Superior lymph node harvest by fluorescent lymphography during minimally invasive gastrectomy for gastric cancer patients with high body mass index.

BACKGROUND: Fluorescent lymphography (FL) using indocyanine green (ICG) allows for the visualization of all draining lymph nodes (LNs), thereby increasing LN retrieval. However, no studies have assessed the efficacy of FL in high body mass index (BMI) gastric cancer patients, even as LN yield decreases with increasing BMI in gastrectomy. This study aimed to investigate the influence of FL on LN retrieval in high BMI gastric cancer patients. METHODS: Gastric cancer patients who underwent laparoscopic or robotic gastrectomies from 2013 to 2021 were included. Patients were classified into two groups, with FL (FL group) or without FL (non-FL group). The effect of FL on LN retrieval was assessed by BMI. Inverse probability of treatment weighting (IPTW) was used to ensure comparability between groups. RESULTS: Retrieved LN number decreased as BMI increased regardless of FL application (P < 0.001). According to the IPTW analysis, the mean retrieved LN number was significantly higher in the FL group (48.4 ± 18.5) than in the non-FL group (39.8 ± 16.3, P < 0.001), irrespective of BMI. The FL group exhibited a significantly higher proportion of patients with 16 or more LNs (99.5%) than the non-FL group (98.1%, P < 0.001). The FL group also had a significantly higher proportion of patients with 30 or more LNs (86.6%) than the non-FL group (72.2%, P < 0.001). In both the normal and high-BMI patients, the FL group had a significantly larger percentage of patients with a higher nodal classification than the non-FL group. CONCLUSION: FL resulted in more LN retrieval, even in high BMI patients. FL ensures accurate staging by maintaining the appropriate retrieved LN number in high BMI gastric cancer patients.

Identifying the best candidates for reduced port gastrectomy.

BACKGROUND: Previous studies have focused on the non-inferiority of RPG compared with conventional port gastrectomy (CPG); however, we assumed that some candidates might derive more significant benefit from RPG over CPG. METHODS: We retrospectively analyzed the clinicopathological and perioperative parameters of 1442 patients with gastric cancer treated by gastrectomy between 2009 and 2022. The C-reactive protein level on postoperative day 3 (CRPD3) was used as a surrogate parameter for surgical trauma. Patients were grouped according to the extent of gastrectomy [subtotal gastrectomy (STG) or total gastrectomy (TG)] and lymph node dissection (D1+ or D2). The degree of surgical trauma, bowel recovery, and hospital stay between RPG and CPG was compared among those patient groups. RESULTS: Of 1442 patients, 889, 354, 129, and 70 were grouped as STGD1+, STGD2, TGD1+, and TGD2, respectively. Compared with CPG, RPG significantly decreased CRPD3 only among patients in the STGD1+ group (CPG: n = 653, 84.49 mg/L, 95% CI 80.53-88.45 vs. RPG: n = 236, 70.01 mg/L, 95% CI 63.92-76.09, P < 0.001). In addition, the RPG method significantly shortens bowel recovery and hospital stay in the STGD1+ (P < 0.001 and P < 0.001), STGD2 (P < 0.001 and P < 0.001), and TGD1+ (P = 0.026 and P = 0.007), respectively. No difference was observed in the TGD2 group (P = 0.313 and P = 0.740). CONCLUSIONS: The best candidates for RPG are patients who undergo STGD1+, followed by STGD2 and TG D1+, considering the reduction in CRPD3, bowel recovery, and hospital stay.

Predictive Value of KLASS-02-QC Assessment Score on KLASS-02 Surgical Outcomes: Validation of Surgeon Quality Control and Standardization for D2 Lymphadenectomy.

