Radioactive Self-Expanding Stents Give Superior Palliation in Patients With Unresectable Cancer of the Esophagus but Should Be Used With Caution if They Have Had Prior Radiotherapy

Esophageal Stenting: How I Do It

Endoscopic esophageal stent placement is an effective palliative treatment for malignant strictures and has also been successfully used for benign indications, including esophageal refractory strictures and iatrogenic leaks and perforations. Despite several decades of evolution and the wide variety of esophageal stents available to choose from, an ideal stent that is both effective and without adverse events such as stent migration, tissue ingrowth, or pressure necrosis has yet to be developed. This paper is an overview of how this evolution happened, and it also addresses the characteristics of some of the currently available stents, like their material and construction, delivery device, radial and axial force pattern, covering and size which may help to understand and avoid the occurrence of adverse events. The insertion delivery systems and techniques of placement of an esophageal self-expandable metal stent are reviewed, as well as some tips and tricks regarding placement and management of adverse events.

Comparison of the Therapeutic Effects of Iodine-125 Seed Implantation and Conventional Radiochemotherapy for Advanced Esophageal Cancer

BACKGROUND

The purpose of this study was to explore the feasibility, safety and efficacy of iodine-125 seed implantation in the treatment of dysphagia of advanced esophageal cancer.

METHODS

We retrospectively analyzed patients with advanced esophageal cancer who underwent EUS-guided iodine-125 seed implantation or conventional chemoradiotherapy in our hospital. The propensity score match was used to reduce the baseline differences.

RESULTS

A total of 127 patients were enrolled, 17 patients received EUS-guided iodine 125 seed implantation (Group A), 31 patients received radiotherapy (Group B), 38 patients received chemotherapy (Group C) and 41 patients received chemotherapy combined with radiotherapy (Group D). At half month postoperatively, the dysphagia remission rate in Group A (100%) was better than that in Groups B (39.3%), C (20%), D (15.8%), respectively, in the original cohort (P < 0.01); At 1 month postoperatively, the dysphagia remission rate in Group A (86.7%) was better than that in Group B (57.1%) (P > 0.05), Group C (25.7%) (P < 0.05) and Group D (34.2%) (P < 0.05), respectively, in the original cohort. There was no statistically significant difference in median overall survival (OS) between Group A (16 months) and Group B (37 months) (P = 0.149), and between Group A (16months) and Group C (16 months) (P = 0.918) in the original cohort. The mean OS of Group D (54 months) was better than that of Group A (20 months) in the original cohort (P = 0.031). The incidences of grade ≥2 myelosuppression in Groups B, C, and D were 12.9%, 28.9%, and 43.9%, respectively; the incidence of grade ≥2 gastrointestinal adverse events in Groups B, C, and D were 12.9%, 15.8%, 12.2%, respectively. No serious adverse events were found in Group A. The radiation dose around the patient was reduced to a safe range after the distance from the implantation site was more than 1 m (4.2 ± 2.6 μSv/h) or with lead clothing (0.1 ± 0.07 μSv/h).

CONCLUSIONS

Compared with conventional radiotherapy or chemotherapy alone, iodine-125 seed implantation might improve dysphagia more quickly and safely, further clinical data is needed to verify whether it could effectively prolong the OS of patients.

Dosimetric Evaluation and Clinical Application of Radioactive Iodine-125 Brachytherapy Stent in the Treatment of Malignant Esophageal Obstruction

Objective

To evaluate the dosimetric characteristics and the clinical application of radioactive iodine-125 brachytherapy stent (RIBS) in malignant esophageal obstruction.

Methods

The dose distribution of RIBS with different seed spacing, diameter and length was studied by treatment planning system (TPS) calculation, thermoluminescence dosimeter (TLD) measurement and Monte Carlo (MC) data fitting. And the data of esophageal cancer patients who were treat with this type of RIBS was analyzed retrospectively.

