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Abstract Although sequence-based studies show that basal-like features lead to worse prognosis and chemotherapy-resistance compared to the classical subtype in advanced pancreatic ductal adenocarcinoma (PDAC), a surrogate biomarker distinguishing between these subtypes in routine diagnostic practice remains to be identified. We aimed to evaluate the utility of immunohistochemistry (IHC) expression subtypes generated by unsupervised hierarchical clustering based on staining scores of four markers (CK5/6, p63, GATA6, HNF4a) applied to endoscopic ultrasound-guided fine needle aspiration biopsy (EUS-FNAB) materials. EUS-FNAB materials taken from 190 treatment-naïve advanced PDAC patients were analyzed, and three IHC patterns were established (Classical, Transitional, and Basal-like pattern). Basal-like pattern (high co-expression of CK5/6 and p63 with low expression of GATA6 and HNF4a) was significantly associated with squamous differentiation histology (p

Abstract Background Automatic staplers are often used to reconstruct the digestive tract during surgeries for gastric cancer. Intragastric free cancer cells adhering to automatic staplers may come in contact with the laparoscopic port area and progress to port site recurrence. This study aimed to investigate the presence/absence of cancer cells adhering to automatic staplers during gastric cancer surgery using cytological examinations. We further determined the positive predictive clinicopathological factors and clinical implications of free cancer cells attached to automatic staplers. Methods This study included 101 patients who underwent distal gastrectomy for gastric cancer. Automatic staplers used for anastomosis in gastric cancer surgeries were shaken in 150 ml of saline solution to collect the attached cells. Papanicolaou stains were performed. We tested the correlation between cancer-cell positivity and clinicopathological factors to identify risk factors arising from the presence of attached cancer cells to the staplers. Results Based on the cytology, cancer cells were detected in 7 of 101 (6.9%) stapler washing fluid samples. Univariate analysis revealed that circular staplers, type 1 tumors, and positive lymph nodes were significantly associated with higher detection of free cancer cells adhering to staplers. No significant differences in other factors were detected. Of the seven cases with positive cytology, one developed anastomotic recurrence. Conclusions Exfoliated cancer cells adhered to the automatic staplers used for anastomoses in 6.9% of the staplers used for distal gastrectomies in patients with gastric cancer. Staplers used for gastric cancer surgeries should be handled carefully.

Objectives: Anastomotic leakage (AL) is the most severe complication of colorectal surgery and is a frequent cause of postoperative mortality. This study aimed to identify the risk factors for AL, including the type of air leak test (ALT) performed, in patients undergoing laparoscopic colorectal cancer surgery. Methods: This study involved a retrospective review of 201 patients who underwent elective laparoscopic procedures using circular stapled anastomosis for colorectal cancer between January 2015 and December 2020 at Kyorin University Hospital, Tokyo, Japan. In all cases, the distance from the anal verge to the anastomotic site was within 15 cm. Results: Overall, AL was observed in 16 patients (8.0%). Univariate analysis revealed that the risk factors for AL included diabetes (P = 0.068), tumor location (P = 0.049), level of anastomosis (P = 0.002), number of linear stapler firings (P = 0.007), and intraoperative colonoscopy (IOCS; P = 0.069). Multivariate analysis revealed that the level of anastomosis (P = 0.029) and IOCS (P = 0.039) were significant and independent risk factors for AL. One of the 107 patients undergoing ALT without IOCS and 3 of the 94 patients undergoing ALT with IOCS were proven to be positive for air leak. However, these four patients underwent additional suturing intraoperatively and developed no AL following surgery. Conclusions: This study identified the level of anastomosis and ALT with IOCS as predictors for AL. The results of our study indicate that ALT with IOCS may be more effective than ALT without IOCS in the diagnosis and prevention of AL.

