Potent candidates for Targeted Auger Therapy: Production and radiochemical considerations

Targeted Radionuclide Therapy Using Auger Electron Emitters: The Quest for the Right Vector and the Right Radionuclide

“…Iodine-125 radiopharmaceuticals have been developed ([ 125 I]I-UdR or mAbs conjugates) [ 20 , 21 , 22 , 23 ], but their clinical use is limited by 125 I’s long physical half-life (t 1/2(Phys) = 59.4 days). A comprehensive list of AEE candidates has recently been reviewed in [ 24 ]. Platinum-193 m (t 1/2(phys) = 4.3 days) and platinum-195 m (t 1/2(phys) = 4.0 days) also are very attractive AEEs because they emit a very high number of Auger electrons (between 20 and 30) per decay and photons of intermediate energy (66 and 76 keV) than can be used for imaging.…”

Novel Bifunctional [16]aneS4-Derived Chelators for Soft Radiometals

“…However, the range of soft radiometals relevant to theranostics is rarely investigated, due to a lack of well-suited bifunctional chelators with active chemical handles that can be practically conjugated to targeting vectors ( Figure 1 A). Suitable soft radiometals for AeRT include isotopes of platinum ( 193m Pt and 195m Pt) and rhodium ( 103m Rh) [ 21 , 22 ]. Additionally, 103 Pd and 105 Rh, an X-ray emitter and a beta particle emitter, respectively, also have potential use in TRT.…”

A Third Generation Potentially Bifunctional Trithiol Chelate, Its nat,1XXSb(III) Complex, and Selective Chelation of Radioantimony (119Sb) from Its Sn Target

“…1,2 Among many TRT radionuclide choices, Meitner-Auger Electron (MAE) emitting radionuclides have unique properties to be advantageously leveraged in cancer TRT. 3−7 Antimony-119 ( 119 Sb, t 1/2 = 38.19 h, EC = 100% (MAE)) 8 is considered one of the most promising MAE emitting radionuclides for TRT applications 9,10 and has potential application in theranostic nuclear medicine with its imaging radioisotope congener antimony-117 ( 117 Sb, t 1/2 = 2.8 h, γ = 85.9%, 158.56 keV, EC = 97.3%, β + = 1.8%). 11 Antimony-119 is a MAE emitting radionuclide that emits 23−24 conversion electrons and MAEs with energies up to 28 keV and no dosimetrically problematic gammas.…”

“…Targeted radionuclide therapy (TRT) has gained momentum as an attractive cancer treatment method, as seen in recent clinical trials. , Among many TRT radionuclide choices, Meitner-Auger Electron (MAE) emitting radionuclides have unique properties to be advantageously leveraged in cancer TRT. − Antimony-119 ( 119 Sb, t 1/2 = 38.19 h, EC = 100% (MAE)) is considered one of the most promising MAE emitting radionuclides for TRT applications , and has potential application in theranostic nuclear medicine with its imaging radioisotope congener antimony-117 ( 117 Sb, t 1/2 = 2.8 h, γ = 85.9%, 158.56 keV, EC = 97.3%, β + = 1.8%) …”

“…Electrons with these energies have high linear energy transfer (LET) and consequently high relative biological effectiveness (RBE) in a short range (nm-μm), capable of delivering lethal radiation doses in subcellular ranges while having little off-target toxicity . The densely ionizing pathlengths up to 15 μm length in tissue reach a cell nucleus from the cell surface. ,− Its lighter radioisotope 117 Sb emits a 158.6 keV gamma ray that is ideal for single photon emission computed tomography (SPECT) . Together, 119 Sb and 117 Sb form a theranostic (therapy and diagnostic) radionuclide pair, facilitating precise measurement of patient specific biodistribution and calculations of in vivo dosimetry.…”