Stereotactic body radiation therapy versus conventional radiation therapy in patients with early stage non-small cell lung cancer: an updated retrospective study on local failure and survival rates.

INTRODUCTION: Stereotactic body radiation therapy (SBRT) for early stage non-small cell lung cancer (NSCLC) is now an accepted and patient friendly treatment, but still controversy exists about its comparability to conventional radiation therapy (RT). The purpose of this single-institutional report is to describe survival outcome for medically inoperable patients with early stage NSCLC treated with SBRT compared with high dose conventional RT.

MATERIAL AND METHODS: From August 2005 to June 2012, 100 medically inoperable patients were treated with SBRT at Odense University Hospital. The thoracic RT consisted of 3 fractions (F) of 15-22 Gy delivered in nine days. For comparison a group of 32 medically inoperable patients treated with conventional RT with 80 Gy/35-40 F (5 F/week) in the period of July 1998 to August 2011 were analyzed. All tumors had histological or cytological proven NSCLC T1-2N0M0.

RESULTS: The median overall survival was 36.1 months versus 24.4 months for SBRT and conventional RT, respectively (p = 0.015). Local failure-free survival rates at one year were in SBRT group 93% versus 89% in the conventional RT group and at five years 69% versus 66%, SBRT and conventional RT respectively (p = 0.99). On multivariate analysis, female gender and performance status of 0-1 and SBRT predicted improved prognosis.

CONCLUSION: In a cohort of patients with NSCLC there was a significant difference in overall survival favoring SBRT. Performance status of 0-1, female gender and SBRT predicted improved prognosis. However, staging procedure, confirmation procedure of recurrence and technical improvements of radiation treatment is likely to influence outcomes. However, SBRT seems to be as efficient as conventional RT and is a more convenient treatment for the patients.