Efficacy and safety of immune checkpoint inhibitors combined with iodine-125 seed implantation in driver gene-negative non-small cell lung cancer: a retrospective cohort study.

BACKGROUND

Non-small cell lung cancer (NSCLC) presents the most common type of lung cancer, accounting for 80-85% of cases. Combining immunotherapy with radiotherapy (RT) has emerged as a significant research area in recent years. However, the risk of radiation pneumonitis, especially in lung cancer patients, poses a significant concern. Iodine-125 (I125) seed implantation offers a precise, less invasive alternative, minimizing damage to surrounding lung tissues and reducing side effects. This study aims to evaluate the safety and efficacy of I125 seed implantation combined with immune checkpoint inhibitors (ICIs) and chemotherapy (CT) in treating driver gene-negative NSCLC patients.

METHODS

Retrospective analysis of 95 patients with driver gene-negative NSCLC who presented to the First Affiliated Hospital of Army Medical University was conducted. Among them, 33 cases in the observation group were treated with I125 seed implantation combined with CT and ICIs (ICIs + CT + I125), and 62 cases in the control group were treated with extracorporeal RT combined with CT and ICIs (ICIs + CT + RT). The primary observational endpoint was median progression-free survival (mPFS), while the secondary observational endpoints included the 1- and 2-year PFS rate and the incidence of adverse events.

RESULTS

mPFS was not reached in the observation group but 11.8 months [95% confidence interval (CI): 9.743-13.857] in the control group, a statistically significant difference (P<0.001). The restricted mean survival time (RMST) was 22.2 (95% CI: 18.257-26.101) and 13.8 (95% CI: 11.912-15.718) months in both groups at 31.7 months, PFS was better in the observation group than in the control group. In the observation group, two cases (6.1%) developed grade 3 pneumothorax or hemorrhage, and in the control group, 16 cases (25.8%) developed grade 3 radiation pneumonitis, which was higher in the control group than in the observation group (P=0.02).

CONCLUSIONS

Compared to RT in combination with CT and immunotherapy, patients with driver gene-negative NSCLC who received I125 seed implantation had greater advantages with longer survival and fewer adverse effects.