Stereotactic body radiation therapy for primary lung cancers clinically diagnosed without pathological confirmation: a single-institution experience

Background: Pathological diagnosis of small lung lesions is sometimes difficult in medically inoperable patients. The purpose of this study was to evaluate the adverse events and the outcomes of stereotactic body radiation therapy (SBRT) for lung lesions which were clinically diagnosed as primary lung cancer without pathological confirmation. Methods: Between April 2003 and April 2011, 88 patients with small lung lesions which were clinically diagnosed as primary lung cancer were treated with SBRT. The median tumor size was 19 mm (range 8–40 mm). The radiation dose was 48 Gy in four fractions in all patients. The median follow-up was 23 months (range 6–91 months). Results: Recurrence was observed in 13 patients. The local control rate, progression-free survival rate, and overall survival rate at 3 years were 90, 67, and 80 %, respectively. Two patients (2.3 %) had Grade 2 radiation pneumonitis, and six patients (6.8 %) had Grade 2 rib fractures. There were no adverse events of Grade 3 or greater. Conclusions: SBRT appears to be a safe and effective treatment option for small lung lesions that are clinically diagnosed as primary lung cancer without pathological confirmation.