Session Item

Stereotactic Ablative Radiotherapy (SABR) has shown high rates of local control and prolonged survival in early-stage non-small cell lung cancer (NSCLC), though its role in oligometastatic disease is undefined. This study aimed to evaluate SABR as a local consolidative therapy in oligometastatic (oligoM) NSCLC patients.

In this prospective trial, we sought to evaluate SABR to primary locally advanced (LA) tumor and metastatic sites  in oligoM NSCLC patients. Fit patients received initial systemic therapy according to international guidelines. Patients without progression after front-line therapy (chemotherapy, immunotherapy and targeted therapy) were evaluated by an 18F-FDG-PET/CT to receive consolidative SABR to the primary and all metastatic sites ( ≤ five lesions). 

Between May 2018 and February 2021, 17 oligoM NSCLC were included. Median age was 71 years (range,38-85), 14 (82%) were male and 10 (59%) had adenocarcinoma histology. The main site of metastasis was bone, adrenal gland and brain in  7 (41%), 4 (23%) and 3 (18%) patients, respectively. 15 (88%) patients received systemic front-line therapy: chemotherapy in 8 (47%), immunotherapy in 4 (23%) and a tyrosine kinase inhibitor in 2 (12%). The median administered dose to primary LA tumor was 45 Gy (range,35-50) in 5 fractions.

Median follow-up achieved 16 months (range, 6-37). 3 (18%) and 7 (41%) patients developed local relapse and distant metastasis after a median time of 14 months (range,9-15) and 4 months (range,3-6), respectively. No adverse events of ≥G3 was recorded. At las follow-up 16 (94%) patients are alive, only 5 (33%) discontinued first front-line therapy and started second-line therapy.

The use of SABR on primary LA tumor in oligoM NSCLC patients was well tolerated and showed favorable clinical outcomes regarding second line therapy-free survival and overall survival.

Also considering the results of other prospective trials, SABR to primary LA tumor should be included as standard of care in oligoM NSCLC patients.