MSOR3 Presentation Time: 5:10 PM

Abstract

Purpose

The study aimed to evaluate the combined efficacy of systemic therapy and iodine-125 seed implantation as a local treatment in patients with oligometastatic non-small cell lung cancer (NSCLC), defined by ≤3 metastatic organs and ≤5 metastatic lesions, and to identify factors that influence patient outcomes.

Materials and Methods

A retrospective review was conducted of 40 patients with oligometastatic NSCLC treated from January 2018 to June 2023 at our institution. Patients were divided into Group A (n=20), receiving both systemic therapy and iodine-125 seed implantation, and Group B (n=20), treated with systemic therapy alone. The primary outcome was progression-free survival (PFS), with overall survival (OS) serving as a secondary outcome. Survival analysis for PFS and OS was performed using Kaplan-Meier curves, with the Log-rank test for intergroup comparisons, and Cox regression analysis was used for univariate and multivariate analyses.

Results

The median PFS for Group A was 14.9 months (95% CI: 12.8-17.0), which was significantly longer than the 6.9 months (95% CI: 4.7-9.1) for Group B (HR=6.50, 95% CI: 4.60-9.20). The median OS was 28.7 months (95% CI: 19.5-37.9) for Group A, surpassing the 17.0 months (95% CI: 13.5-20.5) for Group B (HR=1.60, 95% CI: 1.05-2.40). Multivariate analysis highlighted intracranial metastasis as a significant risk factor for PFS. Influential factors for OS included oligometastatic status, the presence of brain metastases, histologic subtype, the use of immune checkpoint inhibitors (ICIs), driver mutations, anti-angiogenic treatments, and the implementation of iodine-125 seed implantation for local therapy.

Conclusion

In patients with oligometastatic NSCLC and stable primary lesions, the integration of systemic therapy with iodine-125 seed implantation markedly improves PFS and OS compared to systemic therapy alone. This underscores the value of iodine-125 seed implantation in the comprehensive treatment strategy, highlighting its significant role in enhancing patient survival outcomes.