3477 - Real-World Outcomes of Metastasis-Directed Stereotactic Radiotherapy in Driver-Mutated Oligometastatic and Oligoprogressive Metastatic Lung Cancer
Presenter(s)
A. Gonzalez1,2, E. Pulido3, A. Cardona2,4, L. Rojas2,5, V. Ávila-Rodríguez2,6, A. C. Aya3, J. Zuluaga2,5, L. Gutiérrez-Babativa3, N. Sanchez3, Y. V. Sierra1, S. Martínez5, L. Viola5, C. Carvajal5, A. del Vecchio7, D. M. Cuevas1, A. P. Rodríguez1, F. Y. Y. Moraes8, and I. Bobadilla1,2; 1Radiotherapy Functional Unit, Luis Carlos Sarmiento Angulo Cancer Treatment and Research Center–CTIC, Bogota, Colombia, 2GIGA/TERA Research Group (CTIC/Universidad El Bosque), Bogota, Colombia, 3Institute for Research, Science and Education, GIGA research group, Luis Carlos Sarmiento Angulo Cancer Treatment and Research Center (CTIC), Bogotá, Colombia, 4Institute of Research and Education/Thoracic Oncology Unit, Luis Carlos Sarmiento Angulo Cancer Treatment and Research Center-CTIC, Bogotá, Colombia., Bogota, Colombia, 5Thoracic Oncology Unit, Luis Carlos Sarmiento Angulo Cancer Treatment and Research Center-CTIC, Bogota, Colombia, 6Hospitalization Functional Unit, Luis Carlos Sarmiento Angulo Cancer Treatment and Research Center-CTIC, Bogota, Colombia, 7Faculty of Medicine, Pontificia Universidad Javeriana, Bogota, Colombia, 8Department of Radiation Oncology, University of Toronto, Toronto, ON, Canada
Purpose/Objective(s):
Metastasis-directed stereotactic radiotherapy (SRS/SBRT) may prolong benefit of targeted systemic therapy in oncogene-driven metastatic lung cancer with limited metastases or limited progression. Real-world outcomes in driver-mutated populations treated with contemporary targeted agents are limited. We evaluated overall survival (OS) and progression-free survival (PFS) after metastasis-directed RT in patients with actionable drivers receiving active driver-directed therapy, and explored outcomes by EGFR versus other drivers.Materials/Methods:
Ambispective single-institution cohort of consecutive metastatic lung cancer patients with =1 actionable driver alteration receiving active driver-directed systemic therapy who initiated metastasis-directed RT between Nov 2022 and Dec 2025 after multidisciplinary review. RT was predominantly SRS/SBRT. OS was from RT start to death from any cause or administrative censoring; PFS to progression or death. Kaplan–Meier; follow-up by reverse Kaplan–Meier; log-rank tests. Course-count comparisons were exploratory due to time-dependent/immortal-time bias.Results:
Forty patients were included (median age, 66). Drivers were: EGFR 25 (62.5%), ALK 4 (10%), ERBB2 2 (5%), KRAS G12C 2 (5%), MET 2 (5%), RET 2 (5%), ROS1 2 (5%), and BRAF V600E 1 (2.5%). Fifty-two RT courses were delivered; 58% received intracranial-directed treatment and 25% received >1 course. Median follow-up was 11.47 months. Median OS was not reached; 12-month OS was 89.6% with no difference by EGFR status (p=0.61). Twelve-month PFS was 63.1%. Median PFS was 13.0 months in EGFR-mutated patients versus 29.6 months in other driver alterations (p=0.17). Exploratory single vs multiple courses: OS p=0.38; median PFS 13.3 months (95% CI =4.2) vs 29.6 months (95% CI =11.7).Conclusion:
Metastasis-directed stereotactic RT delivered while continuing targeted therapy was associated with favorable short-term OS/PFS, supporting feasibility of a strategic radiotherapy approach in selected patients. Outcomes did not differ significantly between EGFR-mutated and other driver-altered patients. Larger cohorts with standardized progression assessment and time-dependent methods are warranted.