Treatment patterns and results of salvage treatment for regional recurrences after stereotactic ablative radiotherapy for primary non-small cell lung cancer

PurposeStereotactic ablative radiotherapy (SABR) for early-stage lung cancer has shown promising results; however, regional recurrence (RR) development is not uncommon, and salvage treatment strategies have not been established. We aimed to investigate treatment patterns, prognostic factors, and survival outcomes. Materials and methodsA retrospective analysis of 391 patients who underwent SABR for primary lung cancer from 2012 to 2019 was performed. Among these patients, 90 patients showed recurrence, including local recurrence (n = 9), RR (n = 33), distant metastasis (DM) (n = 57), and RR with simultaneous DM (n = 8). The median follow-up duration was 17.3 months. ResultsThe median age was 75 years, and most patients underwent primary SABR due to poor lung function (69.7%). Various salvage treatments were performed in cases of RR, including chemotherapy (n = 15), radiotherapy (n = 7), concurrent chemoradiotherapy (n = 2), and best supportive care (n = 9). The median overall survival (OS) and post-recurrence OS (PR-OS) were 22.9 and 11.2 months, respectively. In multivariate analysis, age & LE;75 years (HR = 0.36, p = 0.040), isolated recurrence (HR = 0.34, p = 0.037), and radiotherapy without chemotherapy (HR = 0.25, p = 0.024) were significant prognostic factors for PR-OS. ConclusionsDespite various salvage treatments, PR-OS was less than 1 year after RR in our frail patients group who underwent primary SABR. The toxicities of salvage chemotherapy could be quite severe; thus, careful patient selection is required. Further research is needed to validate our findings.