加藤 直也

Background Acute cholangitis is caused by cholestasis and bacterial infection, and if exacerbated, sepsis may occur and be fatal. Biliary drainage is recommended for acute cholangitis regardless of severity, except in some cases of mild acute cholangitis, in which antibiotics are effective. A novel integrated device comprising a biliary drainage stent and a nasobiliary drainage tube, called the UMIDAS NB stent (UMIDAS Inc., Kanagawa, Japan), was developed. In this study, we evaluated the efficacy and safety of biliary drainage using the UMIDAS NB stent outside type for acute cholangitis in clinical practice. Methods Patients with acute cholangitis with common bile duct stones or distal biliary strictures who underwent biliary drainage with the UMIDAS NB stent outside type at our institution between January 2022 and December 2022 were examined retrospectively. The UMIDAS NB stent outside type was placed transpapillary using endoscopic retrograde cholangiopancreatography (ERCP). Patients with biliary drainage stent placement other than the UMIDAS NB stent outside type on the same ERCP session and patients with acute cholecystitis were excluded. Results A total of 13 patients were included in this study. The severity of cholangitis was mild in four cases, moderate in five, and severe in four. There were eight cases of common bile duct stones and five cases of pancreatic cancer. The stent diameter was 7 French scale (Fr) in five cases and 8.5 Fr in eight cases. The median procedure time was 20 minutes. Clinical success was achieved in all 13 patients (100%). No treatment-related adverse events were observed. Unintended removal of the nasobiliary drainage tube was not observed. There were no cases of biliary drainage stent dislocation with nasobiliary drainage tube removal. Conclusions Although the sample size was small, our study demonstrated that biliary drainage with the UMIDAS NB stent outside type was effective and safe for patients with acute cholangitis who had common bile duct stones or distal biliary strictures, regardless of the severity of cholangitis.

PURPOSE: Ramucirumab was shown to be effective as a second-line treatment after sorafenib in patients with advanced hepatocellular carcinoma (HCC) with alpha-fetoprotein levels > 400 ng/mL in a worldwide phase 3 trial. Ramucirumab is used in patients pretreated with various systemic therapies in clinical practice. We retrospectively examined the treatment outcomes of ramucirumab administered to advanced HCC patients after diverse systemic therapies. METHODS: Data were collected from patients with advanced HCC who received ramucirumab at three institutions in Japan. Radiological assessments were determined according to both Response Evaluation Criteria in Solid Tumours (RECIST) version 1.1 and modified RECIST and the Common Terminology Criteria for Adverse Events version 5.0 was used to assess adverse events. RESULTS: A total of 37 patients treated with ramucirumab between June 2019 and March 2021 were included in the study. Ramucirumab was administered as second, third, fourth, and fifth-line treatment in 13 (35.1%), 14 (37.8%), eight (21.6%), and two (5.4%) patients, respectively. Most patients (29.7%) who received ramucirumab as a second-line therapy were pretreated with lenvatinib. We found grade 3 or higher adverse events only in seven patients and no significant changes in the albumin-bilirubin score during ramucirumab treatment in the present cohort. The median progression-free survival of patients treated with ramucirumab was 2.7 months (95% confidence interval, 1.6-7.3). CONCLUSION: Although ramucirumab is used for various lines of treatment other than second-line immediately after sorafenib, its safety and effectiveness were not significantly different from the findings of the REACH-2 trial.

BACKGROUND: Patients with inflammatory bowel diseases (IBD) can develop extraintestinal manifestations (EIMs) during the disease course, which sometimes impact their quality of life. OBJECTIVES: This study aimed to clarify the prevalence and types of EIMs using a hospital-based IBD cohort in Japan. METHODS: A patient cohort with IBD was established in 2019, as participated by 15 hospitals in Chiba Prefecture of Japan. Using this cohort, the prevalence and types of EIMs, which are defined based on previous reports and the Japanese guidelines, were investigated. RESULTS: This cohort enrolled 728 patients, including 542 ulcerative colitis (UC) and 186 Crohn's disease (CD). Of these patients with IBD, 10.0% were identified with one or more EIMs (57 (10.5%) with UC and 16 (8.6%) with CD). Arthropathy and arthritis were the most common EIM in 23 (4.2%) patients with UC, followed by primary sclerosing cholangitis (PSC) (2.6%). Arthropathy and arthritis were also the most common in patients with CD, but no cases of PSC were observed. EIMs were more frequently observed in patients with IBD treated by specialists than in those treated by non-specialists (12.7% vs. 5.5%, p = 0.011). The incidence of EIMs in patients with IBD was not significantly different over time. CONCLUSIONS: The prevalence and types of EIMs in our hospital-based cohort in Japan did not significantly differ from those reported in previous or Western studies. However, the incidence might be underestimated due to the limited ability of non-IBD specialists to discover and describe EIMs in patients with IBD.

