Stereotactic body radiotherapy for early-stage non-small cell lung cancer: clinical outcomes from a National Patient Registry.

OBJECTIVES: Stereotactic body radiotherapy (SBRT) is a definitive local treatment option for patients with stage I non-small cell lung cancer (NSCLC) who are not surgical candidates and patients who refuse surgery. The purpose of this study was to assess the impact of SBRT on T1-T2 NSCLC from a national registry, reflecting practices and outcomes in a real-world setting.

METHODS: The RSSearch® Patient Registry was screened for T1-T2N0M0 NSCLC patients treated from May 2004 to May 2013 with SBRT. Descriptive analyses were used for patient, tumor, and treatment characteristics. Overall survival (OS) and local control (LC) were calculated using the Kaplan-Meier method.

RESULTS: In total, 723 patients with 517 T1 and 224 T2 lesions were treated with SBRT. Median follow-up was 12 months (1-87 months) with a median age of 76 years. Median SBRT dose was 54 Gy (range 10-80 Gy) delivered in a median of 3 fractions (range 1-5), and median biological equivalent dose (BED10) was 151.2 Gy (range 20-240 Gy). Median OS was 30 and 26 months for T1 and T2 tumors, respectively (p = 0.019). LC was associated with higher BED10 for T2 tumors, but not in T1 tumors at a median follow-up of 17 months. Seventeen-month LC for T2 tumors treated with BED10 < 105 Gy, BED10 105-149, and BED10 ≥ 150 Gy was 43, 74, and 95 %, respectively (p = 0.011). Local failure rates for T2 tumors treated with BED10 < 105 Gy, 105-149 Gy, and ≥150 Gy were 32, 21, and 8 % (p = 0.029), respectively. Median OS for patients with T2 tumors treated with BED10 < 105 Gy was 17 vs. 32 months for T2 tumors treated with BED10 105-149 Gy (p = 0.062).

CONCLUSION: SBRT for T1-T2 NSCLC is feasible and effective in the community setting. OS was greater for patients with T1 lesions compared to T2 lesions. An improvement in LC was observed in patients with T2 lesions treated with BED10 > 105 Gy.