Intraluminal implantation of radioactive stents for treatment of primary carcinomas of the peripancreatic-head region: a pilot study

Therapeutic biliary stents: applications and opportunities

INTRODUCTION

Biliary stents are used to optimize ductal patency and enable bile flow in the management of obstruction or injury related to biliary tract tumors, strictures, stones, or leaks. Although direct therapeutic applications of biliary stents are less well developed, stents can be used to deliver drugs, radioisotopes, and photodynamic therapy.

AREAS COVERED

This report provides an in-depth overview of the clinical indications, and therapeutic utility of biliary stents. Unique considerations for the design of biliary stents are described. The properties and functionalities of materials used for stents such as metal alloys, plastic polymers, or biodegradable materials are described, and opportunities for design of future stents are outlined. Current and potential applications of stents for therapeutic applications for biliary tract diseases are described.

EXPERT OPINION

Therapeutic biliary stents could be used to minimize inflammation, prevent stricture formation, reduce infections, or provide localized anti-cancer therapy for biliary tract cancers. Stents could be transformed into therapeutic platforms using advanced materials, 3D printing, nanotechnology, and artificial intelligence. Whilst clinical study and validation will be required for adoption, future advances in stent design and materials are expected to expand the use of therapeutic biliary stents for the treatment of biliary tract disorders.

Biliary drainage combined with simultaneous 125I seed strand brachytherapy for the treatment of hilar cholangiocarcinoma

BACKGROUND

To evaluate the clinical efficacy of percutaneous biliary drainage (PBD) combined with ¹²⁵I seed strand brachytherapy (ISSB) for the treatment of hilar cholangiocarcinoma (HCCA).

METHODS

The clinical data of 64 patients with HCCA (median age 62.5, male 29, female 35) treated in our department from April 2017 to April 2021 were retrospectively analyzed. Thirty-four patients in the experimental group (EG) were treated with PBD combined with ISSB, while 30 patients in the control group (CG) were treated with PBD alone. The primary study endpoints were technical success, clinical success and the 2-month local tumor control (LTC) rate. Secondary endpoints were early/late complications, median progression-free survival (mPFS) and overall survival (mOS).

RESULTS

The technical and clinical success in the EG and CG showed no significant differences (100 vs. 100%, 94.1 vs. 93.3%, P > 0.05). Both early and late complications showed no significant differences between the two groups (P > 0.05). The 2-month LTC rates were significantly better in the EG versus the CG (94.1% vs. 26.7%, 157.7 ± 115.3 vs. 478.1 ± 235.3 U/ml), respectively (P < 0.05). The mPFS and mOS were 4.3 (95% CI 3.9-4.7) months and 2.8 (95% CI 2.5-3.1) months and 13.5 (95% CI 10.7-16.3) months and 8.8 (95% CI 7.8-9.8) months, respectively, with significant differences (P < 0.05).

CONCLUSION

PBD combined with ISSB is a safe and effective treatment for HCCA that can inhibit local tumors and prolong PFS and OS.

Pancreatic duct stents

Pancreatic duct stenting using endoscopy or surgery is widely used for the management of benign and malignant pancreatic diseases. Endoscopic pancreatic stents are mainly used to relieve pain caused by chronic pancreatitis and pancreas divisum, and to treat pancreatic duct disruption and stenotic pancreaticointestinal anastomosis after surgery. They are also used to prevent postendoscopic retrograde cholangiopancreatography pancreatitis and postoperative pancreatic fistula, treat pancreatic cancer, and locate radiolucent stones. Recent advances in endoscopic techniques, such as endoscopic ultrasonography and balloon enteroscopy, and newly designed stents have broadened the indications for pancreatic duct stenting. In this review we outlined the types, insertion procedures, efficacy, and complications of endoscopic pancreatic duct stent placement, and summarized the applications of pancreatic duct stents in surgery.

Brachytherapy Drainage Catheter and Chemotherapy for Unresectable Pancreatic Carcinoma Combined with Obstructive Jaundice

Background

Most patients with advanced pancreatic cancer do not have the chance to undergo surgery or chemotherapy because of their poor conditions. Biliary drainage is a palliative treatment to restore liver function and alleviate jaundice, but most patients still face the risk of biliary obstruction in the short term after operation. The purpose of this study is to evaluate the efficacy and safety of brachytherapy drainage catheter (BDC)-combined chemotherapy in the treatment of pancreatic cancer complicated with obstructive jaundice.