BACKGROUND/AIM: MHC-class I-related chain A (MICA) functions as a ligand for natural killer group D, an activating receptor on natural killer (NK) cells, and its expression correlates with the carcinogenesis and progression of hepatocellular carcinoma (HCC). Although membranous MICA (mMICA) activates NK cells, soluble forms of MICA (sMICA), shed by cleaving enzymes, such as A disintegrin and metalloprotease (ADAM) 9, suppress NK cells. Therefore, the prevention of MICA shedding through the inhibition of ADAM9 has the potential to activate cancer immunity. Although we have discovered several ADAM inhibitors, many did not sufficiently activate NK cells without being cytotoxic, and, thus, new ADAM9 inhibitor candidates are needed. MATERIALS AND METHODS: To identify possible compounds for drug development, chemical library screening (a total of 741 compounds) was conducted using a fluorescence assay. Compounds with reduced fluorescence intensity were used as hit compounds in a subsequent analysis. Their impact on sMICA and mMICA in HCC cell lines was assessed using ELISA and flow cytometry, respectively. The cytotoxicity of NK cells was also evaluated by co-culturing NK cells with HCC cells. RESULTS: CCL347, a symmetrical compound with five benzene rings, was identified as a hit compound. CCL347 significantly reduced sMICA levels in the culture medium supernatant with negligible cytotoxicity. Although mMICA was also reduced, CCL347 successfully enhanced NK cell cytotoxicity in co-cultures of NK cells and HCC cells. CONCLUSION: CCL347 has potential as a novel therapeutic drug for HCC.

Video 1Use of a super-soft hood (Space Adjuster; TOP, Tokyo, Japan) for esophageal endoscopic submucosal dissection below an esophageal stricture.

Transforming growth factor (TGF)-β/Smad pathway is implicated in the pathogenesis of liver fibrosis, a condition characterized by excessive deposition of extracellular matrix (ECM) proteins such as collagen in response to chronic inflammation. It has been reported that ceramide regulates collagen production through TGF-β/Smad pathway activation. In this study, we examined whether miglustat, an inhibitor of glucosylceramide synthase, can suppress liver fibrosis by reducing TGF-β/Smad pathway activity. Human hepatic stellate cells (HHSteCs) were cultured with TGF-β and multiple miglustat concentrations to examine dose-dependent effects on the expression levels of ECM-related genes and Smad proteins. To evaluate the efficacy of miglustat for fibrosis mitigation, C57BL/6 mice were treated with carbon tetrachloride (CCl4) for 4 weeks to induce liver fibrosis, followed by combined CCl4 plus miglustat for a further 2 weeks. To examine if miglustat can also prevent fibrosis, mice were treated with CCl4 for 2 weeks, followed by CCl4 plus miglustat for 2 weeks. Miglustat dose-dependently downregulated expression of α-smooth muscle actin and ECM components in TGF-β-treated HHSteCs. Both phosphorylation and nuclear translocation of Smad2 and Smad3 were also suppressed by miglustat treatment. Sirius-Red staining and hydroxyproline assays of model mouse liver samples revealed that miglustat reduced fibrosis, an effect accompanied by decreased expression of ECM. Our findings suggest that miglustat can both prevent and reverse liver fibrosis by inhibiting TGF-β/Smad pathway.

