Radiolabeled Somatostatin Analogues in the Treatment of Non-GEP-NET Tumors

Versari, Annibale; Filice, Angelina; Casali, Massimiliano; Sollini, Martina; Frasoldati, Andrea

doi:10.1007/978-3-319-63067-0_37

Cited by 1 publication

(2 citation statements)

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Section: Introductionmentioning

confidence: 99%

“…Currently, octreotide, a synthetic analogue of the somatostatin hormone, is widely used in nuclear medicine and investigated for diagnostics and therapy of neuroendocrine tumors and other somatostatin receptor positive tumors. 1 Octreotide conjugates with diethylenetriaminepentaacetic acid (DTPA) and 1,4,7,10-tetraaza cyclododecane-1,4,7,10-tetraacetic acid (DOTA) ligands form stable complexes with Y 3+ , Lu 3+ , In 3+ , and Cu 2+ . Among the labeled conjugates, there are radiopharmaceuticals that are used in routine therapy ( 177 Lu-DOTATATE) or diagnostics ( 111 In-DTPAoctreotide) or are under clinical trials ( 90 Y-DOTATOC, 90 Y-DOTATATE, 64 Cu-DOTATATE, and 213 Bi-DOTATOC).…”

Section: Introductionmentioning

confidence: 99%

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From octreotide to shorter analogues: Synthesis, radiolabeling, stability

Yakusheva

Titchenko

Egorova

et al. 2019

Labelled Comp Radiopharmac

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This study aims at analyzing complexation properties of two new short somatostatin analogues, their synthesis, radiolabeling with 44Sc, 207Bi, and 152Eu and stability in vitro. Short tetrapeptide Phe‐d‐Trp‐Lys‐Thr and pentapeptide Thz‐Phe‐d‐Trp‐Lys‐Thr were first conjugated with the DOTA macrocyclic chelator. These conjugates were radiolabeled with 44Sc, 207Bi, and 152Eu and characterized by thin‐layer chromatography (TLC) and HPLC. The radiochemical purity was measured using digital autoradiography and gamma spectrometry. Optimum conditions of DOTA‐conjugate labeling were found: 0.1mM, pH 8.0 to 8.4 at 90°C for DOTA‐tetrapeptide complexes with 207Bi and 152Eu; 0.05mM, pH 4.0 to 5.0 at 90°C for 44Sc‐DOTA‐tetrapeptide; 0.2mM, pH 4.0 to 5.0 at 90°C for 44Sc‐DOTA‐pentapeptide. Complexes of DOTA‐pentapeptide with 207Bi and 152Eu of radiochemical purity more than 95% were probably unstable at temperature higher than 37°C and were obtained at 37°C, pH 8.0 to 8.4 within 4 days. Mass spectra of the Eu‐DOTA‐pentapeptide revealed the presence of small fragments of the pentapeptide conjugate in the complex solution. in vitro stability studies were performed in saline in the presence of serum proteins and biologically relevant metal cations. All complexes demonstrated no cation release in vitro within 1 to 4 hours.

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Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%