Radiotherapy planning complexity and survival after treatment of advanced stage lung cancer in the elderly

Abstract

PURPOSE: Complex radiotherapy (RT) planning is increasingly common in the treatment of lung cancer though it remains unclear if these treatments are associated with better outcomes. We evaluated the association between the complexity of RT planning simulation with survival among elderly Stage IIIB non-small cell lung cancer (NSCLC) patients. METHODS: We included all patients aged >65 years with histologically confirmed Stage IIIB NSCLC diagnosed between 1992 and 2002 receiving chemotherapy and RT from the Surveillance, Epidemiology, and End Results registry linked to Medicare claims. Patients were divided into simple, intermediate, and complex RT planning groups using Medicare physician codes. Kaplan-Meier curves and Cox regression were used to compare overall and lung cancer-specific survival rates across groups. RESULTS: We identified 1,733 patients: 148 (8%), 1,138 (66%), and 447 (26%) were classified as having received simple, intermediate and complex RT planning, respectively. Baseline characteristics were similar across groups. Increasing complexity of RT planning was significantly associated with better overall survival (p=0.0002). Multivariate analyses showed that intermediate (HR: 0.75, 95% CI: 0.62 to 0.91) and complex planning (HR: 0.69, 95% CI: 0.55 to 0.86) were associated with better overall survival compared to simple RT planning. Similar results were observed for lung cancer-specific survival analyses. Toxicities were comparable across groups. CONCLUSIONS: The use of more complex RT planning and simulation methods is associated with better survival in elderly patients with Stage IIIB NSCLC. Although these results should be further validated in prospective clinical trials, this data suggests that complex planning may improve the outcomes of these patients.