Page 188 - 89Zr-Immuno-PET:Towards a Clinical Tool to Guide Antibody-based Therapy in Cancer

Chapter 9
uptake. For liver, an increased Ki was observed for 89Zr-antiEGFR, 89Zr-antiPSMA and 89Zr-antiHER2 (3.8, 5.7 and 1.7 respectively compared to 1.1), corresponding with known target expression (20). No increased Ki was observed for lung and spleen (Table 3).
Table 3 Net rate of irreversible uptake Ki
Kidney Liver Lung Spleen
89Zr-antiCD20 0.4(0.2-0.6) 1.1(0.8-2.1) 0.2(0.1-0.3) 0.6(0.5-0.8)
89Zr-antiEGFR 0.7(0.4-1.2) 3.8(1.9-5.8) 0.4(0.2-0.6) 0.5(0.3-0.5)
89Zr-antiPSMA 2.8(2.4-3.1) 5.7(4.9-8.4) 0.1(0.0-0.2) 1.5(1.2-1.7)
89Zr-antiHER2 1.5(0.9-1.8) 1.7(1.4-2.0) 0.2(0.0-0.5) 0.7(0.4-0.8)
Baseline 0.7(0.4-1.3) 1.1(0.8-2.1) 0.2(0.1-0.3) 0.5(0.3-0.7)
Ki (μL×g-1×h-1) presented as median (interquartile range)
Figure 3 Transfer constants for 89Zr-antiPSMA in the kidney
Example for one patient in the 89Zr-antiPSMA study, with (A) measured activity concentrations in serum (A) and (B) measured activity concentrations in the kidney. Patlak linearization (C) to determine the offset (VT) and slope (Ki) of the linear fit to the last three time points (same data). (D) Total reversible (red line) and total irreversible (blue line) contributions to the measured signal (black line).
Dashed lines represent estimated values for non-specific reversible uptake (calculated as baseline ) and non-specific irreversible uptake (calculated as baseline ).
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