⁹⁰Y-Transarterial Radioembolization Combined with Immune Checkpoint Inhibitors in Hepatocellular Carcinoma: A Systematic Review

Background: Transarterial radioembolization with yttrium-90 (⁹⁰Yt-TARE) and immune checkpoint inhibitors (ICIs) are emerging as treatment modalities for intermediate to advanced hepatocellular carcinoma (HCC) based on randomized controlled trials. Herein, we systematically reviewed the published literature on the effects of ⁹⁰Yt-TARE and ICIs combined on clinical outcomes of HCC. Methods: Medical databases of PubMed, Embase, and Cochrane Library were systematically searched for all studies assessing the use of concomitant immunotherapy of ICI with TARE in patients with HCC. Patient characteristics, treatment protocols, treatment outcomes, treatment adverse events, and survival outcomes were extracted after the screening phase. The primary outcomes were overall survival (OS) and patient-free survival (PFS), while the secondary outcomes were imaging objective response (OR) and adverse events. Results: Among 3432 reviewed, ten studies were included in this systematic review, including four randomized controlled trials and six retrospective studies. These consisted of 413 patients with HCC, and seven studies included patients with Child-Pugh A or B7 scores. Most studies allowed advanced or intermediate HCC stages, but only two specified BCLC stages (B and C). Median tumor sizes ranged from 56 to 78.5 mm. Various agents with different administration schedules were used as ICIs for immunotherapy by different studies for the combination of ⁹⁰Yt-TARE with ICIs. Median OS ranged from 16.2 to 27 months between different studies while the PFS also ranged from 5.6 to 13.3 months. The OR rates according to imaging-based response assessments were reported between 31 and 89%, and the incidence rate of any grade toxicities was between 50 and 80%. Conclusion: Concomitant treatment with ⁹⁰Yt-TARE and ICIs has shown promising results in the treatment of patients with HCC. Further studies are required to reach a consensus on the optimal treatment protocol and the outcome of these treatments for patients with intermediate to advanced HCC.