Publications by authors named "Zhihao Zha"

Cervical lymph node (LN) metastasis is highly prevalent in thyroid cancer (TC). However, the lack of diagnostic modalities that enable real-time assessment of LN metastasis remains a challenge in providing efficient clinical decision-making and optimal patient care. Sodium-ascorbate co-transporters (SVCTs) have shown high expression levels in TC, presenting a potential target for visualizing LN metastasis.

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Recently, a novel radiohybrid tracer [F]Lu-LuFL targeting the fibroblast activation protein (FAP) has been developed for PET imaging of solid tumors. This tracer has shown promising results, prompting us to conduct a first-in-human study to evaluate its efficacy for PET imaging of FAP in human body. In order to facilitate the routine production and clinical application of [F]Lu-LuFL, a straightforward and efficient automated synthesis is described.

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Purpose: To compare the detection ability of Ga-labelled DOTA-l-Nal3-octreotide ([Ga]Ga-DOTA-NOC) and 6-[F]fluoro-L-3,4-dihydroxyphenylalanine ([F]DOPA) in patients with phaeochromocytomas and paragangliomas (PPGLs) of different origins and gene mutations, such as germline succinate dehydrogenase complex genes (SDHx).

Methods: Eighty-five patients with histopathologically confirmed PPGLs who underwent both [Ga]Ga-DOTA-NOC and [F]DOPA PET/CT from March 2017 to June 2023 were enrolled in this retrospective study. For comparative analyses, PPGLs were classified as phaeochromocytoma (PCC), sympathetic paraganglioma (sPGL), and head/neck paraganglioma (HNPGL).

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Prostate-specific membrane antigen (PSMA) is an excellent target for imaging and radionuclide therapy of prostate cancer. Recently, [Lu]Lu-PSMA-617 (Pluvicto) was approved by the FDA for radionuclide therapy. To develop hetero-bivalent agents targeting both PSMA and bone metastasis, [Lu]Lu-P17-079 ([Lu]Lu-1) and [Lu]Lu-P17-081 ([Lu]Lu-2) were prepared.

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Purpose: Clinical studies on the use of ascorbic acid (AA) have become a hot spot in cancer research. There remains an unmet need to assess AA utilization in normal tissues and tumors. 6-Deoxy-6-[F]fluoro-L-ascorbic acid ([F]DFA) displayed distinctive tumor localization and similar distribution as AA in mice.

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Fibroblast activation protein (FAP) is selectively expressed in tumors and highly important for maintaining the microenvironment in malignant tumors. Radioisotope-labeled FAP inhibitors (FAPIs) were proven to be useful for diagnosis and radionuclide therapy of cancer and are under active clinical investigations. Ga-HBED complex displays a higher stability constant (log: 38.

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Purpose: A series of radiotracers targeting fibroblast activation protein (FAP) with great pharmacokinetics have been developed for cancer diagnosis and therapy. Nevertheless, the use of dominant PET tracers, gallium-68-labeled FAPI derivatives, was limited by the short nuclide half-life and production scale, and the therapeutic tracers exhibited rapid clearance and insufficient tumor retention. In this study, we developed a FAP targeting ligand, LuFL, containing organosilicon-based fluoride acceptor (SiFA) and DOTAGA chelator, capable of labeling fluorine-18 and lutetium-177 in one molecular with simple and highly efficient labeling procedure, to achieve cancer theranostics.

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Prostate-specific membrane antigen (PSMA) is a promising target for the diagnosis and radionuclide therapy of prostate cancer. This study reports conversion of a previously reported Ga-imaging agent, [Ga]Ga-P16-093, to a Lu-177 radionuclide therapeutic agent. Substitution of the HBED-CC metal chelating group with DOTA(GA) led to P17-087 () and P17-088 ().

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Purpose: Prostate-specific membrane antigen (PSMA) is an important biomarker for molecular imaging and a target for radionuclide therapy of prostate cancer. Recently, U.S.

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Objective: Glucagon-like peptide-1 receptor (GLP1R) specifically expressed on the surface of pancreatic β-cells and insulinoma, is a potential biomarker for imaging β-cell mass (BCM). In this study, two new Ga-labelled GLP1R targeting agents were prepared and their biological properties for imaging BCM and insulinoma were evaluated.

Methods: [Ga]Ga-HBED-CC-MAL-Cys-exendin-4 ([Ga]Ga-4) and its dimer ([Ga]Ga-5) were synthesized from corresponding precursors.

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[F]AV-45 (florbetapir f18, Amyvid) is an FDA-approved PET imaging agent targeting Aβ plaques in the brain for diagnosis of Alzheimer's disease (AD). Its metabolites led to a high background in the brain and large bone uptake of [F]F, produced from dealkylation of the PEG chain. To slow down the in vivo metabolism, we report the design, synthesis, and evaluation of a highly deuterated derivative, [F]D15FSP, and compared it with -methyl-deuterated [F]D3FSP and nondeuterated [F]AV-45.

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Prostate-specific membrane antigen (PSMA)-targeted radioligands have played an increasing role in the diagnosis of prostate cancer. [Ga]Ga-P16-093 is a PSMA-targeting agent for positron emission tomography imaging, currently under a Phase 2 clinical trial. In the present study, P16-093 was labeled with F via [F]AlF complex formation, and the biological properties of [F]AlF-P16-093 were evaluated.

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L-ascorbic acid (AA) was reported to have an anti-cancer effect over 40 years. In recent years, several ongoing clinical trials are exploring the safety and efficacy of intravenous high-dose AA for cancer treatment. The lack of appropriate imaging modality limits the identification of potentially suitable patients for AA treatment.

