Is stereotactic body radiotherapy an alternative to surgery in early stage non small cell lung cancer

PURPOSE: To determine local control and overall survival of patients with medically inoperable early-stage non-small cell lung cancer (NSCLC) treated with stereotactic ablative radiotherapy. METHODS: Included were a total of 52 patients (7;13% females and 45;87% males) with medically inoperable early-stage NSCLC and who were treated with stereotactic ablative body radiotherapy (SBRT) by a CyberKnife robotic radiotherapy machine between 2009 and 2017. Depending on tumor size and location, median 45 Gy (30-60) were delivered in median 3 fractions (3-5) to Planning Target Volume. As regards the tumor-tracking system; X-Sight lung tracking system was used in 43 (83%) patients, gold fiducials in 4 (8%) patients, and X-Sight spine tracking system in 5 (9%) patients. RESULTS: The median age of patients was 67 years (54-86). Tumor was staged as cT1 in 38 (73%) patients and cT2 in 14 (27%) patients. Median follow up was found to be 23 months (10-84 months). Median survival time was 38 months and, 1-3-5 year survival rates were respectively 94%-53%-33.6%. Locoregional recurrence occurred in 8 (15%) patients and recurrence was local only in 4 (8%) patients, while it was regional only in 3 (6%) and distant only in 12 (23%) patients. During follow up, local, regional and distant recurrence was detected in 27 (52%) cases and median progression free survival was found to be 25 months. 1-3-5 year progression free survival was 71.2%-39%-26%, respectively. Grade 3 toxicity was observed in only one patient; no grade 4-5 toxicity was observed. CONCLUSION: A high local control rate with no major toxicity was obtained by SBRT in the patients with medically inoperable early-stage NSCLC. In the near future, SBRT may be an alternative that has growing evidence to support comparable outcomes in selected stage I patients.