Stereotactic Ablative Body Radiotherapy (SABR) in Pulmonary Oligometastatic/Oligorecurrent Non-small Cell Lung Cancer Patients: A New Therapeutic Approach

Abstract

Aim: Stage IV non-small cell lung cancer (NSCLC) is characterized by poor prognosis. Palliative chemotherapy and/or best supportive care are considered standard treatment. Nevertheless, for patients with limited distant metastases (1-5 metastases), called oligometastatic disease, better prognosis has been observed. We evaluated response rate, survival, time to progression and toxicity in oligometastatic/oligorecurrent NSCLC patients treated with stereotactic body radiotherapy (SBRT) delivered to all active sites in the lung.

Patients and methods: Twenty-nine lung metastases in 22 patients affected by oligometastatic/oligorecurrent NSCLC were treated with SBRT to all active sites of disease. Inclusion criteria were: controlled primary tumor with complete response or stable disease after surgery/radiotherapy/combined therapy; ≤4 synchronous or metachronous lung metastases at the time of treatment; no other active sites of distant metastases.

Results: Response to treatment was as follows: complete response in 21% of lesions, partial response in 69% of metastases, stable disease in 10%. Ninenty-one percent of patients had complete metabolic response, and 9% had a partial metabolic response. Median follow-up was 18 months. The 1-year and 2-year OS was 86% and 49%, respectively. The 1-year and 2-year PFS was 79% and 40%, respectively. Median time to progression and median OS were 18 months and 24 months, respectively. Local control was 93% at 1 year and 64% at 2 years. Overall, acute toxicity occurred in 18% (4/22) of patients; two patients experienced grade 2 pneumonitis. Grade ≤2 late toxicity occurred in 50% of patients. No grade ≥3 toxicities were recorded.

Conclusion: Aggressive stereotactic radiotherapy is a feasible and well-tolerated treatment for oligometastatic/oligorrecurrent NSCLC patients with lung metastases offering longer survival. Ablative radio therapy has a potential role in the management of well-selected stage IV NSCLC patients while increasing their quality of life and survival.

Keywords: Stereotactic body radiotherapy; lung metastases; oligometastatic non-small lung cancer.