Table 3.

PET parameters and cut-off values to determine ER status by [¹⁸F]-FES-PET (n = 23).

Parameter	ROI Size	Cut-Off ER− Sensitivity >90%	Cut-Off ER+ Specificity >90%	NPV *	PPV ‖	Equivocal Metastases (%) ‡
SUVmax	whole-tumor	<4.9	≥11.4	75	90	39
SUVmean	whole-tumor	<2.2	≥7.7	75	100	48
SUVmin	whole-tumor	<1.2	≥4.8	67	89	48
SUVmax	two-thirds	<2.5	≥9.5	75	100	52
SUVmean	two-thirds	<1.7	≥6.9	75	100	57
SUVmin	two-thirds	<1.3	≥5.2	67	100	57
SUVmax	one-third	<1.6	≥6.5	67	100	48
SUVmean	one-third	<1.5	≥5.8	67	100	52
SUVmin	one-third	<1.3	≥5.3	67	100	52
TBRmax	whole-tumor	<0.33	≥0.73	75	100	30
TBRmean	whole-tumor	<0.14	≥0.45	75	92	30
TBRmin	whole-tumor	<0.07	≥0.29	50	100	52
TBRmax	two-thirds	<0.15	≥0.65	75	100	48
TBRmean	two-thirds	<0.10	≥0.42	67	90	43
TBRmin	two-thirds	<0.08	≥0.37	67	100	57
TBRmax	one-third	<0.10	≥0.39	67	100	39
TBRmean	one-third	<0.09	≥0.34	50	91	43
TBRmin	one-third	<0.08	≥0.32	67	100	48

* Negative predictive value, and the lowest cut-off value was used for ER− metastases; ^‖ Positive predictive value, and the highest cut-off value was used for ER+ metastases; ^‡ All measurements in-between the cut-off values can be defined as equivocal metastases. Abbreviations: ER = estrogen receptor; ROI = region-of-interest; NPV = negative predictive value; PPV = positive predictive value; SUV = standardized uptake value; TBR = tumor-to-background ratio.