Page 107 - 89Zr-Immuno-PET:Towards a Clinical Tool to Guide Antibody-based Therapy in Cancer

Table 1 Repeatability coefficients (%) of Zr-89-mAbs
Noise-induced variability of 89Zr-immuno-PET
VOI type
Brain Kidney Lung Spleen Liver Combined
Blood pool Bone marrow
89Zr-antiCD20 89Zr-antiEGFR 89Zr-antiCD44 37 MBq74inj 18 MBq74inj 18 MBq37inj 18 MBq37inj
D0 D3 D6 D0 D3 D6 D0 D3 D6 D0 D1 D4
abcbacd
n=7 n=6 n=6 n=7
3.5 6.0 5.2 2.4 1.2 4.8 5.2 2.6 1.1 0.6 0.8 1.5 1.9 4.7 8.2 3.4 1.5 1.6 1.4 1.6 2.3 4.7 5.5 2.5
8.3 17.1 42.7 10.6 15.1 12.4 20.6 23.9
- D3 D6 - n=26 n=32
n=6 n=6
6.5 7.6 6.5 6.8 1.6 2.7 8.8 17.2 0.8 3.9 6.3 11.1
29.9 38.5 21.0 38.4
D3 D6 n=26 n=32
39.1 45.5 35.7 37.1 26.8 26.6
n=6 n=6 n=6 n=12
3.0 7.6 13.8 3.7 3.5 7.1 12.5 3.7 1.6 1.8 3.4 1.0 5.2 8.4 13.9 4.4 1.4 1.6 1.6 1.2 4.2 6.4 10.7 3.4
13.4 28.8 47.4 10.4 20.7 19.6 26.6 13.0
- D3 D6 - n=7 n=7
- 34.9 54.1 - - 28.8 48.2 - - 35.4 32.7 -
n=12 n=12
2.9 7.3 3.5 9.1 1.6 6.7 3.7 7.8 2.4 1.7 3.0 7.1
18.3 32.3 17.8 20.7
D1 D4 n=19 n=19
29.5 33.5 5 20.7 28.0
20.1 24.2
Tumor
SUVmax - 41.6 41.5 -
SUVpeak SUVmean
- 35.2 31.6 - - 26.7 24.5 -
n = number of VOIs per group.
Combined = all VOIs of brain, kidney, lung, spleen and liver, analyzed together as one group.
a No brain VOI obtained in patient 2 (outside field of view) and 6 (tumor localization in the nasopharynx). b No brain VOI obtained in patient 6 (tumor localization in the nasopharynx).
c No kidney, lung, spleen, liver, blood pool, bone marrow in patient 2 (outside field of view). No brain VOI obtained in patient 6 (tumor localization in the nasopharynx). No brain VOI obtained in patient 1 (mismatch between low dose CT and PET image due to patient movement).
d No brain VOI obtained in patient 8 (outside field of view).
Data marked in grey is presented as Bland-Altman plots in Figure 2 (normal tissue) and 4 (tumor).
For 18 MBq74inj, the RC for the manually delineated large organs remained within 12% for all time points (Figure 3A). For the image derived blood pool (Figure 3B), RC increased from 8 to 43% from D0 to D6. We observed similar RC for 89Zr-antiCD20 (18 MBq74inj), 89Zr-antiEGFR (18 MBq37inj) and 89Zr-antiCD44 (18 MBq37inj) for the manually delineated organs (Fig. 3C) and for the image derived blood pool (Figure 3D). For the individual normal tissue VOI (brain, kidney, lung, spleen, liver, bone marrow), we found no apparent differences in RC for the various antibodies, except for kidney D6.
A decrease in RC was observed for increasing SUV and volume (Supplemental Figure 1). For example, for the fixed size blood pool VOI (2.9 mL) for 89Zr-antiCD20 mAb (37MBq74inj), a decrease in RC from 42%, 17% to 8% was observed, with a corresponding increase in SUV from 3.9, 5.8 to 11.7. For VOI with similar SUV (3.1-3.3) for 89Zr-antiCD44 mAb (18MBq37inj), a decrease in RC
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