Search results for "Positron"
showing 10 items of 1346 documents
Vascular imaging of solid tumors in rats with a radioactive arsenic-labeled antibody that binds exposed phosphatidylserine.
2008
Abstract Purpose: We recently reported that anionic phospholipids, principally phosphatidylserine, become exposed on the external surface of vascular endothelial cells in tumors, probably in response to oxidative stresses present in the tumor microenvironment. In the present study, we tested the hypothesis that a chimeric monoclonal antibody that binds phosphatidylserine could be labeled with radioactive arsenic isotopes and used for molecular imaging of solid tumors in rats. Experimental Design: Bavituximab was labeled with 74As (β+, T1/2 17.8 days) or 77As (β−, T1/2 1.6 days) using a novel procedure. The radionuclides of arsenic were selected because their long half-lives are consistent w…
Potential use of 68Ga-apo-transferrin as a PET imaging agent for detecting Staphylococcus aureus infection.
2010
Abstract Introduction 67 Ga citrate has been extensively used to detect infection and inflammation since 1971. However, its clinical utility is compromised due to several limitations. The present project explored whether 68 Ga- apo -transferrin ( 68 Ga-TF), when prepared in vitro, is a useful agent for positron emission tomography (PET) imaging of bacterial infection. Methods An infection was induced in male Wistar rats by injecting 5×10 5 CFU units of Staphyococcus aureus in the right thigh muscle. 68 Ga-TF was synthesized by mixing 68 GaCl 3 with apo -transferrin (TF, 2 mg) in sodium carbonate (0.1 M, pH 7.0) and incubating at 40°C for 1 h. Animals were injected with 10–15 MBq of 68 Ga-TF…
Influence of cell proportions and proliferation rates on FDG uptake in squamous-cell esophageal carcinoma: a PET study.
2008
We investigated the influence of cell proportions and proliferation activities on tumor maximum standard uptake value (SUV(max)) in patients with squamous-cell esophageal cancer (SCEC).Sixteen (16) patients with untreated SCEC were examined with (18)F-flourodeoxyglucose positron emission tomography (FDG-PET). The tumor SUV(max) were calculated. Tumors were resected by transthoracic esophagectomy. Tissues were stained with hematoxylin and eosin for the measurement of cell proportions and MIB-1 for measurement of proliferation indices (PIs). Tumor SUV and histologic data were related by using multiple linear regression analysis.The mean proportion of tumor cells in the tumor site was 58.1% (+…
Impact of positron emission tomography on strategy in liver resection for primary and secondary liver tumors.
2003
Outcome of patients with metastatic disease mainly depends on accurate preoperative tumor staging. 18[F]fluorodeoxyglucose positron emission tomography (18F-PET) has been proven to be a valuable diagnostic tool in a number of different tumors but its direct influence on liver surgery has not been thoroughly investigated. Between July 1999 and March 2000, 50 consecutive patients with 174 suspected liver lesions were admitted to the University Hospital Jena. All 50 patients underwent abdominal ultrasound, CT-scan, and 18-FDG positron emission tomography scanning. In 23 patients the diagnostic work-up was completed by MRI scan. Altogether there were a total of 174 histologically proven intrahe…
Abdomen/pelvis computed tomography in staging of pediatric Hodgkin Lymphoma: is it always necessary?
