A novel approach for treatment of unresectable extrahepatic bile duct carcinoma: design of radioactive stents and an experimental trial in healthy pigs

A Functional Stent Encapsulating Radionuclide in Temperature-Memory Spiral Tubes for Malignant Stenosis of Esophageal Cancer

Stent implantation is a commonly used palliative treatment for alleviating stenosis in advanced esophageal cancer. However, tissue proliferation induced by stent implantation and continuous tumor growth can easily lead to restenosis. Therefore, functional stents are required to relieve stenosis while inhibiting tissue proliferation and tumor growth, thereby extending the patency. Currently, no ideal functional stents are available. Here, iodine-125 (125 I) nuclides are encapsulated into a nickel-titanium alloy (NiTi) tube to develop a novel temperature-memory spiral radionuclide stent (TSRS). It has the characteristics of temperature-memory, no cold regions at the end of the stent, and a uniform spatial dose distribution. Cell-viability experiments reveal that the TSRS can reduce the proliferation of fibroblasts and tumor cells. TSRS implantation is feasible and safe, has no significant systemic radiotoxicity, and can inhibit in-stent and edge stenosis caused by stent-induced tissue proliferation in healthy rabbits. Moreover, TSRS can improve malignant stenosis and luminal patency resulting from continuous tumor growth in a VX2 esophageal cancer model. As a functional stent, the TSRS combines the excellent properties of NiTi with brachytherapy of the 125 I nuclide and will make significant contributions to the treatment of malignant esophageal stenosis.

Endoscopic luminal stenting: Current applications and future perspectives

Endoscopic luminal stenting (ELS) represents a minimally invasive option for the management of malignant obstruction along the gastrointestinal tract. Previous studies have shown that ELS can provide rapid relief of symptoms related to esophageal, gastric, small intestinal, colorectal, biliary, and pancreatic neoplastic strictures without compromising cancer patients’ overall safety. As a result, in both palliative and neoadjuvant settings, ELS has largely surpassed radiotherapy and surgery as a first-line treatment modality. Following the abovementioned success, the indications for ELS have gradually expanded. To date, ELS is widely used in clinical practice by well-trained endoscopists in managing a wide variety of diseases and complications, such as relieving non-neoplastic obstructions, sealing iatrogenic and non-iatrogenic perforations, closing fistulae and treating post-sphincterotomy bleeding. The abovementioned development would not have been achieved without corresponding advances and innovations in stent technology. However, the technological landscape changes rapidly, making clinicians’ adaptation to new technologies a real challenge. In our mini-review article, by systematically reviewing the relevant literature, we discuss current developments in ELS with regard to stent design, accessories, techniques, and applications, expanding the research basis that was set by previous studies and highlighting areas that need to be further investigated.

125I seeds inhibit proliferation and promote apoptosis in cholangiocarcinoma cells by regulating the AGR2-mediated p38 MAPK pathway

¹²⁵I seeds can effectively inhibit the growth of a variety of cancer cells. It has been used in the treatment of a variety of cancers, and has achieved certain curative effect. However, to the best of our knowledge, no report has described the effects of ¹²⁵I seeds on the biological functions of cholangiocarcinoma (CCA) and the mechanisms underlying the effects of the seeds on this cancer. In this study, we demonstrated that ¹²⁵I seeds could inhibit the proliferation, migration and invasion of CCA cells, as well as promoting apoptosis and blocking the cell cycle in these cells. Moreover, ¹²⁵I seeds inhibited the growth of CCA xenografts and promoted the apoptosis of CCA cells in vivo. Furthermore, transcriptome sequencing showed that ¹²⁵I seeds could inhibit the growth of CCA by inhibiting the expression of AGR2 and regulating p38 MAPK pathway. Finally, this finding indicated that ¹²⁵I seeds can inhibit proliferation and promote apoptosis in CCA cells by inhibiting the expression of AGR2 and DUSP1 and increasing the expression of p-p38 MAPK and p-p53. This study provides a new research direction for studies investigating the mechanisms underlying the effects of ¹²⁵I seeds on CCA.

Novel brachytherapy drainage tube loaded with double 125I strands for hilar cholangiocarcinoma: A case report

BACKGROUND

Hilar cholangiocarcinoma (CC) is a common malignant tumor with high malignancy and poor prognosis. Most patients have lost the opportunity to undergo radical surgery when diagnosed. Although palliative drainage or biliary stent placement is a preferable choice, the tumor cannot be controlled. This study aimed to develop a novel brachytherapy drainage tube for low-dose-rate brachytherapy with an effective drainage, thereby prolonging the survival time of patients.

CASE SUMMARY

A 54-year-old male patient had undergone choledochal stent implantation due to obstructive jaundice. He was admitted to the hospital because of the recurrence of jaundice. Preoperative imaging and pathological biopsy revealed hilar CC (Bismuth-Corlette type IIIa). First, the patient underwent percutaneous transhepatic cholangial drainage and the symptoms of jaundice gradually relieved. To further treat hilar CC and remove the biliary drainage tube as far as possible, the patient chose to use the novel brachytherapy drainage tube after a multi-disciplinary consultation. After 1 mo of brachytherapy, the re-examination revealed that the obstructive lesions disappeared, and the drainage tube was finally removed. During the following 10 mo of follow-up, the patient's hilar CC did not recur.

CONCLUSION

The novel brachytherapy drainage tube may be a new choice for patients with unresectable hilar CC.

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.

Recent Advances in Gastrointestinal Stent Development

Endoscopic stenting is increasingly being used in the management of gastrointestinal luminal obstruction, and has become the current treatment of choice for the palliation of blockage caused by malignant or benign growths. A variety of stents have been developed to enhance the efficacy of the procedure, and improvements are ongoing. In this article, we review the history of, and recent advances in, gastrointestinal stenting. We describe the rationale behind the design as well as the resulting outcome for each stent type.

Recent Advances in Gastrointestinal Stent Development

Endoscopic stenting is increasingly being used in the management of gastrointestinal luminal obstruction, and has become the current treatment of choice for the palliation of blockage caused by malignant or benign growths. A variety of stents have been developed to enhance the efficacy of the procedure, and improvements are ongoing. In this article, we review the history of, and recent advances in, gastrointestinal stenting. We describe the rationale behind the design as well as the resulting outcome for each stent type.

Functional self-expandable metal stents in biliary obstruction

Biliary stents are widely used not only for palliative treatment of malignant biliary obstruction but also for benign biliary diseases. Each plastic stent or self-expandable metal stent (SEMS) has its own advantages, and a proper stent should be selected carefully for individual condition. To compensate and overcome several drawbacks of SEMS, functional self-expandable metal stent (FSEMS) has been developed with much progress so far. This article looks into the outcomes and defects of each stent type for benign biliary stricture and describes newly introduced FSEMSs according to their functional categories.

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.

Endoscopic palliation of pancreatic cancer

There is no doubt that our long-range goal is to cure pancreatic cancer. Realistically, most of what we can do currently is treat the disabling symptoms of this dreadful disease. Biliary decompression, intestinal stenting, celiac plexus neurolysis, and fiducial placement are some of the endoscopic procedures that aim to provide better quality of life to patients suffering from this disease. A thorough understanding of these options will help patients make good decisions in choosing the proper treatment. Endoscopists who perform these procedures must possess great skills, but importantly, they must also be compassionate and act with good judgment.

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.