CONSORT diagram for plasma ctDNA analysis. A total of 38 patients from the NCI cohort, 79 patients from the institutional clinical cohort, and 43 patients from the imaging cohort were eligible for plasma ctDNA analysis. Of these, 78 patients were eligible for plasma response analysis, 16 patients were eligible for plasma response versus best radiographic response, and 26 patients were eligible for pre-treatment ctDNA variability analysis. ctDNA, circulating tumor DNA; ddPCR, droplet digital polymerase chain reaction.