Patients and Methods

From November 2017 and May 2019, 48 patients underwent the BDC or conventional drainage catheter (CDC) intervention with chemotherapy. The outcomes/endpoints analyzed were technical and clinical success, early complications, stent patency period, and survival.

Results

The technical and clinical success rates in both groups were 100%, and the early complication rates were not significantly different (P = 0.43). The median stent patency in the BDC group was significantly longer than that in the CDC group (7.8 ± 1.5 vs. 5.7 ± 0.7 months, P = 0.001), and the median overall survival period in the BDC group was prone to significant difference than that in the CDC group (9.4 ± 4.0 vs. 8.2 ± 0.3 months, P = 0.089).

Conclusion

The findings of this study show that BDC with chemotherapy was associated with better stent patency and survival. However, since the sample size was very small, large randomized controlled multicenter studies are needed to further evaluate the long-term survival effects of BDC in patients with advanced pancreatic carcinoma combined with obstructive jaundice.

Endoscopic ultrasound role in pancreatic adenocarcinoma treatment: A review focusing on technical success, safety and efficacy

The impressive technological advances in recent years have rapidly translated into the shift of endoscopic ultrasound (EUS) from diagnostic modality into an interventional and therapeutic tool. Despite the great advance in its diagnosis, the majority of pancreatic adenocarcinoma cases are inoperable when diagnosed, thus demanding alternative optional therapies. EUS has emerged as an easy, minimally invasive modality targeting this carcinoma with different interventions that have been reported recently. In this review we summarize the evolving role of interventional therapeutic EUS in pancreatic adenocarcinoma management.

Preliminary application of brachytherapy with double-strand 125I seeds and biliary drainage for malignant obstructive jaundice

AIM

To evaluate the efficacy and safety of brachytherapy with double-strand ¹²⁵I seeds and biliary drainage for malignant obstructive jaundice.

METHODS AND MATERIALS

42 patients with obstructive jaundice because of extrahepatic cholangiocarcinoma were enrolled. 22 patients (group A) received a biliary stent with common drainage tube implantation, and 20 patients (group B) received a biliary stent with double-strand ¹²⁵I seeds radiotherapy drainage tube placement. The length, location and pathological stage of biliary stricture were recorded in the two groups. Total bilirubin (TBIL), direct bilirubin (DBIL), IgA, IgG, IgM, alanine aminotransferase and white blood cell (WBC) count were measured before and after percutaneous transhepatic cholangial drainage (PTCD). Tumor diameter was measured before and three months after PTCD, and the difference were calculated. Stent patency time, survival time, and complications were recorded.

RESULTS

There was no significant difference in the length, location and pathological stage of biliary stenosis between the two groups. There was no significant difference in TBIL, DBIL, IgA, IgG, IgM, alanine aminotransferase and WBC count between the two groups before or after PTCD (P > 0.05). Three months after PTCD, tumors growth in group A and tumors shrinkage in group B. The difference in tumor size between the two groups before and after PTCD was statistically significant (P < 0.05). The average stent patency times in groups A and B were 3.55 ± 0.76 months and 8.76 ± 1.85 months, respectively (P < 0.05). The average survival times in groups A and B were 133.5 ± 27.8 days and 252.5 ± 114.5 days, respectively (P < 0.05). There was no statistically significant difference in the incidence of complications between the two groups (P > 0.05).

CONCLUSION

Double-strand ¹²⁵I seeds radiotherapy biliary drainage tubes can safely and effectively control tumors, prolong the patency of biliary stents, and prolong patient survival.

Managing occluded stents in biliary obstruction using radiofrequency ablation combined with 125I-strand brachytherapy

PURPOSE

We aimed to assess the effectiveness of percutaneous radiofrequency ablation (PRFA) combined with iodine-125 (125I) seed strand brachytherapy (125I-BT) for treatment of occluded biliary stents.

METHODS

From November 2015 to September 2017, 13 consecutive patients with occluded biliary metal stents, implanted for malignant obstruction, underwent PRFA combined with 125I-BT to reopen the bile duct. Data included clinical and technical success, stent patency, complications, and overall survival.