AIM: The prognosis of patients with acute liver failure has improved dramatically in the past three decades due to advances in medical critical care and use of liver transplantation (LT) in Western countries, where the etiology of acute liver failure is different from that in Japan. We analyzed patients with fulminant hepatitis (FH) and late-onset hepatic failure (LOHF) admitted to our unit over a 32-year period to clarify the nature of Japanese patients with FH and LOHF. METHODS: A total of 137 Japanese patients with FH and LOHF between 1986 and 2017 were analyzed for etiologies, disease types, treatment protocols, and outcome. RESULTS: Of 137 patients, 124 were FH (53 acute type and 71 subacute type) and 13 LOHF. The major etiology was due to viral infections in 48% of patients. A total of 23.4% of patients recovered without LT, 7.3% received LT, and 69.3% died without LT. The number of patients showed rise and fall without an evident decrease during the period. Patients with autoimmune hepatitis increased after the establishment of autoimmune hepatitis criteria in 1999 (p < 0.001), and that with indeterminate cause decreased (p < 0.01). The mean age was older in the last decade than in the first decade (p = 0.036). Spontaneous and overall survival rates were not different during the period. CONCLUSIONS: The prognosis of our patients with FH and LOHF has not improved, probably because of aging and the increasing proportion of etiologies with poor prognosis and difficult-to-treat patients without response to medications regardless of advancement of clinical management, including artificial liver support devices and LT.

症例は73歳男性で、6年前に肝細胞癌(HCC)に対し肝切除を行ったが再発した。入院時血液検査でトランスアミナーゼ、γ-GTPの低下、腫瘍マーカーの著明な低下を認め、造影CTで肝腫瘍の縮小を認めた。肝内腫瘍は自然退縮したが骨転移を認めたため、全身化学療法を行った。腫瘍の自然退縮は治療介入前であり、禁酒が要因であると考えられた。

AIM: Carbon-ion radiotherapy (C-ion RT) has shown potential as a curative treatment for patients with hepatocellular carcinoma (HCC). However, no reports have compared the effectiveness of C-ion RT and radiofrequency ablation (RFA). This study aimed to compare clinical outcomes between C-ion RT and RFA for patients with early-stage HCC. METHODS: Medical records of consecutive patients with HCC (single lesion ≤5 cm or two to three lesions ≤3 cm) who received either C-ion RT or RFA as initial treatment were retrospectively reviewed. Propensity score matching (PSM) was used to adjust for clinical factors between both groups. RESULTS: A total of 560 patients were included, among whom 69 and 491 received C-ion RT and RFA, respectively. After PSM (C-ion RT, 54 patients; RFA, 95 patients), both groups were well balanced. Carbon-ion radiotherapy had significantly lower cumulative intrasubsegmental recurrence rate after PSM compared to RFA (p = 0.004) (2-year, 12.6% vs. 31.7%; 5-year, 15.5% vs. 49.6%, respectively). However, no significant difference in cumulative local recurrence rate, stage progression-free survival, or overall survival (OS) was observed between both groups. In the RFA group, 6 of 491 patients (1.2%) showed grade 3 adverse events, whereas no grade 3 or higher adverse events were observed in the C-ion RT group. CONCLUSION: Carbon-ion radiotherapy provided a lower cumulative intrasubsegmental recurrence rate, but a comparable cumulative local recurrence rate, stage progression-free survival, and OS compared to RFA. Thus, C-ion RT appears to be one of the effective treatment options for early-stage HCC when RFA is deemed not indicated.

This study aimed to evaluate the feasibility of performing endoscopic ultrasound-guided hepaticogastrostomy using a 22-gauge fine-needle aspiration needle. This was a single-center retrospective study. Fourteen patients who underwent endoscopic ultrasound-guided hepaticogastrostomy with a 22-gauge fine-needle aspiration needle were examined. Fourteen eligible patients were included in this study. The age of patients ranged from 55 to 93 years, with a median of 76 years. Of patients with existing underlying diseases, there were 8 cases of pancreatic cancer (57.1%), 2 cases of metastatic liver tumor (14.3%), 2 cases of bile duct stones (14.3%), 1 case of hilar cholangiocarcinoma (7.1%), and 1 case of gallbladder cancer (7.1%). Regarding gastrointestinal anatomy, there were 11 cases (78.6%) of normal and 3 cases (21.4%) of gastric resection with Roux-en-Y. Reasons for endoscopic ultrasound-guided hepaticogastrostomy were duodenal obstruction in 7 cases (50.0%), surgically altered anatomy in 3 cases (21.4%), and 4 cases (28.6%) of failed endoscopic retrograde cholangiopancreatography. Technical success was achieved in 11 cases (78.6%). Subsequently, 11 cases of technical success were analyzed. There were 5 cases of puncturing B2 (45.5%). The puncture bile duct diameter ranged from 3.1 to 5.7 mm, with a median of 4.4 mm. endoscopic ultrasound-guided antegrade procedures was combined with endoscopic ultrasound-guided hepaticogastrostomy in 2 cases (18.2%). Clinical success was achieved in all the cases. The procedure time ranged from 15 to 93 minutes, with a median duration of 35 minutes. Regarding the type of stent placed in hepaticogastrostomy, a plastic stent was placed in 10 cases (90.9%) and a metal stent was placed in 1 case (9.1%). Early adverse events occurred in 4 cases (36.4%), and all of these cases developed biliary peritonitis, late adverse events occurred in 1 case (9.1%), this was biloma. A change to a 0.025-inch guidewire during the procedure was required in 8 cases (72.7%). Esophageal puncture was not performed. endoscopic ultrasound-guided hepaticogastrostomy using a 22-gauge fine-needle aspiration needle is effective. However, in 72.7% of the cases started using the 0.018-inch guidewire, the guidewire was exchanged for a 0.025-inch guidewire during procedure.