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One of the commonly performed studies in nuclear medicine are bone scans with [Tc]Tc-methylene diphosphonate (MDP) for detecting various bone lesions, including cancer metastasis. The recent emergence of commercially available Ge/Ga radionuclide generators makes it possible to provide Ga-labelled bisphosphonates as positron emission tomography (PET) tracers for bone imaging. Preliminary human studies suggested that [Ga]Ga-HBED-CC-BP ([Ga]Ga-P15-041) in conjunction with PET/computed tomography (CT) showed accumulation in known bone lesions, fast clearance from blood and soft tissue, and an ability to provide high contrast images.

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Prostate-specific membrane antigen (PSMA) is overexpressed in prostate cancer cells and therefore is an attractive target for prostate cancer diagnosis and radionuclide therapy. Recently, published results from clinical studies using a new PSMA-targeting PET imaging agent, [Ga]Ga-PSMA-093 ([Ga]Ga-HBED-CC--carboxymethyl-Tyr-CO-NH-Glu), support the development of this agent for the diagnosis of prostate cancer. In this study, the HBED-CC chelating group in PSMA-093 was replaced by stereoselective ()- or ()-DOTAGA.

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Introduction: [Ga]Ga-P15-041 ([Ga]Ga-HBED-CC-BP) is a novel bone-seeking PET radiotracer that can be generator-produced. We undertook a Phase 0/I clinical trial to assess its potential for imaging bone metastases in prostate cancer including assessment of radiotracer biodistribution and dosimetry.

Methods: Subjects with prostate cancer and known or suspected osseous metastatic disease were enrolled into one of two arms: dosimetry or dynamic.

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Positron emission tomography (PET) imaging using Ga-labeled bisphosphonates to target bone metastasis could be a valuable tool in cancer diagnosis and monitoring therapeutic treatment. A Ga labeled ligand, ,-bis[2-hydroxy-5-(carboxyethyl)benzyl]ethylenediamine-,-diacetic acid (HBED-CC) containing one bisphosphonate group (HBED-CC-BP, ) was prepared and evaluated. The new ligand, , reacted rapidly to form [Ga]Ga-, via complexing with [Ga]GaCl eluted from a commercially available Ge/Ga generator (in a sodium acetate buffer at pH 4, reaching >95% labeling yield at room temperature in 5 min).

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Introduction: Since the approval of three F labeled β-amyloid-targeting PET imaging agents, Amyvid (florbetapir f18, AV-45), Neuraceq (florbetaben f18, AV-1) and Vizamyl (flutemetamol f18, F-PIB), they have increasingly been employed to assist differential diagnosis of Alzheimer's disease in patients with dementia. Also, they are frequently used in selecting patients participating drug trials aiming to reduce β-amyloid (Aβ) plaques in the brain. The first approved tracer in this class was [F]AV-45, which is metabolized rapidly in blood and some of its N-demethylated metabolites cross the blood brain barrier and resulted in lowering the image contrast.

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Radioligand therapy (RLT) using prostate-specific membrane antigen (PSMA) targeting ligands is an attractive option for the treatment of Prostate cancer (PCa) and its metastases. We report herein a series of radioiodinated glutamate-urea-lysine-phenylalanine derivatives as new PSMA ligands in which l-tyrosine and l-glutamic acid moieties were added to increase hydrophilicity concomitant with improvement of in vivo targeting properties. Compounds 8, 15, 19a/19b and 23a/23b were synthesized and radiolabeled with I by iododestannylation.

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HBED-CC (-bis[2-hydroxy-5-(carboxyethyl)benzyl]ethylene diamine--diacetic acid, ) is a common bifunctional chelating agent in preparation of Ga-radiopharmaceuticals. Due to its high stability constant for the Ga complex (logK = 38.5) and its acyclic structure, it is well known for a rapid and efficient radiolabelling at ambient temperature with Gallium-68 and its high stability.

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Amyvid (florbetapir f18, [ F]AV-45, [ F]5) was the first FDA-approved positron emission tomography imaging agent targeting β-amyloid (Aβ) plaques for assisting the diagnosis of Alzheimer disease. This work aimed to improve the [ F]AV-45 ([ F]5) preparation by using solid-phase extraction (SPE) purification. [ F]AV-45 ([ F]5) was synthesized by direct nucleophilic radiofluorination of O-tosylated precursor (1 mg) at 120°C in anhydrous dimethyl sulfoxide (DMSO), followed by acid hydrolysis of the N-Boc protecting group.

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Objectives: Recently, a deuterated tracer, D6-[F]FP-(+)-DTBZ, 9-O-hexadeutero-3-[F]fluoropropoxyl-(+)-dihydrotetrabenazine ([F]9), targeting vesicular monoamine transporter 2 (VMAT2) in the central nervous system, was reported as a useful imaging agent for the diagnosis of Parkinson's disease (PD). The production of [F]9 was optimized and simplified by using solid-phase extraction (SPE) purification.

Methods: Three major nonradioactive impurities were synthesized and characterized.

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Introduction: Alzheimer's disease is a common neurodegenerative disease that is characterized by the presence of Aβ plaques in the brain. The FDA has approved the use of Amyvid (florbetapir f18, AV-45) as a PET imaging agent for detecting Aβ plaques in the living human brain. In an attempt to reduce N-demethylation in vivo by taking advantage of more stable C-D bonds, an analog of AV-45, [F]D3FSP ([F]7), was synthesized to improve image contrast for detecting and monitoring the Aβ plaques.

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We report initial experience in synthesis of (2S,4R)-4-[ F]fluoroglutamine, [ F]FGln, which has been used as a tool for monitoring glutamine metabolism in cancer patients. [ F]FGln was prepared by a fully automated PET-MF-2V-IT-I synthesizer under GMP-compliant conditions for routine clinical studies. The total radiosynthesis time was about 65 minutes, the decay-corrected radiochemical yield was 18.

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