Role of thoracic conformal radiotherapy in patients with extensive-stage small cell lung cancer

Abstract

Objective To evaluate the role of thoracic three-dimensional conformal radiotherapy (3DCRT) in patients with extensive-stage small cell lung cancer (ES-SCLC).Methods A total of 171 patients with ES-SCLC admitted from 2004 to 2009 were included in the study.Eighty-six patients received thoracic 3DCRT and systemic chemotherapy (CT),while 85 patients received systemic CT alone.3DCRT was delivered at 1.5 Gy/fraction twice daily or 2.0 Gy/fraction once daily,with a total dose ranging from 40 to 62 Gy.The CT regimen consisted of carboplatin/cisplatin and etoposide.The survival time and survival rate were calculated by the Kaplan-Meier method,and the log-rank test was used for univariate prognostic analysis;the Cox model was used for multivariate prognostic analysis.Results The follow-up rate was 100％.The median overall survival (OS) time and the 2-and 5-year OS rates were 15 months,31.5％,and 2.4％,respectively,for all patients;they were 18 months,35.3％,and 2.4％,respectively,for the CT/3DCRT group,versus 12 months,14.5％,and 2.4％ for the CT group (P =0.023).The median progression-free survival (PFS) time and the 1-and 2-year PFS rates were 8 months,27.5％,and 2.4％,respectively,for all patients;they were 9 months,35.4％,and 6.0％,respectively,for the CT/3DCRT group,versus 6 months,20.5％,and 6.0％ for the CT group (P =0.004).In the CT/3DCRT group,the 22 patients who received 45 Gy at 1.5 Gy/fraction twice daily had a median PFS time of 11 months,versus 9 months for the 26 patients who received 60 Gy at 2.0 Gy/fraction once daily (P =0.037).Multivariate analysis revealed that receiving ≥ 4 cycles of CT (P =0.001) and 3DCRT (P =0.008) were favorable prognostic factors for OS.Conclusions Thoracic 3DCRT can improve the OS and PFS in patients with EDSCLC,and it has good efficacy when delivered with a total dose of 45 Gy at 1.5 Gy/fraction twice daily.Thoracic 3DCRT and receiving ≥4 cycles of CT are independent favorable prognostic factors for OS. Key words: Lung neoplasms/radiotherapy; Radiotherapy, three-dimensional conformal; Radiotherapy, hyperfraction; Prognosis