C型肝炎ウイルス(HCV)感染透析患者は非感染患者より予後不良であるとされており,HCV感染の予防・診断・治療は重要な課題である.そこで2020年に血液透析患者のHCVの保有,検査,治療などの現状に関するアンケートを,千葉県内の透析医療機関に行った.HCV抗体陽性者は3.7%,HCV-RNA検査陽性者は1.7%であり,2018年の全国調査(5.2%,2.5%)より低率であった.肝臓専門医紹介率は41%で同全国調査(22.8%)より高い傾向にあった.抗ウイルス治療はHCV抗体陽性者の24%に行われており,そのうち71%の患者が直接作用型抗ウイルス薬による治療であった.肝臓癌の治療は過去5年間にHCV抗体陽性者の7.5%で行われていた.千葉県内では全国調査結果に比べHCV感染について高い関心を持ち検査,治療が行われているがまだ改善の余地があると考えられ,より一層の疾患啓蒙,治療,検査の周知が必要と考えられた.(著者抄録)

症例は77歳の男性.当院を受診する12ヵ月前に急性胆管炎を発症し,CTで遠位胆管末端の隆起を認めた.ERCPで内視鏡的乳頭括約筋切開術を行って胆管プラスチックステントを留置した.遠位胆管末端の隆起には病理学的な悪性所見を認めなかった.約3ヵ月毎にERCPを行い,胆管ステントの交換と遠位胆管末端の隆起部からの生検を行っていたが,患者本人の希望で当院受診の約1ヵ月前に胆管ステントを抜去し,精査目的で当院へ紹介となった.造影CTとMRCPでは遠位胆管末端に長径10mmの隆起を認め,EUSでは遠位胆管末端の隆起は経時的に形態変化をする様子が観察された.これらの所見から,腫瘍ではなくPapillary foldsと判断し,Papillary foldsの突出を伴う胆道型乳頭括約筋機能不全と診断した.胆管ステントの留置をしない状態で経過をみているが,血中肝胆道系酵素上昇や黄疸の出現なく経過している.(著者抄録)

Although the efficacy and safety of salvage techniques for biliary cannulation in endoscopic retrograde cholangiopancreatography (ERCP) have been reported, few reports analyzed the choice of techniques and their clinical outcomes in large cohorts. This study aimed to evaluate the outcomes of biliary cannulation in patients with native papillae. We retrospectively identified 1021 patients who underwent initial ERCP from January 2013 to March 2020. We investigated background factors, treatment details, cannulation success rates, and adverse event rates. Then we analyzed a series of treatment processes, including salvage techniques such as double guidewire technique (DGT), needle knife pre-cutting (NKP), and transpancreatic pre-cut papillotomy (TPPP). The initial ERCP success rate using standard technique alone was 62.8%, which increased to 94.3% including salvage techniques. Salvage techniques were frequently required in patients with long oral protrusions (OR 2.38; 95% CI 1.80-3.15; p < 0.001). A total of 503 cases (49.3%) had long oral protrusions, 47.5% of which required the salvage techniques, much higher than 27.5% of not-long cases. Patients with long oral protrusions had a higher frequency of NKP. In conclusion, patients with long oral protrusions frequently required salvage techniques. Salvage techniques may help to overcome many difficult biliary cannulation cases.

