Correlation of baseline, 1 month, and 3 months MTV with ctDNA at different time points. (A-B) Baseline MTV correlated best with ctDNA at prelymphodepletion (n = 41) (rs, 0.61; P < .0001) within the first month and overall: day 0 (n = 28) (rs, 0.56; P = .002), day 7 (n = 41) (rs, 0.57; P = .0001), day 14 (n = 38) (rs, 0.6; P < .0001), day 21 (n = 33) (rs, 0.54; P = .001), day 28 (n = 38) (rs, 0.6; P < .0001), day 56 (n = 23) (rs, 0.64; P = .001), day 90 (n = 31) (rs, 0.48; P = .006), day 180 (n = 19) (rs, 0.53; P = .02), day 270 (n = 5) (rs, 0.71; P = .4), and day 365 (n = 13) (rs, 0.58; P = .04). (C) MTV at 1 month correlated best with ctDNA on day 28 (n = 53) (rs, 0.60; P < .0001): prelymphodepletion (n = 56) (rs, 0.38; P = .004), day 0 (n = 43) (rs, 0.50; P = .0007), day 7 (n = 56) (rs, 0.58; P < .0001), day 14 (n = 53) (rs, 0.50; P = .0001), day 21 (n = 48) (rs, 0.59; P < .0001), day 56 (n = 34) (rs, 0.41; P = .02), day 90 (n = 41) (rs, 0.48; P = .002), day 180 (n = 25) (rs, 0.39; P = .05), day 270 (n = 12) (rs, 0.32; P = .15), and day 365 (n = 19) (rs, 0.18; P = .47). (D) MTV at 3 months correlated best with ctDNA on day 90 (n = 37) (rs, 0.89; P < .0001): prelymphodepletion (n = 46) (rs, 0.28; P = .06), on day 0 (n = 32) (rs, 0.39; P = .03), day 7 (n = 46) (rs, 0.54; P = .0001), day 14 (n = 44) (rs, 0.46; P = .002), day 21 (n = 39) (rs, 0.49; P = .002), day 28 (n = 44) (rs, 0.41; P = .006), day 56 (n = 30) (rs, 0.69; P < .0001), day 180 (n = 25) (rs, 0.53; P = .007), day 270 (n = 12) (rs, 0.23; P = .64), day 365 (n = 20) (rs, 0.15; P = .54).