Introduction: The phase III REFLECT trial demonstrated that lenvatinib was superior to sorafenib in terms of progression-free survival (PFS), time to progression, and objective response rate (ORR) for patients with unresectable hepatocellular carcinoma (HCC). This study assessed the efficacy and safety of preoperative lenvatinib therapy for patients with oncologically or technically unresectable HCC. Methods: In this multicenter single-arm phase II trial, patients with advanced HCC and factors suggestive of a poor prognosis (macroscopic vascular invasion, extrahepatic metastasis, or multinodular tumors) were enrolled. Patients with these factors, even with technically resectable HCC, were defined as oncologically unresectable because of the expected poor prognosis after surgery. After 8 weeks of lenvatinib therapy, the patients were assessed for resectability, and tumor resection was performed if the tumor was considered technically resectable. The primary endpoint was the surgical resection rate. The secondary endpoints were the macroscopic curative resection rate, overall survival (OS), ORR, PFS, and the change in the indocyanine green retention rate at 15 min as measured before and after lenvatinib therapy. The trial was registered with the Japan Registry of Clinical Trials (s031190057). Results: Between July 2019 and January 2021, 49 patients (42 oncologically unresectable patients and 7 technically unresectable patients) from 11 centers were enrolled. The ORR was 37.5% based on mRECIST and 12.5% based on RECIST version 1.1. Thirty-three patients underwent surgery (surgical resection rate: 67.3%) without perioperative mortality. The surgical resection rate was 76.2% for oncologically unresectable patients and 14.3% for technically unresectable patients. The 1-year OS rate and median PFS were 75.9% and 7.2 months, respectively, with a median follow-up period of 9.3 months. Conclusions: The relatively high surgical resection rate seen in this study suggests the safety and feasibility of lenvatinib therapy followed by surgical resection for patients with oncologically or technically unresectable HCC.

Abstract Despite the increasing prevalence of Nonalcoholic steatohepatitis (NASH) worldwide, there is no effective treatment available for this disease. “Ballooned hepatocyte” is a characteristic finding in NASH and is correlated with disease prognosis, but their mechanisms of action are poorly understood; furthermore, neither animal nor in vitro models of NASH have been able to adequately represent ballooned hepatocytes. Herein, we engineered cell sheets to develop a new in vitro model of ballooned hepatocytes. Primary human hepatocytes (PHH) and Hepatic stellate cells (HSC) were co-cultured to produce cell sheets, which were cultured in glucose and lipid containing medium, following which histological and functional analyses were performed. Histological findings showed hepatocyte ballooning, accumulation of fat droplets, abnormal cytokeratin arrangement, and the presence of Mallory–Denk bodies and abnormal organelles. These findings are similar to those of ballooned hepatocytes in human NASH. Functional analysis showed elevated levels of TGFβ-1, SHH, and p62, but not TNF-α, IL-8. Exposure of PHH/HSC sheets to a glucolipotoxicity environment induces ballooned hepatocyte without inflammation. Moreover, fibrosis is an important mechanism underlying ballooned hepatocytes and could be the basis for the development of a new in vitro NASH model with ballooned hepatocytes.

Fibrolamellar hepatocellular carcinoma (FLHCC) is a rare a rare subtype of hepatocellular carcinoma. The IMbrave150 trial demonstrated that atezolizumab and bevacizumab therapy (ABT) has better treatment outcomes than sorafenib for advanced HCC. However, since patients with known FLHCC were excluded from this trial, the effects of ABT on FLHCC remain unknown. We report the first case of ABT for advanced FLHCC followed by hepatectomy presenting pseudoprogression of lymph node (LN) metastases which was pathologically proven after surgery. The patient was a 30-year-old man with advanced FLHCC and multiple LN metastases behind the pancreatic head, and ABT was introduced. After four courses of treatment, CT indicated a minor decrease in the intratumor vascularity of the liver tumor. However, the size of metastatic LNs increased. Subsequently, the patient presented with bloody stool, and colonoscopy revealed immune-related colitis caused by atezolizumab. Therefore, the fifth course was canceled. A right hemihepatectomy following percutaneous transhepatic portal vein embolization (PTPE) was performed to increase the future liver remnant volume. After PTPE, dynamic CT revealed an objective response to ABT; SD in RECIST 1.1 (7% increase in the LN size and no change of liver tumor), and PR in modified RECIST (47% decrease in the intratumor vascularity of the liver tumor and LNs). Three weeks after PTPE, right hemihepatectomy plus nodal dissection was successfully performed. Pathological findings revealed that approximately 60%–70% of the liver tumor and 70%–80% of the metastatic LNs were necrotic, indicating a good response to ABT. The increasing size of metastatic LNs that occurred during the treatment course was deemed pseudoprogression. Pseudoprogression can be found in patients with solid malignancies treated with immune checkpoint inhibitors, however, rarely occurs in HCC. The first response to metastatic LNs was observed 20 weeks after ABT initiation combined with an increase in nodal volume and a decrease in vascularity. In the updated data of the IMbrave150 trial, 19% of the first responses occurred after week 24. Physicians should consider that ABT may also be effective in FLHCC and may cause pseudoprogression before determining a treatment strategy.

