Abstract: Objective The aim of this study was to investigate the safety and efficacy of immunotherapy and stereotactic body radiation therapy (SBRT) in the treatment of patients with advanced primary liver cancer (aPLC). Methods A total of 102 patients with aPLC were encountered in our hospital between January 2020 and January 2024, and were randomly assigned to receive SBRT in 61 patients in control or receive intravenous camrelizumab after SBRT in another 60 patients in observation. Objective response rate (ORR) and disease control rate (DCR) were observed. Serum alpha-fetoprotein (AFP), thymidine kinase 1 (TK1) and abnormal prothrombin (DCP) levels were measured by ELISA. Peripheral blood T lymphocyte and natural killer (NK) cells were measured by flow cytometry. Survival curves were drawn by Kapkan-Meier method and compared by Log-Rank test. Results The ORR and DCR in the observation group were 60.0% and 95.0%, both much higher than 36.1% and 82.0%(P＜0.05) in the control; after treatment, serum AFP, TK1 and DCP levels in the observation were (82.4±18.3)ng/mL, (1.6±0.3)μg/L and (27.5±3.2)mAU/mL, all much lower than [(143.6±31.9)ng/mL, (2.2±0.4)μg/L and (38.6±3.9)mAU/mL, respectively, P＜0.05] in the control; percentage of peripheral blood CD3⁺ cells, CD4⁺/CD8⁺ cell ratio and percentage of NK cells were (70.5±4.7)%,(1.7±0.2) and (16.3±2.7)%, all significantly higher than [(60.8±4.3)%, (1.4±0.2) and (11.1±2.2), respectively, P＜0.05] in the control; the incidence adverse effects in the observation was 53.3%, much higher than 36.1%(P<0.05) in the control; by end of one-year follow-up, the survival rate in the observation was 80.0%, much higher than 56.9%(P＜0.05) in the control group. Conclusion Immunotherapy after SBRT in the treatment of patients with aPLC is efficacious, which could prolong short-term survival and merits further clinical investigation.

Key words: Hepatoma, Stereotactic body radiation therapy, Camrelizumab, Safety, Therapy