Ideas in this flowchart

• Monitoring dynamic ctDNA changes during treatment can indicate treatment success or emerging resistance.
• Declining or disappearing ctDNA generally signals treatment sensitivity.
• In non–small cell lung cancer, ctDNA dynamics were evaluated during sotorasib treatment.
• Sotorasib is a targeted therapy that blocks the KRAS G12C protein.
• Early disappearance of detectable KRAS G12C ctDNA was linked to better outcomes.
• Persistent ctDNA predicted a poor response.
• Evidence: Skoulidis F, et al. (2025), Nature Medicine.
• In small cell lung cancer, ctDNA decline after chemotherapy indicated treatment sensitivity.
• A greater than two-fold ctDNA drop after one chemotherapy cycle indicated sensitivity to platinum-based treatment.
• This ctDNA decline was associated with longer survival.
• Evidence: Murciano-Goroff YR, et al. (2024), JCO Precision Oncology, 8: e2400216.