RESULTS

The clinical and technical success rates were both 100%. One month after treatment, the total serum bilirubin level had decreased significantly (P < 0.001). Early complications of cholangitis or hemobilia were experienced by one patient each. Three patients (23.1%) had late complications, including two cases of cholangitis and one case of cholecystitis. During the mean follow-up of 233±82.9 days (range, 88-365 days), the stent patency time was 239±26.5 days (95% CI, 187-291 days), and the 6-month stent patency rate was 68.4%. Five patents died; the mean survival time was 298±30.1 days (95% CI, 239-358 days). The 6-month survival rate was 83%.

CONCLUSION

PRFA therapy combined with 125I-BT is feasible and safe for patients with occluded metal stents placed for malignant biliary obstruction. Nevertheless, randomized controlled trails are needed to confirm the effectiveness of this new approach.

Iodine-125 Seeds Combined With Biliary Stent Placement Versus Stent Placement Alone For Unresectable Malignant Biliary Obstruction: A Meta-Analysis Of Randomized Controlled Trials

Background and Aims: Malignant biliary obstruction is always caused by tumors which are unresectable so that palliative stent placement is conducted for drainage of bile duct tree. Recently, irradiation stent with 125I seeds has been used to improve the stent patency and survival time of patients. We conducted this meta-analysis to evaluate the therapeutic efficacy and safety of biliary stent placement with 125I seeds compared with stent placement alone in patients with malignant biliary obstruction. Methods: We searched Pubmed, Web of Science, ClinicalTrials.gov, Cochrane Library, Embase and CNKI databases for all relevant studies up to 1 May 2020. Patient survival, stent patency, and adverse events were the primary outcome measured. Also, Review Manager 5.3 and Stata/SE15.0 were used to perform the analysis. Results: Eleven randomized controlled trials with a total of 767 patients were included for meta-analysis. Stent combined with 125I seeds showed lower risk of stent occlusion at 3 month (Odds Ratios(OR) = 0.15; 95%CI: 0.05-0.49, P =0.002), 6 month (OR = 0.18; 95%CI: 0.08-0.44, P = 0.0001), 9 month (OR = 0.10; 95%CI: 0.05-0.20, P < 0.00001) and 1 year (OR = 0.15; 95%CI: 0.07-0.31, P < 0.00001) and better mean survival (MD = 125days; 95% CI 91-159 days; P < 0.00001) compared with stent placement alone. Also, reconstructed Kaplan-Meier data demonstrated improved survival in patients treated with stent plus 125I seeds (hazard ratio(HR)= 1.886; 95% CI: 1.609 to 2.210; P < 0.0001) Moreover, our analysis did not show significant difference between the two groups about the risk of adverse events including abdominal pain, hemobilia, pancreatitis, cholangitis and cholecystitis. Conclusion: 125I seeds combined with stent demonstrated superior stent patency and improved survival time compared to stent alone with acceptable complications.

Managing occluded stents in biliary obstruction using radiofrequency ablation combined with 125I-strand brachytherapy

PURPOSE

We aimed to assess the effectiveness of percutaneous radiofrequency ablation (PRFA) combined with iodine-125 (125I) seed strand brachytherapy (125I-BT) for treatment of occluded biliary stents.

METHODS

From November 2015 to September 2017, 13 consecutive patients with occluded biliary metal stents, implanted for malignant obstruction, underwent PRFA combined with 125I-BT to reopen the bile duct. Data included clinical and technical success, stent patency, complications, and overall survival.

RESULTS

The clinical and technical success rates were both 100%. One month after treatment, the total serum bilirubin level had decreased significantly (P < 0.001). Early complications of cholangitis or hemobilia were experienced by one patient each. Three patients (23.1%) had late complications, including two cases of cholangitis and one case of cholecystitis. During the mean follow-up of 233±82.9 days (range, 88-365 days), the stent patency time was 239±26.5 days (95% CI, 187-291 days), and the 6-month stent patency rate was 68.4%. Five patents died; the mean survival time was 298±30.1 days (95% CI, 239-358 days). The 6-month survival rate was 83%.

CONCLUSION

PRFA therapy combined with 125I-BT is feasible and safe for patients with occluded metal stents placed for malignant biliary obstruction. Nevertheless, randomized controlled trails are needed to confirm the effectiveness of this new approach.

