High SUVs Have More Robust Repeatability in Patients with Metastatic Prostate Cancer: Results from a Prospective Test-Retest Cohort Imaged with ¹⁸F-DCFPyL

Table 2

Head-to-head comparison of semiquantitative parameters for both scans, for all lesions (), osseous (), and lymph node lesions (), mean value and standard deviation along with respective Pearson correlation, Kendall’s tau (), and within-subject coefficient of variation (wCOV).

	Test	Retest		Kendall’s	wCOV (%)
All lesions ()
SUVmax			0.988	0.87	12.1
SUVmean			0.996	0.93	7.3
PSMA-TV			0.987	0.83	23.5
TL-PSMA			0.991	0.85	24.0
Osseous lesions ()
SUVmax			0.990	0.87	12.0
SUVmean			0.996	0.92	7.8
PSMA-TV			0.988	0.85	22.8
TL-PSMA			0.991	0.86	23.3
Lymph node lesions ()
SUVmax			0.984	0.86	8.8
SUVmean			0.996	0.95	3.8
PSMA-TV			0.987	0.78	24.1
TL-PSMA			0.994	0.86	23.5

Regardless which statistical test was used, mean standardized uptake value (SUV_mean) achieved the highest correlative indices (Pearson correlation, Kendall’s ) and the lowest wCOV, indicating excellent repeatability, in particular for lymph node disease (marked in italic). Volumetric features, however, revealed lower and still acceptable repeatability, as indicated by increased wCOV. SUV_max: maximum standardized uptake value; PSMA-TV: PSMA tumor volume; TL-PSMA: total lesion PSMA.