Role of stereotactic body radiation therapy for lung metastases from radio-resistant primary tumours.

OBJECTIVES: A retrospective analysis was performed on patients treated for lung oligo-metastatic disease from radio-resistant histology groups.

METHODS: The primary end point was local control (LC), secondary end points were overall survival (OS) and progression free survival (PFS). Toxicity was scored according to CTCAE 4.03.

RESULTS: 200 patients were analyzed: 49.5% of the cases derived from colorectal primary tumors, 20.5% from sarcomas, 12.0% from renal cell carcinoma and the rest from other mixed origin. The mean follow-up was 24.2 months. LC at 1 and 2 years was 91, 84.9%. Primary histology and the presence of extra-pulmonary disease had a significant impact on LC. OS at 1 and 2 years was 88.7, 65.4%. Primary histology, disease free interval, presence of extra-pulmonary disease, number of irradiated lung lesions and age showed a correlation with prognosis at univariate analysis. PFS at 1 and 2 years was 84, 57.7%. The presence of extra-pulmonary disease and the number of irradiated lung lesions correlated with prognosis. Treatment was well tolerated with no G3-4 acute or late toxicity recorded.

CONCLUSION: Colorectal metastases showed a higher rate of local relapse. However, the factors mostly influencing prognosis were the presence of extra-pulmonary disease and the number of lung lesions.