An automated synthesis method for 68Ga-labelled ubiquicidin 29–41

Published methods for radiolabelling of 1,4,7-triazacyclononane-1,4,7-triacetic acid ubiquicidin (NOTA-UBI) 29–41 to date describe manual or kit-based procedures. The purpose of this study was to develop an automated synthesis method for the synthesis of [68Ga]Ga-NOTA-UBI. NOTA-UBI was successfully labelled with gallium-68 using three different automated procedures. The use of radical scavengers to improve radiochemical purity is also discussed. The automated procedures showed a high degree of robustness and repeatability. The validated automated synthesis protocols using a Scintomics GRP Module will contribute to provide GMP-compliant [68Ga]Ga-NOTA-UBI for clinical infection imaging.Africa- X-ray Industrial and Medical (AXIM)http://link.springer.com/journal/109672020-11-01hj2020Nuclear Medicin

Synthetic approaches to radiochemical probes for imaging of bacterial infections

This present review provides an account on the available synthetic strategies employed to radiolabel commercial and potential bacteria-selective probes fortomographic imaging. These molecular probes encompass leukocytes, antibodies, small molecules, peptides, antibiotics, macrolides, vitamins, oligomers and siderophores. Although this technique has shown to be a valuable tool for non-invasive infection imaging, more development is required to create easy-to-radiolabel kit solutions procedures for the preparation of the probes.http://www.elsevier.com/locate/ejmech2018-06-16hj2017Nuclear Medicin

Article towards facile radiolabeling and preparation of gallium-68-/bismuth-213-dota-[thi8, met(O2)11]-substance p for future clinical application : first experiences

Please read abstract in the article.The Nuclear Technologies in Medicine and the Biosciences Initiative (NTeMBI) and the Technology Innovation Agency (TIA).http://www.mdpi.com/journal/pharmaceuticspm2022Nuclear Medicin

Metastatic prostate carcinoma presenting as a superscan on Ga-68-PSMA PET/CT

We describe the finding of a metastatic superscan detected by Ga-PSMA PET/CT imaging. A 63-year-old man with metastatic prostate carcinoma underwent Ga-PSMA PET/CT imaging for staging and evaluation of the most appropriate therapeutic option. Images demonstrated diffuse and extensive skeletal uptake in the axial and appendicular skeleton, corresponding to the typical red marrow distribution. Intense soft tissue uptake was also seen in the prostate and multiple pelvic and abdominal lymph nodes.http://journals.lww.com/nuclearmed/pages/default.aspx2016-09-30hb2016Nuclear Medicin

A perspective on the radiopharmaceutical requirements for imaging and therapy of glioblastoma

Despite numerous clinical trials and pre-clinical developments, the treatment of glioblastoma (GB) remains a challenge. The current survival rate of GB averages one year, even with an optimal standard of care. However, the future promises efficient patient-tailored treatments, including targeted radionuclide therapy (TRT). Advances in radiopharmaceutical development have unlocked the possibility to assess disease at the molecular level allowing individual diagnosis. This leads to the possibility of choosing a tailored, targeted approach for therapeutic modalities. Therapeutic modalities based on radiopharmaceuticals are an exciting development with great potential to promote a personalised approach to medicine. However, an effective targeted radionuclide therapy (TRT) for the treatment of GB entails caveats and requisites. This review provides an overview of existing nuclear imaging and TRT strategies for GB. A critical discussion of the optimal characteristics for new GB targeting therapeutic radiopharmaceuticals and clinical indications are provided. Considerations for target selection are discussed, i.e. specific presence of the target, expression level and pharmacological access to the target, with particular attention to blood-brain barrier crossing. An overview of the most promising radionuclides is given along with a validation of the relevant radiopharmaceuticals and theranostic agents (based on small molecules, peptides and monoclonal antibodies). Moreover, toxicity issues and safety pharmacology aspects will be presented, both in general and for the brain in particular.http://www.thno.orgdm2022Nuclear Medicin

Fluorine-18-Fluoroethylcholine PET/CT in the detection of prostate cancer : a South African experience

OBJECTIVE : Imaging with fluorine-18-fluoro-2-deoxy-D-glucose positron emission tomography/computed tomography (18F-FDG PET/CT) has, until recently provided disappointing results with low sensitivity ranging from 31%-64% in patients with well-differentiated prostate cancer (PC) at all prostatic specific antigen (PSA) levels while fluorine-18-fluoroethylcholine (18F-FECh) PET/CT showed about 85% sensitivity in restaging patients after relapse. We present our experience of the sensitivity of 18F-FECh PET/CT in the early stages of PC. SUBJECT AND METHODS : Fifty patients were prospectively recruited and imaged, of which 40 fulfilled all inclusion criteria. Our patients had an average age of 65.5 years. Fifteen patients were referred for initial staging, with the remaining 25 referred for restaging and all patients had histologically confirmed adenocarcinoma. Patients were imaged by 18F-FECh PET/CT. Findings were evaluated qualitatively and quantitatively and compared to the results of histology, PSA, Gleason score and bone scintigraphy. The prostate SUV max was also used. RESULTS : Thirty-one patients demonstrated abnormal pelvic- and or extrapelvic findings on 18F-FECh PET/CT, which was consistent with malignant or metastatic involvement. The prostate SUVmax could not be used to predict the presence or absence of metastatic disease. CONCLUSION : Findings of this paper suggest that 18F-FECh PET/CT in 30/40 cases (estimated as 75%) was helpful in the initial staging, restaging and lymph node detection of patients with PC. The SUVmax was not helpful. We diagnosed more PC cases in our African-American patients as compared to the Caucasian patients.http://nuclmed.web.auth.gr/hb2016Nuclear MedicineUrolog

