Nuclear Model Calculations on the Production of Auger Emitter 165Er for Targeted Radionuclide Therapy

Sadeghi, Mahdi; Enferadi, Milad; Tenreiro, Claudio

doi:10.4236/jmp.2010.14033

Cited by 13 publications

(9 citation statements)

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“…For the pre-equilibrium complex particle emission, the phenomenological model is used. Hauser-Feshbach formalism is used to describe the equilibrium particle emission (Sadeghi et al, 2010).…”

Section: Methodsmentioning

confidence: 99%

“…124 Te(p,2n) 123 I and 124 Te(d,3n) 123 I reactions require highly enriched 124 Te in order to minimize the possible contamination in the target material (Braghirolli et al, 2014;Herzog et al, 2002;Sheh et al, 2000;Goriely, 1998;Kondo et al, 1977). 124 Te (d,xn) 124 I reaction cross sections are essential to determine the best possible way to produce 124 I, since different production methods will result in different impurities and economical viabilities viabilities (Braghirolli et al, 2014;Sadeghi et al, 2010;Sadeghi et al, 2008;Bastian et al, 2001;Clem and Lambrecht, 1991;Firouzbakht et al, 1993).…”

Section: Introductionmentioning

confidence: 99%

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124,125Te(p,xn)123,124I ve 123,124Te(d,xn)123,124I İçin Reaksiyon Tesir Kesitleri

Ünal¹,

Akçaalan²

2020

European Journal of Science and Technology

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The iodine isotopes of 123 I and 124 I with half lives of 13.2 hours and of 4.2 days respectively are commonly used in nuclear medicine and are becoming more widespread recently. The isotope of 123 I is ideal for a gamma camera with the energy of 159 keV to the patient with a much less radiation dose whereas the radionuclide 124 I is a positron emitter and is useful in some positron emission tomography (PET) for radiopharmaceuticals. The gamma ray will penetrate tissue very effectively without an excessive radiation dose. Iodine-123 decays by electron capture emitting gamma rays at 0.028 and 0.160 MeV that has high penetration power to tissue but no excessive radiation dose. The half-life of 4.2 d and the 23% positron decay allow localization with monoclonal antibodies, and the PET imaging which makes Iodine-124 radionuclide a good candidate for being a diagnostic and a therapeutic.This study aims on the calculation of the excitation functions for 123 I and 124 I various production mechanisms. TALYS 1.6 is used to calculate the reaction cross sections for 123,124,125 Te bombarded with protons and deuteriums to produce 123,124 I radioisotopes commonly used in medical applications. The calculated results were compared with available experimental results from EXFOR. The results are interpreted in terms of deciding which radoisotope is more appropriate to produce with which reaction and evaluating the effects in the reaction mechanisms. In addition, the relative reaction cross-sections of 123,124 I radioisotopes obtained by bombarding 124 Te target with protons were discussed, and the common reaction for the production of 123 I was evaluated to be the 124 Te(p, 2n) 123 I reaction on the highly enriched 124 Te. Thus, it is considered that a very high level of enrichment on the target must be achieved in order to prevent contamination caused by competing reactions of (p, n) and (p,2n). It is concluded that 123 I production is more suitable for small and mediumi-sized cyclotrons.

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Section: Methodsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

124,125Te(p,xn)123,124I ve 123,124Te(d,xn)123,124I İçin Reaksiyon Tesir Kesitleri

Ünal¹,

Akçaalan²

2020

European Journal of Science and Technology

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“…The recent phase III clinical trial of Lutathera ® ([ 177 Lu]DOTATATE) for neuroendocrine tumors [1] and phase II clinical trial of [ 177 Lu]PSMA-617 for prostate cancer [2] show receptor targeted, medium energy electron-emitting radiopharmaceuticals are effective in treating these solid tumors. However, for the treatment of micrometastatic or disseminated cancers, radiopharmaceuticals emitting shorter range, higher linear energy Proton, deuteron, or alpha particle irradiation of erbium or holmium targets produces no-carrier-added 165 Er through a variety of nuclear reaction routes [14]. Proton or deuteron irradiation of erbium produces 165 Tm (t 1/2 = 30.06 h) via nat Er(p,xn) 165 Tm [15,16] or nat Er(d,xn) 165 Tm [17], respectively, which can be chemically isolated prior to its β − decay to 165 Er.…”