Abstract Repeat hepatectomy for recurrent colorectal liver metastases (CRLM) for the remnant hemiliver is sometimes challenging due to the insufficient future liver remnant (FLR) volume. We present an aggressive strategy for resection of the recurrent CRLM involving bisegmentectomy of the remnant right hemiliver with the aid of portal vein embolization (PVE) and venous reconstruction. The patient was a 50‐year‐old woman who had undergone left hemihepatectomy for a CRLM 10 months ago. Three metastatic tumors were found in the remnant segments 7 and 8 (S7&8) of the liver, and one of them involved the right hepatic vein (RHV). Conducting bisegmentectomy of S7&8 with resection of the RHV, the non‐congestive FLR volume was calculated as 34.9% of the remnant total liver volume, which was deemed insufficient considering the mild liver damage after repeated chemotherapy. After trans‐ileocecal PVE of the portal branches in S7&8 in a hybrid angio room, the non‐congestive FLR volume increased to 42.3%, which could be further advanced to 58.0% if the RHV was reconstructed. Segmentectomies of S7&8 with resection and reconstruction of the RHV using the right superficial femoral vein graft was performed. The patient was discharged without any complications, and the postoperative computed tomography (CT) scan showed the good patency of the reconstructed venous graft. Aggressive segmentectomies and venous reconstruction of the remnant hemiliver after PVE might be a new strategy to overcome the insufficient FLR volume.

This paper presents the first version of clinical practice guidelines for intrahepatic cholangiocarcinoma (ICC) established by the Liver Cancer Study Group of Japan. These guidelines consist of 1 treatment algorithm, 5 background statements, 16 clinical questions, and 1 clinical topic, including etiology, staging, pathology, diagnosis, and treatments. Globally, high incidence of ICC has been reported in East and Southeast Asian countries and the incidence has been gradually increasing in Japan and also in Western countries. Reported risk factors for ICC include cirrhosis, hepatitis B/C, alcohol consumption, diabetes, obesity, smoking, nonalcoholic steatohepatitis, and liver fluke infestation, as well as biliary diseases, such as primary sclerosing cholangitis, hepatolithiasis, congenital cholangiectasis, and Caroli disease. Chemical risk factors include thorium-232, 1,2-dichloropropane, and dichloromethane. CA19-9 and CEA are recommended as tumor markers for early detection and diagnostic of ICC. Abdominal ultrasonography (US), CT, and MRI are effective imaging modalities for diagnosing ICC. If bile duct invasion is suspected, imaging modalities for examining the bile ducts may be useful. In unresectable cases, tumor biopsy should be considered when deemed necessary for the differential diagnosis and drug therapy selection. The mainstay of treatment for patients with Child-Pugh class A or B liver function is surgical resection and drug therapy. If the patient has no regional lymph node metastasis and has a single tumor, resection is the treatment of choice. If both regional lymph node metastasis and multiple tumors are present, drug therapy is the first treatment of choice. If the patient has either regional lymph node metastasis or multiple tumors, resection or drug therapy is selected depending on the extent of metastasis or the number of tumors. If distant metastasis is present, drug therapy is the treatment of choice. Percutaneous ablation therapy may be considered for patients who are ineligible for surgical resection or drug therapy due to decreased hepatic functional reserve or comorbidities. For unresectable ICC without extrahepatic metastasis, stereotactic radiotherapy (tumor size ≤5 cm) or particle radiotherapy (no size restriction) may be considered. ICC is generally not indicated for liver transplantation, and palliative care is recommended for patients with Child-Pugh class C liver function.

