Optimized SPECT Imaging of²²⁴Ra α-Particle Therapy by²¹²Pb Photon Emissions

Abstract

Visual Abstract

Preparation of Medical 228Th-224Ra Radionuclide Generator Based on SiO2@TiO2 Microspheres

“…In a compelling demonstration of this potential, Mikalsen et al have illustrated the feasibility of SPECT/CT imaging based on 224 Ra, affirming its clinical utility in intraperitoneally administered activity trials. 12 Compared with the decay diagram of 223 Ra (Figure 1), an undeniable point is that daughter radionuclides with longer half-lives (specifically 212 Pb and 212 Bi) in the decay chain of 224 Ra may induce secondary radioactivity biodistribution, leading to potential biotoxicity in radionuclide therapy. From 1948 to 1975, 1471 patients with ankylosing spondylitis were adopted radionuclide therapy via intravenous injection of free 224 Ra in Germany.…”

“…Additionally, the γ-rays (241 keV) released during the decay of 224 Ra can be utilized for single-photon emission computed tomography (SPECT) imaging during the treatment process. In a compelling demonstration of this potential, Mikalsen et al have illustrated the feasibility of SPECT/CT imaging based on 224 Ra, affirming its clinical utility in intraperitoneally administered activity trials . Compared with the decay diagram of 223 Ra (Figure ), an undeniable point is that daughter radionuclides with longer half-lives (specifically 212 Pb and 212 Bi) in the decay chain of 224 Ra may induce secondary radioactivity biodistribution, leading to potential biotoxicity in radionuclide therapy.…”

Theranostic Imaging Surrogates for Targeted Alpha Therapy: Progress in Production, Purification, and Applications

“…Approximately 400 alpha-emitting radionuclides (5-100% emission intensity) are known; however, only radionuclides that possess a sufficiently long half-life, absence of long-lived toxic progeny, and feasible high-yield production routes are suitable for TAT consideration [8,9]. Radionuclides that have shown potential for TAT include 227 Th, 225 Ac, 224 Ra, 223 Ra, 212 Pb, 211 At, and 149 Tb [1,2,[10][11][12][13][14][15][16][17][18][19][20].…”

Influence of the Molar Activity of 203/212Pb-PSC-PEG2-TOC on Somatostatin Receptor Type 2-Binding and Cell Uptake

“…Recently, the true matched pair 203/212 Pb has come into focus through several first in-human theranostic applications [9][10][11]. While 203 Pb (t 1/2 = 52 h; 279 keV gamma ray; 81% intensity) represents an ideal elementally matched imaging surrogate, 212 Pb itself can be used for SPECT imaging [12]. A true matched pair could finally overcome the differential pharmacokinetic/pharmacological properties observed between diagnostic and therapeutic radiotracers with unmatched radionuclides pairs [13].…”