RESULTS: Of the advanced Stage IIIa NSCLC cohort (n=31694), 24 received +PDT, and 188 received +non-PDT ablation. Mean age, marital status and race was comparable between +PDT and +non-PDT ablation groups. However, the +PDT group had higher proportion of patients with one or more comorbidity, compared to +non-PDT group (75% vs 52%; p=0.05). Un-adjusted five year survival days were highest for +PDT group (mean 881, SD 738), compared to +non-PDT ablation group (mean 630,SD 679). Patients receiving + PDT showed lower hazard of overall five year mortality (HR=0.69, CI=0.43, 1.12), as well as lung cancer-specific mortality (HR=0.62, CI=0.35, 1.09), compared to +non-PDT ablation group. Five year medical care cost was higher for +PDT group (β=0.8425, p=0.0010), compared to the +non-PDT ablation therapy group.