Palliative Thoracic Radiotherapy for Non-small Cell Lung Cancer: Is There any Impact of Target Volume Size on Survival?

Abstract

Recent studies suggested that target volume size impacts survival in patients with non-small cell lung cancer (NSCLC) receiving radical radiotherapy. Little is known about the impact of target volume size in palliative radiotherapy or chemoradiotherapy. Therefore, we analyzed the overall survival stratified for clinical and planning target volume (CTV and PTV) size. A retrospective study of 77 patients who received palliative (chemo)radiotherapy (at least 30 Gy) for non-metastatic NSCLC, largely stage III was performed. Typical radiation doses were 10-13 fractions of 3 Gy and 15 fractions of 2.8 Gy. Median survival was 12 months (2-year rate 18%). Three prognostic factors emerged in the multivariate analysis. Hospitalization in the last 4 weeks before radiotherapy increased the hazard of death by a factor of 2.8 (p=0.002). Presence of a T1 or 2 tumor decreased the hazard of death by a factor of 0.5 (p=0.03). Concomitant chemoradiotherapy decreased the hazard of death by a factor of 0.4 (p=0.003). Target volume size was not significantly associated with survival, suggesting that large size should not preclude palliative (chemo)radiotherapy as long as normal tissue dose constraints can be met.