BACKGROUND: Early evidence suggests that using radiofrequency ablation as an adjunct to standard care
(i.e. endoscopic retrograde cholangiopancreatography with stenting) may improve outcomes in patients
with malignant biliary obstruction. OBJECTIVES: To assess the clinical effectiveness, cost-effectiveness and potential risks of endoscopic
bipolar radiofrequency ablation for malignant biliary obstruction, and the value of future research. DATA SOURCES: Seven bibliographic databases, three websites and seven trials registers were searched
from 2008 until 21 January 2021. REVIEW METHODS: The study inclusion criteria were as follows: patients with biliary obstruction caused
by any form of unresectable malignancy; the intervention was reported as an endoscopic biliary
radiofrequency ablation to ablate malignant tissue that obstructs the bile or pancreatic ducts, either to
fit a stent (primary radiofrequency ablation) or to clear an obstructed stent (secondary radiofrequency
ablation); the primary outcomes were survival, quality of life or procedure-related adverse events; and
the study design was a controlled study, an observational study or a case report. Risk of bias was
assessed using Cochrane tools. The primary analysis was meta-analysis of the hazard ratio of mortality.
Subgroup analyses were planned according to the type of probe, the type of stent (i.e. metal or plastic)
and cancer type. A de novo Markov model was developed to model cost and quality-of-life outcomes
associated with radiofrequency ablation in patients with primary advanced bile duct cancer. Insufficient
data were available for pancreatic cancer and secondary bile duct cancer. An NHS and Personal Social
Services perspective was adopted for the analysis. A probabilistic analysis was conducted to estimate
the incremental cost-effectiveness ratio for radiofrequency ablation and the probability that
radiofrequency ablation was cost-effective at different thresholds. The population expected value of
perfect information was estimated in total and for the effectiveness parameters. RESULTS: Sixty-eight studies (1742 patients) were included in the systematic review. Four studies
(336 participants) were combined in a meta-analysis, which showed that the pooled hazard ratio for
mortality following primary radiofrequency ablation compared with a stent-only control was 0.34
(95% confidence interval 0.21 to 0.55). Little evidence relating to the impact on quality of life was found. There was no evidence to suggest an increased risk of cholangitis or pancreatitis, but radiofrequency
ablation may be associated with an increase in cholecystitis. The results of the cost-effectiveness analysis
were that the costs of radiofrequency ablation was £2659 and radiofrequency ablation produced
0.18 quality-adjusted life-years, which was more than no radiofrequency ablation on average. With an
incremental cost-effectiveness ratio of £14,392 per quality-adjusted life-year, radiofrequency ablation
was likely to be cost-effective at a threshold of £20,000 per quality-adjusted life-year across most
scenario analyses, with moderate uncertainty. The source of the vast majority of decision uncertainty
lay in the effect of radiofrequency ablation on stent patency. LIMITATIONS: Only 6 of 18 comparative studies contributed to the survival meta-analysis, and few data
were found concerning secondary radiofrequency ablation. The economic model and cost-effectiveness
meta-analysis required simplification because of data limitations. Inconsistencies in standard reporting
and study design were noted. CONCLUSIONS: Primary radiofrequency ablation increases survival and is likely to be cost-effective. The
evidence for the impact of secondary radiofrequency ablation on survival and of quality of life is limited.
There was a lack of robust clinical effectiveness data and, therefore, more information is needed for this
indication. FUTURE WORK: Future work investigating radiofrequency ablation must collect quality-of-life data. Highquality randomised controlled trials in secondary radiofrequency ablation are needed, with appropriate
outcomes recorded. STUDY REGISTRATION: This study is registered as PROSPERO CRD42020170233. FUNDING: This project was funded by the National Institute for Health and Care Research (NIHR)
Health Technology Assessment programme and will be published in full in Health Technology
Assessment; Vol. 27, No. 7. See the NIHR Journals Library website for further project information