OBJECTIVE: The aim of this study was to audit the 22 items and assessed each item's predictive value on surgical outcomes. BACKGROUND: The KLASS-02 trial revealed that the oncologic outcomes of laparoscopic distal gastrectomy are not inferior to open distal gastrectomy in patients with advanced gastric cancer. The surgeons participating in this trial were chosen based on the assessment scores from the KLASS-02-QC trial, which used 22 items for standardization of D2 lymphadenectomy and quality control. METHODS: We reviewed proficiency scores (PSs) for 22 items for 20 surgeons who participated in KLASS-02. The surgeons were divided into 2 groups according to PS, and the perioperative outcomes of 924 patients enrolled in KLASS-02 were compared between groups. Each item's predictive value for perioperative outcome was then assessed using multivariable regression models. RESULTS: Of the total 924 patients, 529 were operated on by high-score surgeons (high PS) and 395 were operated on by low-score surgeons (low-PS). High-PS group had less intraoperative blood loss, longer operation times, and fewer complications, major complications, reoperations, and shorter first flatus and hospital stay than low-PS group ( P =0.006, P <0.001, P <0.001, P <0.001, P =0.042, P =0.013, and P <0.001, respectively). Some items used in KLASS-02-QC predicted perioperative outcomes, such as intraoperative blood loss, major complications, reoperation, and hospital stay. CONCLUSIONS: Although this study only analyzed data associated with qualified surgeons, the 22 items effectively assessed the surgeons based on PS. A high score was associated with longer operation times, but better perioperative outcomes.

Preoperative Fistula Risk Prediction Using Computed Tomography Image Before Pancreatoduodenectomy.

BACKGROUND: Although many formulas for predicting postoperative pancreatic fistula (POPF) have been introduced, POPF is generally predicted during pancreatic surgery due to pancreatic texture. This study was designed to verify the correlation between Hounsfield units (HU) and pancreatic texture and to suggest a fistula risk score (FRS) that can be used before surgery. METHODS: Data from 545 patients who underwent pancreatoduodenectomy for malignant disease between January 2008 and December 2019 were retrospectively reviewed. The HU level of the pancreas was measured, and odds ratio (OR) of the HU for POPF was analyzed. Additionally, the assessed HU was compared with the pancreatic texture (soft vs. hard) and calculated cutoff level. Finally, the preoperatively chosen pancreatic texture according to HU level was applied to the FRS formula (preoperative-FRS: p-FRS), and the results were compared with a previously reported FRS formula (updated alternative-FRS: ua-FRS). RESULTS: The Hounsfield unit levels were correlated with clinically relevant POPF (CR-POPF) (odds ratio [OR]: 1.04 (1.01-1.07), p = 0.015). In the receiver operating characteristic curve, the HU showed significant prediction potential for pancreatic texture (area under the curve [AUC]: 0.744, p < 0.001). The p-FRS also showed acceptable results in predicting CR-POPF (AUC = 0.702, p < 0.001). There was no statistically significant difference in the DeLong's test compared with the ua-FRS (p = 0.314). In the Hosmer-Lemeshow test, observed probabilities were correlated with predicted probabilities (p = 0.596). CONCLUSIONS: The HU level on preoperative computed tomography (CT) is a predictive factor for POPF and could represent for pancreatic texture.

Standard follow-up after curative surgery for advanced gastric cancer: secondary analysis of a multicentre randomized clinical trial (KLASS-02).

BACKGROUND: The benefit of regular follow-up after curative resection for gastric cancer is controversial as there is no evidence that it will improve survival. This study assessed whether regular follow-up leads to improved survival in patients after surgery for gastric cancer. METHODS: A secondary analysis was undertaken of patients who participated in an RCT of laparoscopic versus open distal gastrectomy for advanced gastric cancer between November 2011 and April 2015. Depending on whether patients were compliant with the initial trial follow-up protocol or not, they were analysed as having had either regular or irregular follow-up. Clinicopathological characteristics, recurrence patterns, detection, treatments, and survival were compared between the groups. RESULTS: The regular and irregular follow-up groups comprised 712 and 263 patients respectively. Disease recurrence within 36 months was more common in the regular group than in the irregular group (17.0 versus 11.4 per cent; P = 0.041). Recurrence patterns did not differ between the groups. The 3-year recurrence-free survival rate was worse in the regular than in the irregular group (81.2 versus 86.5 per cent; P = 0.031). However, the 5-year overall survival rate was comparable (84.5 versus 87.5 per cent respectively; P = 0.160). Multivariable analysis revealed that type of follow-up was not an independent factor affecting 5-year overall survival. CONCLUSION: Regular follow-up after radical gastrectomy was not associated with improved overall survival.

