Fig. 4

In vitro saturation cell binding calculation of [68Ga/177Lu]-DOTA-estradiol derivatives with the ER-positive MCF-7 cancer cell line. [68Ga]-DOTA-estradiol showed a binding affinity of 17.68 nM (left), whereas its [177Lu]-DOTA-estradiol counterpart (right) displayed a somewhat better cell binding affinity, with the Kd value of 14.38 nM (n = 3).