Recommendations for a practical implementation of circulating tumor DNA mutation testing in metastatic non-small-cell lung cancer

•LB is a rapidly evolving diagnostic tool that may be an adjunct or an alternative to TB in clinic.•Pragmatic scenarios for ctDNA mutation testing to identify actionable targets in NSCLC are explored.•ctDNA mutation testing may identify resistance mechanisms, discordant clinical history, and intertumor/intratumor heterogeneity.•ctDNA mutation testing may be useful if the tumor location is hard to biopsy or if an insufficient tumor sample was taken.•Proper implementation of ctDNA mutation testing in routine clinical practice is envisioned in the near future.