An iodine-125 seed strand combined with a metal stent versus a metal stent alone for obstructive jaundice caused by pancreatic ductal adenocarcinoma

PURPOSE

The purpose of this study was to assess the efficacy of an iodine-125 (¹²⁵I) seed strand combined with a metal stent compared with a metal stent for treatment of obstructive jaundice caused by pancreatic ductal adenocarcinoma (PDAC).

METHODS AND MATERIALS

A retrospective analysis was carried out of patients who were referred to Shanghai Zhongshan Hospital of Fudan University with a diagnosis of PDAC between January 1, 2010 and January 31, 2019. A total of 110 consecutive patients with obstructive jaundice caused by PDAC were divided into the iodine-125 seed strand combined with a metal stent group (Group A = 48) and the metal stent group (Group B = 62). The primary outcome was stent obstruction-free survival time, and secondary outcomes were overall survival and complications.

RESULTS

The median stent obstruction-free survival time was 133.0 (95% confidence interval (CI): 166.093-149.907) days, and the median overall survival was 212.0 (95% CI: 187.183-236.817) days in all patients. Median stent obstruction-free survival time was 175 days (95% CI 103.165-246.835 days) in Group A versus 120 days (95% CI 87.475-152.525 days) in Group B (p = 0.035). A lower Eastern Cooperative Oncology Group (ECOG) score (p = 0. 000) and iodine-125 seed strand combined with metal stent implantation (p = 0.008) were associated with a longer stent obstruction-free survival time. Obstruction length (p = 0.083), ECOG score (p = 0.000), and iodine-125 seeds (p = 0.037) might have potential impact on stent obstruction-free survival time and were included for multivariable analysis using the Cox proportional hazards model. Stent restenosis was observed in 18.8% (9/48) of patients in Group A and 54.8% (34/62) in Group B, respectively. There was no significant difference in median survival between Group A and Group B (p = 0.409). The median survival in Group A was 209 days (95% CI 150.750-267.250) and 202 days (95% CI 190.624-233.376) in Group B. The median survival of patients with a lower ECOG score was better than that of patients with a higher ECOG score (267 days vs 132 days, p = 0.000). The Grade 3 or 4 complications occurred in 4 (8.3%) of the 48 patients in Group A (one case of hemobilia, one case of liver abscess, two cases of choleperitonitis) and in 5 (8.1%) of the 62 patients in Group B (one case of hemobilia, two cases of liver abscess, two cases of choleperitonitis) (p = 0.972).

CONCLUSIONS

Implantation of an iodine-125 seed strand combined with a metal stent provides longer obstruction-free survival time compared with a metal stent in patients with obstructive jaundice caused by PDAC. It seems reasonable to choose an iodine-125 seed strand combined with a metal stent as a treatment for these patients.

Biliary self-expandable metallic stent combined with Iodine-125 seeds strand in the treatment of hilar malignant biliary obstruction

Objective

To assess the safety and effectiveness of a self-expandable metallic stent (SEMS) combined with Iodine-125 seeds strand to treat hilar malignant biliary obstruction (MBO).

Methods

This retrospective study included patients who had received SEMS with ¹²⁵I seeds strand (seeds group) or SEMS alone (controls) to treat hilar MBO. Demographic, biochemical, stent patency, overall survival and complications data were extracted and analysed.

Results

A total of 76 patients were included (seeds group, n = 40; controls, n = 36), with a total of 608 seeds deployed in the seeds group (mean, 15.2 ± 4.1 [range, 8–25] seeds per patient). Statistically significant between-group differences were shown in median stent patency time (seeds group, 387.0 ± 27.9 days [95% confidence interval {CI} 332.4, 441.6] versus controls, 121.0 ± 9.1 days [95% CI 103.2, 138.8]) and in median overall survival (seeds group, 177.0 ± 17.9 days [95% CI 141.8, 212.2] versus controls, 123.0 ± 20.4 [95% CI 83.0, 163.0]). There were no statistically significant between-group differences in complication rates.

Conclusion

SEMS combined with ¹²⁵I seeds strand is safe, feasible, and tolerable in treating patients with hilar MBO, and may be effective in prolonging stent patency time and overall survival.