Results

Doses around the RIBS calculated by the TPS lay between those measured by the TLDs and those simulated by the MC, and the differences between the three methods were significant (p&lt;0.05), the overall absolute dose differences among the three methods were small. Dose coverage at 1.5 cm from the center was comprehensive when the activity reached 0.6 mCi. Both the conformability and the uniformity of isodose lines produced by a seed spacing of 1.0 cm were superior to those produced by a seed spacing of 1.5 cm. The data of 50 patients treated with RIBS was analyzed. They were followed up until February 2020 when all of the patients died. The overall improvement rate of dysphagia after RIBS implant was 90%. Moderate and severe complications with an incidence of more than 10% were hematemesis (28%), pain (20%), and lung infection (10%). Stent restenosis occurred in 4 patients at a median interval of 108 days from the procedure. The overall incidence of fatal complications was 38% (including hematemesis, infection and asphyxia). The median survival time of patients with and without a history of radiotherapy were 3.4 months and 6 months, respectively, the difference of which was significant (p=0.021). No other factors affecting survival were identified. For patients with and without a history of radiotherapy, the incidences of fatal complications were 51.7% and 19%, respectively (p=0.019). No correlation between dose and stent restenosis was found.

Conclusion

TPS calculations are suitable for clinical applications. RIBS can effectively alleviate obstructive symptoms for patients with malignant esophageal obstruction, but the incidence of fatal complications was high, care should be taken when choosing this treatment.

Futuristic Developments and Applications in Endoluminal Stenting

Endoscopic stenting is a well-established option for the treatment of malignant obstruction, temporary management of benign strictures, and sealing transmural defects, as well as drainage of pancreatic fluid collections and biliary obstruction. In recent years, in addition to expansion in indications for endoscopic stenting, considerable strides have been made in stent technology, and several types of devices with advanced designs and materials are continuously being developed. In this review, we discuss the important developments in stent designs and novel indications for endoluminal and transluminal stenting. Our discussion specifically focuses on (i) biodegradable as well as (ii) irradiating and drug-eluting stents for esophageal, gastroduodenal, biliary, and colonic indications, (iii) endoscopic stenting in inflammatory bowel disease, and (iv) lumen-apposing metal stent.

I-125 seed-loaded versus normal stent insertion for obstructive esophageal cancer: a meta-analysis

Introduction

Malignant esophageal obstruction is usually caused by esophageal and other chest cancers. More than 80% of cases of obstructive esophageal cancer (OEC) have lost the chance of curative resection. Stent insertion is a first-line palliative approach used to treat incurable OEC.

Aim

To gauge the relative clinical efficacy of I-125 seed-loaded stent (ISS) versus normal stent (NS) insertion as a treatment for OEC.

Material and methods

Querying of the PubMed, Embase, and Cochrane Library databases was conducted to find all relevant studies published up to November 2020. The meta-analysis was undertaken using RevMan v5.3.

Results

We identified 158 studies initially, eight (4 randomized controlled trials and 4 retrospective studies) of which were used in this meta-analysis. We found that the two groups exhibited the comparable pooled Δdysphagia scores (MD = 0.02; p = 0.80), stent restenosis rates (OR = 0.97; p = 0.89), stent migration rates (OR = 0.81; p = 0.63), severe chest pain rates (OR = 1.05; p = 0.81), hemorrhage rates (OR = 1.53; p = 0.16), aspiration pneumonia rates (OR = 0.72; p = 0.38), and fistula formation rates (OR = 1.47; p = 0.44). The pooled time-to-restenosis and survival were both significantly longer in the ISS group (p = 0.04 and < 0.0001, respectively). Significant heterogeneity was detected in the endpoints of Δdysphagia scores and survival (I² = 73% and 86%, respectively). Funnel plot analysis indicated an absence of publication bias related to the selected study endpoints.

Conclusions

For patients with OEC, our meta-analysis indicated that ISS insertion could provide longer stent patency and survival than NS insertion.

Characterization of Partially Covered Self-Expandable Metallic Stents for Esophageal Cancer Treatment: In Vivo Degradation

Partially covered self-expandable metallic esophageal stent (SEMS) placement is the most frequently applied palliative treatment in esophageal cancer. Structural characterization of explanted 16 nitinol-polyurethane SEMS (the group of 6 females, 10 males, age 40-80) was performed after their removal due to dysfunction. The adverse bulk changes in the polymer structure were identified using differential scanning calorimetry (DSC), differential mechanical thermal analysis (DMTA), and attenuated total reflectance infrared spectroscopy (ATR-IR) and discussed in terms of melting point shift (9 °C), glass-transition shift (4 °C), differences in viscoelastic behavior, and systematic decrease of peaks intensities corresponding to C-H, C═O, and C-N polyurethane structural bonds. The scanning electron and confocal microscopic observations revealed all major types of surface degradation, i.e., surface cracks, peeling off of the polymer material, and surface etching. The changes in the hydrophobic polyurethane surfaces were also revealed by a significant decrease in wettability (74°) and the corresponding increase of the surface free energy (31 mJ/m²). To understand the in vivo degradation, the in vitro tests in simulated salivary and gastric fluids were performed, which mimic the environments of proximal and distal ends, respectively. It was concluded that the differences in the degradation of the proximal and distal ends of prostheses strongly depend on the physiological environment, in particular stomach content. Finally, the necessity of the in vivo tests for SEMS degradation is pointed out.