Phonozen-mediated photodynamic therapy comparing two wavelengths in a mouse model of peritoneal carcinomatosis.

BACKGROUND: This study assessed the therapeutic efficacy of intraperitoneal photodynamic therapy (PDT) using photosensitizer activation at two different wavelengths, 405 and 664 nm, in a mouse model of peritoneal carcinomatosis. METHODS: The dark and light cytotoxicity of chlorin e6-polyvinylpyrrolidone (Phonozen) were measured in vitro under 402 ± 14 and 670 ± 18 nm LED activation in bioluminescent human gastric cancer cells, MKN45-luc. Cell viability was measured at 6 h after irradiation using the PrestoBlue assay. Corresponding in vivo studies were performed in athymic nude mice by intraperitoneal injection of 1 × 106 MKN45-luc cells. PDT was performed 10 d after tumor induction and comprised intraperitoneal injection of Phonozen followed by light irradiation at 3 h, delivered by a diffusing-tip optical fiber placed in the peritoneal cavity and coupled to a 405 or 664 nm diode laser to deliver a total energy of 50 J (20 mice per cohort). Whole-body bioluminescence imaging was used to track the tumor burden after PDT out to 130 days, and 5 mice in each cohort were sacrificed at 4 h post treatment to measure the acute tumor necrosis. RESULTS: Photosensitizer dose-dependent photocytotoxicity was higher in vitro at 405 than 664 nm. In vivo, PDT reduced the tumor growth rate at both wavelengths, with no statistically significant difference. There was substantial necrosis, and median survival was significantly prolonged at both wavelengths compared with controls (46 and 46 vs. 34 days). CONCLUSIONS: Phonozen-mediated PDT results in significant cytotoxicity in vitro as well as tumor necrosis and prolonged survival in vivo following intraperitoneal light irradiation. Blue light was more photocytotoxic than red in vitro and had marginally higher efficacy in vivo.

Trans-pacific multicenter collaborative study of minimally invasive proximal versus total gastrectomy for proximal gastric and gastroesophageal junction cancers.

BACKGROUND: The current standard operation for proximal gastric and gastroesophageal junction (P/GEJ) cancers with limited esophageal extension is total gastrectomy (TG). TG is associated with impaired appetite and weight loss due to the loss of gastric functions such as production of ghrelin and with anemia due to intrinsic factor loss and vitamin B12 malabsorption. Theoretically, proximal gastrectomy (PG) can mitigate these problems by preserving gastric function. However, PG with direct esophagogastric reconstruction is associated with severe postoperative reflux, delayed gastric emptying, and poor quality of life (QoL). Minimally invasive PG (MIPG) with antireflux techniques has been increasingly performed by experts but is technically demanding owing to its complexity. Moreover, the actual advantages of MIPG over minimally invasive TG (MITG) with regards to postoperative QoL are unknown. Our overall objective of this study is to determine the short-term QoL benefits of MIPG. Our central hypotheses are that MIPG is safe and that patients have improved appetite after MIPG with effective antireflux techniques, which leads to an overall QoL improvement when compared with MITG. METHODS: Enrollment of a total of 60 patients in this prospective survey-collection study is expected. Procedures (MITG versus MIPG, antireflux techniques for MIPG [double-tract reconstruction versus the double-flap technique]) will be chosen based on surgeon and/or patient preference. Randomization is not considered feasible because patients often have strong preferences regarding MITG and MIPG. The primary outcome is appetite level (reported on a 0-10 scale) at 3 months after surgery. With an expected 30 patients per cohort (MITG versus MIPG), this study will have 80% power to detect a one-point difference in appetite level. Patient-reported outcomes will be longitudinally collected (including questions about appetite and reflux), and specific QoL items, body weight, body mass index and ghrelin, albumin, and hemoglobin levels will be compared. DISCUSSION: Surgeons from the US, Japan, and South Korea formed this collaboration with the agreement that the surgical approach to P/GEJ cancers is an internationally important but controversial topic that requires immediate action. At the completion of the proposed research, our expected outcome is the establishment of the benefit and safety of MIPG. TRIAL REGISTRATION: This trial was registered with Clinical Trials Reporting Program Registration under the registration number NCI-2022-00267 on January 11, 2022, as well as with ClinicalTrials.gov under the registration number NCT05205343 on January 11, 2022.