Neoadjuvant chemoradiotherapy followed by liver transplantation is a promising treatment for patients with unresectable hilar cholangiocarcinoma: A case report

Hilar cholangiocarcinoma is a highly malignant tumor and is currently treated by surgical resection or liver transplantation; however, these treatments result in poor patient prognosis accompanied with high recurrence and low patient mortality rates. Neoadjuvant therapy with liver transplantation is a novel treatment that exhibits promising clinical application, with a reported 5-year survival rate of 82%. However, transplantation centers conducting research into this treatment are limited due to its length and complexity. In the current study, the effects of brachytherapy and chemoradiotherapy followed by orthotopic liver transplantation (OLT) were investigated in a patient with unresectable hilar cholangiocarcinoma. Following treatment, the liver function of the patient normalized and physical status significantly improved. Furthermore, tomographic evaluation demonstrated no sign of recurrence 8 months later following continued adjunct chemotherapy. Therefore, neoadjuvant therapy followed by OLT may be an effective novel therapeutic strategy to treat patients with unresectable hilar cholangiocarcinoma.

In vitro Dosimetric Study of Biliary Stent Loaded with Radioactive 125I Seeds

Background:

A novel radioactive ¹²⁵I seed-loaded biliary stent has been used for patients with malignant biliary obstruction. However, the dosimetric characteristics of the stents remain unclear. Therefore, we aimed to describe the dosimetry of the stents of different lengths — with different number as well as activities of ¹²⁵I seeds.

Methods:

The radiation dosimetry of three representative radioactive stent models was evaluated using a treatment planning system (TPS), thermoluminescent dosimeter (TLD) measurements, and Monte Carlo (MC) simulations. In the process of TPS calculation and TLD measurement, two different water-equivalent phantoms were designed to obtain cumulative radial dose distribution. Calibration procedures using TLD in the designed phantom were also conducted. MC simulations were performed using the Monte Carlo N-Particle eXtended version 2.5 general purpose code to calculate the radioactive stent's three-dimensional dose rate distribution in liquid water. Analysis of covariance was used to examine the factors influencing radial dose distribution of the radioactive stent.

Results:

The maximum reduction in cumulative radial dose was 26% when the seed activity changed from 0.5 mCi to 0.4 mCi for the same length of radioactive stents. The TLD's dose response in the range of 0–10 mGy irradiation by ¹³⁷Cs γ-ray was linear: y = 182225x − 6651.9 (R²= 0.99152; y is the irradiation dose in mGy, x is the TLDs’ reading in nC). When TLDs were irradiated by different energy radiation sources to a dose of 1 mGy, reading of TLDs was different. Doses at a distance of 0.1 cm from the three stents’ surface simulated by MC were 79, 93, and 97 Gy.

Conclusions:

TPS calculation, TLD measurement, and MC simulation were performed and were found to be in good agreement. Although the whole experiment was conducted in water-equivalent phantom, data in our evaluation may provide a theoretical basis for dosimetry for the clinical application.

Preliminary clinical application of integrated 125I seeds stents in the therapy of malignant lower biliary tract obstruction

PURPOSE

To evaluate the clinical efficacy of percutaneous trans-hepatic integrated 125I seed stents implantation for malignant lower biliary tract obstruction.

METHODS

Thirty-two patients with malignant lower biliary obstruction were randomly divided into two groups. One group underwent the therapy with integrated 125I seed stents (Test group, n = 13), and another group received conventional metal stents implantation for treatment (Control group, n = 19). The pre- and post-operative changes in biochemical indices, white blood cell count, IgG level, stent patency, survival time, tumor size and complications were compared between the two groups. RECIST 1.1 (Response Evaluation Criteria In Solid Tumors) was used to evaluate therapeutic effects. The average follow-up time was 12.3 months.

RESULTS

The differences between pre- and post-operative (30 days) intragroup biochemical indices had statistically significant difference (P < 0.05), but there were no significant differences (P > 0.05) in leukocyte counts and IgG levels. As to the median time of stent patency and patients' survival, there were significant differences (P < 0.05) between Control and Test groups (3.9 months vs. 8.1 months, 139 days vs. 298 days, respectively). Three months after the operation, the average tumor size was reduced in the Test group, but was increased in the Control group (P < 0.05). There was no significant difference in the incidence of complications between the two groups. The evaluation results using RECIST 1.1 showed that there were statistically significant differences between the two groups in terms of the rates of remission, control, and progression (χ2 = 17.5, P < 0.05).

