Abstract Body (Do not enter title and authors here): Background: Physical activity is associated with prognosis in cancer. However, in non-small cell lung cancer (NSCLC), a high cardiovascular (CV) population, the relationships between RT dose, physical activity, and CV patient-reported outcomes remain unclear. We determined the associations between cardiac radiation dose-volume metrics and changes in physical activity and quality-of-life (QoL) in patients treated with definitive chemoradiation.

Methods: NSCLC participants treated with chemoradiation were enrolled in a multi-center longitudinal cohort study. Self-reported physical activity via Godin–Shephard Leisure-Time Physical Activity Questionnaire (Godin) and QoL via Functional Assessment of Chronic Illness Therapy (FACIT) Fatigue and Dyspnea Scales were collected at baseline, end of RT, 6, and 12 months post-RT. Changes in Godin and FACIT scores over time were examined using linear mixed-effects models. Multivariable linear regression via generalized estimating equations assessed the associations between: 1) mean heart dose (MHD) and longitudinal changes in physical activity and QoL, and 2) concurrent changes in physical activity and FACIT scores.

Results: Across 101 participants, the mean age was 66 years, with 57% male, 66% White, and 25% Black. The median (Q1, Q3) MHD was 10.8 Gy (6.1,16.3). Very low physical activity [9 (0, 25)], high dyspnea [4 (1, 9)], and low fatigue [39 (31,46)] were reported at baseline. With chemoRT, there was a significant worsening of physical activity (P = 0.03), fatigue (P < 0.001), and dyspnea (P < 0.001). Each 1-Gy increase in MHD was associated with a modest decline in physical activity (-0.28; 95% CI -0.53, -0.02, P = 0.03), and higher physical activity was associated with a concurrent decrease in fatigue (P < 0.001) and dyspnea (P = 0.007) (Table).

Conclusions: In locally advanced NSCLC, physical activity levels prior to RT were very low, and higher cardiac radiation dose was associated with a further decline in physical activity. Increased physical activity was associated with concurrent decreases in fatigue and dyspnea. Strategies to promote physical activity may result in improved QoL in this high CV group.