Abstract Recent developments in systemic chemotherapy for advanced hepatocellular carcinoma have been outstanding. However, reports on conversion surgery after lenvatinib therapy are scarce. We present the first case of advanced hepatocellular carcinoma with tumor thrombus in the suprahepatic vena cava close to the right atrium, which shrank after 12 weeks’ administration of lenvatinib, thereby leading to successful conversion surgery without using total vascular exclusion or extracorporeal circulation. The treatment strategy for hepatocellular carcinoma with macroscopic hepatic vein tumor thrombus is controversial, however, from a Japanese nationwide survey, surgical resection has been accepted as one of the treatment options for advanced hepatocellular carcinoma with hepatic vein tumor thrombus in Japan. However, the survival rate after resection of hepatocellular carcinoma having inferior vena cava tumor thrombus with extracorporeal circulation was reported to be worse than without extracorporeal circulation, and some preoperative down-sizing therapy for inferior vena cava tumor thrombus was advocated. Preoperative lenvatinib therapy might be a promising option among the multidisciplinary treatments for hepatocellular carcinoma with macroscopic tumor thrombus in the hepatic veins.

Study DesignCase–control study.PurposeThe aim of the present study was to identify physical findings useful for differentiating between cervical spondylotic amyotrophy (CSA) and rotator cuff tears to prevent the misdiagnosis of CSA as a rotator cuff tear.Overview of LiteratureCSA and rotator cuff tears are often confused among patients presenting with difficulty in shoulder elevation.MethodsTwenty-five patients with CSA and 27 with rotator cuff tears were enrolled. We included five physical findings specific to CSA that were observed in both CSA and rotator cuff tear patients. The findings were as follows: (1) weakness of the deltoid muscle, (2) weakness of the biceps muscle, (3) atrophy of the deltoid muscle, (4) atrophy of the biceps muscle, and (5) swallow-tail sign (assessment of the posterior fibers of the deltoid).ResultsAmong 25 CSA patients, 10 (40.0%) were misdiagnosed with a rotator cuff tear on initial diagnosis. The sensitivity and specificity of each physical finding were as follows: (1) deltoid weakness (sensitivity, 92.0%; specificity, 55.6%), (2) biceps weakness (sensitivity, 80.0%; specificity, 100%), (3) deltoid atrophy (sensitivity, 96.0%; specificity, 77.8%), (4) biceps atrophy (sensitivity, 88.8%; specificity, 92.6%), and (5) swallow-tail sign (sensitivity, 56.0%; specificity, 74.1%). There were statistically significant differences in each physical finding.ConclusionsCSA is likely to be misdiagnosed as a rotator cuff tear; however, weakness and atrophy of the biceps are useful findings for differentiating between CSA and rotator cuff tears to prevent misdiagnosis.

Introduction Since pheochromocytomas present with various complications due to catecholamine hypersecretion, their perioperative management needs special attention. Case presentation A 45‐year‐old man visited our hospital with a complaint of abdominal swelling. Radiological and endocrinological assessments determined the tumor as a giant (>20 cm) cystic pheochromocytoma. After administration of doxazosin, the patient underwent radical surgery. Since the tumor was extremely large and fixed to surrounding structures, we punctured it and aspirated cystic fluid to improve the tumor's mobility. However, during the aspiration, the patient developed acute hypotension, which could be reversed by suction withdrawal and vasopressor administration. A similar event occurred during a second aspiration. Eventually, the tumor was successfully excised with negative surgical margin. The cystic fluid proved to contain extremely high concentrations of catecholamines, which might result in the hypotension. Conclusion We report the first case who developed acute hypotension due to aspiration of cystic fluid from giant pheochromocytoma.

A hyperbolic positioning method with antenna arrays consisting of proximately-located antennas and a multi-channel pseudolite is proposed in order to overcome the problems of indoor positioning with conventional pseudolites (ground-based GPS transmitters). A two-dimensional positioning experiment using actual devices is conducted. The experimental result shows that the positioning accuracy varies centimeter- to meter-level according to the geometric relation between the pseudolite antennas and the receiver. It also shows that the bias error of the carrier-phase difference observables is more serious than their random error. Based on the size of the bias error of carrier-phase difference that is inverse-calculated from the experimental result, three-dimensional positioning performance is evaluated by computer simulation. In addition, in the three-dimensional positioning scenario, an initial value convergence analysis of the non-linear least squares is conducted. Its result shows that initial values that can converge to a right position exist at least under the proposed antenna setup. The simulated values and evaluation methods introduced in this work can be applied to various antenna setups; therefore, by using them, positioning performance can be predicted in advance of installing an actual system.

