Re-irradiation for local recurrence after definitive stereotactic body radiotherapy for early-stage non-small cell lung cancer.

BACKGROUND

Salvage treatment for local recurrence of non-small cell lung cancer (NSCLC) after stereotactic body radiotherapy (SBRT) remains unestablished. We investigated the safety and efficacy of a second SBRT course for in-field local recurrence of NSCLC after definitive SBRT.

METHODS

This study included 35 patients with NSCLC who received a second SBRT course between July 2004 and August 2021. The median interval between the first and second SBRT was 24 months (range, 6-81 months). The median prescription dose was 60 Gy in eight fractions (range, 48-66 Gy) for the second SBRT. Overall survival (OS), local control (LC), progression-free survival (PFS), and toxicity after a second SBRT were assessed.

RESULTS

The median follow-up period was 29 months (range, 3-124 months). The three-year OS, LC, and PFS rates were 50%, 47%, and 34% for all 35 patients and 72% vs. 21%, 85% vs. 34%, and 62% vs. 9% in the adenocarcinoma and squamous cell carcinoma groups, respectively (P=0.04, 0.01, and 0.003, respectively). Four patients demonstrated no further recurrence for more than five years after the second SBRT. Radiation pneumonitis after the second SBRT was grade 2 in three (8.5%) patients, rib fractures occurred in nine (25.7%) patients, and no patient developed grade 3 or higher toxicity.

CONCLUSIONS

Re-irradiation with SBRT was safe and can be a salvage treatment option for in-field local recurrence of NSCLC, especially adenocarcinoma, after definitive SBRT.