Positron emission tomography and pharmacokinetics of 2-[18F]-fluoroethyl choline for metabolic studies in breast cancer xenografts

Figures & data

Figure 1. Coronal [¹⁸F]FECh PET images for the HBCx34, MAS98.06 and MAS98.12 xenografts 90 minutes after [¹⁸F]FECh injection. Red line indicates location of bilaterally implanted xenografts. Volumes of interest were delineated in the corresponding computer tomography image.

Figure 2. Mean arterial input functions for the HBCx34, MAS98.06 and MAS98.12 breast cancer xenografts.

Figure 3. Median SUV curves for the HBCx34, MAS98.06 and MAS98.12 breast cancer xenografts at different time points after injection. Standard deviation for positive direction is shown.

Figure 4. Measured SUV in the individual representative HBCx34, MAS98.06 and MAS98.12 breast cancer xenografts and corresponding fitted curves for a two-tissue compartment model.

Figure 5. (a) Relationship between Patlak slope KP and metabolic rate constant k₃. Regression line: y = 1.13x + 0.01, r = 0.57. (b) Relationship between Patlak slope K_P and metabolic rate MR_[18F]FECh. Regression line: y = 0.87x–0.001, r = 0.97.

Table I. Mean two-tissue compartment model and Patlak plot parameters and mean SUV for the HBCx34, MAS98.06 and MAS98.12 breast cancer xenografts.

Xenograft Name	Two-tissue compartment model parameters						Patlak Plot parameters		SUV
	Blood fraction, %	k1, min^−1	k2, min^−1	k3, 10^−3 min^−1	MR[18F]FECh, 10^−3	R^2	KP; 10^−3 ml/ min/ml	V	mean SUVt = 90
MAS98.12	0.9	0.06	0.11	9	4.3	0.97	3.3	0.56	0.53
	(± 0.9)	(± 0.02)	(± 0.01)	(± 2)	(± 0.8)	(± 0.02)	(± 0.6)	(± 0.20)	(± 0.15)
HBCx34	2.0	0.06	0.21*	9	3.2	0.97	2.5	0.35	0.33
	(± 2.1)	(± 0.05)	(± 0.08)	(± 4)	(± 3.0)	(± 0.03)	(± 2.7)	(± 0.30)	(± 0.20)
MAS98.06	0.5	0.07	1.16*	13*	5.1	0.98	4.2*	0.43	0.45
	(± 0.3)	(± 0.01)	(± 0.01)	(± 2)	(± 0.3)	(± 0.01)	(± 0.3)	(± 0.04)	(± 0.12)

All values shown as mean ± SD. *p < 0.05, compared to MAS98.12 xenografts.

Table II. Pearson's correlation coefficients for two-tissue compartment model and Patlak plot parameters and mean SUV.

	SUV	Two-tissue compartment model parameters
	mean SUVt = 90	Blood fraction	MR[18F]FECh	k1, min^−1	k2, min^−1	k3, min^−1
Patlak Slope, KP	0.71^†	−0.12	0.97^†	0.48	− 0.58*	0.57*
Intercept, V	0.81^†	0.44	0.80^†	0.80^†	− 0.39	0.04
SUV mean, 90 minutes post-injection		0.11	0.87^†	0.52*	− 0.50	0.31
Blood fraction			0.08	0.71^†	0.46	− 0.36
MR[18F]FECh				0.69^†	−0.50	0.59*

*p < 0.05; ^†p < 0.01.