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Abstract Background Spacer placement surgery is useful in particle therapy (PT) for patients with abdominopelvic malignant tumors located adjacent to the gastrointestinal tract. This study aimed to assess the safety, efficacy, and long-term outcomes of spacer placement surgery using an expanded polytetrafluoroethylene (ePTFE) spacer. Methods This study included 131 patients who underwent ePTFE spacer placement surgery and subsequent PT between September 2006 and June 2019. The overall survival (OS) and local control (LC) rates were calculated using Kaplan-Meier method. Spacer-related complications were classified according to the National Cancer Institute Common Terminology Criteria for Adverse Events (version 5.0). Results The median follow-up period after spacer placement surgery was 36.8 months. The 3-year estimated OS and LC rates were 60.5% and 76.5%, respectively. A total of 130 patients (99.2%) were able to complete PT. Spacer-related complications of ≥ grade 3 were observed in four patients (3.1%) in the acute phase and 13 patients (9.9%) in the late phase. Ten patients (7.6%) required removal of the ePTFE spacer. Conclusions Spacer placement surgery using an ePTFE spacer for abdominopelvic malignant tumors is technically feasible and acceptable for subsequent PT. However, severe spacer-related late complications were observed in some patients. Since long-term placement of a non-absorbable ePTFE spacer is associated with risks for morbidity and infection, careful long-term follow-up and prompt therapeutic intervention are essential when complications associated with the ePTFE spacer occur. Trial registration retrospectively registered.

Abstract Background Long-term outcomes and prognostic factors of proton radiotherapy for locally advanced pancreatic cancer (LAPC) in the body and tail are still unknown. The aim of this study was to determine the prognostic factors after proton radiotherapy in a large group of patients with LAPC in the body and tail. Methods The medical records of 200 patients with LAPC in the body and tail who underwent proton radiotherapy between February 2009 and January 2021 at the Hyogo Ion Beam Medical Center were retrospectively reviewed to identify prognostic factors that contribute to long-term survival. Results The overall survival rate at 1- and 2-year after PT was 69.6% and 35.4% with a median overall survival of 18.4 months. The 1- and 2-year local progression-free, and progression-free survival rates were 84.3% and 68.0%, and 44.3% and 19.4%, respectively. In multivariate analysis, superior mesenteric artery (SMA) invasion (SMA only invasion vs. celiac artery only invasion; P = 0.049: SMA and celiac artery invasion vs. celiac artery only invasion; P = 0.017), carbohydrate antigen 19-9 (CA 19-9) level ≥ 231.9 U/mL (P = 0.001), anterior peripancreatic invasion (P = 0.006), and incomplete scheduled concurrent chemotherapy (P = 0.009) were statistically significant prognostic factors for overall survival. There was no significant difference in local progression-free survival; however, distant metastasis-free survival was statistically worse in patients with prognostic factors than in those without. Conclusions Proton radiotherapy for LAPC in the body and tail may be a valuable multidisciplinary treatment option. Patients with SMA invasion, higher pre-proton radiotherapy serum CA 19-9 level, anterior peripancreatic invasion, or incomplete scheduled concurrent chemotherapy had worse overall survival because of worse distant metastasis-free survival, suggesting that distant metastases have a significant impact on overall survival in such patients. Trial registration: Retrospectively registered.

Abstract Pancreatic cancer primarily arises from microscopic precancerous lesions, such as pancreatic intraepithelial neoplasia (PanIN) and acinar-to-ductal metaplasia (ADM). However, no established method exists for predicting pancreatic precancerous conditions. Endoscopic ultrasonography (EUS) can detect changes in pancreatic parenchymal histology, including fibrosis. This study aimed to elucidate the relationship between pancreatic parenchymal EUS findings and microscopic precancerous lesions. We retrospectively analyzed 114 patients with pancreatobiliary tumors resected between 2010 and 2020 and evaluated the association between pancreatic parenchymal EUS findings and the number of PanIN, ADM, and pancreatic duct gland (PDG). Of the 114 patients, 33 (29.0%), 55 (48.2%), and 26 (22.8%) had normal EUS findings, hyperechoic foci/stranding without lobularity, and hyperechoic foci/stranding with lobularity, respectively. Multivariate analyses revealed that abnormal EUS findings were significantly associated with the frequency of PanIN (hyperechoic foci/stranding without lobularity: OR [95% CI] = 2.7 [1.0–7.3], with lobularity: 6.5 [1.9–22.5], P trend = 0.01) and ADM (hyperechoic foci/stranding without lobularity: 3.1 [1.1–8.2], with lobularity: 9.7 [2.6–36.3], P trend = 0.003) but not with PDG (hyperechoic foci/stranding without lobularity: 2.2 [0.8–5.8], with lobularity: 3.2 [1.0–10.2], P trend = 0.12). We observed a trend toward a significantly higher number of precancerous lesions in the following order: normal findings, hyperechoic foci/stranding without lobularity, and hyperechoic foci/stranding with lobularity. Pancreatic parenchymal EUS findings were associated with the increased frequency of PanIN and ADM. Lobularity may help predict the increased number of precancerous lesions.