Antibiotic-derived radiotracers for positron emission tomography : nuclear or “unclear” infection imaging?

The excellent features of non-invasive molecular imaging, its progressive technology (real-time, whole-body imaging and quantification), and global impact by a growing infrastructure for positron emission tomography (PET) scanners are encouraging prospects to investigate new concepts, which could transform clinical care of complex infectious diseases. Researchers are aiming towards the extension beyond the routinely available radiopharmaceuticals and are looking for more effective tools that interact directly with causative pathogens. We reviewed and critically evaluated (challenges or pitfalls) antibiotic-derived PET radiopharmaceutical development efforts aimed at infection imaging. We considered both radiotracer development for infection imaging and radio-antibiotic PET imaging supplementing other tools for pharmacologic drug characterization; overall, a total of 20 original PET radiotracers derived from eleven approved antibiotics.The Nuclear Medicine Research Infrastructure NPC.http://www.angewandte.orgam2023Nuclear Medicin

Single photon emission tomography in the diagnostic assessment of cardiac and vascular infectious diseases

Please read abstract in the articlehttp://www.benthamscience.comcrp/index.htmhj2022Nuclear Medicin

Microwave-assisted synthesis of meso-carboxyalkyl-BODIPYs and an application to fluorescence imaging

Please read abstract in the article.http://pubs.rsc.org/en/Journals/JournalIssues/OB2021-09-21hj2021Nuclear Medicin

Peptide synthesis, characterization and 68Ga-radiolabeling of NOTA-conjugated ubiquicidin fragments for prospective infection imaging with PET/CT

INTRODUCTION: Human antimicrobial peptides are of interest for the development of positron emission tomography (PET) tracers as they exhibit desirable characteristics that make them good candidates for targeting vectors. Due to their natural role in the innate immune system they selectively bind to pathogenic bacteria and yeast, whilst remaining minimally immunogenic and cytotoxic to humans. Research into ubiquicidin (UBI)-based tracers has focused on 99mTc as a radionuclide, however, the use of bi-functional chelators such as 1,4,7-triazacyclononane-1,4,7-triacetic acid (NOTA), in combination with 68Ga as a radionuclide, allows for a simple radiolabeling procedure which is preferable in a clinical setting using PET/CT. METHODS: The peptides fragments UBI29-41, UBI30-41 were synthesized by standard microwave Fmoc/tert-butyl (tBu)-solid phase synthetic protocols. Characterizations were performed using analytical HPLC and LC/MS. Both NOTA-conjugated peptides were exposed to natGa3 +; their complexed form was quantified by direct LC/MS injection. This complexation was utilized to testify bacterial and mammalian cell binding potential of fluorophore-linked NOTA-UBI29-41/30-41. 68Ga labeled NOTA-UBI fragments were also tested for competitive interaction to Staphylococcus aureus to proof the binding target. 68Ga was eluted from SnO2- and TiO2-based 68Ge/68Ga generators using fractionated elution and anion exchanged-based post-procession. NOTA-peptide radiolabeling was carried out including optimization of buffer molarity, NOTA-peptide concentration(s), incubation temperature and –duration as well as considering various SPE purification cartridges. RESULTS: Pure UBI29-41, UBI30-41 and NOTA-UBI30-41 were successfully characterized. Both, NOTA-UBI fragments exhibited complexation rates to natGa3 + ≥ 99%. The percentage binding was significantly higher to Staphylococcus aureus bacilli over Mt4 human leucocytes (P > 0.05) for NOTA-UBI29-41[Lys(Abz)] 0.03) after pre-incubation with excess unlabeled NOTA-UBI. Reproducible 68Ga radiolabeling ranged for 51–85% and 46–78% for NOTA-UBI29-41 and NOTA-UBI30-41, respectively. CONCLUSION: Aside from successful peptide syntheses the first ever 68Ga-radiolabeling method is reported for NOTA-UBI fragments. The NOTA-conjugation didn’t compromise the selective and specific interaction with bacterial cells in vitro. Both tracers are warranting prospective imaging of infection with PET/CT.National Research Foundation (NRF), the University of KwaZulu Natal (UKZN) and The Nuclear Technologies in Medicine and the Biosciences Initiative (NTeMBI)http://www.elsevier.com/locate/nucmedbiohb201