Meta-analysis of efficacy and complications of intraluminal radioactive stent and common covered stent in treatment of advanced esophageal cancer

BACKGROUND

The main symptom of advanced esophageal cancer is dysphagia. Because there is no indication for surgery, in order to improve the patient's symptoms and quality of life, esophageal stent therapy has become the main palliative treatment. Based on the results of many studies, it can be speculated that intraluminal radioactive stent is better since it combines the function of ordinary stent and brachytherapy.

AIM

To evaluate the difference in the curative effect and complications between intraluminal radioactive stent (iodine 125 particle scaffold) and common covered stent in patients with mid-advanced esophageal cancer.

METHODS

A computer search of the electronic databases PubMed (1989/2020-03), Web of Science (2000/2020-03), Wiley Online Library (1992/2020-03), CNKI database (1978/2020-03), Wanfang database (1997/2020-03), and VIP database (2000/2020-03) and a manual search of Cochrance library were performed to retrieve articles using the method recommended by the Cochrance System Evaluator's Manual (version 4.2.2). The Oxford's 2011 evidence level assessment was used to evaluate the quality of the included articles, and Meta-analysis was performed using Revman 5.3 software.

RESULTS

Ten articles were finally included, with a total of 943 patients involved. Among the patients, 449 were implanted with an intraluminal radioactive stent and 494 were implanted with a common covered stent. A meta-analysis of 10 articles showed that the average survival time of the intraluminal radioactive stent group was 3.91 mo longer than that of the common covered stent group (95%CI: 1.68-6.13, Z = 3.44, P = 0.0006), and the median survival time was 3.12 mo longer 95%CI: 1.78-4.47, Z = 4.57, P = 0.0001). The dysphagia scores of the two groups of patients were significantly reduced within 1 and 3 mo after the stent was placed (P < 0.05), but there was no statistical difference between the two groups (P > 0.05). After stenting, there was no statistically significant difference in the incidence of pain (odds ratio [OR] = 0.89, 95%CI: 0.65-1.21, Z = 0.77, P = 0.44), bleeding (OR = 0.80, 95%CI: 0.52-1.22, Z = 1.03, P = 0.30), perforation (OR = 1.16, 95%CI: 0.55-2.43, Z = 0.39, P = 0.70), or stent displacement (R = 0.66, 95%CI: 0.31-1.38, Z = 1.10, P = 0.27) between the intraluminal radioactive stent group and the common covered stent group; but there was a statistical difference in the incidence of restenosis [OR = 0.61 , 95%CI (0.42-0.87), Z = 3.73 P = 0.006] between them.

CONCLUSION

The use of intraluminal radioactive stent in the treatment of advanced esophageal cancer can prolong the average survival time and median survival time of patients, and signficantly reduce the incidence of restenosis after surgery; however, the two types of stents have no significant difference in relieving the symptoms of dysphagia within 1-3 mo or in reducing postoperative complications such as pain, hemorrhage, perforation, and stent displacement.

Factors associated with overall survival and relief of dysphagia in advanced esophageal cancer patients after 125I seed-loaded stent placement: a multicenter retrospective analysis