CONCLUSIONS

The study indicates that integrated 125I seed stents are effective in reducing jaundice symptoms, inhibiting tumor growth, improving stent patency and prolonging patient survival, which may serve as a safer and more feasible method in treating malignant lower biliary obstruction with minimal invasiveness.

Study of self-expandable metallic stent placement intraluminal 125I seed strands brachytherapy of malignant biliary obstruction

OBJECTIVE

To evaluate the safety and efficacy of self-expandable metallic stent placement combined with or without intraluminal ¹²⁵I seed strands brachytherapy in patients with malignant biliary obstruction.

METHODS

Participants were randomly assigned to receive treatment with a self-expandable metallic stent (SEMS) placement combined with intraluminal ¹²⁵I seed strands brachytherapy (brachytherapy group) or a SEMS without brachytherapy (control group). The outcomes were measured in terms of technical success, clinical success, stent patency, complications related to the procedure, and patient survival. A P value of less than 0.05 indicated a significant difference. Results There were no significant differences in technical and clinical success between brachytherapy and control group (100 vs. 100%-100 vs. 93.3%). During the median 273.4 ± 154.6 days follow-up time, the median stent patency time in the brachytherapy group was longer than those in the control group (368.0 ± 42.4 vs. 220.0 ± 34.8 days), and the duration of survival in the brachytherapy groups was higher than those in the control group (355.0 ± 71.5 vs. 209.0 ± 17.2 days). There were no significant differences in the complications between the two groups. Conclusions SEMS placement combined with intraluminal ¹²⁵I seed strands brachytherapy are feasible and effective for malignant biliary obstruction, and seems to prolong the stent patency and survival time.

Interventional Therapy for Pancreatic Cancer

BACKGROUND

Palliative therapy and primarily chemoradiotherapy are the mainstream treatments in patients with locally advanced or metastatic pancreatic cancer (PC). Conventional endoscopy and endoscopic ultrasound (EUS)-guided interventional therapy has emerged as an important procedure for PC management. In this review, the progress in conventional endoscopy and EUS for PC management is discussed.

SUMMARY

For local palliative therapy against PC, EUS-guided fine needle injection (FNI) could deliver different kinds of agents, such as radioactive seeds and fiducials. Although their feasibility and safety have been proven, the long-term efficiency of EUS-FNI is still not established. For pain, EUS-celiac plexus neurolysis (CPN) is effective. However, CPN can only relieve the pain to a limited degree, with short duration. Endoscopy-guided stent placement is the preferred strategy for biliary and duodenal obstruction. Plastic and metal stents are equally effective for the relief of obstructive jaundice. The functional times of metal stents are longer than those of a plastic stent.

KEY MESSAGE

For biliary obstruction, a metal stent is the first choice. The long-term efficiency of EUS-FNI still needs further study.

PRACTICAL IMPLICATIONS

Endoscopy and EUS-guided interventions have gradually become the mainstream method for local treatment of PC due to mini-invasiveness and real-time observation. PC is the second most common gastrointestinal malignancy and the sixth leading cause of cancer mortality in the United States, leading to about 4.0% of all cancer deaths [Siegel et al: CA Cancer J Clin 2014;64:9-29]. The only curative approach for patients with PC is surgical resection, but unfortunately 80-90% of patients have a surgically inoperable disease, with 53% having local metastases at the time of diagnosis [Weinberg et al: Oncology (Williston Park) 2015;29:809-820, 886]. Therefore, palliative therapy and primarily chemoradiotherapy are the mainstream of treatment in patients with locally advanced or metastatic PC. Although overall survival has improved from 6 to 8.5-11 months (some of them even survived for a year or more), the overall survival rate has not improved, and the 5-year survival is less than 4% [Weinberg et al: Oncology (Williston Park) 2015;29:809-820, 886; Greenlee et al: CA Cancer J Clin 2001;51:15-36; Zhang et al: Gastroenterol Res Pract 2016;2016:8962321]. Hence, it is crucial to develop more effective local treatment strategies for tumor tissue and symptom palliation. At present, endoscopy has gradually become the mainstream method for local treatment of gastrointestinal cancer due to mini-invasiveness and real-time observation. Conventional endoscopy can be used to manage the complication caused by PC, including endoscopic biliary stent placement for obstructive jaundice, and duodenal stent placement for duodenal obstruction. In addition, in those cases in whom obstructive jaundice failed to be relieved by endoscopic biliary stent placement, EUS-guided biliary drainage has emerged as an alternative procedure. Furthermore, antitumor agents can be delivered into tumor tissue or celiac plexus directly under interventional EUS guided to manage the tumor or the pain caused by the tumor. In this review, the progress in conventional endoscopy and EUS for PC management is discussed.