Trends in clinical outcomes and long-term survival after robotic gastrectomy for gastric cancer: a single high-volume center experience of consecutive 2000 patients.

BACKGROUND: Minimally invasive surgery is now a standard treatment for gastric cancer. Many retrospective studies have reported that robotic gastrectomy is safe and feasible, with similar short- and long-term outcomes as laparoscopic gastrectomy. However, no studies have reported the details of surgical and survival outcomes for robotic gastrectomy. This study aimed to evaluate the surgical trends and techniques of robotic gastrectomy and analyze the surgical outcomes of 2000 consecutive patients with gastric cancer who underwent robotic gastrectomy over 14 years. METHODS: Between July 2005 and January 2019, 2000 consecutive robotic gastrectomies were performed. We evaluated short- and long-term outcomes as well as surgical trends after robotic gastrectomy. RESULTS: There were 1,560 subtotal gastrectomies (78%), 324 total gastrectomies (16.2%), 83 proximal gastrectomies (4.2%), and 33 completion total gastrectomies (1.7%). The rates of major complications and mortality were 3.1% and 0.3%, respectively. In a subgroup analysis, there were no significant differences in the rate of complications over time (P = 0.696). Five-year overall survival rates were 97.6% for stage I, 91.9% for stage II, and 69.2% for stage III, with a total recurrence rate of 5.3%. Since its adoption in 2005, the proportion of robotic gastrectomies, as well as technically demanding procedures have increased over time. CONCLUSIONS: Our 14 years' experience of 2000 robotic gastrectomies has shown the proportion, as well as the number of robotic gastrectomies, have tended to increase and trends toward to technically demanding procedures. Outcomes of robotic gastrectomy appear safe and feasible with acceptable short- and long-term outcomes.

Revisiting the Oxidizing Capacity of the Periodate-H2O2 Mixture: Identification of the Primary Oxidants and Their Formation Mechanisms.

This study reexamined the mechanisms for oxidative organic degradation by the binary mixture of periodate and H2O2 (PI/H2O2) that was recently identified as a new advanced oxidation process. Our findings conflicted with the previous claims that (i) hydroxyl radical (•OH) and singlet oxygen (1O2) contributed as the primary oxidants, and (ii) •OH production resulted from H2O2 reduction by superoxide radical anion (O2•-). PI/H2O2 exhibited substantial oxidizing capacity at pH < 5, decomposing organics predominantly by •OH. The likelihood of a switch in the major oxidant under varying pH conditions was revealed. IO4- as the major PI form under acidic conditions underwent one-electron reduction by H2O2 to yield radical intermediates, whereas H2I2O104- preferentially occurring at pH > 7 caused 1O2 generation through two-electron oxidation of H2O2. PI reduction by O2•- was suggested to be a key reaction in •OH production, on the basis of the electron paramagnetic resonance detection of methyl radicals in the dimethyl sulfoxide solutions containing PI and KO2, and the absence of deuterated and 18O-labeled hydroxylated intermediates during PI activation using D2O and H218O2. Finally, simple oxyanion mixing subsequent to electrochemical PI and H2O2 production achieved organic oxidation, enabling a potential strategy to minimize the use of chemicals.

Surface Electrochemistry of Carbon Electrodes and Faradaic Reactions in Capacitive Deionization.

Recent advances in electrochemical desalination techniques have paved way for utilization of saline water. In particular, capacitive deionization (CDI) enables removal of salts with high energy efficiency and economic feasibility, while its applicability has been challenged by degradation of carbon electrodes in long-term operations. Herein, we report a thorough investigation on the surface electrochemistry of carbon electrodes and Faradaic reactions that are responsible for stability issues of CDI systems. By using bare and membrane CDI (MCDI) as model systems, we identified various electrochemical reactions of carbon electrodes with water or oxygen, with thermodynamics and kinetics governed by the electrode potential and pH. As a result, a complete overview of the Faradaic reactions taking place in CDI was constructed by tracing the physicochemical changes occurring in CDI and MCDI systems.

Fluorescent lymphography during minimally invasive total gastrectomy for gastric cancer: an effective technique for splenic hilar lymph node dissection.