Iodine-125 (125I) seed-loaded stent placement has served as an effective palliation for malignant esophageal strictures in China. We performed a retrospective study to identify the prognostic factors of this irradiation stent placement in advanced esophageal cancer patients. A total of 201 patients who underwent 125I seed-loaded stent placement were included in this study from June 2012 to March 2016 at five hospitals in China. The Cox regression models adjusted for stratification factors were used, and a stepwise multivariate analysis was performed to predict the overall survival and relief of dysphagia on the basis of pretreatment clinical characteristics, respectively. Three independent prognostic factors were identified for overall survival: histopathological subtype (squamous cell carcinoma vs. adenocarcinoma, hazard ratio [HR] 1.45, 95% confidence interval [CI95%]: 1.01-2.09, P = 0.046), serum total protein (≥66 g/L vs. <66 g/L, HR 0.61, CI95%: 0.48-0.59, P = 0.023), and performance status (<2 vs. ≥2, HR 1.57, CI95%: 1.09-2.08, P = 0.013). Four factors were significantly associated with the relief of dysphagia: T stage (T3 vs. T4, P = 0.003), tumor location (superior vs. inferior, P = 0.049), tumor-node-metastasis classification (IV vs. II, P = 0.025), and age (≥71 years vs. <71 years, P = 0.029). Prognostic factors identified from this analysis can be used to aid clinical decision-making and design future clinical trials.

Radioactive self-expanding stents for palliative management of unresectable esophageal cancer: a systematic review and meta-analysis

Stent insertion is a feasible and safe palliative management for advanced unresectable esophageal cancer. The aim of this study is to assess the efficacy of radioactive stent for unresectable esophageal cancer compared with conventional stent. Systematic searches of the PubMed and Web of science are dated from their beginning to January 25, 2016. Studies that compared radioactive stent with conventional stent for unresectable esophageal cancer were included. The outcomes were postimplantation survival, relief of dysphagia, and complications related to stent implant. Six studies with 539 patients were included. All of them used stent equipped with radioactive iodine beads as a radioactive stent. The pooled weighted mean difference for median survival was 2.734 months (95% CI 1.710-3.775; Z = 5.21, P = 0.000) between two groups. The 1,3,6 month survival rates were higher in radioactive stents than conventional stent, with the pooled ORs 3.216 (95% CI 1.293-7.999; Z = 2.51, P = 0.012), 3.095 (95% CI 1.908-5.020; Z = 4.58, P = 0.000), and 7.503 (95% CI 2.206- 25.516; Z = 3.23, P = 0.001, respectively). The pooled hazard ratio was 0.464 (95% CI 0.328-0.655; Z = 4.35, P = 0.000) between two groups. For relief of dysphagia, two stents all have good relief of the dysphagia effect, but radioactive stent showed a better effect at 3, 6 months follow-up after implantation. For complications related to stent implant, no significant differences were found between two stents in terms of severe chest pain (30.0% vs. 35.7%, OR 0.765, 95% CI 0.490-1.196), gastroesophageal reflux (18.6% vs. 16.1%, OR 1.188, 95% CI 0.453-3.115), fever (12.1% vs. 12.1%, OR 1.014, 95% CI 0.332-3.097), bleeding (16.7% vs. 14.2%, OR 1.201, 95% CI 0.645-2.236), perforation or fistula (6.1% vs. 9.0%, OR 0.658, 95% CI 0.291-1.486), pneumonia (10.7% vs. 14.1%, OR 0.724, 95% CI 0.343-1.526), stent migration (7.0% vs. 10.2%, OR 0.651, 95% CI 0.220-1.924), and restenosis (24.2% vs. 20.6%, OR 1.228, 95% CI 0.674-2.239). Radioactive stent insertion had potential benefits for palliative management for patients with unresectable esophageal cancer. This method prolonged survival and dysphagia relief period without more complications. However, this conclusion should be confirmed by more trials.

History of the Use of Esophageal Stent in Management of Dysphagia and Its Improvement Over the Years

The art and science of using stents to treat dysphagia and seal fistula, leaks and perforations has been evolving. Lessons learnt from the deficiencies of previous models led to several improvements making stent deployment easier, and with some designs, it was also possible to remove the stents if needed. With these improvements, besides malignant dysphagia, newer indications for using stents emerged. Unfortunately, despite several decades of evolution, as yet, there is no perfect stent that "fits all." This article is an overview of how this evolution process happened and where we are currently with using stents to manage patients with dysphagia and with other esophageal disorders.

The Mechanism of Computed Tomography-Guided 125I Particle in Treating Lung Cancer

Background

The incidence of malignant tumor has gradually increased. How to improve the survival and quality of life of patients who lose the opportunity for surgery or who are unwilling to receive surgery remains an obstacle. At present, ¹²⁵I particle interstitial implant therapy has been applied in a variety of treatments of tumors. However, the mechanism of computed tomography (CT)-guided ¹²⁵I particle therapy in lung cancer has not been fully elucidated.

