Fig 1.
Decay scheme and energy spectrum of Actinium-225.
(A) Actinium-225 decay scheme [simplified] (B) Energy spectrum of Actinium-225 from a Siemens’ SPECT system). Dashed lines indicate gamma and X-ray emissions and their abundance, including 218 keV representing Francium-221 and 440 keV representing Bismuth-213 for SPECT imaging.
Fig 2.
Biodistribution data in tumor-bearing mice.
Biodistribution of [111In]In-DOTA-TDA (37 kBq) with and without ethiodized oil emulsification in Hep2G tumor-bearing NCG mice at 48 hours post-injection (n = 3, p≤0.0001).
Fig 3.
Survival plots of tumor-bearing mice.
Kaplan-Meier survival plots in Hep2G-tumor bearing mice receiving the following treatments: 1. Saline (60 μL) 2. ethiodized oil alone (60 μL) or 3. 225Ac-DOTA-TDA emulsion (37 kBq, 60 μL).
Fig 4.
Individual tumor growth curves in a subcutaneous model of liver cancer.
NCG mice were injected in the right flank with HEP2G cells when the tumors reached an average volume of 266.5 ± 23.2 mm3 the following treatments were administered intratumorally: 1. Saline (60 μL) 2. ethiodized oil alone (60 μL) or 3. [225Ac]Ac-DOTA-TDA emulsion (37 kBq, 60 μL).
Fig 5.
SPECT/CT images of a rabbit with VX2 hepatic tumor.
Fused SPECT/CT images of rabbit with a VX2 hepatic tumor at 24, 72 and 144-hours post-injection of [225Ac]Ac-DOTA-TDA emulsion. Left Panels: Francium-221 energy window. Right panels: Bismuth- 213 energy window.
Table 1.
Ex vivo biodistribution of [225Ac]Ac-DOTA-TDA in a technical rabbit model.
Table 2.
Tumor ratios based on SPECT imaging of francium-221 and bismuth-213.