BACKGROUND: Fluorescent lymphography is an excellent technique for complete lymph node dissection during minimally invasive surgery for gastric cancer. This study aimed to evaluate the role of fluorescent lymphography in splenic hilar lymph node dissection during minimally invasive total gastrectomy. METHODS: We retrospectively analyzed 168 gastric cancer patients who underwent minimally invasive total gastrectomy with D2 + No. 10 lymph node dissection from 2013 to 2018. Fluorescent lymphography was used whenever it is possible. However, when near-infrared imaging system and endoscopic indocyanine green injection were not available, we performed surgery without fluorescent lymphography. A total of 74 patients underwent surgery with fluorescent lymphography (FL group) and 94 underwent surgery without it (non-FL group). Perioperative and long-term outcomes including the number of retrieved lymph nodes at each nodal station were compared between groups. RESULTS: The median number of retrieved lymph nodes at the splenic hilum was larger in the FL group {2.5 [Interquartile range (IQR), 1-5]} than in the non-FL group [1 (IQR, 1-3); P = 0.012]. The negative predictive value of fluorescent lymphography for lymph node metastasis at the splenic hilum was 97.1%, although the sensitivity was 66.7%. The overall survival (FL: 96.9% vs. non-FL: 88.9%; P = 0.334) and relapse-free survival (FL: 90.5% vs. non-FL: 65.5%; P = 0.054) were higher in the FL group, although there were no statistical differences. However, among the patients without lymph node metastasis, the relapse-free survival was significantly higher in the FL group (100%) than in the non-FL group (67.1%; P = 0.017). CONCLUSIONS: Fluorescent lymphography is an effective tool for complete lymph node dissection at the splenic hilum. Moreover, it may help select patients who do not need splenic hilar lymph node dissection during a total gastrectomy.

Applicability of endoscopic submucosal dissection for patients with early gastric cancer beyond the expanded indication for endoscopic submucosal dissection.

BACKGROUND: Endoscopic submucosal dissection (ESD) application for patients with tumors beyond the expanded indication for ESD is inconclusive. This study aimed to identify the preoperative clinical features that can be curatively treated with ESD in patients with early gastric cancer (EGC) beyond the indication of ESD. METHODS: From 2006 to 2016, 673 patients who underwent gastrectomy for EGC beyond the expanded indication for ESD based on preoperative assessments were retrospectively reviewed. We identified tumors curatively resected by ESD based on the postoperative pathologic findings. We also analyzed the clinical and pre-treatment features to determine the risk factors associated with curative resection of ESD. RESULTS: 39% of the patients (263/673) who had undergone gastrectomy had tumors of endoscopic curability A or B (eCuraA/B) that could be treated by ESD alone. In multivariate analysis, tumor size ≤ 10 mm (OR 0.240; 95% CI = 0.12-0.46), no ulceration (OR 0.500; 95% CI = 0.29-0.87), differentiated histology (OR 0.599; 95% CI = 0.43-0.84), and location in the distal two-thirds of the stomach (OR 0.499; 95% CI = 0.28-0.88) in pre-treatment assessment were identified as independent predictors of eCuraA/B. Considering the risk factors, 63.6% (7/11)/61.3% (19/31) of patients with a differentiated/undifferentiated tumor size ≤ 10 mm located in distal two-third of the stomach without ulceration were deemed as eCuraA/B. CONCLUSIONS: This study suggests that patients with EGC indicated for surgery can be treated by ESD by adding tumor locations in the indication for ESD. Thus, ESD can be applied for patients with a tumor size ≤ 10 mm located in the lower/middle stomach without ulceration.

Comprehensive Learning Curve of Robotic Surgery: Discovery From a Multicenter Prospective Trial of Robotic Gastrectomy.

