Risk-adapted stereotactic body radiation therapy delivered in four fractions in patients with non-small cell lung cancer.

Risk-adapted stereotactic body radiation therapy is preferred over conventional radiotherapy at the authors' institution based on the hypothesis that even with a lower than recommended dose, stereotactic body radiation therapy would yield better local control than conventional radiotherapy. This retrospective study was performed to verify the hypothesis. Data from 34 patients with non-small cell lung cancer, who underwent risk-adapted stereotactic body radiation therapy delivered in 4 fractions between 2012 and 2018, were analyzed. The 3-year local control rate for patients receiving 42-44 Gy, 40 Gy, and 32-38 Gy was 80.8%, 75.0%, and 66.7%, respectively. The 3-year overall survival rate was 63.5%, 63.5%, and 40.0%, respectively. Three patients experienced grade 3 toxicities, with no toxicities > grade 3 observed. The results support the use of risk-adapted stereotactic body radiation therapy, both with a relatively high dose and a low dose.