Objective: To describe the case of a patient with intraperitoneal bleeding from the gastroepiploic artery by endoscopic ultrasound who was successfully treated with transcatheter arterial coil embolization. Patient and Methods: An 87-year-old man was referred to our hospital for examination of a gallbladder tumor. Endoscopic ultrasonography was performed using an oblique-view echoendoscope. After the endoscopic ultrasound, the patient went into shock. Computed tomography revealed a huge intraperitoneal hematoma and an aneurysm in the right gastroepiploic artery that were not seen on previous computed tomography images. Thus, urgent catheter angiography was performed, which showed a pseudoaneurysm of the right gastroepiploic artery and extravasation of the contrast medium from the pseudoaneurysm. Results: Transcatheter arterial coil embolization was subsequently performed, and the bleeding stopped. Thereafter, his hemodynamics stabilized and his general condition improved. The patient was discharged 22 days post-treatment with an uneventful course. Conclusion: Observation-only endoscopic ultrasound without invasive procedures can cause intraperitoneal bleeding due to a ruptured splanchnic artery. Thus, endoscopic ultrasonography should be performed more carefully in elderly patients.

Objective: Retrieval is challenging once prophylactic pancreatic stents migrate deep into the pancreatic duct. Herein, we describe a case of successful endoscopic retrieval of a migrated prophylactic pancreatic stent using a basket catheter through a biliary plastic stent pusher tube. Patient: A 71 year-old man was referred to our hospital for removal of a straight-shaped migrated 5-Fr 3-cm prophylactic pancreatic stent with a flap on the duodenal side. There were no subjective symptoms at the time of the hospital visit. Results: During endoscopic retrograde cholangiopancreatography, we inserted an 8.5-Fr plastic biliary stent pusher tube in front of the migrated pancreatic stent. The stent was then grasped using a basket catheter for peroral cholangioscopy through the biliary stent pusher tube. The stent was pulled into the pusher tube and was successfully retrieved from the pancreatic duct. No complications were associated with endoscopic retrograde cholangiopancreatography. Conclusion: Although rare, prophylactic pancreatic duct stent migration after pancreatic duct guidewire placement should be noted. In our case, endoscopic retrieval of a migrated prophylactic pancreatic stent using a basket catheter for peroral cholangioscopy through the biliary plastic stent pusher tube was successful.

Background: Sarcopenia, defined as the loss of skeletal muscle mass (MM), physical performance, and strength, has been associated with poor clinical outcomes in hepatocellular carcinoma (HCC) patients treated with several therapies. As systemic therapies, including molecular targeted agents, have a strong impact on sarcopenia, we aimed to review the impact of sarcopenia in patients receiving systemic therapies, especially sorafenib and hepatic arterial infusion chemotherapy (HAIC). Summary: Several studies have demonstrated that sarcopenia is associated with poor clinical outcomes in patients receiving sorafenib or lenvatinib, while HAIC has no association with overall survival (OS) and sarcopenia. Furthermore, based on our previous study, we developed the management of sorafenib score (MS score) to stratify patients' survival according to the positivity of three parameters (skeletal MM, disease control of sorafenib, and post-sorafenib therapy), ranging from 0 to 3. Patients with an MS score ≥2 (median survival time [MST], 16.4 months) showed significantly longer survival than those with an MS score ≤1 (MST, 8.4 months) (p < 0.001). This result indicates that patients need at least two positive parameters to prolong OS. Although performance status (PS) has been used in the Barcelona Clinic Liver Cancer staging system, we consider that the assessment of sarcopenia has the potential to replace PS. Key Messages: Sarcopenia is associated with poor clinical outcomes in patients of HCC receiving sorafenib or lenvatinib. The MS score, based on the positivity of three prognostic factors, including skeletal MM, in patients receiving sorafenib, can be a reliable indicator of prolonged survival.

がん遺伝子パネル検査が臨床実装されているが、進行期で診断されることの多い悪性胆道腫瘍においては手術検体がなく、また、生検で得られる検体は微小である。このため、がん遺伝子パネル検査提出に必要な十分量の組織採取が困難であることより、腫瘍組織の代替となる検体の探索が重要である。血液を用いたリキッドバイオプシーは低侵襲であることより注目され有用性の報告がなされているが、腫瘍量や癌腫による検出感度の相違などの懸念点がある。われわれは、日常臨床で用いられる胆汁検体に着目し、胆膵癌において高頻度に検出される60遺伝子(280,220bp)にわたる胆膵癌パネルをinhouseで構築しターゲットシークエンスを施行し胆汁細胞診検体、胆汁液体検体のゲノム解析への活用を検討した。(著者抄録)

