Is microwave ablation an alternative to stereotactic ablative body radiotherapy in patients with inoperable early-stage primary lung cancer?

A best evidence topic was written according to a structured protocol. The question addressed was: in patients with inoperable early-stage primary lung cancer does microwave ablation (MWA) or stereotactic ablative body radiotherapy (SBRT) achieve improved outcomes in terms of local control, recurrence, survival and complications? Altogether, more than 550 papers were found using the reported search, of which 12 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. No single study directly compared the effects of MWA with SBRT. However, the best available evidence for MWA (7 studies) was compared to that for SBRT (5 studies). The range of 3-year survival reported for MWA was 29.2-84.7%, compared with 42.7-63.5% for SBRT. The range of median survival was 35-60 months for MWA and 32.6-48 months for SBRT. This suggests similar outcomes between these two 2 techniques. Different side-effect profiles were observed between techniques with MWA associated with pneumothorax and fever and SBRT most commonly causing radiation pneumonitis and rib fractures. The evidence base for MWA is less than that for SBRT and is heterogenous in terms of participants and technical design. However, within these limitations, we conclude that MWA appears comparable with SBRT in terms of local control and survival rates.