Effect of Cyber Knife radiosurgery on survival rate of patients with recurrent liver cancer after surgery

Objective To investigate the clinical effect of Cyber Knife radiosurgery, a type of stereotactic body radiotherapy, in the treatment of recurrent liver cancer after resection or ablation, as well as the effect of clinical factors on survival rate. Methods A retrospective analysis was performed for the clinical data of 34 patients with recurrent liver cancer after surgery who were treated with Cyber Knife radiosurgery. The patients' survival rate and survival time after radiotherapy were calculated, and the influencing factors for survival were analyzed.The gross tumor volume of tumor target was 1. 475-1082. 075 cm3 ( median 162. 99 cm3) . The fraction dose was 7-20 Gy ( median 9 Gy) , the number of times of irradiation was 2-8 times ( median 5 times) , and the tumor dose was 24-60 Gy ( median 45 Gy) once a day. The major indices for observation were short-term outcome, toxic and side effects, and long-term outcome. The log-rank test was used to analyze the surviral-related factors. The chi-square test and fisher test were used for comparison of categorical data between groups. Results The 1-, 2-, and 3-year overall survival rates after radiotherapy were 91. 2%, 70. 6%, and 44. 1%, respectively, and the median survival time was 34 months. The 1-, 2-, and 3-year progression-free survival rates were 55. 9%, 38. 2%, and 29. 4%, respectively.There were no significant differences in 1-, 2-, and 3-year overall survival rates after radiotherapy between the ≤1-year ( early) postoperative group and the > 1-year ( late) postoperative group ( 89%/73. 7%/57. 9% vs 93%/73. 3%/33. 3%, χ2= 0. 354, P = 0. 368) .The univariate analyses showed that sex, age, time to postoperative recurrence, diameter and number of recurrent lesions, liver function classification, alpha-fetoprotein level, and chemotherapy were not significantly associated with patients' survival after radiotherapy. Conclusion Cyber Knife radiosurgery is safe and effective in the treatment of recurrent liver cancer, with the advantages of good local control of liver cancer, a high overall survival rate, noninvasiveness, few side effects, and good tolerability, and thus provides a new direction for the treatment of intrahepatic recurrence of primary liver cancer.