Background and objective In this study, we aimed to evaluate the efficacy and safety of a single pigtail stent made by cutting a nasobiliary drainage tube (NBD stent) by comparing the clinical outcomes of using an NBD stent and those of using a ready-made double pigtail stent (RDP stent) in endoscopic gallbladder stenting (EGBS) for acute cholecystitis. Materials and methods This was a single-center retrospective study involving 20 cases that had technical success with EGBS for acute cholecystitis; the patients were divided into two groups: those using NBD stent (NBD group) and those using RDP stent (RDP group). The baseline characteristics and clinical outcomes were compared between the two groups. Results There were 13 patients in the NBD group and seven in the RDP group. The rates of clinical success (NBD group: 92% vs. RDP group: 100%, p=0.45) did not differ significantly between the groups. Regarding adverse events, gallbladder perforation occurred in one case in the NBD group; however, no other adverse events occurred in either group (NBD group: 7.7% vs. RDP group: 0%, p=0.45). The stent patency periods did not differ significantly between the groups [NBD group: 43 (12-64) days vs. RDP group: 97 (58-215) days, p=0.17]. The stent patency period in cases of long-term stent placement after EGBS was 1,381 days and 1,579 days in the NBD group and 305 days in the RDP group, respectively. Conclusion NBD stents are considered as effective as RDP stents in EGBS for acute cholecystitis. They are highly versatile and can be used for both bridging to surgery and long-term stent placement.

BACKGROUND: To evaluate the effect of regorafenib on soluble MHC class I polypeptide-related sequence A (MICA) (sMICA) level in vitro. In addition, we clinically examined whether its plasma levels were associated with regorafenib activity in terms of progression-free survival (PFS) in patients with CRC. METHODS: Human CRC cell line HCT116 and HT29 cells were treated with regorafenib and its pharmacologically active metabolites, M2 or M5 at the same concentrations as those in sera of patients. We also examined the sMICA levels and the area under the plasma concentration-time curve of regorafenib, M2 and M5. RESULTS: Regorafenib, M2, and M5 significantly suppressed shedding of MICA in human CRC cells without toxicity. This resulted in the reduced production of sMICA. In the clinical examination, patients with CRC who showed long median PFS (3.7 months) had significantly lower sMICA levels than those with shorter median PFS (1.2 months) (p = 0.045). CONCLUSIONS: MICA is an attractive agent for manipulating the immunological control of CRC and baseline sMICA levels could be a predictive biomarker for the efficacy of regorafenib treatment.

INTRODUCTION: Advanced hepatocellular carcinoma (HCC) with macrovascular invasion (MVI) has the worst prognosis among all phenotypes. This trial aims to evaluate whether treatment with durvalumab, alone or in combination with tremelimumab, plus particle therapy is a safe and synergistically effective treatment in patients with advanced HCC and MVI. METHODS AND ANALYSIS: This phase Ib, multicentre (two sites in Japan), open-label, single-arm, investigator-initiated clinical trial will assess durvalumab monotherapy in combination with particle therapy (cohort A) and that of durvalumab plus tremelimumab in combination with particle therapy (cohort B) for patients with advanced HCC with MVI. Cohort A will receive 1500 mg durvalumab every 4 weeks. Cohort B will receive 1500 mg durvalumab every 4 weeks in principle and 300 mg tremelimumab only on day 1 of the first cycle. Carbon-ion radiotherapy will be administered after day 8 of the first cycle. The primary endpoints are rates of any and severe adverse events, including dose-limiting toxicities (DLTs); secondary endpoints are overall survival, 6-month survival, objective response, 6-month progression-free survival and time to progression. Patients are initially enrolled into cohort A. If cohort A treatment is confirmed to be tolerated (ie, no DLT in three patients or one DLT in six patients), the trial proceeds to enrol more patients into cohort B. Similarly, if cohort B treatment is confirmed to be tolerated (ie, no DLT in three patients or one DLT in six patients), a total of 15 patients will be enrolled into cohort B. ETHICS AND DISSEMINATION: This study was approved by the ethics committees of the two participating institutions (Chiba University Hospital and National Institutes for Quantum (approval number: 2020040) and Radiological Science and Technology, QST Hospital (approval number: C20-001)). Participants will be required to provide written informed consent. Trial results will be reported in a peer-reviewed journal publication. TRIAL REGISTRATION NUMBER: jRCT2031210046.