Final report of survival and late toxicities in the Phase i study of stereotactic body radiation therapy for peripheral T2N0M0 non-small cell lung cancer (JCOG0702)

Purpose A dose escalation study to determine the recommended dose with stereotactic body radiation therapy (SBRT) for peripheral T2N0M0 non-small cell carcinomas (JCOG0702) was conducted. The purpose of this paper is to report the survival and the late toxicities of JCOG0702. Materials and methods The continual reassessment method was used to determine the dose level that patients should be assigned to and to estimate the maximum tolerated dose. The starting dose was 40 Gy in four fractions at D 95 of PTV. Results Twenty-eight patients were enrolled. Ten patients were treated with 40 Gy at D 95 of PTV, four patients with 45 Gy, eight patients with 50 Gy, one patient with 55 Gy and five patients with 60 Gy. Ten patients were alive at the last follow-up. Overall survival (OS) for all patients was 67.9% (95% CI 47.3-81.8%) at 3 years and 40.8% (95% CI 22.4-58.5%) at 5 years. No Grade 3 or higher toxicity was observed after 181 days from the beginning of the SBRT. Compared to the toxicities up to 180 days, chest wall related toxicities were more frequent after 181 days. Conclusions The 5-year OS of 40.8% indicates the possibility that SBRT for peripheral T2N0M0 non-small cell lung cancer is superior to conventional radiotherapy. The effect of the SBRT dose escalation on OS is unclear and further studies are warranted.