) and primary 2G-NBI followed by secondary WLI (2G-NBI group: n=2265) performed by the same examiner. Suspected early gastric cancer (EGC) lesions in both groups were biopsied. Primary endpoint was the rate of EGC patients in the primary examination. The main secondary endpoint was the positive predictive value (PPV) for EGC in suspicious lesions detected (primary examination). RESULTS: EGCs were found in 44 (1.9%) and 53 (2.3%; p=0.412) patients in the WLI and 2G-NBI groups, respectively, during primary EGD. In a post hoc analysis, the overall rate of lesions detected at the second examination was 25% (n=36/145), with no significant differences between groups. PPV for EGC in suspicious lesions was 13.5% and 20.9% in the WLI (50/371 target lesions) and 2G-NBI groups (59/282 target lesions), respectively (p=0.015). CONCLUSION: The overall sensitivity of primary endoscopy for the detection of EGC in high-risk patients was only 75% and should be improved. 2G-NBI did not increase EGC detection rate over conventional WLI. The impact of a slightly better PPV of 2G-NBI has to be evaluated further. TRIAL REGISTRATION NUMBER: UMIN000014503.

Artificial intelligence for the detection of esophageal and esophagogastric junctional adenocarcinoma.

BACKGROUND AND AIM: Conventional endoscopy for the early detection of esophageal and esophagogastric junctional adenocarcinoma (E/J cancer) is limited because early lesions are asymptomatic, and the associated changes in the mucosa are subtle. There are no reports on artificial intelligence (AI) diagnosis for E/J cancer from Asian countries. Therefore, we aimed to develop a computerized image analysis system using deep learning for the detection of E/J cancers. METHODS: A total of 1172 images from 166 pathologically proven superficial E/J cancer cases and 2271 images of normal mucosa in esophagogastric junctional from 219 cases were used as the training image data. A total of 232 images from 36 cancer cases and 43 non-cancerous cases were used as the validation test data. The same validation test data were diagnosed by 15 board-certified specialists (experts). RESULTS: The sensitivity, specificity, and accuracy of the AI system were 94%, 42%, and 66%, respectively, and that of the experts were 88%, 43%, and 63%, respectively. The sensitivity of the AI system was favorable, while its specificity for non-cancerous lesions was similar to that of the experts. Interobserver agreement among the experts for detecting superficial E/J was fair (Fleiss' kappa = 0.26, z = 20.4, P < 0.001). CONCLUSIONS: Our AI system achieved high sensitivity and acceptable specificity for the detection of E/J cancers and may be a good supporting tool for the screening of E/J cancers.

Gastric Adenoma: A High Incidence Rate of Developing Carcinoma and Risk of Metachronous Gastric Cancer according to Long-Term Follow-Up.

INTRODUCTION: Gastric adenomas are histologically defined as benign epithelial tumors. While some of them remain adenomas for a long time, others progress to carcinomas. However, long-term outcomes of such cases are not entirely clear. Here, we explored the risk factors and incidence of developing carcinoma from gastric adenoma as well as metachronous gastric cancer. METHODS: This study was conducted at a facility that adopted a follow-up strategy for gastric adenoma. Lesions histologically diagnosed as gastric intestinal-type adenomas between January 2004 and December 2016 were analyzed. Clinicopathological data were collected from patients' medical records, and histological changes from adenoma to carcinoma during endoscopic follow-up and risk factors of cancer development were evaluated. RESULTS: This study involved 409 lesions from 376 patients. The analysis of the development of gastric cancer from adenoma and metachronous gastric cancer was ultimately performed for 282 lesions from 258 patients and 269 lesions from 246 patients, respectively, due to different follow-up periods. The 5-year rate of carcinoma development was 34.0%. Risk factors for carcinoma development upon multivariate analysis were lesion size ≥15 mm and morphological depression. All cases with both factors developed gastric carcinoma, and 50.5% of those with either factor developed carcinoma within 5 years. Gastric adenoma was accompanied by metachronous gastric cancer in 1.5% of the patients annually. The only risk factor for metachronous gastric carcinoma was primary adenoma progressing to carcinoma during the follow-up period. DISCUSSION/CONCLUSION: Given the high rate of carcinoma development in patients with risk factors, resection of gastric adenoma should be considered during the initial examination. Careful observation and follow-up should also be conducted to detect not only changes in the primary adenoma but also the occurrence of metachronous carcinoma, especially in cases of adenoma progressing to carcinoma.