2016
Abstract The purpose of the study was to determine if abdomen/pelvis computed tomography (CT) can be safety omitted in the initial staging of a subgroup of children affected by Hodgkin Lymphoma (HL). Every participating center of A.I.E.O.P (Associazione Italiana di Ematologia ed Oncologia Pediatrica) sent local staging reports of 18F‐fluorodeoxyglucose positron emission tomography (PET) and abdominal ultrasound (US) along with digital images of staging abdomen/pelvis CT to the investigation center where the CT scans were evaluated by an experienced pediatric radiologist. The local radiologist who performed the US was unaware of local CT and PET reports (both carried out after US), and the r…
A DOTA based bisphosphonate with an albumin binding moiety for delayed body clearance for bone targeting
2016
Radiolabeled bisphosphonates are commonly used in the diagnosis and therapy of bone metastases. Blood clearance of bisphosphonates is usually fast and only 30%-50% of the injected activity is retained in the skeleton, while most of the activity is excreted by the urinary tract. A longer blood circulation may enhance accumulation of bisphosphonate compounds in bone metastases. Therefore, a chemically modified macrocyclic bisphosphonate derivative with an additional human albumin binding entity was synthesized and pharmacokinetics of its complex was evaluated. The DOTA-bisphosphonate conjugate BPAMD was compared against the novel DOTAGA-derived albumin-binding bisphosphonate DOTAGA(428-d-Lys)…
68Ga-BPAMD: PET-imaging of bone metastases with a generator based positron emitter
2012
Abstract Purpose Bone metastases are a serious aggravation for patients suffering from cancer. Therefore, early recognition of bone metastases is of great interest for further treatment of patients. Bisphosphonates are widely used for scintigraphy of bone lesions with 99m Tc. Using the 68 Ge/ 68 Ga generator together with a macroyclic bisphosphonate a comparable PET-tracer comes into focus. Procedures The bisphosphonate DOTA-conjugated ligand BPAMD was labelled with 68 Ga. [ 68 Ga]BPAMD was evaluated in vitro concerning binding to hydroxyapatite and stability. The tracer's in vivo accumulation was determined on healthy rats and bone metastases bearing animals by μ-PET. Results BPAMD was lab…
Radiolabelling and preliminary evaluation of 68Ga-tetrapyrrole derivatives as potential tracers for PET
2013
article i nfo Tetrapyrroles are multisided natural products which are of relevance in clinical medicine. Owing to their specific accumulation in tumour tissue, porphyrins, metalloporphyrins and chlorins have been used as in photodynamic therapy and optical imaging. Moreover, their specific uptake into inflammatory atheromatous plaques via LDL endocytosis has been reported. The present study is concerned with the synthesis of 68 Ga labelled porphyrin derivatives and an in vitro assessment of the utility of radiotracers in positron emission tomography. A set of five porphyrin derivatives were labelled using 68 Ga from a commercially obtained radionuclide generator. Dedicated post-processing o…
A fronto-parietal network is mediating improvement of motor function related to repetitive peripheral magnetic stimulation: A PET-H2O15 study.
2006
Repetitive peripheral magnetic stimulation (RPMS) is a focused and painless stimulation method, in which muscle contractions are elicited by depolarization of the terminal motor branches. Clinical-experimental investigations on different disorders of sensorimotor integration in the last decade have shown that RPMS can be used for the rehabilitation of motor functions after stroke. It is supposed that this therapeutic effect is based on the RPMS-induced proprioceptive inflow to the CNS. To analyze the conditioning effects of RPMS on reorganization of the motor system on cortical level positron emission tomography (PET) is used. Regional cerebral blood flow (rCBF) has been measured using H(2)…
[18F]PR04.MZ PET/CT Imaging for Evaluation of Nigrostriatal Neuron Integrity in Patients With Parkinson Disease.
2020
Introduction Degeneration of dopaminergic, nigrostriatal neurons is the hallmark of Parkinson disease (PD), and PET quantification of dopamine transporters is a widely accepted method for differential diagnosis between idiopathic PD and essential tremor. [18F]PR04.MZ is a new PET tracer with excellent imaging properties allowing for precise quantification of striatal and extrastriatal dopamine transporter. Here we describe our initial experience with [18F]PR04.MZ PET/CT in a larger cohort of healthy controls and PD patients as a proof-of-concept study for this tracer. Methods Eighteen healthy subjects, 19 early PD patients (Hoehn-Yahr I–II), and 13 moderate-advanced PD patients (Hoehn-Yahr …