[(68)Ga]Pentixafor-PET/CT for Imaging of Chemokine Receptor 4 Expression After Myocardial Infarction

14.12.2015

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Upregulated myocardial CXCR4-expression after myocardial infarction assessed by simultaneous GA-68 pentixafor PET/MRI

14.12.2015

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Diagnostic Efficacy of (68)Gallium-PSMA Positron Emission Tomography Compared to Conventional Imaging for Lymph Node Staging of 130 Consecutive Patients with Intermediate to High Risk Prostate Cancer

09.12.2015

Current standard imaging techniques are insufficient to reliably detect lymph node metastases in prostate cancer. Recently ligands of PSMA (prostate specific membrane antigen) were introduced in PET (positron emission tomography) of prostate cancer. Thus the aims of this retrospective analysis were to 1) investigate the diagnostic efficacy of (68)Ga-PSMA-PET imaging for lymph node staging in patients with prostate cancer scheduled for radical prostatectomy and 2) compare it to morphological imaging (computerized tomography and magnetic resonance tomography) with histopathological evaluation as the standard of reference…

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[111In]PSMA-I&T: expanding the spectrum of PSMA-I&T applications towards SPECT and radioguided surgery

25.11.2016

The relevance of prostate-specific membrane antigen (PSMA) targeting in the clinical management of prostate cancer (PCa) is continually increasing, entailing the development of PSMA-targeted molecular probes. Recently, a first PSMA-targeted theranostic concept has been successfully implemented by [(68)Ga/(177)Lu]PSMA-I&T. To further exploit the excellent PSMA-targeting characteristics and in vivo performance of the PSMA-I&T platform, [(111)In]PSMA-I&T was evaluated as a complementary probe for radioguided surgery and SPECT imaging…

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First-in-Human Experience of CXCR4-Directed Endoradiotherapy with 177Lu- and 90Y-Labeled Pentixather in Advanced-Stage Multiple Myeloma with Extensive Intra- and Extramedullary Disease

12.11.2015

Chemokine receptor 4 (CXCR4) is a key factor for tumor growth and metastasis in several types of human cancer. Based on promising experiences with a radiolabeled CXCR4 ligand ((68)Ga-pentixafor) for diagnostic receptor targeting, (177)Lu- and (90)Y-pentixather were recently developed as endoradiotherapeutic vectors. Here, we summarize the first-in-human experience in 3 heavily pretreated patients…

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Molecular Imaging of the Chemokine Receptor CXCR4 After Acute Myocardial Infarction

11.11.2015

An assay for molecular imaging of myocardial CXCR4 expression was evaluated, in order to obtain mechanistic insights noninvasively based on quantitative positron emission tomography (PET). The chemokine receptor CXCR4 has emerged as a therapeutic target after acute myocardial infarction (AMI), because of its role in inflammatory and progenitor cell recruitment. PET with the specific CXCR4 ligand, gallium-68 ((68)Ga)-pentixafor, was performed…

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In vivo biokinetic and metabolic characterization of the 68Ga-labelled α5β1-selective peptidomimetic FR366

24.10.2015

Integrins are transmembrane receptors responsible for cell–cell adhesion and cell–extracellular matrix binding and play an important role in angiogenesis and tumour metastasis. For this reason, integrins are increasingly used as targets for molecular imaging. Up to now interest has mostly been focused on the integrin subtype αvβ3. However, targeting of other subtypes such as the integrin α5β1 is also of high interest due to its central role in colonization of metastatic cells, resistance of tumour cells to chemotherapy and ionizing radiation, and tumour aggressiveness.

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68Ga-PSMA PET/MR with multimodality image analysis for primary prostate cancer

01.08.2016

Current imaging procedures for prostate cancer including positron emission tomography (PET) exhibit considerable limitations and are not always able to meet the diagnostic needs. Recently, a (68)Gallium-labeled ligand of the prostate-specific membrane antigen ((68)Ga-PSMA) has been introduced in PET-imaging of prostate cancer with first promising results. Due to relatively exclusive expression of PSMA in prostatic tissue as well as increased expression in prostate cancer, 68 Ga-PSMA was reported to exhibit a favorable lesion to background ratio...