Section: Introductionmentioning

confidence: 99%

A High Separation Factor for 165Er from Ho for Targeted Radionuclide Therapy

et al. 2021

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Background: Radionuclides emitting Auger electrons (AEs) with low (0.02–50 keV) energy, short (0.0007–40 µm) range, and high (1–10 keV/µm) linear energy transfer may have an important role in the targeted radionuclide therapy of metastatic and disseminated disease. Erbium-165 is a pure AE-emitting radionuclide that is chemically matched to clinical therapeutic radionuclide 177Lu, making it a useful tool for fundamental studies on the biological effects of AEs. This work develops new biomedical cyclotron irradiation and radiochemical isolation methods to produce 165Er suitable for targeted radionuclide therapeutic studies and characterizes a new such agent targeting prostate-specific membrane antigen. Methods: Biomedical cyclotrons proton-irradiated spot-welded Ho(m) targets to produce 165Er, which was isolated via cation exchange chromatography (AG 50W-X8, 200–400 mesh, 20 mL) using alpha-hydroxyisobutyrate (70 mM, pH 4.7) followed by LN2 (20–50 µm, 1.3 mL) and bDGA (50–100 µm, 0.2 mL) extraction chromatography. The purified 165Er was radiolabeled with standard radiometal chelators and used to produce and characterize a new AE-emitting radiopharmaceutical, [165Er]PSMA-617. Results: Irradiation of 80–180 mg natHo targets with 40 µA of 11–12.5 MeV protons produced 165Er at 20–30 MBq·µA−1·h−1. The 4.9 ± 0.7 h radiochemical isolation yielded 165Er in 0.01 M HCl (400 µL) with decay-corrected (DC) yield of 64 ± 2% and a Ho/165Er separation factor of (2.8 ± 1.1) · 105. Radiolabeling experiments synthesized [165Er]PSMA-617 at DC molar activities of 37–130 GBq·µmol−1. Conclusions: A 2 h biomedical cyclotron irradiation and 5 h radiochemical separation produced GBq-scale 165Er suitable for producing radiopharmaceuticals at molar activities satisfactory for investigations of targeted radionuclide therapeutics. This will enable fundamental radiation biology experiments of pure AE-emitting therapeutic radiopharmaceuticals such as [165Er]PSMA-617, which will be used to understand the impact of AEs in PSMA-targeted radionuclide therapy of prostate cancer.

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“…Moreover, there are several other elements for which there exist multiple isotopes, where some can be used in targeted imaging and therapy, and others are suitable for PAC. The most attractive example might be the lanthanides, which possess similar chemical properties and are represented by several candidates useful in targeted imaging and therapy (e.g., 177 Lu (β – therapy), 152, 155, 149, 161 Tb, − and 165 Er) and also several candidates suitable as PAC isotopes (e.g., 152, 154 Eu). All properties of the selected probes for PAC measurements are presented in Table (see also Figure ).…”

Section: Introductionmentioning

confidence: 99%

Perturbed Angular Correlation as a Tool to Study Precursors for Radiopharmaceuticals

et al. 2020

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One of the key components of radiopharmaceuticals for targeting imaging and therapy is a stable bifunctional chelating system to attach radionuclides to selective delivery systems. After-effects of radioactive decay can cause the release of a radioactive isotope from its chelation agent. Perturbed angular correlation (PAC) of γ-rays has become a unique technique to study the behavior of complexes formed between a chelating agent and radionuclide in vivo (in real time) over a relevant range of concentrations (10 −12 M). In the present work, four radionuclides, 111 In, 111m Cd, and 152, 154 Eu, were investigated with diethylenetriaminepentaacetic acid (DTPA) at different pH values to determine the stability constants of the complexes as well as the effects of post-decay processes, which play a major role in determining the suitability of these complexes for application as radiopharmaceuticals (e.g., in vivo generators). The study provides a convenient parameter for the characterization of radionuclide−chelator systems using the PAC method. PAC is proven to be a suitable tool to study novel chelators and radiopharmaceutical precursors attached to radiometals.

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Nuclear Model Calculations on the Production of Auger Emitter 165Er for Targeted Radionuclide Therapy

Cited by 13 publications

References 14 publications

124,125Te(p,xn)123,124I ve 123,124Te(d,xn)123,124I İçin Reaksiyon Tesir Kesitleri

124,125Te(p,xn)123,124I ve 123,124Te(d,xn)123,124I İçin Reaksiyon Tesir Kesitleri

A High Separation Factor for 165Er from Ho for Targeted Radionuclide Therapy

Perturbed Angular Correlation as a Tool to Study Precursors for Radiopharmaceuticals

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