Abstract Background and Aim The purpose of this study was to analyze factors associated with the overall survival (OS) of atezolizumab/bevacizumab combination therapy for advanced hepatocellular carcinoma (aHCC). We also assessed the OS of patients with ineffective therapy and those who discontinued treatment owing to adverse events (AEs). Methods This retrospective multicenter study involved 139 patients with aHCC who received atezolizumab/bevacizumab combination therapy between November 2020 and September 2022. Results The median duration of treatment was 136.5 days, and the median observation period was 316 days. The overall response rate was 40%, and the disease control rate was 78% according to mRECIST criteria. Grade ≥2 AEs occurred in 63 patients (43%) and led to treatment discontinuation in 16 patients. Multivariate analysis revealed that treatment response and occurrence of grade ≥2 AEs after therapy, as well as low level of albumin‐bilirubin (ALBI) grade and low level of des‐gamma carboxy prothrombin (DCP) before therapy, were extracted as factors that contributed to OS. Log‐rank tests with the Kaplan–Meier method showed significant differences in OS among these factors. The OS of patients who discontinued owing to AEs was significantly shorter than that of other patients. Conclusion Not only factors before therapy but also treatment response and the appearance of AEs are involved in OS for atezolizumab/bevacizumab combination therapy. Although the development of AEs also contributed to OS, appropriate management of AEs is important to avoid discontinuing treatment with this combination.

Abstract To assess the value of nonenhancing capsule by adding to enhancing capsule in gadoxetic acid-enhanced MRI (EOB-MRI) in comparison with contrast-enhanced CT (CE-CT) for diagnosing histological capsule in hepatocellular carcinoma (HCC). One-hundred fifty-one patients with HCC who underwent both CE-CT and EOB-MRI were retrospectively reviewed. Liver Imaging-Reporting and Data System (LI-RADS) v2018 imaging features, including enhancing and nonenhancing capsule were evaluated by two readers in CE-CT and EOB-MRI. Frequencies of each imaging feature were compared between CE-CT and EOB-MRI. The area under the receiver operating characteristic (AUC) curve for the diagnosis of histological capsule was compared across the following three imaging criteria: (1) enhancing capsule in CE-CT, (2) enhancing capsule in EOB-MRI, and (3) enhancing/nonenhancing capsule in EOB-MRI. Enhancing capsule in EOB-MRI was significantly less frequently depicted than that in CE-CT (p

Abstract Endoscopic papillectomy for early ampullary tumors is considered a minimally invasive and useful alternative to pancreatoduodenectomy; however, its indications remain unclear. This study aimed to clarify the advantages of endoscopic papillectomy by investigating the clinical outcomes of patients who underwent endoscopic papillectomy or pancreatoduodenectomy for early ampullary tumors. Patients diagnosed with early ampullary tumors (adenoma, Tis, T1a) who underwent endoscopic papillectomy or pancreatoduodenectomy between June 2008 and October 2019 were included, and their clinical outcomes were analyzed. Seventy-four patients (34 patients with adenomas and 40 patients with adenocarcinomas) were divided into two groups, namely endoscopic papillectomy (n = 43) and pancreatoduodenectomy (n = 31). The estimated 5-year overall survival rate of all early ampullary tumors was 92%. Complete resection rate was significantly lower for endoscopic papillectomy patients versus pancreatoduodenectomy patients (48.8% vs. 100%; p

Background and purpose: To examine the role of proton beam therapy (PBT) in the treatment of extrahepatic biliary tract cancer (EBC). Methods and materials: We analyzed the data accumulated in the Proton-Net database, which prospectively registered all individual patient data treated with PBT in all Japanese proton institutions from May 2016 to June 2019. The primary endpoint was overall survival (OS), and the secondary endpoints were local control (LC), progression-free survival (PFS), and toxicity. Results: Ninety-three patients with unresectable and/or recurrent EBC were treated with PBT using a median prescribed dose of 67.5 Gy (RBE) (range, 50–72.6 Gy) in 25 (22–30 fractions). With a median follow-up of 16.3 months, the median survival time was 20.1 months and the 2-year OS was 37.8%. Two-year PFS and LC rates were 20.6% and 66.5%, respectively. Poor liver function (Child-Pugh B, C), a narrower distance between the tumor and digestive tract (2 cm >), and a larger tumor diameter (2 cm

In the treatment of retroperitoneal sarcoma involving major vessels, complete resection with vascular reconstruction is challenging. We describe the case of a 72-year-old man who presented with 8 months of abdominal pain. Diagnostic workup revealed occlusion of the celiac trunk and the origin of the superior mesenteric artery due to a soft tissue sarcoma. Radical resection of the tumor and vessels was performed. Guided by intraoperative angiography, arterial reconstruction was performed without mesenteric ischemia. All arterial margins were negative. At the 6-year follow-up, the patient was alive with no evidence of recurrence.