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An optimized strategy for the mild and efficient solution phase iodination of tyrosine residues in bioactive peptides

29.07.2015

Usually, the accessibility of 3-iodo-Tyr-containing peptides relies on the time-consuming de novo solid phase peptide synthesis. In this study, methods for the direct (mono)iodination of unprotected peptides were evaluated. The use of N-iodosuccinimide (NIS) in acetonitrile/water proved to be a particularly mild, fast (⩽5 min) and efficient method with broad applicability to structurally diverse peptides. NIS iodination therefore represents a very practicable tool for the generation of iodinated peptides on a small ...

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The Influence of the Combination of Carboxylate and Phosphinate Pendant Arms in 1,4,7-Triazacyclononane-Based Chelators on Their 68Ga Labelling Properties

21.07.2015

In order to compare the coordination properties of 1,4,7-triazacyclononane (tacn) derivatives bearing varying numbers of phosphinic/carboxylic acid pendant groups towards 68Ga, 1,4,7-triazacyclononane-7-acetic-1,4-bis(methylenephosphinic) acid (NOPA) and 1,4,7- triazacyclononane-4,7-diacetic-1-[methylene(2-carboxyethyl)phosphinic] acid (NO2AP) were synthesized using Mannich reactions with trivalent or pentavalent forms of H-phosphinic acids as phosphorus components. Stepwise protonation constants logK1–312.06, 3.90 and 1.95, and stability constants with GaIII and CuII, logKGaL 24.01 and logKCuL 16.66, were potentiometrically determined for NOPA.

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68Ga- and 177Lu-Labeled PSMA I&T: Optimization of a PSMA-Targeted Theranostic Concept and First Proof-of-Concept Human Studies

18.06.2015

On the basis of the high and consistent expression of prostate-specific membrane antigen (PSMA) in metastatic prostate cancer (PC), the goal of this study was the development, preclinical evaluation, and first proof-of-concept investigation of a PSMA inhibitor for imaging and therapy (PSMA I&T) for (68)Ga-based PET and (177)Lu-based endoradiotherapeutic treatment in patients with metastatic and castration-resistant disease. PSMA I&T was synthesized in a combined solid phase and solution chemistry strategy…

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Prostate-specific membrane antigen-radioguided surgery for metastatic lymph nodes in prostate cancer

06.05.2015

With the advent of (68)Ga-labeled prostate-specific membrane antigen-N,N'-bis[2-hydroxy-5-(carboxyethyl)benzyl]ethylenediamine-N,N'-diacetic acid ((68)Ga-PSMA-HBED-CC) positron emission tomography (PET) hybrid imaging in prostate cancer (PCa), even small metastatic lymph nodes (LNs) can be visualized. However, intraoperative detection of such LNs may not be easy owing to their inconspicuous morphology and/or atypical localization. The aim of our feasibility study was to evaluate PSMA-radioguided surgery for detection of metastatic LNs…

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A shortcut to high-affinity Ga-68 and Cu-64 radiopharmaceuticals: one-pot click chemistry trimerisation on the TRAP platform

05.05.2015

Due to its 3 carbonic acid groups being available for bioconjugation, the TRAP chelator (1,4,7-triazacyclononane-1,4,7-tris(methylene(2-carboxyethylphosphinic acid))) is chosen for the synthesis of trimeric bioconjugates for radiolabelling. We optimized a protocol for bio-orthogonal TRAP conjugation via Cu(I)-catalyzed Huisgen-cycloaddition of terminal azides and alkynes (CuAAC), including a detailed investigation of kinetic properties of Cu(II)–TRAP complexes. TRAP building blocks for CuAAC, ...

