ESTRO 2025 - Abstract Book

S1302

Clinical - Lung

ESTRO 2025

Univariate and multivariate Cox regression analyses were conducted to investigate the correlation between dosimetric parameters and overall survival. Statistical Package for the Social Sciences (SPSS) version 23.0 (IBM, Armonk, NY, USA) was utilized for statistical analyses. Results: Characteristics of the patient, tumor, and treatment are detailed in Table 1. The median age of the patients was 58 years (range, 25–85). The median PORT dose was 54 Gy (range, 50-66) in 27 fractions, and 21 patients (35%) received doses greater than 54 Gy. Three-dimensional (3D) conformal RT was applied to 32 (53.3%) of the patients and IMRT was applied to 28 (46.7%) of them. In 32 patients (53.3%), elective nodal irradiation (ENI) were also performed in addition to the positive stations. Median follow-up was 30.9 months (range, 4.4-138.5) while the median follow-up for surviving patients was 56.5 months (range, 24.1-138.5). The 2-year and 5-year OS rates were 69% and 40%, respectively. Right atrium (RA) maximum dose (Dmax) was sole variable that was significantly associated with a shorter OS (HR: 1.029, p = 0.04). Heart Dmean approached statistical significance and evaluated as clinically relevant (p = 0.05). ROC analysis indicated that the optimal cut-off value for RA Dmax was 43.6 Gy, demonstrating a sensitivity of 69% and a specificity of 62% (AUC: 0.668; p = 0.03; 95% CI: 0.518−0.819). The inclusion of upper right paratracheal (2R), lower right paratracheal (4R), left pulmonary ligament (9L), and right hilus (10R) lymphatic stations in the treatment field resulted in an increase in RA Dmax.