Abstract Background Factors associated with long-term survival in gemcitabine-concurrent proton radiotherapy (GPT) for non-metastatic, locally advanced pancreatic cancer (LAPC) remain unclear. This study aimed to determine the factors associated with long-term survival in GPT for non-metastatic LAPC. Methods The medical records of 123 patients with LAPC treated with GPT between February 2009 and December 2019 at Hyogo Ion Beam Medical Center were retrospectively reviewed to assess the factors associated with long-term survival outcomes. Results The median overall survival of the total cohort treated with GPT was 18.7 months. The 1- and 2-year overall, local progression-free, and progression-free survival rates were 70.4% and 35.7%, 78.2% and 59.0%, and 38.6% and 20.8%, respectively. Multivariate analysis revealed that LAPCs at the pancreatic body-tail and those without anterior peripancreatic invasion were independently associated with longer overall survival (P = 0.040 and P = 0.015, respectively). The median overall survival of patients with LAPC at the pancreatic body-tail and those with LAPC without anterior peripancreatic invasion were 24.1 and 28.1 months, respectively. LAPCs at the pancreatic body-tail had a higher volume ratio irradiated over 60 Gy equivalents at gross tumor volume than those at the pancreatic head (P

Abstract Background Shogi is a traditional board game in Japan. A preventive stress management program based on Shogi-assisted cognitive behavioral therapy (S-CBT) was applied in the Japanese municipality of Kakogawa City. The study aimed to develop an S-CBT preventive stress management program for the elderly and determine its efficacy. Methods The participants were 67 elderly men with amateur-level Shogi skills. They were randomly assigned to either the S-CBT group (n = 33) or the waiting-list control group (n = 34). The S-CBT program was conducted over six 90-min sessions. The outcome measures were recorded using K6 instrument, the Japanese version of the abbreviated Lubben Social Network Scale, five items on cognitive behavioral functioning, and subjective well-being scale. Results and conclusions The dropout rates of the S-CBT group and waiting-list control groups were 36.4 and 44.1%, respectively. Effect sizes (Cohen’s d) and 95% confidence intervals (CIs) were calculated for each group. Domains that changed immediately after the S-CBT intervention were problem-solving skills, self-reinforcement, and negative automatic thoughts. Future research should promote mental and physical health through the design of intervention programs using familiar materials. Trial registration University Hospital Medical Information Network (UMIN CTR) UMIN000036003 .

Abstract Background Hepatocellular carcinoma (HCC) with major portal vein tumor thrombus (Vp4 PVTT) is an extremely advanced tumor with limited treatment options. Systemic chemotherapy is the only recommended treatment option, and atezolizumab plus bevacizumab has recently emerged as a first-line treatment option. Case presentation We describe the case of an 82-year-old man with unresectable advanced HCC with Vp4 PVTT who achieved a significant response to atezolizumab plus bevacizumab treatment. A single administration of atezolizumab plus bevacizumab ensured significant anti-tumor effects (regression in the tumor size and PVTT, portal vein recanalization, and serum alfa-fetoprotein levels decreased from 90,770 to 89 ng/mL). The patient continued with atezolizumab monotherapy, and after nine consecutive regimens, there was no apparent sign of residual tumor. Conclusions This case demonstrates the powerful anti-tumor effect of atezolizumab plus bevacizumab treatment for advanced HCC with Vp4 PVTT, suggesting that these agents can be a promising treatment option for such refractory tumors.