Material/Methods

A total of 42 patients with advanced non-small cell lung cancer were retrospectively analyzed between January 2013 and December 2013, including 19 patients who received CT-guided ¹²⁵I particle therapy and 23 patients who received chemotherapy. Curative effect and adverse reactions at 6 months and 12 months were compared and analyzed. A rabbit lung cancer VX2 model was treated by ¹²⁵I particle implantation therapy under CT guidance. The change in tumor volume was detected. Tumor cell apoptosis was tested by flow cytometry. Bcl-2 and Bax expression were determined by real-time polymerase chain reaction (PCR) and Western blot.

Results

¹²⁵I particle therapy obviously reduced tumor volume after 6 months and 12 months. It showed significantly higher efficiency (57.9%, 57.9%) and control (78.9%, 73.7%) than the rates of efficiency and control in the chemotherapy group (P<0.05). ¹²⁵I particle implantation therapy markedly suppressed rabbit VX2 transplanted tumor cell proliferation, promoted tumor regression, induced tumor cell apoptosis, reduced Bcl-2 expression, and upregulated Bax expression level (P<0.05).

Conclusions

CT-guided ¹²⁵I particle implantation therapy can inhibit tumor proliferation and growth by regulating the expression of apoptosis-related genes and proteins, which is a promising approach in lung cancer treatment.

Brachytherapy for the palliation of dysphagia owing to esophageal cancer: A systematic review and meta-analysis of prospective studies

BACKGROUND

The management of dysphagia owing to esophageal cancer is challenging. Brachytherapy has been proposed as an alternative option to stent placement. We performed a systematic review to examine its efficacy and safety in the resolution of dysphagia.

METHODS

Prospective studies recruiting at least 20 patients with malignant dysphagia and published up to April 2016 were eligible. The dysphagia-free survival (DFS) and adverse event rates were pooled by means of a random effect model.

RESULTS

Six studies for a total of 9 treatment arms (623 patients) were eligible for inclusion. After 1month since treatment, the DFS rate was 86.9% [95%CI: 76.0-93.3%]; after 3months, it was 67.2% [95%CI: 56.1-76.7%]; after 6months, it was 47.4% [95%CI: 38.5-56.5%]; after 9months, it was 37.6% [95%CI:30.0-45.9%]; and, finally, after 12months, it was 29.4% [95%CI: 21.6-38.7%]. The heterogeneity between studies was high at 1-, 3- and 6-month assessment; the values of I² were 86.3%, 80.0% and 57.8%, respectively. The meta-regression analysis showed total radiation dose and number of fractions as the only positively influencing factors. Severe adverse event rate was 22.6% (95%CI 19.4-26.3). The main reported adverse events were brachytherapy-related stenosis (12.2%) and fistula development (8.3%). Two cases (0.3%) of deaths were reported due to esophageal perforation.

CONCLUSION

Brachytherapy is a highly effective and relatively safe treatment option therefore its underuse is no longer justified. Further studies should investigate the optimal radiation dose and number of fractions able to achieve the highest DFS rates.

The clinical research of the endoscopic sequential treatment for patients with intermediate-advanced esophageal cancer: a randomized clinical trial

We tried to find an ideal therapeutic regimen for patients with advanced esophageal cancer. Totally 240 patients with advanced esophageal cancer were randomly divided into experimental group (endoscopic sequential treatment, 126 cases) and control group (traditional treatment, 114 cases) with a 2-year follow-up period. The experimental group was randomly divided into three subgroups: group A: local chemotherapeutic drug injection with ordinary metal stent implantation; group B: local chemotherapeutic drug injection with iodine-125 particle implantation; and group C: radiofrequency (RF) therapy with ordinary metal stent group. The control group was also randomly divided into three subgroups: group D: local chemotherapeutic drug injection group; group E: RF therapy group; and group F: common metal stent implantation group. The survival rate, survival quality, adverse reactions, and complications were compared among these groups. A significant improvement of curative effect was found in the experimental group. Group A and B had higher survival rate and survival quality, and lower esophagotracheal fistula incidence and metastasis rate, compared with group C. There was no significant difference in survival rate between group A and group B, while the quality of life was higher in group B than in group A. While patients in group B had lower esophagotracheal fistula incidence and metastasis rate comparing with group A. Local chemotherapeutic drug injection combined with iodine-125 particle stent might be an effective sequential treatment to improve the life quality of advanced esophageal cancer patients.