Usability of detecting delivery errors during treatment of prostate VMAT with a gantry-mounted transmission detector.

Volumetric-modulated arc therapy (VMAT) requires highly accurate control of multileaf collimator (MLC) movement, rotation speed of linear accelerator gantry, and monitor units during irradiation. Pretreatment validation and monitoring of these factors during irradiation are necessary for appropriate VMAT treatment. Recently, a gantry mounted transmission detector "Delta4 Discover® (D4D)" was developed to detect errors in delivering doses and dose distribution immediately after treatment. In this study, the performance of D4D was evaluated. Simulation plans, in which the MLC position was displaced by 0.5, 1.0, 1.5, 2.0, 2.5, and 3.0 mm from the clinically used original plans, were created for ten patients who received VMAT treatment for prostate cancer. Dose deviation (DD), distance-to-agreement (DTA), and gamma index analysis (GA) for each plan were evaluated by D4D. These results were compared to the results (DD, DTA and GA) measured by Delta4 Phantom + (D4P). We compared the deviations between the planned and measured values of the MLC stop positions A-side and B-side in five clinical cases of prostate VMAT during treatment and measured the GA values. For D4D, when the acceptable errors for DD, DTA, and GA were determined to be ≤3%, ≤2 mm, and ≤3%/2 mm, respectively, the minimum detectable errors in the MLC position were 2.0, 1.5, and 1.5 mm based on DD, DTA, and GA respectively. The corresponding minimum detectable MLC position errors were 2.0, 1.0, and 1.5 mm, respectively, for D4P. The deviation between the planned and measured position of MLC stopping point of prostate VMAT during treatment was stable at an average of -0.09 ± 0.05 mm, and all GA values were above 99.86%. In terms of delivering doses and dose distribution of VMAT, error detectability of D4D was comparable to that of D4P. The transmission-type detector "D4D" is thus suitable for detecting delivery errors during irradiation.

[Clinical characteristics of five patients with gastric emphysema].

Gastric emphysema is a rare condition in which gas from a nonbacterial source accumulates within the gastric wall. In this study, we retrospectively analyzed the cases of five patients who were diagnosed with gastric emphysema at the Okayama University Hospital between January 2010 and April 2021, to reveal the clinical features of the disease. Based on their reviews, we revealed that:i) gastric emphysema occurred in hospitalized bedridden patients (n=5), such as those during/after endotracheal intubation (n=3), those undergoing gastric tube placement (n=3), those undergoing percutaneous endoscopic gastrostomy (n=1), and those undergoing treatment for cerebral infarction (n=1);ii) gastric emphysema was accompanied by the accumulation of gas in the portal (n=4) or gastric veins (n=1);iii) gastric emphysema was accompanied by colon wall thickness increase (n=4);iv) esophagogastroduodenoscopy showed redness, erosions, coarse mucosa, and/or ulcers (n=5);v) a clear boundary between the damaged area and the intact mucosa was observed (n=5);vi) the anterior wall of the stomach was less affected (n=4);vii) mucosal damage was predominant in the gastric folds, whereas the furrow of the mucosa was less affected;and viii) treatment with enteral nutrition suspension and the administration of proton pump inhibitors and antibiotics resulted in the recovery of patients from gastric emphysema (n=5). These results indicate that patients with gastric emphysema have distinct clinical, endoscopic, and radiological features. Furthermore, our results show that these patients can be conservatively managed.

Long-term outcomes of endoscopic versus surgical resection for MM-SM1 esophageal squamous cell carcinoma using propensity score analysis.

