Background Hepatocellular carcinoma is the most common type of primary liver cancer. Treatment choice is dependent on underlying liver dysfunction and cancer stage. Treatment options include conventional transarterial therapies for patients with intermediate-stage disease and systemic therapy [e.g. sorafenib (Nexavar®; Bayer plc, Leverkusen, Germany)] for patients with advanced-stage disease. Selective internal radiation therapies deliver radiation to liver tumours via microspheres that are injected into the hepatic artery. There are three selective internal radiation therapies: TheraSphere™ [BTG Ltd, London, UK (now Boston Scientific, Marlborough, MA, USA)], SIR-Spheres® (Sirtex Medical Ltd, Woburn, MA, USA) and QuiremSpheres® (Quirem Medical BV, Deventer, the Netherlands). Objective To assess the clinical effectiveness and cost-effectiveness of selective internal radiation therapies for treating patients with unresectable early-, intermediate- or advanced-stage hepatocellular carcinoma. Methods A search was undertaken to identify clinical effectiveness literature relating to selective internal radiation therapies and relevant comparators for the treatment of hepatocellular carcinoma. Studies were critically appraised and summarised. The network of evidence was mapped to estimate the relative effectiveness of the different selective internal radiation therapies and comparator treatments. An economic analysis evaluated the cost-effectiveness. Results Twenty studies were included in the clinical effectiveness review. Two large randomised controlled trials rated as having a low risk of bias [SARAH: Vilgrain V, Pereira H, Assenat E, Guiu B, Ilonca AD, Pageaux GP, et al. Efficacy and safety of selective internal radiotherapy with yttrium-90 resin microspheres compared with sorafenib in locally advanced and inoperable hepatocellular carcinoma (SARAH): an open-label randomised controlled Phase 3 trial. Lancet Oncol 2017;18:1624–36; and SIRveNIB: Chow PKH, Gandhi M, Tan SB, Khin MW, Khasbazar A, Ong J, et al. SIRveNIB: selective internal radiation therapy versus sorafenib in Asia-Pacific patients with hepatocellular carcinoma. J Clin Oncol 2018;36:1913–21] found no significant difference in overall survival or progression-free survival between SIR-Spheres and sorafenib (systemic therapy) in an advanced population, despite greater tumour response in the SIR-Spheres arm of both trials. There were some concerns regarding generalisability of the SARAH and SIRveNIB trials to UK practice. All other studies of SIR-Spheres, TheraSphere or QuiremSpheres were either rated as being at a high risk of bias or caused some concerns regarding bias. A network meta-analysis was conducted in adults with unresectable hepatocellular carcinoma who had Child–Pugh class A liver cirrhosis and were ineligible for conventional transarterial therapies. The analysis included the SARAH and SIRveNIB trials as well as a trial comparing lenvatinib (Kisplyx®; Eisai Ltd, Tokyo, Japan) (systemic therapy) with sorafenib. There were no meaningful differences in overall survival between any of the treatments. The base-case economic analysis suggested that TheraSphere may be cost-saving relative to both SIR-Spheres and QuiremSpheres. However, incremental cost differences between TheraSphere and SIR-Spheres were small. In a fully incremental analysis, which included confidential Patient Access Scheme discounts, lenvatinib was the most cost-effective treatment and dominated all selective internal radiation therapies. In pairwise comparisons of sorafenib with each selective internal radiation therapy, sorafenib also dominated all selective internal radiation therapies. Limitations The existing evidence cannot provide decision-makers with clear guidance on the comparative effectiveness of treatments in early- and intermediate-stage hepatocellular carcinoma or on the efficacy of TheraSphere or QuiremSpheres. Conclusions In the advanced-stage hepatocellular carcinoma population, two large randomised trials have shown that SIR-Spheres have similar clinical effectiveness to sorafenib. None of the selective internal radiation therapies was cost-effective, being more costly and less effective than lenvatinib, both at list price and with Patient Access Scheme discounts. Future work Future studies may wish to include early- and intermediate-stage hepatocellular carcinoma patients and the low tumour burden/albumin–bilirubin 1 subgroup of advanced-stage patients. Future high-quality studies evaluating alternative selective internal radiation therapies would be beneficial. Study registration This study is registered as PROSPERO CRD42019128383. Funding This project was funded by the National Institute for Health Research (NIHR) Health Technology Assessment programme and will be published in full in Health Technology Assessment; Vol. 24, No. 48. See the NIHR Journals Library website for further project information.

This study was funded by Pfizer, which determined the research topic and paid York Health Economics Consortium to develop the analysis and conduct the research. York Health Economics Consortium has received consultancy fees from Pfizer. Gerber, Wallenstein, Mendelsohn, Bourret, Singh, and Moynagh are employees and shareholders of Pfizer. Editorial support was funded by Pfizer and was provided by Claxton, Jenks, and Taylor, who are employees of York Health Economics Consortium. Study concept and design were contributed primarily by Taylor, Jenks, Gerber, and Singh, along with the other authors. Gerber, Moynagh, and Singh collected the data, assisted by Bouret and Mendelsohn; data interpretation was performed by Claxton, Gerber, Bouret, and Mendelsohn. The manuscript was written primarily by Claxton, with assistance from the other authors, and revised by Claxton, Gerber, Bouret, and Mendelsohn, with assistance from the other authors.

Combined stent-retriever neurothrombectomy and IV t-PA is a cost-effective treatment for acute ischemic stroke compared with IV t-PA alone.