Re-irradiation in lung disease by SBRT: a retrospective, single institutional study

Background: The loco regional relapse is frequent in the lung disease. The aim of this study was to evaluate the outcomes of re-irradiation by SBRT in terms of Local Control (LC) and toxicities. Methods: From April 2011 to December 2016, twenty-two patients received a re-irradiation by SBRT. Twenty-seven lesions were treated. The medium BED(10) of re-irradiation was 100.6 Gy (range: 48-151.2 Gy) and the medium EQD2 (10) was 93.8 Gy (range: 40-126 Gy). In the previous treatment the medium BED(10) was 97.2 Gy (range: 40-120 Gy), the medium EQD2(10) was 81 Gy (range: 32.5-100 Gy). The median time between the first and the second treatment was 18 months. Results: Local Control was reached in 18 out of 27 (66%) re-irradiated lesions, with rates of 67 and 54% at 1-year and 2-years respectively. The treatment was well tolerated; the maximum recorded toxicity was Grade 3. Conclusions: Re-irradiation by SBRT may represent an option for the treatment of lung disease with good results in terms of LC and toxicity.