Abstract Background Radical antegrade modular pancreatosplenectomy (RAMPS) is an isolation procedure in pancreatosplenectomy for pancreatic body/tail cancer. Connective tissues around the bifurcation of the celiac axis are dissected, followed by median-to-left retroperitoneal dissection. This procedure has the potential to isolate blood and lymphatic flow to the area of the pancreatic body/tail and the spleen to be excised. This is achieved by division of the inflow artery, transection of the pancreas, and then division of the outflow vein in the early phases of surgery. In cases of pancreatic ductal adenocarcinoma (PDAC), the procedure has been shown to decrease intraoperative blood loss and increase R0 resection rate by complete clearance of the lymph nodes. This trial investigates whether the isolation procedure can prolong the survival of patients with pancreatic ductal adenocarcinoma who undergo distal pancreatosplenectomy (DPS) compared with those that undergo the conventional approach. Methods/design Patients with PDAC scheduled to undergo DPS are randomized before surgery to undergo either a conventional procedure (arm A) or to undergo the isolation procedure (arm B). In arm A, the pancreatic body, tail, and spleen are mobilized, followed by removal of the regional lymph nodes. The splenic vein is transected at the end of the procedure. The timing of division of the splenic artery (SA) is not restricted. In arm B, regional lymph nodes are dissected, then we transect the root of the SA, the pancreas, then the splenic vein. At the end of the procedure, the pancreatic body/tail and spleen are mobilized and removed. In total, 100 patients from multiple Japanese high-volume centers will be randomized. The primary endpoint is 2-year recurrence-free survival by intention-to-treat analysis. Secondary endpoints include intraoperative blood loss, R0 resection rate, and overall survival. Discussion If this trial shows that the isolation procedures can improve survival with a similar R0 rate and with a similar number of lymph node dissections to the conventional procedure, the isolation procedure is expected to become a standard procedure during DPS for PDAC. Conversely, if there were no significant differences in endpoints between the groups, it would demonstrate justification of either procedure from surgical and oncological points of view. Trial registration UMIN Clinical Trials Registry UMIN000041381 . Registered on 10 August 2020. ClinicalTrials.gov NCT04600063 . Registered on 22 October 2020.

Abstract Aim With the increased use of particle therapy for liver cancer, local recurrence after particle therapy increased. Salvage hepatectomy is an acceptable treatment option for local recurrence following particle therapy; however, its safety and effectiveness remain unclear. Therefore, this multi‐center study aimed to verify the feasibility and efficacy of salvage hepatectomy and assess clinical issues associated with its application. Methods We retrospectively assessed the perioperative outcomes, prognosis, and pathological characteristics of 15 patients who underwent salvage hepatectomy for local recurrence after particle therapy between 2006 and 2019. Results Hepatocellular carcinoma and metastatic liver tumors were noted in eight and seven patients, respectively. The mean total dose and number of fractions were 66.5 Gy and 12, respectively, and the mean interval between particle therapy and surgery was 30.1 months. Major hepatectomy was performed in seven cases. Moreover, the mortality rate was 0%, and surgical complications of Clavien‐Dindo grade IIIa or higher were observed in four cases (27%)—two bile leakages, one pleural effusion, and one refractory skin fistula. The median overall survival time and 5‐year overall survival rate after salvage hepatectomy were 29.9 months and 43.1%, respectively. Histological examination of the irradiated liver tissue surrounding the tumor showed sinusoidal dilatation, loss of hepatocyte, and fibrosis in most cases. Conclusion Salvage hepatectomy after particle therapy is a feasible therapy; however, the risk of refractory complications associated with particle therapy is relatively high. Therefore, the first‐line treatment for resectable liver cancer should be carefully determined considering second‐line treatment after local recurrence.

Abstract Background Particle radiotherapy has increasingly gained acceptance for locally advanced pancreatic cancers owing to superior tumor conformity and dosimetry compared to conventional photon radiotherapy. However, the close proximity of the pancreas to the stomach and duodenum leads to radiation-induced gastrointestinal toxicities, which hinder the delivery of curative doses to the tumor. To overcome this problem, a surgical spacer was placed between the tumor and gastrointestinal tract, and subsequent proton radiotherapy was performed in this study. Methods Data from 9 patients who underwent surgical spacer placement and subsequent proton radiotherapy were analyzed. The safety and feasibility of the spacer placement surgery were evaluated; the impact of the spacer on dosimetry was also assessed using dose volume histogram (DVH) analyses, before and after surgical spacer placement. Results Surgical spacer placement and subsequent proton radiotherapy were successfully completed in all cases. Surgical spacer placement significantly improved the dose intensity covering 95%, mean, and minimum doses for the gross tumor volume, and the clinical and planning target volume based on the DVH, while respecting the dose constraints of the gastrointestinal tract. Based on the Common Terminology Criteria for Adverse Events, two patients (22.2%) developed gastrointestinal ulcer (Grade 2) at 1 and 35 months, and one patient (11.1%) developed gastric perforation (Grade 4) at 4 months after proton radiotherapy. Conclusions Surgical spacer placement in the locally advanced pancreatic body and tail cancers is relatively safe and technically feasible. Comparing radiation plans, surgical spacer placement seems to improve the dose distribution in the locally advanced pancreatic body and tail cancers, which are close to the gastrointestinal tract.