OBJECTIVE: To evaluate the complication-based learning curve and identify learning-associated complications of robotic gastrectomy. SUMMARY BACKGROUND DATA: With the increased popularity of robotic surgery, a sound understanding of the learning curve in the surgical outcome of robotic surgery has taken on great importance. However, a multicenter prospective study analyzing learning-associated morbidity has never been conducted in robotic gastrectomy. METHODS: Data on 502 robotic gastrectomy cases were prospectively collected from 5 surgeons. Risk-adjusted cumulative sum analysis was applied to visualize the learning curve of robotic gastrectomy on operation time and complications. RESULTS: Twenty-five cases, on average, were needed to overcome complications and operation time-learning curve sufficiently to gain proficiency in 3 surgeons. An additional 23 cases were needed to cross the transitional phase to progress from proficiency to mastery. The moderate complication rate (CD ≥ grade II) was 20% in phase 1 (cases 1-25), 10% in phase 2 (cases 26-65), 26.1% in phase 3 (cases 66-88), and 6.4% in phase 4 (cases 89-125) (P < 0.001). Among diverse complications, CD ≥ grade II intra-abdominal bleeding (P < 0.001) and abdominal pain (P = 0.01) were identified as major learning-associated morbidities of robotic gastrectomy. Previous experience on laparoscopic surgery and mode of training influenced progression in the learning curve. CONCLUSIONS: This is the first study suggesting that technical immaturity substantially affects the surgical outcomes of robotic gastrectomy and that robotic gastrectomy is a complex procedure with a significant learning curve that has implications for physician training and credentialing.

Lymphovascular Invasion: Traditional but Vital and Sensible Prognostic Factor in Early Gastric Cancer.

BACKGROUND: Although patients with early gastric cancer have good prognosis, recurrence after treatment may occur. Lymphovascular invasion (LVI) in gastric cancer has long been suggested as a poor prognostic indicator. This study sought to evaluate the prognostic effect of LVI in patients with early gastric cancer. METHODS: From 2005 to 2016, 6516 patients with early gastric cancer who underwent radical gastrectomy were analyzed. The patients were categorized according to LVI and lymph node (LN) status. RESULTS: LVI was present in 853 patients (13.1%). Patients with LVI or LN metastasis had more aggressive tumor characteristics than patients without both LVI and LN metastasis. The overall and relapse-free survival in patients with LVI were significantly worse than in patients without LVI. When we compared the survival rate of patients stratified by LVI and LN status, there was a significant overall and relapse-free survival difference between patients without both LVI and LN metastasis compared with those with LVI but without LN metastasis (p < 0.001). The overall and relapse-free survival of patients with LVI but without LN metastasis were similar to those without LVI but with LN metastasis (p = 0.818). Patients with LVI or LN metastasis showed a high frequency of recurrence (p < 0.001). Multivariate analysis showed that LVI and LN status were independent risk factors for relapse-free survival of early gastric cancer patients. CONCLUSIONS: Early gastric cancer with LVI is associated with poor prognosis and frequent recurrence. When predicting the prognosis of patients with early gastric cancer, LVI should be considered.

Surgical Merits of Open, Laparoscopic, and Robotic Gastrectomy Techniques with D2 Lymphadenectomy in Obese Patients with Gastric Cancer.

BACKGROUND: Robotic surgery has been widely adopted for complex procedures to overcome technical limitations of open or laparoscopic methods. However, evidence of any subsequent benefit is lacking. This study was undertaken to compare open, laparoscopic, and robotic gastrectomy in technically demanding procedure-D2 dissection in obese patients with gastric cancer. METHODS: Data collected between 2010 and 2018 on D2 gastrectomy in obese patients with gastric cancer were used to conduct retrospective analysis, comparing short- and long-term outcomes of open, laparoscopic, and robotic techniques. RESULTS: In a total of 185 patients, there were 69 open, 62 laparoscopic, and 54 robotic gastrectomy procedures. Median ages for respective surgical groups were 66 (interquartile range [IQR]: 61-64 years), 63 (IQR: 59-63), and 59 years (IQR: 56-60 years) (p = 0.009). Early-stage gastric cancer ranked proportionately higher in the laparoscopic group (p = 0.005), but operative times were similar among groups. Estimated blood loss (p < 0.001) and drainage volumes (p = 0.001) were higher in the open group, relative to others. Although a robotic approach performed best in overall compliance and in mean number of retrieved lymph node, observed rates of early or late complications did not differ by technique. The open group experienced significantly poorer overall (p = 0.039) and relapse-free (p < 0.001) survival compared with the laparoscopic or robotic group. Robotic surgery emerged from multivariable Cox regression as a protective factor for relapse-free survival (HR = 0.314, 95% CI 0.116-0.851). CONCLUSIONS: In obese patients with gastric cancer, robotic gastrectomy with D2 lymphadenectomy proved comparable to open or laparoscopic technique short-term, yielding better long-term outcomes.