BACKGROUND: Esophageal squamous cell carcinoma (ESCC) confined to the muscularis mucosae (MM) or up to 200 µm of the submucosa (SM1) confers the risk for lymph node metastasis, and is defined as relative indication for endoscopic submucosal dissection (ESD) by the Japan Esophageal Society guidelines. Although additional surgical treatment after ESD is recommended, long-term outcomes of ESD compared with those of surgery have not been clarified. This study aimed to evaluate the long-term outcomes of ESD and surgery for cN0M0 relative indication lesions of ESCC. METHODS: Between 2006 and 2016, patients with relative indication lesions of ESCC who underwent ESD or surgery at nine participating hospitals were examined retrospectively. Using propensity score matching, we evaluated survival curves for and hazard ratios associated with endoscopic submucosal dissection and surgery. RESULTS: In total, 155 lesions in the ESD group and 106 lesions in the surgery group met the pathological criteria of relative indication for endoscopic resection. After matching, 50 matched pairs of patients who underwent ESD or surgery were selected. The 5-year overall survival rates were 84.5% [95% confidence interval (CI) 68-93] in the ESD group and 79% [95% CI 60-90] in the surgery group. The hazard ratio of mortality for ESD compared with that for surgery estimated by Cox regression analysis was 0.79 (95% CI 0.3-2.06, p = 0.63). CONCLUSIONS: Compared with surgery, ESD does not compromise long-term outcomes. ESD alone or ESD with chemotherapy and/or radiotherapy may be an option for the treatment of MM and SM1 ESCC.

Tolerability and efficacy of the concentration of iodine solution during esophageal chromoendoscopy: a double-blind randomized controlled trial.

BACKGROUND AND AIMS: Esophageal chromoendoscopy with iodine solution is an important diagnostic method for the detection of superficial esophageal cancer. However, the concentration of iodine solution has differed among reports. This study aimed to evaluate patient discomfort with different iodine concentrations. METHODS: We performed a prospective, double-blind, randomized study. We prospectively enrolled and analyzed 77 patients who were at high risk for esophageal carcinoma and scheduled to undergo EGD from March 2018 to January 2019. All patients were divided into 2 groups before the procedure to compare pain measurements: a 1% iodine solution group (group A) and a 2% iodine solution group (group B). The primary endpoint of this study was the difference in pain measurement between 1% and 2% iodine solution chromoendoscopy. Secondary endpoints were safety, detection yield, and color evaluation based on both the endoscopist's survey and color values, as determined using the Commission Internationale de l'Eclairage (CIELAB, Vienna, Austria) color evaluation system, in the iodine-faded and iodine-stained area of each group. RESULTS: Heartburn and retrosternal pain in group A were significantly lower than those in group B (P = .02). Eleven patients reported heartburn and retrosternal pain (group A, 2; group B, 9). Four patients reported pain above the sternal angle and 7 below the sternal angle. There was no significant difference between the 2 groups with regard to detection yield, color evaluation by the endoscopist's assessment, or color values. No patients had any adverse events, and all safely completed this study. CONCLUSIONS: The 2% iodine solution resulted in significantly greater pain than the 1% iodine solution, and the color of the stained esophageal images of each group was the same from this study. Therefore, the 1% iodine solution is recommended for esophageal chromoendoscopy. (Clinical trial registration number: UMIN 000029796.).

The Color Difference between Differentiated Early Gastric Cancer and Suspicious Mucosal Areas on Linked Color Imaging.

BACKGROUND: Image enhanced endoscopy (IEE) contributes to the early detection of gastrointestinal cancer. IEE enhances the color between a lesion and the background mucosa. Linked color imaging (LCI), a novel form of IEE, is a unique system for enhancing color and some studies have demonstrated the efficacy of LCI in the diagnosis of early gastric cancer (EGC) based on the color difference between cancer and the background mucosa. However, the effect may increase the area in which cancer is suspected and lead to an increase in false-positive results. SUMMARY: We conducted a retrospective study of linked color images of differentiated EGC and suspicious mucosal areas to compare the colors between each lesion. Images of 38 EGCs and 23 suspicious areas were analyzed. The mean color values of EGC were as follows; L*(lightness), 61.7; a*(green to red), 41.2; and b*(blue to yellow), 27.1. Those of suspicious mucosal areas were as follows; L*, 56.1; a*, 44.2; and b*, 21.3. EGC had significantly higher L*, b* values and lower a* values in comparison to suspicious mucosal areas. EGC and suspicious mucosal areas had significantly higher a* values in comparison to the background mucosa. Key Messages: EGC had higher b* values in comparison to suspicious mucosal areas, and was not only reddish but also mixed with yellow, with an orange-like color.