The efficacy and safety of (125)I seeds combined with biliary stent placement versus stent placement alone for malignant biliary obstruction: a systematic review and meta-analysis

BACKGROUND: Currently, it is unknown whether iodine-125 ((125)I) stent implantation has the same therapeutic effect on patients with malignant biliary obstruction (MBO) caused by different cancers. This meta-analysis aimed to investigate whether (125)I implantation in patients with MBO is superior to biliary stent placement in efficacy and safety, and to further explore the difference in efficacy and safety of seed implantation in different patients through subgroup analysis. METHODS: A systematic search of the PubMed, Wiley Online Library, Cochrane library, Google Scholar, the Web of Science, China National Knowledge Infrastructure (CNKI), VIP, and Wanfang databases was conducted to screen all relevant studies up to October 30, 2022. Articles were not subjected to language or geographical limitations, but were required to meet the inclusion and exclusion criteria for this study. The Newcastle-Ottawa Scale (NOS) was used to evaluate the quality of articles. The primary endpoint was survival, which was defined as the interval between initial treatment and death or the end of study. Meta analysis was performed using Stata/SE15.0. RESULTS: A total of 12 eligible studies were enrolled including 679 patients. All the included studies were single-center studies carried out in China. The results showed that the death risk and stent occlusion risk in the (125)I group was 0.441 times [95% confidence interval (CI): 0.315 to 0.619, P<0.001; I(2)=0%, fixed, IV] and 0.534 times (95% CI: 0.433 to 0.658, P=0.003; I(2)=45.4%, fixed, IV) lower than the control group, respectively. There was no significant statistical difference in the risk of complications between the 2 groups [risk ratio (RR) =1.024, 95% CI: 0.963 to 1.090, P=0.450; P(Q)=0.640; I(2)=0%]. The reduction level of total bilirubin [TBIL; weighted mean differences (WMDs) =−14.969, 95% CI: −28.670 to −1.267, P=0.032; P(Q)=0.409, I(2)=2.1%) and aspartate transaminase (AST; WMD =−14.653, 95% CI: −23.246 to −6.060, P=0.001; P(Q)=0.900, I(2)=0%) in the (125)I group was higher than that in the control group 1 week after surgery. The efficacy and safety of (125)I for MBO patients were found to be independent of the type of tumor causing MBO (P for meta regression >0.05). CONCLUSIONS: For patients with MBO caused by hilar tumor or other tumors, (125)I seed implantation can reduce the death risk and stent occlusion risk, prolong the time of survival and stent patency, and does not increase the complication risk. Due to the limitations of the study population, these findings should be further validated in other populations and regions.