Sarah Verhoeff

32 Chapter 2 Figure 3 A Violin plot of actual distribution of [89Zr]Zr-DFO-girentuximab and [18F]FDG SUV max in tumor lesions per organ site. Black vertical lines are 95% CIs of geometric mean SUVmax, white dots within black lines and values are the actual geometric means; colored dots are individual metastases. The locations represent organ sites with at least five suspect lesions. *Compared to lung lesions, a difference was seen in the height of [89Zr]Zr-DFO-girentuximab SUV max values of lymph node, soft tissue, adrenal gland and kidney lesions (p < 0∙05). **The height of [18F]FDG SUV max values of kidney lesions was significantly higher compared to soft tissue lesions (p < 0∙05). Determinants of tracer-uptake [18F]FDG-uptake was not related to [89Zr]Zr-DFO-girentuximab-uptake (p = 0.29). Univariableanalysis showed a strong relation of tracer-uptake to lesion location (p < 0.005; explaining 61% and 12% of the variation in [89Zr]Zr-DFO-girentuximab and [18F]FDG SUVmax). Largest measured CT lesion diameter was associated with tracer-uptake (p < 0.001, explaining 13% and 16% of the variation in [89Zr]Zr-DFO-girentuximab and [18F]FDG SUVmax), with [89Zr]Zr-DFO-girentuximab SUVmax increasing on average 59% (95%CI 25–102) and [18F]FDG SUVmax 33% (95%CI 14–54) per doubling diameter. In multivariable analysis, mutual adjustment for location, size, and uptake of the other tracer did not substantially alter the correlation between tracer uptake and location. Size and [89Zr]Zr-DFO-