Presenter(s)
J. L. Livschitz1, P. Balter2, S. Gandhi3, S. H. Lin3, M. S. Ning3, D. C. Qian3, J. K. Bronk3, A. B. Chen3, M. S. O'Reilly3, Q. N. Nguyen3, J. W. Welsh3, J. M. Pollard3, M. Altan4, Y. Elamin4, T. Cascone4, Z. Liao3, J. Heymach4, and J. Y. Chang3; 1Department of Radiation Oncology, MD Anderson Cancer Center, Houston, TX, 2Department of Radiation Physics, The University of Texas MD Anderson Cancer Center, Houston, TX, 3Department of Thoracic Radiation Oncology, The University of Texas MD Anderson Cancer Center, Houston, TX, 4Department of Thoracic/Head and Neck Medical Oncology, The University of Texas MD Anderson Cancer Center, Houston, TX
Purpose/Objective(s): Consolidative radiotherapy (RT) is established for oligometastatic non–small cell lung cancer (NSCLC), but its role in polymetastatic disease is unclear. With integration of targeted therapy, chemotherapy and immunotherapy, using multiple (“pulsed”) courses of RT to eradicate sites of systemic treatment resistant disease as a part of comprehensive management strategy has not been well studied. We retrospectively identified a cohort of polymetastatic NSCLC patients (synchronous and metachronous metastases) treated with pulsed targeted consolidative RT—defined as multiple, discrete RT courses to successive oligoprogressive or oligopersistent sites over years. Clinical outcomes and safety of this approach are reported.
Materials/Methods: Single-institution retrospective cohort study of patients with polymetastatic (Stage IV) NSCLC who received RT between 2007–2025. Using the institutional MOSAIQ database, we identified patients who received =3 distinct RT courses for NSCLC over years. A course was defined as a completed RT regimen to a specific site (stereotactic and/or hypofractionated); each brain SRS session counted as one treatment regardless of lesion count. Patients with multifocal primary lung tumors were excluded. Chart review captured age, smoking history, date of Stage IV diagnosis, survival status/last follow-up, driver mutation status, number and sites of RT courses, and RT regimens. Overall survival (OS) from Stage IV diagnosis was estimated by Kaplan–Meier. Toxicities were recorded from clinical documentation.
Results: 115 patients met inclusion criteria; mean age 67 years. Patients received 3–19 RT courses (median 5); 66.1% received =5 courses, 30.4% =7, and 7.8% =10. Common regimens included stereotactic RT (20–70 Gy in 1–10 fractions) and hypofractionated regimens (20–30 Gy in 5–10 fractions). Driver mutation status: 34.7% EGFR, 6.1% ALK, and 59.1% without either mutation. Median OS was 3.81 years (5-year OS 43.1%; 10-year OS 13.3%). In patients with EGFR and ALK gene mutations, median OS was 5.65 years (5-year OS 60.1%; 10-year OS 14.8%). No Grade 4–5 radiation toxicities were documented.
Conclusion: In this retrospectively identified cohort of patients with polymetastatic NSCLC, dynamic integration of multiple courses of “pulsed” targeted consolidative RT to salvage systemic therapy resistant sites over time appears feasible and safe, with promising survival outcomes. This strategy may serve as a useful tool to keep patients on systemic therapy for longer. Prospective studies are needed to define selection criteria and quantify benefit.