Abstract Background Postoperative biliary strictures are commonly related to accidental bile duct injuries or occur at the site of biliary anastomosis. The first-line treatment for benign biliary strictures is endoscopic therapy, which is less invasive and repeatable. However, recanalization for biliary complete obstruction is technically challenging to treat. The present report describes a successful case of treatment by extraluminal recanalization for postoperative biliary obstruction using a transseptal needle. Case presentation A 66-year-old woman had undergone caudal lobectomy for the treatment of hepatocellular carcinoma. The posterior segmental branch of the bile duct was injured and repaired intraoperatively. Three months after the surgery, the patient had developed biliary leakage from the right hepatic bile duct, resulting in complete biliary obstruction. Since intraluminal recanalization with conventional endoscopic and percutaneous approaches with a guidewire failed, extraluminal recanalization using a transseptal needle with an internal lumen via percutaneous approach was performed under fluoroscopic guidance. The left lateral inferior segmental duct was punctured, and an 8-F transseptal sheath was introduced into the ostium of right hepatic duct. A transseptal needle was advanced, and the right hepatic duct was punctured by targeting an inflated balloon that was placed at the end of the obstructed right hepatic bile duct. After confirming successful puncture using contrast agent injected through the internal lumen of the needle, a 0.014-in. guidewire was advanced into the right hepatic duct. Finally, an 8.5-F internal–external biliary drainage tube was successfully placed without complications. One month after the procedure, the drainage tube was replaced with a 10.2-F drainage tube to dilate the created tract. Subsequent endoscopic internalization was performed 5 months after the procedure. At the 1-year follow-up examination, there was no sign of biliary obstruction and recurrence of hepatocellular carcinoma. Conclusions Recanalization using a transseptal needle can be an alternative technique for rigid biliary obstruction when conventional techniques fail.

Abstract The bifid pancreas is a rare anatomical variation of the pancreatic duct in which double main pancreatic ducts in the body and tail of the pancreas join at the pancreas head and drain through the major papilla. When pancreaticoduodenectomies are carried out on bifid pancreases, close attention must be paid to the reconstruction because of the possibility that there may be two pancreatic ducts that need to be reconstructed. We present a case of pancreaticoduodenectomy for the bifid pancreas and a novel technique named the ‘two‐in‐one’ method for double pancreatic duct to jejunum anastomosis. Using the two‐in‐one method, we anastomosed one jejunal hole to a double pancreatic duct. Pancreatic texture was normal and postoperative volumes of pancreatic juice from the two external pancreatic duct stents were 250 mL and 100 mL/day, respectively. Postoperative recovery went well although the patient needed a slightly longer hospital stay as a result of surgical site infection. This novel anastomotic technique was as simple to carry out as a normal pancreaticojejunostomy and may be useful for reconstruction of the bifid pancreas.

ObjectivesSmall proline-rich protein 1A (SPRR1A) is recognized as a squamous differentiation marker but is also upregulated in some non-squamous cancers. However, its expression in pancreatic ductal adenocarcinoma (PDAC) has not been investigated. This study elucidated the expression of SPRR1A in PDAC and its effect on the prognosis and malignant behavior of PDAC.MethodsWe examined the SPRR1A expression by immunohistochemistry in 86 surgical PDAC cases and revealed the relationship between its expression and the prognosis of the PDAC patients. Furthermore, we overexpressed SPRR1A in pancreatic cancer cell lines (PK-1 and Panc-1) and assessed the phenotype and gene expression changes in vitro.ResultsAmong the 84 cases, excluding 2 with squamous differentiation, 31 (36.9%) had a high SPRR1A expression. The overall survival (median 22.1 months vs. 33.6 months, p = 0.0357) and recurrence-free survival (median 10.7 months vs. 15.5 months, p = 0.0298) were significantly lower in the high-SPRR1A-expression group than in the low-SPRR1A-expression group. A multivariate analysis indicated that a high SPRR1A expression (HR 1.706, 95% CI 1.018 to 2.862, p = 0.0427) and residual tumor status (HR 2.687, 95% CI 1.487 to 4.855, p = 0.00106) were independent prognostic factors. The analysis of TCGA transcriptome data demonstrated that the high-SPRR1A-expression group had a significantly worse prognosis than the low-SPRR1A-expression group, which supported our data. SPRR1A overexpression in PK-1 and Panc-1 did not result in remarkable changes to in vitro phenotypes, such as the cell proliferation, chemo-resistance, EMT, migration or global gene expression.ConclusionIncreased expression of SPRR1A is associated with a poor prognosis in PDAC and may serve as a novel prognostic marker. However, our in vitro study suggests that the SPRR1A expression may be a consequence, not a cause, of the aggressive behavior of PDAC.