Novel Silicone-Coated 125I Seeds for the Treatment of Extrahepatic Cholangiocarcinoma

125I seeds coated with titanium are considered a safe and effective interstitial brachytherapy for tumors, while the cost of 125I seeds is a major problem for the patients implanting lots of seeds. The aim of this paper was to develop a novel silicone coating for 125I seeds with a lower cost. In order to show the radionuclide utilization ratio, the silicone was coated onto the seeds using the electro-spinning method and the radioactivity was evaluated, then the anti-tumor efficacy of silicone 125I seeds was compared with titanium 125I seeds. The seeds were divided into four groups: A (control), B (pure silicone), C (silicone 125I), D (titanium 125I) at 2 Gy or 4 Gy. Their anti-tumour activity and mechanism were assessed in vitro and in vivo using a human extrahepatic cholangiocarcinoma cell line FRH-0201 and tumor-bearing BALB/c nude mice. The silicone 125I seeds showed higher radioactivity; the rate of cell apoptosis in vitro and the histopathology in vivo demonstrated that the silicone 125I seeds shared similar anti-tumor efficacy with the titanium 125I seeds for the treatment of extrahepatic cholangiocarcinoma, while they have a much lower cost.

Damage to pig bile duct caused by intraluminal brachytherapy using a (125)I ribbon

BACKGROUND

Stent occlusion by tumor ingrowth or overgrowth is the main cause of jaundice recurrence after metal stent insertion in patients with malignant obstructive jaundice (MOJ). The application of intraluminal brachytherapy (ILBT) in patients with MOJ results in local control of malignant tumors, which prolong stent patency.

PURPOSE

To evaluate the safety of ILBT in pig bile ducts using ribbons of iodine-125 ((125)I) seeds.

MATERIAL AND METHODS

Sixteen healthy pigs were randomly assigned to four groups of four pigs each. A (125)I seed ribbon was implanted into the common bile duct of each animal through an incision in the duct wall, and was fixed by suturing. The four groups of animals were sacrificed at 15, 30, 60, and 120 days after ribbon implantation, respectively. Serum bilirubin concentrations, alanine aminotransferase concentrations, and white blood cell counts before and after implantation were compared within each group. Pathological changes to the bile duct wall were observed using a light microscope. Morphological changes in biliary epithelial cells and organelles were observed with electron microscopy.

RESULTS

(125)I ribbons were successfully implanted in all animals without surgery-related death. We found no significant difference in pre- and post-implant serum bilirubin, alanine aminotransferase, or white blood cell counts. Light and electron microscopy showed that the most severe bile duct damage occurred in the 15-day group, which exhibited necrosis and detachment of numerous epithelial cells, and infiltration of inflammatory cells. Repair and proliferation of the bile duct epithelium began 30 days after implantation and was nearly complete at 60 days.

CONCLUSION

This study demonstrated the safety of ILBT using a (125)I ribbon in the pig bile duct. (125)I seed ribbons may be used in the treatment of MOJ in humans.

A novel biliary stent loaded with (125)I seeds in patients with malignant biliary obstruction: preliminary results versus a conventional biliary stent

BACKGROUND & AIMS

Stenting is a palliative therapy method for relieving malignant biliary obstruction. The aim of this study was to evaluate the safety and effectiveness of an irradiation stent compared to a conventional biliary stent in patients with biliary obstruction caused by both primary and metastatic adenocarcinomas.

METHODS

Participants were randomly assigned to receive treatment with a biliary irradiation stent (irradiation stent group) or a conventional biliary stent (control group). After stent implantation, the outcomes were measured in terms of relief of obstructive jaundice, survival time, complications related to the procedure. A p value of less than 0.05 indicated a significant difference.

RESULTS

The stents were successfully placed in all the 23 patients. The obstructive jaundice was relieved in all patients except three in the control group. The median and mean overall survivals in the irradiation stent group were higher than those in the control group (7.40 months versus 2.50 months, 8.03 months versus 3.36 months, p=0.006). The patients with stent patent at 3, 6, and 12 months in the irradiation stent group were 11 (91.7%), 7 (58.3%), and 1 (8.3%), respectively. While in the control group, 4 (36.4%), 1 (9.1%), and 0 (0%), respectively. There were no significant differences in the complications related to stent insertion between the two groups.