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MA-NOTMP: A Triazacyclononane Trimethylphosphinate Based Bifunctional Chelator for Gallium Radiolabelling of Biomolecules

01.05.2015

In the past few years, gallium-68 has demonstrated significant potential as a radioisotope for positron emission tomography (PET), and the optimization of chelators for gallium coordination is a major goal in the development of radiopharmaceuticals. Methylaminotriazacyclononane trimethylphosphinate (MA-NOTMP), a new C-functionalized triazacyclononane derivative with phosphinate pendant arms, presents excellent coordination properties for 68Ga (low ligand concentration, labelling at low pH even at room temperature).

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Biodistribution and radiation dosimetry for a probe targeting prostate-specific membrane antigen for imaging and therapy

16.04.2015

Prostate-specific membrane antigen (PSMA) is a promising target for diagnosis and treatment of prostate cancer. EuK-Subkff-(68)Ga-DOTAGA ((68)Ga-PSMA Imaging & Therapy [PSMA I&T]) is a recently introduced PET tracer for imaging PSMA expression in vivo. Whole-body distribution and radiation dosimetry of this new probe were evaluated. Five patients with a history of prostate cancer were injected intravenously with 91-148 MBq of (68)Ga-PSMA I&T (mean ± SD, 128 ± 23 MBq)…

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Evaluation of Hybrid [68Ga]PSMA Ligand PET/CT in 248 Patients with Biochemical Recurrence After Radical Prostatectomy

19.03.2015

The expression of prostate-specific membrane antigen (PSMA) is increased in prostate cancer. Recently, (68)Ga-PSMA (Glu-NH-CO-NH-Lys-(Ahx)-[(68)Ga(HBED-CC)]) was developed as a PSMA ligand. The aim of this study was to investigate the detection rate of (68)Ga-PSMA PET/CT in patients with biochemical recurrence after radical prostatectomy. Two hundred forty-eight of 393 patients were evaluable for a retrospective analysis. Median prostate-specific antigen (PSA) level was 1.99 ng/mL (range, 0.2-59.4 ng/mL). All patients underwent contrast-enhanced PET/CT after injection of 155 ± 27 MBq of (68)Ga-PSMA ligand…

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In vivo molecular imaging of chemokine receptor CXCR4 expression in patients with advanced multiple myeloma

03.03.2015

CXCR4 is a G-protein-coupled receptor that mediates recruitment of blood cells toward its ligand SDF-1. In cancer, high CXCR4 expression is frequently associated with tumor dissemination and poor prognosis. We evaluated the novel CXCR4 probe [(68)Ga]Pentixafor for in vivo mapping of CXCR4 expression density in mice xenografted with human CXCR4-positive MM cell lines and patients with advanced MM…

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Disclosing the CXCR4 expression in lymphoproliferative diseases by targeted molecular imaging

01.03.2015

Chemokine ligand-receptor interactions play a pivotal role in cell attraction and cellular trafficking, both in normal tissue homeostasis and in disease. In cancer, chemokine receptor-4 (CXCR4) expression is an adverse prognostic factor. Early clinical studies suggest that targeting CXCR4 with suitable high-affinity antagonists might be a novel means for therapy. In addition to the preclinical evaluation of [(68)Ga]Pentixafor in mice bearing human lymphoma xenografts…

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Biodistribution and radiation dosimetry for the chemokine receptor CXCR4-targeting probe 68Ga-pentixafor

19.02.2015

(68)Ga-pentixafor is a promising PET tracer for imaging the expression of the human chemokine receptor 4 (CXCR4) in vivo. The whole-body distribution and radiation dosimetry of (68)Ga-pentixafor were evaluated. Five multiple-myeloma patients were injected intravenously with 90-158 MBq of (68)Ga-pentixafor (mean ± SD, 134 ± 25 MBq), and a series of 3 rapid multiple-bed-position…

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