185 research outputs found
EANM guideline on quality risk management for radiopharmaceuticals
This document is intended as a supplement to the EANM "Guidelines on current Good Radiopharmacy Practice (cGRPP)" issued by the Radiopharmacy Committee of the EANM (Gillings et al. in EJNMMI Radiopharm Chem. 6:8, 2021). The aim of the EANM Radiopharmacy Committee is to provide a document that describes how to manage risks associated with small-scale "in-house" preparation of radiopharmaceuticals, not intended for commercial purposes or distribution
Preclinical pharmacokinetics, biodistribution, radiation dosimetry and toxicity studies required for regulatory approval of a phase I clinical trial with 111In-CP04 in medullary thyroid carcinoma patients
Introduction: From a series of radiolabelled cholecystokinin (CCK) and gastrin analogues, 111In-CP04 (111In-DOTA-(DGlu)6-Ala-Tyr-Gly-Trp-Met-Asp-Phe-NH2) was selected for further translation as a diagnostic radiopharmaceutical towards a first-in-man study in patients with medullary thyroid carcinoma (MTC). A freeze-dried kit formulation for multicentre application has been developed. We herein report on biosafety, in vivo stability, biodistribution and dosimetry aspects of 111In-CP04 in animal models, essential for the regulatory approval of the clinical trial. Materials and methods: Acute and extended single dose toxicity of CP04 was tested in rodents, while the in vivo stability of 111In-CP04 was assessed by HPLC analysis of mouse blood samples. The biodistribution of 111In-CP04 prepared from a freeze-dried kit was studied in SCID mice bearing do
Preparation and in vitro evaluation of 177Lu-iPSMA-RGD as a new heterobivalent radiopharmaceutical
This study aimed to synthesize a new 177Lu-iPSMA-RGD heterobivalent radiopharmaceutical, as well as to assess the in vitro radiopharmaceutical potential to target cancer cells overexpressing PSMA and a(v) b(3) integrins. The radiotracer prepared with a radiochemical purity of 98.8 ± 1.0% showed stability in human serum, specific recognition with suitable affinity to PSMA and a(v)b(3) integrins, and capability to inhibit cancer cell proliferation and VEGF signaling (antiangiogenic effect). Results warrant further preclinical studies to establish the 177Lu-iPSMA-RGD potential as a dual therapeutic radiopharmaceutical.CONACyT-CB-2016-01-28152
Gastrin-releasing peptide receptor-based targeting using bombesin analogues is superior to metabolism-based targeting using choline for in vivo imaging of human prostate cancer xenografts
Purpose: Prostate cancer (PC) is a major health problem. Overexpression of the gastrin-releasing peptide receptor (GRPR) in PC, but not in the hyperplastic prostate, provides a promising target for staging and monitoring of PC. Based on the assumption that cancer cells have increased metabolic activity, metabolism-based tracers are also being used for PC imaging. We compared GRPR-based targeting using the68Ga-labelled bombesin analogue AMBA with metabolism-based tar
PET imaging of αvβ3 integrin expression in tumours with 68Ga-labelled mono-, di- and tetrameric RGD peptides
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97195.pdf (publisher's version ) (Closed access)PURPOSE: Due to the restricted expression of alpha(v)beta(3) in tumours, alpha(v)beta(3) is considered a suitable receptor for tumour targeting. In this study the alpha(v)beta(3)-binding characteristics of (68)Ga-labelled monomeric, dimeric and tetrameric RGD peptides were determined and compared with their (111)In-labelled counterparts. METHODS: A monomeric (E-c(RGDfK)), a dimeric (E-[c(RGDfK)](2)) and a tetrameric (E{E[c(RGDfK)](2)}(2)) RGD peptide were synthesised, conjugated with DOTA and radiolabelled with (68)Ga. In vitro alpha(v)beta(3)-binding characteristics were determined in a competitive binding assay. In vivo alpha(v)beta(3)-targeting characteristics of the compounds were assessed in mice with subcutaneously growing SK-RC-52 xenografts. In addition, microPET images were acquired using a microPET/CT scanner. RESULTS: The IC(50) values for the Ga(III)-labelled DOTA-E-c(RGDfK), DOTA-E-[c(RGDfK)](2) and DOTA-E{E[c(RGDfK)](2)}(2) were 23.9 +/- 1.22, 8.99 +/- 1.20 and 1.74 +/- 1.18 nM, respectively, and were similar to those of the In(III)-labelled mono-, di- and tetrameric RGD peptides (26.6 +/- 1.15, 3.34 +/- 1.16 and 1.80 +/- 1.37 nM, respectively). At 2 h post-injection, tumour uptake of the (68)Ga-labelled mono-, di- and tetrameric RGD peptides (3.30 +/- 0.30, 5.24 +/- 0.27 and 7.11 +/- 0.67%ID/g, respectively) was comparable to that of their (111)In-labelled counterparts (2.70 +/- 0.29, 5.61 +/- 0.85 and 7.32 +/- 2.45%ID/g, respectively). PET scans were in line with the biodistribution data. On all PET scans, the tumour could be clearly visualised. CONCLUSION: The integrin affinity and the tumour uptake followed the order of DOTA-tetramer > DOTA-dimer > DOTA-monomer. The (68)Ga-labelled tetrameric RGD peptide has excellent characteristics for imaging of alpha(v)beta(3) expression with PET
Dual-Labeling Strategies for Nuclear and Fluorescence Molecular Imaging: A Review and Analysis
Molecular imaging is used for the detection of biochemical processes through the development of target-specific contrast agents. Separately, modalities such as nuclear and near-infrared fluorescence (NIRF) imaging have been shown to non-invasively monitor disease. More recently, merging of these modalities has shown promise owing to their comparable detection sensitivity and benefited from the development of dual-labeled imaging agents. Dual-labeled agents hold promise for whole-body and intraoperative imaging and could bridge the gap between surgical planning and image-guided resection with a single, molecularly targeted agent. In this review, we summarized the literature for dual-labeled antibodies and peptides that have been developed and have highlighted key considerations for incorporating NIRF dyes into nuclear labeling strategies. We also summarized our findings on several commercially available NIRF dyes and offer perspectives for developing a toolkit to select the optimal NIRF dye and radiometal combination for multimodality imaging
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