Appropriate Number of Adjuvant Chemotherapy Cycles for Patients with Stage 2 or 3 Gastric Cancer After Curative Gastrectomy: A Multicenter Cohort Study.

BACKGROUND: Few studies have presented evidence pertaining to the adequate minimum number of adjuvant chemotherapy (AC) cycles required to achieve an oncologic benefit for gastric cancer. METHODS: From January 2012 to December 2013, data from patients who underwent curative radical gastrectomy and consequently received AC for pathologic stage 2 or 3 gastric cancer at 27 institutions in South Korea were analyzed. RESULTS: The study enrolled 925 patients, 661 patients (71.5%) who completed 8 cycles of AC and 264 patients (28.5%) who did not. Compared with the mean disease-free survival (DFS) of the patients who completed 8 AC cycles (69.3 months), the mean DFS of patients who completed 6 AC cycles (72.4 months; p = 0.531) and those who completed 7 AC cycles (63.7 months; p = 0.184) did not differ significantly. However, the mean DFS of the patients who completed 5 AC cycles (48.2 months; p = 0.016) and those who completed 1-4 AC cycles (62.9 months; p = 0.036) was significantly lower than the DFS of those who completed 8 AC cycles. In the multivariate Cox proportional hazards analysis, the mean DFS was significantly affected by advanced stage, large tumor size, positive vascular invasion, and number of completed AC cycles (1-5 cycles: hazard ratio 1.45; 95% confidence interval 1.01-2.08; p = 0.041). CONCLUSION: The current multicenter observational cohort study showed that the mean DFS for 6 or 7 AC cycles was similar to that for 8 AC cycles as an adjuvant treatment for gastric cancer.

Detection of sarcopenic obesity and prediction of long-term survival in patients with gastric cancer using preoperative computed tomography and machine learning.

BACKGROUND: Previous studies evaluating the prognostic value of computed tomography (CT)-derived body composition data have included few patients. Thus, we assessed the prevalence and prognostic value of sarcopenic obesity in a large population of gastric cancer patients using preoperative CT, as nutritional status is a predictor of long-term survival after gastric cancer surgery. METHODS: Preoperative CT images were analyzed for 840 gastric cancer patients who underwent gastrectomy between March 2009 and June 2018. Machine learning algorithms were used to automatically detect the third lumbar (L3) vertebral level and segment the body composition. Visceral fat area and skeletal muscle index at L3 were determined and used to classify patients into obesity, sarcopenia, or sarcopenic obesity groups. RESULTS: Out of 840 patients (mean age = 60.4 years; 526 [62.6%] men), 534 (63.5%) had visceral obesity, 119 (14.2%) had sarcopenia, and 48 (5.7%) patients had sarcopenic obesity. Patients with sarcopenic obesity had a poorer prognosis than those without sarcopenia (hazard ratio [HR] = 3.325; 95% confidence interval [CI] = 1.698-6.508). Multivariate analysis identified sarcopenic obesity as an independent risk factor for increased mortality (HR = 2.608; 95% CI = 1.313-5.179). Other risk factors were greater extent of gastrectomy (HR = 1.928; 95% CI = 1.260-2.950), lower prognostic nutritional index (HR = 0.934; 95% CI = 0.901-0.969), higher neutrophil count (HR = 1.101; 95% CI = 1.031-1.176), lymph node metastasis (HR = 6.291; 95% CI = 3.498-11.314), and R1/2 resection (HR = 4.817; 95% CI = 1.518-9.179). CONCLUSION: Body composition analysis automated by machine learning predicted long-term survival in patients with gastric cancer.

Assessment of diagnostic value of fluorescent lymphography-guided lymphadenectomy for gastric cancer.