In the present study, we investigated the clinicopathologic significance of intratumoral lymphoplasmacytic infiltration in a large cohort of patients with solitary hepatocellular carcinoma (HCC). Based on examination of hematoxylin and eosin-stained sections, significant infiltration was defined as dense lymphoplasmacytic infiltration, either multifocal or diffuse, in 2 or more fields under low-power magnification. Of 544 cases, 216 (39.7%) were positive for significant infiltration (HCC-LI group), while 328 (60.3%) were negative (HCC-NLI group). There were no significant between-group differences in patient age, sex, or background etiology. The lower incidence of Child-Pugh stage B (P = 0.001) and lower level of indocyanine green retention rate at 15 minutes (P < 0.001) in the HCC-LI group indicated better liver function in this group. Histologically, tumors were significantly smaller in size in the HCC-LI group than in the HCC-NLI group (P < 0.001). In addition, prominent neutrophilic infiltration, interstitial fibrosis and tumor steatosis were significantly more frequent (P < 0.001) in the HCC-LI group, while tumor necrosis was significantly less frequent (P = 0.008). Kaplan-Meier analyses revealed that overall and recurrence-free survival were significantly better in the HCC-LI group (P < 0.001). Multivariate Cox regression analysis showed that intratumoral lymphoplasmacytic infiltration was independently prognostic of both overall and recurrence-free survival (P < 0.001), with absence of infiltration showing high Cox-hazard ratios for poor prognosis. In conclusion, intratumoral lymphoplasmacytic infiltration, as determined by assessment of hematoxylin and eosin-stained slides, was significantly associated with the clinical and pathologic features of HCC and has profound prognostic importance.

Most patients with hepatocellular carcinoma (HCC) have underlying liver disease, therefore, precise preoperative evaluation of the patient's liver function is essential for surgical decision making.We developed a grading system incorporating only two variables, namely, the serum albumin level and the indocyanine green retention rate at 15 minutes (ICG R15), to assess the preoperative liver function, based on the overall survival of 1868 patients with HCC who underwent liver resection. We then tested the model in a European cohort (n = 70) and analyzed the predictive power for the postoperative short-term outcome.The Albumin-Indocyanine Green Evaluation (ALICE) grading system was developed in a randomly assigned training cohort: linear predictor = 0.663 × log10ICG R15 (%)-0.0718 × albumin (g/L) (cut-off value: -2.20 and -1.39). This new grading system showed a predictive power for the overall survival similar to the Child-Pugh grading system in the validation cohort. Determination of the ALICE grade in Child-Pugh A patients allowed further stratification of the postoperative prognosis. This result was reproducible in the European cohort. Determination of the ALICE grade allowed better prediction of the risk of postoperative liver failure and mortality (ascites: grade 1, 2.1%; grade 2, 6.5%; grade 3, 16.0%; mortality: grade 1, 0%; grade 2, 1.3%; grade 3, 5.3%) than the previously reported model based on the presence/absence of portal hypertension.This new grading system is a simple method for prediction of the postoperative long-term and short-term outcomes.

Hereditary hemorrhagic telangiectasia (HHT) is a rare autosomal dominant hereditary disease. Early diagnosis is important to avoid complications from vascular lesions, but diagnosis is difficult in asymptomatic patients. A 69-year-old Japanese male patient was referred to our hospital for evaluation of hepatic vascular malformations. He had mild anemia with iron deficiency, and dynamic contrast-enhanced computed tomography revealed significant arteriovenous and arterioportal shunts throughout the liver. Telangiectasia from the pharynx to the duodenum was confirmed by gastrointestinal endoscopy. The patient history revealed episodes of epistaxis as well as a family history of epistaxis. He was diagnosed with HHT, although no other family member had been diagnosed with definite HHT. A diagnosis of HHT must be considered in patients with hepatic vascular malformations.