Abstract Background Pancreatic resection and radiotherapy are powerful tools in the multidisciplinary local treatment of pancreatic ductal adenocarcinoma (PDAC). However, 10–20% of patients with preoperatively resectable PDAC have radiographically occult metastases, which results in laparotomy without resection. This study aims to explore the utility of intraoperative near-infrared (NIR) imaging with indocyanine green (ICG) during staging laparoscopy to detect PDAC metastasis. Methods This prospective study will evaluate patients with radiographically non-metastatic PDAC before they undergo planned pancreatic resection or chemoradiotherapy. Enrolled patients will receive ICG intravenously (0.5 mg/kg) before the staging laparoscopy. During the staging laparoscopy, the abdominal cavity will be observed using standard white-light laparoscopic imaging and then using NIR-ICG imaging. Suspicious lesions that are detected using standard imaging and/or NIR-ICG imaging will be examined intraoperatively using frozen sections and permanent specimens. We will evaluate the benefit of NIR-ICG imaging based on its ability to identify additional liver or peritoneal lesions that were not detected during standard white-light imaging. Discussion This study will help establish the clinical utility of NIR-ICG imaging to more precisely identify metastases from radiographically non-metastatic PDAC. This approach may help avoid needless major surgery or radiotherapy. Trial registration This protocol was registered on April 1, 2017 on the UMIN Clinical Trials Registry: UMIN000025900 and February 26, 2019 on the Japan Registry of Clinical Trials: jRCT1051180076 .

Purpose: Surgical spacer placement (SSP) is useful in particle therapy (PT) for patients with abdominal or pelvic tumors located adjacent to normal organs. We developed a nonwoven fabric bioabsorbable spacer made of polyglycolic acid (PGA) sutures that degrades via hydrolysis. We then conducted this first-in-human phase 1 study of the combination of SSP and PT using the PGA spacer, which we termed space-making PT (SMPT). This study aimed to evaluate the safety and efficacy of SMPT in patients with unresectable malignant tumor located adjacent to normal organs. Methods and Materials: The eligibility criteria included histologically proven malignant abdominal or pelvic tumor adjacent to the intestines, no metastasis, and no previous radiation therapy. Periodic computed tomography (CT) images were obtained before SSP and before, during, and after PT until the spacer disappeared. Treatment planning was performed for each CT image set until the end of PT, and doses for the planning target volume and organs at risk were analyzed. The thickness and volume of the PGA spacer were measured in each CT image set. Adverse events were evaluated according to the Common Terminology Criteria for Adverse Events version 4.0. Results: Five patients were enrolled in this study. All patients received 70.4 Gy (relative biological effectiveness) of irradiation. V95% of the planning target volume before SSP, at the beginning of PT, and at the end of PT was 82.1% ± 11.3%, 98.1% ± 1.1%, and 97.1% ± 0.8%, respectively. The PGA spacers maintained enough thickness (≥1 cm) until the end of PT and disappeared within 8 months after SSP in all patients. No grade ≥3 acute adverse events were observed. Conclusions: The SMPT is feasible and useful for abdominal or pelvic tumors adjacent to the intestines. This method may be applicable to unresectable tumors located adjacent to normal organs and may expand the indications of PT.

Abstract Background The use of surgical metal clips is crucial for ligating vessels in various operations. The currently available metal clips have several drawbacks; they are permanent and interfere with imaging techniques such as computed tomography (CT) or magnetic resonance (MR) imaging and carry the potential risk of endo-clip migration. We recently developed a novel magnesium (Mg) alloy for biodegradable clips that reduces artifacts on CT imaging. This study aimed to examine the tolerance, biodegradability, and biocompatibility of the Mg alloy clips compared with those of standard titanium (Ti) clips in hepatectomy. Methods Thirty Wistar rats were divided into two groups based on the clip used (groups A and B). The vascular pedicle, including hepatic artery, portal vein, bile duct, and hepatic vein of the left lateral lobe, was ligated with the Ti clip in group A or the Mg alloy clip in group B, and then the left lateral lobe was removed. The rats were sacrificed at 1, 4, 12, 24, and 36 weeks after surgery. Clinical and histological evaluations were performed. Absorption rate was calculated by measuring the clip volume. Results Although the Mg alloy clips showed biodegradability over time, there were no significant differences in the serum concentration of Mg between the two groups. The remaining volume ratio of Mg alloy clips was 95.5, 94.3, 80.0, 36.2, and 16.7% at 1, 4, 12, 24, and 36 weeks, respectively. No side effects occurred. Most of the microscopic changes were similar in both groups. Conclusions The new biodegradable Mg alloy clips are safe and feasible in vessel ligation for hepatectomy in a rat model and reduce artifacts in CT imaging compared with the standard Ti clips.

