Survival and prognostic factors in 321 patients treated with stereotactic body radiotherapy for oligo-metastases

Background and purpose: To establish a model to predict survival after SBRT for oligo-metastases in patients considered ineligible for surgical resection (SR) and radiofrequency ablation (RFA). Material and methods: Overall survival (OS) rates were estimated in 321 patients treated for 587 metastases with SBRT over 13 years. Patients were treated for a variety of metastasis types with colorectal cancer (CRC) being the most frequent (n = 201). Results: With a median follow-up time of 5.0 years, the median OS was 2.4 years (95% CI 2.3-2.7) and the survival rates were 80%, 39%, 23% and 12% at 1, 3, 5 and 7.5 years after SBRT, respectively. WHO performance status (PS) (0-1) (HR 0.49; p < 0.001), solitary metastasis (HR 0.75; p = 0.049), metastasis <= 30 mm (HR 0.53; p < 0.001), metachronous metastases (HR 0.71; p = 0.02) and pre-SBRT chemotherapy (HR 0.59; p < 0.001) were independently related to favorable OS. Median OS rates were 7.5, 2.8, 2.5, 1.7 and 0.8 years with 0, 1, 2, 3, >= 4 unfavorable prognostic factors, respectively. The treatment-related morbidity was moderate. However, three deaths were possibly treatment-related. Conclusion: Prognostic factors may predict long-term survival in patients with oligo-metastases treated with SBRT. (C) 2015 Elsevier Ireland Ltd. All rights reserved.