BACKGROUND: The reoperation rate remains high after liver transplantation and the impact of reoperation on graft and recipient outcome is unclear. The aim of our study is to evaluate the impact of early reoperation following living-donor liver transplantation (LDLT) on graft and recipient survival. METHODS: Recipients that underwent LDLT (n = 111) at the University of Tokyo Hospital between January 2007 and December 2012 were divided into two groups, a reoperation group (n = 27) and a non-reoperation group (n = 84), and case-control study was conducted. RESULTS: Early reoperation was performed in 27 recipients (24.3%). Mean time [standard deviation] from LDLT to reoperation was 10 [9.4] days. Female sex, Child-Pugh class C, Non-HCV etiology, fulminant hepatitis, and the amount of intraoperative fresh frozen plasma administered were identified as possibly predictive variables, among which females and the amount of FFP were identified as independent risk factors for early reoperation by multivariable analysis. The 3-, and 6- month graft survival rates were 88.9% (95%confidential intervals [CI], 70.7-96.4), and 85.2% (95%CI, 66.5-94.3), respectively, in the reoperation group (n = 27), and 95.2% (95%CI, 88.0-98.2), and 92.9% (95%CI, 85.0-96.8), respectively, in the non-reoperation group (n = 84) (the log-rank test, p = 0.31). The 12- and 36- month overall survival rates were 96.3% (95%CI, 77.9-99.5), and 88.3% (95%CI, 69.3-96.2), respectively, in the reoperation group, and 89.3% (95%CI, 80.7-94.3) and 88.0% (95%CI, 79.2-93.4), respectively, in the non-reoperation group (the log-rank test, p = 0.59). CONCLUSIONS: Observed graft survival for the recipients who underwent reoperation was lower compared to those who did not undergo reoperation, though the result was not significantly different. Recipient overall survival with reoperation was comparable to that without reoperation. The present findings enhance the importance of vigilant surveillance for postoperative complication and surgical rescue at an early postoperative stage in the LDLT setting.

Single nucleotide polymorphisms of interleukin-28B (IL28B) rs8099917 are reported to be associated with virologic clearance in interferon-and ribavirin -based treatment for hepatitis C virus (HCV)-infected patients. We examined virologic response in accordance with IL28B polymorphisms in our living donor liver transplantation series under a preemptive interferon and RBV treatment approach. Adequate DNA samples from both the recipient and donor for the study of single nucleotide polymorphisms of IL28B were available from 96 cases and were the subjects of the present study. Various clinical factors related with virologic response including early virologic response (EVR) and sustained virologic response (SVR) were examined. Totally 51% presented with EVR and 44% achieved SVR. Presence of the major allele (TT) in either the recipient or the donor corresponded to SVR of 53% and 48%. Presence of the minor allele (TG or GG) corresponded to SVR of 26% and 32%. Multivariate analysis revealed that genotype of HCV or EVR, but not IL28B polymorphisms in either the recipient or donor, was an independent factor for achieving SVR. When virologic response to treatment was incorporated into analysis, the impact of IL28B polymorphism on virological clearance remained relative to other factors and was not significantly independent.

Analysis of acetylation and tri-methylation of the same residue of histone molecules might identify a subset of hepatocellular carcinoma (HCC) with aggressive behavior. In the present study, we examined acetylation and tri-methylation of lysine 27 on histone H3 (H3K27ac and H3K27me3, respectively) because these two modifications are known to exhibit opposite effects (enhancing and silencing) on gene expression. Neoplastic and non-neoplastic tissues from 198 HCC cases were immunostained with specific monoclonal antibodies against H3K27ac and H3K27me3. The stained tissues were evaluated by an image analyzing program to generate histological scores (H-scores, range 0-300), which were determined by multiplying the percentage of positive-stained cells with the classified immunohistochemical marker intensity (0-3). HCC tissues showed significantly higher H3K27ac (156.7±86.8) and H3K27me3 H-scores (151.8±78.1) compared with the background liver (40.3±33.0 and 64.7±45.6, respectively) (both P

Indoor positioning remains an open problem, because it is difficult to achieve satisfactory accuracy within an indoor environment using current radio-based localization technology. In this study, we investigate the use of Indoor Messaging System (IMES) radio for high-accuracy indoor positioning. A hybrid positioning method combining IMES radio strength information and pedestrian dead reckoning information is proposed in order to improve IMES localization accuracy. For understanding the carrier noise ratio versus distance relation for IMES radio, the signal propagation of IMES radio is modeled and identified. Then, trilateration and extended Kalman filtering methods using the radio propagation model are developed for position estimation. These methods are evaluated through robot localization and pedestrian localization experiments. The experimental results show that the proposed hybrid positioning method achieved average estimation errors of 217 and 1846 mm in robot localization and pedestrian localization, respectively. In addition, in order to examine the reason for the positioning accuracy of pedestrian localization being much lower than that of robot localization, the influence of the human body on the radio propagation is experimentally evaluated. The result suggests that the influence of the human body can be modeled.