Is stereotactic radiotherapy equivalent to metastasectomy in patients with pulmonary oligometastases?

A best evidence topic in thoracic surgery was written according to a structured protocol. The question addressed was whether stereotactic body radiotherapy (SBRT) was equivalent to metastasectomy in patients with pulmonary oligometastases arising from solid tumours. Altogether, 1612 papers were found using the reported search, of which 5 cohort studies derived from 4 patient populations represented the best evidence to answer the clinical question. The authors, journal, date and country of publication, patient group studied, study type, relevant outcomes and results of these papers are tabulated. All 5 studies demonstrated no significant difference in post-treatment overall survival, disease-free survival or local control between SBRT and metastasectomy for pulmonary oligometastases. One of the 5 studies showed a significantly decreased rate of severe complications among the patients treated with SBRT. The other papers reported higher rates of complications in the SBRT groups, invariably due to radiation, but with uncertain clinical significance. The evidence strength of these findings may be largely attenuated due to the small sample size, heterogeneity of SBRT protocols and incomparable follow-up periods between the 2 treatment groups. The selection criteria for the choice of treatment were not stated. We conclude, based on limited evidence, that SBRT has equivalent outcomes to metastasectomy in the treatment of patients with pulmonary oligometastases.