CONCLUSIONS

This interim analysis shows that treatment with the biliary intraluminal irradiation stent in patients with biliary obstruction caused by adenocarcinomas appears safe and technically feasible, has benefits in relieving jaundice, and seems to extend survival when compared to a conventional biliary stent.

The use of ¹²⁵I seed strands for intraluminal brachytherapy of malignant obstructive jaundice

This study is sought to evaluate the feasibility and safety of using ¹²⁵I seed strands for intraluminal brachytherapy (ILBT) in the treatment of malignant obstructive jaundice (MOJ), and its clinical effect on stent patency. A total of 34 patients found to have MOJ were randomly assigned to an ILBT treatment group or a control group before biliary stent insertion. For the ILBT group, ¹²⁵I seed strands were implanted into the obstructive segment of the bile duct after stent insertion. For the control group, only the biliary stent was inserted. Alimentary and hematologic complications were examined for patients in the ILBT group. The stent patency of the two groups were compared. In the ILBT group, the number of ¹²⁵I seeds per strand varied from 6 to 16 (mean, 10.9), and were successfully implanted in 17 patients. Serum levels of bilirubin, alanine aminotransferase, granulocytes, and platelets assayed 2 and 4 weeks following the procedure demonstrated no significant difference between the ILBT group and the control group. The mean stent patency for ILBT group (10.2 months) was significantly longer than that of the control group (7.2 months, p=0.032). ¹²⁵I seed strands for ILBT is a feasible and safe palliative therapy for the treatment of MOJ, and may prolong stent patency.

Endoscope-assisted brachytherapy for pancreatic cancer: From tumor killing to pain relief and drainage

Locally advanced or metastatic pancreatic cancer has been a long-term challenge to clinicians, due to the poor overall survival rate compared with that of other gastrointestinal malignancies. Recently, with the emerging applications of therapeutic endoscopic ultrasonography (EUS), EUS- guided fine needle injection with antitumor agents is considered a promising modality. In this review, we summarize recently published data on the efficacy of endoscope guided interventional procedures with radioactive seeds. Firstly, EUS-guided iodine-125 seed implantation was reported to have a short-term efficacy on pancreatic cancer, with a three-month partial remission rate of 13.6% to 27%. Thereafter, feasibility of celiac ganglion radiation was tested in animal models to achieve pain relief. Recently, a seed-based stent has been introduced in the endoscopic retrograde cholangio-pancreatography (ERCP) drainage of biliary obstruction caused by pancreatic cancer, with a response rate of 72.7%. In addition, we discuss the potential of radioactive seed-based, endoscope-assisted interventional treatment of patients with locally advanced pancreatic cancer. Further studies should focus on the precise amount and distribution of seeds with the aim to improve the survival rate as well as the quality of life.

Endoscopic biliary drainage by stent placement for carcinoma of the head of the pancreas with hepatic metastasis: a report of 16 cases

AIM: To evaluate the clinical significance of endoscopic biliary drainage by stent placement in the treatment of carcinoma of the head of the pancreas with hepatic metastasis.

METHODS: Sixteen patients with obstructive jaundice, who were diagnosed as carcinoma of the head of the pancreas with hepatic metastasis by imaging between May 2006 and December 2008, were included in the study. All patients underwent stent placement for endoscopic biliary drainage to cure obstructive jaundice.

RESULTS: Retroperitoneal lymph node metastasis was found in 5 patients. Of all patients, 12 underwent biliary drainage with expandable metallic biliary stents, 4 with plastic biliary stents, and 6 with pancreatic duct stents. Complete resolution of obstructive jaundice was achieved in all patients. Mental state, appetite and sleep were improved obviously in 75.0%, 25.0% and 37.5% of patients. The survival time was extended from 9 d to 134 d, with an average value of 81.4 d ± 50.2 d. The follow-up data showed that appreciable outcome and satisfactory outcome were achieved in 97% and 69% of patients, respectively.

CONCLUSION: Endoscopic biliary drainage by stent placement can not only cure completely obstructive jaundice but also improve survival quality in patients with carcinoma of the head of the pancreas with hepatic metastasis.