BACKGROUND: Indocyanine green fluorescent lymphography helps visualize the lymphatic drainage pattern in gastric cancer; however, it is unknown whether fluorescent lymphography visualizes all metastatic lymph nodes. This study aimed to evaluate the sensitivity of fluorescent lymphography to detect metastatic lymph node stations and lymph nodes and the risk of false-negative findings. METHODS: Patients with clinical T1-4a gastric cancer were included. Indocyanine green was peritumorally injected the day prior to surgery by endoscopy. Gastrectomy with systematic D1+ or D2 lymphadenectomy was performed. Stations and lymph nodes were retrieved at the back-table using near-infrared imaging and classified as "fluorescent" or "non-fluorescent" and later matched with histopathological findings. RESULTS: Among 592 patients who underwent minimally invasive gastrectomy from September 2013 until December 2016, lymph node metastases were present in 150. The sensitivity of fluorescent lymphography in detecting all metastatic lymph node stations was 95.3% (143/150 patients), with a false-negative rate of 4.7% (7/150 patients) and the sensitivity in detecting all metastatic lymph nodes was 81.3% (122/150 patients). The negative predictive value was 99.3% for non-fluorescent stations and 99.2% for non-fluorescent LNs. For detecting all metastatic LN stations, subgroup analysis revealed 100% sensitivity for pT1a, 96.8% for pT1b, 100% for pT2, 91.3% for pT3, and 93.6% for pT4a tumors. CONCLUSIONS: Fluorescent lymphography-guided lymphadenectomy can be a useful method for radical lymphadenectomy by facilitating the complete dissection of all potentially positive LN stations. Fluorescent lymphography-guided lymphadenectomy appears to be a reasonable alternative to conventional systematic lymphadenectomy for gastric cancer.

Evaluation of thermal properties and acetaldehyde adsorption performance of sustainable composites using waste wood and biochar.

In order to vitalize the use of wood, which is a sustainable resource, increase the utilization of resources through the recycling of wood waste, and reduce environmental pollution in the waste disposal process, biocomposite was manufactured by using biochar which can be produced with wood waste and is effective in carbon isolation. The thermal characteristics and acetaldehyde adsorption performance of the prepared biocomposite were evaluated based on the pore characteristics, surface functional groups, crystal structure, and elemental analysis results of the biochar. As a result of the experiment, as the content of biochar increased, the thermal conductivity of the biocomposite decreased and the specific heat was not affected. The acetaldehyde concentration tended to decrease as the content of biochar increased, adsorbed up to 4.4685 ppm of acetaldehyde more than the reference. From these results, it is judged that the biocomposite produced in this study can function as a sustainable composite that uses waste wood to improve indoor air quality and satisfies the performance as a building material.

Real-time identification of aberrant left hepatic arterial territories using near-infrared fluorescence with indocyanine green during gastrectomy for gastric cancer.

BACKGROUND: An aberrant left hepatic artery is frequently encountered during upper gastrointestinal surgery, and researchers have yet to propose optimal strategies with which to address this arterial variation. The objective of this study was to determine whether the areas perfused by an aberrant left hepatic artery can be visualized in real-time using near-infrared fluorescence imaging with indocyanine green. METHODS: Patients with gastric adenocarcinoma who underwent minimally invasive radical gastrectomy from May 2018 to August 2019 were enrolled and retrospectively analyzed at a single-center. Patients with an aberrant left hepatic artery and normal preoperative liver function were examined. After the clamping of an aberrant left hepatic artery, indocyanine green was administered via a peripheral intravenous route during surgery. Fluorescence at the liver was visualized under near-infrared fluorescence imaging. RESULTS: In 31 patients with aberrant left hepatic arteries, near-infrared fluorescence imaging was used without adverse events associated with indocyanine green. Six (19%) patients were reported to have an aberrant left hepatic artery upon preoperative CT imaging, while all other instances were detected during surgery. Fluorescence excitation on the liver was, on average, visible after 43 s (range, 25-65). Fluorescence across the entire surface of the liver was noted in 20 (65%) patients in whom the aberrant left hepatic artery could be ligated. Aberrant left hepatic arteries were safely preserved in 10 (32%) patients who showed areas of no or partial fluorescence excitation. Guided by near-infrared fluorescence imaging, ligation of aberrant left hepatic arteries elicited no significant changes in postoperative liver function. CONCLUSION: Near-infrared fluorescence imaging facilitates the identification of aberrant left hepatic arterial territories, guiding decisions on the preservation or ligation of this arterial variation.