The role of stereotactic body radiotherapy (SBRT) in the treatment of recurrent / progressive lung lesions after primary treatment

To evaluate treatment outcomes and toxicity of pulmonary SBRT for intrathoracic recurrence in patients with locally advanced NSCLC treated as a combination of surgery, radiotherapy or chemotherapy.

A total of 46 patients with NSCLC who received thoracic SBRT for local or non local intrapulmonary recurrent lesions in our department from 2009 to 2019 were retrospectively enrolled in this study. The patients received median 43.4 Gy (25 Gy -60 Gy) radiotherapy using the CyberKnife radiosurgery system in median 3.6 fractions (range, 1-8).Univariate and multivariate Cox regression analyses were performed on the factors predicting outcomes.

The median follow up time after SBRT was 23.5 months. Treatment of the primary tumor consisted of surgical resection, radiochemotherapy, and systemic therapy in 25, 8 and 13 patients, respectively. İsolated local recurrence, intrathoracic recurrence and distant metastasis were detected in 5 (10.9%), 12 (26.1%) and 8 (17.4%) patients, respectively. Kaplan-Meier analysis of 2 year OS, PFS and LC for all tumors treated after SBRT were; 51%, 56% and 91%, respectively. In parameters related to patient and treatment; no statistical significance was found affecting local control and survival.(p>0.05). Grade 2 radiation pneumonitis and chest wall pain were observed in 2 (4.3%) and 1 (2.1 %) patients. Grade 3 toxicity was detected in 3 ( 6.5%) cases.

Pulmonary SBRT for recurrent NSCLC is a good treatment option with favourable LC and promising survival. SBRT can be an effective treatment modality in the treatment of patients with local/limited pulmonary relapses with acceptable toxicity rates.