Abstract Background Carbohydrate antigen (CA) 19–9 levels after resection are considered to predict prognosis; however, the significance of decreased CA19–9 levels after neoadjuvant therapy has not been clarified. This study aimed to define the prognostic significance of decreased CA19–9 levels after neoadjuvant therapy in patients with pancreatic adenocarcinoma. Methods Between 2001 and 2012, 240 consecutive patients received neoadjuvant therapy and subsequent resection at seven high-volume institutions in Japan. These patients were divided into three groups: Normal group (no elevation [≤37 U/ml] before and after neoadjuvant therapy), Responder group (elevated levels [> 37 U/ml] before neoadjuvant therapy but decreased levels [≤37 U/ml] afterwards), and Non-responder group (elevated levels [> 37 U/ml] after neoadjuvant therapy). Analyses of overall survival and recurrence patterns were performed. Uni- and multivariate analyses were performed to clarify the clinicopathological factors influencing overall survival. The initial metastasis sites were also evaluated in these groups. Results The Responder group received a better prognosis than the Non-responder group (3-year overall survival: 50.6 and 41.6%, respectively, P = 0.026), but the prognosis was comparable to the Normal group (3-year overall survival: 54.2%, P = 0.934). According to the analysis of the receiver operating characteristic curve, the CA19–9 cut-off level defined as no elevation after neoadjuvant therapy was ≤103 U/ml. The multivariate analysis revealed that a CA19–9 level ≤ 103 U/ml, (P = 0.010, hazard ratio: 1.711; 95% confidence interval: 1.133–2.639), tumor size ≤27 mm (P = 0.040, 1.517; (1.018–2.278)), a lack of lymph node metastasis (P = 0.002, 1.905; (1.276–2.875)), and R0 status (P = 0.045, 1.659; 1.012–2.627) were significant predictors of overall survival. Moreover, the Responder group showed a lower risk of hepatic recurrence (18%) compared to the Non-responder group (31%), though no significant difference in loco-regional, peritoneal or other distant recurrence were observed between groups (P = 0.058, P = 0.700 and P = 0.350, respectively). Conclusions Decreased CA19–9 levels after neoadjuvant therapy predicts a better prognosis, with low incidence of hepatic recurrence after surgery.

Abstract Background Hepatocellular carcinoma (HCC) can develop in patients who are negative for the hepatitis B surface antigen (HBsAg) in serum but positive for hepatitis B virus (HBV) DNA in the liver, referred to as occult HBV infection (OBI). Previous reports showed that HBV variants in OBI-related HCC are different from those in HBsAg-positive HCC. In the present study, HBV quasispecies based on the pre-S/S gene in OBI-related HCC patients were examined by high throughput sequencing and compared with those in HBsAg-positive HCC. Methods Nineteen tissue samples (9 OBI-related and 10 HBsAg-positive non-cancerous tissues) were collected at the time of surgery at Kobe University Hospital. The quasispecies with more than 1% variation in the pre-S/S region were isolated and analysed by ultra-deep sequencing. Results There were no significant differences in the major HBV populations, which exhibit more than 20% variation within the entire pre-S/S region, between OBI-related HCC and HBsAg-positive HCC. However, the prevalences of major populations with pre-S2 region mutations and of minor populations with polymerized human serum albumin-binding domain mutations were significantly higher in OBI-related HCC than in HBsAg-positive HCC. Moreover, the major variant populations associated with the B-cell epitope, located within the pre-S1 region, and the a determinant domain, located in the S region, were detected frequently in HBsAg-positive HCC. The minor populations of variants harbouring the W4R, L30S, Q118R/Stop, N123D and S124F/P mutations in the pre-S region and the L21F/S and L42F/S mutations in the S region were detected more frequently in OBI-related HCC than in HBsAg-positive HCC. Conclusions Ultra-deep sequencing revealed that the B-cell epitope domain in the pre-S1 region and alpha determinant domain in the S region were variable in HBsAg-positive HCC, although the quasispecies associated with the pre-S2 region were highly prevalent in OBI-related HCC. Trial registration Ref: R000034382/UMIN000030113; Retrospectively registered 25 November 2017.

Abstract Background Pancreatic ductal adenocarcinoma (PDAC) often infiltrates to the adjacent major vasculatures; however, direct invasion of PDAC to the inferior vena cava (IVC) is uncommon. Case presentation We report our experience with three cases of PDAC directly invading the IVC wall. All three patients underwent pancreatoduodenectomy along with wedge resection of the IVC wall without severe postoperative complications. Histopathological studies revealed tumor infiltration to the adventitia of the IVC. All patients achieved negative surgical margins. One patient was still alive 26 months after surgery without tumor recurrence. Two patients experienced recurrence; one patient experienced liver metastasis but was still alive and in a stable condition without further tumor progression 12 months after surgery. Another patient experienced multiple liver metastasis 10 months after surgery and died 26 months after surgery. Conclusions Pancreatoduodenectomy along with wedge resection of the IVC wall for patients with PDAC directly invading the adventitia of the IVC can be performed safely. Further accumulation of cases is needed to elucidate the prognostic impact of IVC invasion.

Abstract This is the response article to correspondence article received for our published article in BMC surgery titled “A prospective single-center protocol for using near-infrared fluorescence imaging with indocyanine green during staging laparoscopy to detect small metastasis from pancreatic cancer”. Peter L. Labib, MBChB pointed out the necessity to administer indocyanine green intravenously in separate timing for detection of metastasis in liver and peritoneum. Preoperative injection is suitable to detect hepatic metastasis and intraoperative injection is reported to be well suited to detect peritoneal metastasis. However, we could not find the usefulness of intraoperative injection of indocyanine green for detecting peritoneal metastasis in cases with staging laparoscopy prior to this study. We employed this study protocol with only preoperative injection of indocyanine green to simplify the procedure with consideration of probably more frequent cases of hepatic metastasis that is difficult to detect with white-light imaging than those of peritoneal metastasis.

IntroductionMultimodal treatment prolongs the survival of patients with biliary tract cancer (BTC). However, the chemotherapy choices for this disease are few, and completing each chemotherapy session is important. Adjuvant chemotherapy has been attempted for BTC, but has only had a 75% completion rate. Body weight loss and cholangitis are reasons for the interruption of chemotherapy. Previous reports suggested that nutritional intervention with omega-3 fatty acids maintained body weight and improved the completion rate for chemotherapy. Moreover, omega-3 fatty acids have an anti-inflammatory effect. Therefore, we theorised that omega-3 fatty acids would improve the completion rate of adjuvant chemotherapy in patients with BTC. The aim of this study is thus to evaluate the effectiveness of omega-3 fatty acids for patients planning adjuvant chemotherapy for BTC.Method and analysisThis study is a single-centre, open-label, single-arm, historically controlled study with a planned enrolment of 55 participants. Protocol treatment consists of four courses of S-1 adjuvant chemotherapy and an oral omega-3 fatty acid pharmaceutic adjuvant (LOTRIGA 2 g (Takeda Pharmaceutical Co.)), which includes 2 g of omega-3 fatty acids from day 1 until day 168 of the treatment period. The primary endpoint is the completion rate of four total courses of S-1. Secondary endpoints are postoperative cholangitis, time to recurrence or distant metastasis, changes in nutritional index, changes in the lymphocyte blast transformation test induced by phytohaemagglutinin, and concanavalin A and diamine oxidase serum activity during adjuvant chemotherapy. All adverse events will be evaluated.Ethics and disseminationThis protocol was approved by the Institutional Review Board of Kobe University Hospital. The findings from this study will be presented at national and international conferences and published in peer-reviewed journals.Trial registration numberUMIN000031247.

IntroductionIn-vivo fluorescence imaging techniques using indocyanine green (ICG) to identify liver tumours and hepatic segment boundaries have been recently developed. The purpose of this study is to evaluate the efficacy of fusion ICG-fluorescence imaging for navigation during hepatectomy.Methods and analysisThis will be an exploratory single-arm clinical trial; patients with liver tumours will undergo hepatectomy using the ICG-fluorescence imaging system. In total, 110 patients with liver tumours scheduled for elective hepatectomy will be included in this study. Preoperatively, ICG will be intravenously injected at a dose of 0.5 mg/kg body weight within 2 days. To detect liver tumours intraoperatively, the hepatic surface will be initially observed using the ICG-fluorescence imaging system. After identifying and clamping the portal pedicle corresponding to the hepatic segments, including the liver tumours to be resected, additional ICG will be injected intravenously at a dose of 0.5 mg/kg body weight to identify the boundaries of the hepatic segments. The primary outcome measure will be the success or failure of the ICG-fluorescence imaging system in identifying hepatic segments. The secondary outcomes will be the success or failure in identifying liver tumours, liver function indicators, operative time, blood loss, rate of postoperative complications and recurrence-free survival. The findings obtained through this study are expected to help to establish the utility of ICG-fluorescence imaging systems, and therefore contribute to prognostic outcome improvements in patients undergoing hepatectomy for various causes.Ethics and disseminationThe protocol has been approved by the Kobe University Clinical Research Ethical Committee. The findings of this study will be disseminated widely through peer-reviewed publications and conference presentations.Trial registration numberUMIN000031054 and jRCT1051180070

Pregenomic RNA (pgRNA) is generated from covalently closed circular DNA (cccDNA) and plays important roles in viral genome amplification and replication. Hepatic pgRNA and cccDNA expression levels indicate viral persistence and replication activity. This study was aimed to measure hepatic pgRNA and cccDNA expression levels in various states of hepatitis B virus (HBV) infection. Thirty-eight hepatocellular carcinoma (HCC) patients, including 14 positive for hepatitis B surface antigen (HBsAg) and 24 negative for HBsAg but positive for anti-hepatitis B core (anti-HBc) antibody, were enrolled in this study. In HBsAg-negative but anti-HBc-positive group, HBV-DNA was detected in 20 of 24 (83%) noncancerous liver tissues for at least two genomic regions based on polymerase chain reaction (PCR) analysis. pgRNA and cccDNA expression levels in occult HBV-infected patients were significantly lower than those in HBsAg-positive patients (P