Search results for "radionuclide"
showing 10 items of 196 documents
Analysis of radionuclide concentration in air released through the stack of a radiopharmaceutical production facility based on a medical cyclotron
2015
Abstract Positron emitting radionuclides are increasingly used in medical diagnostics and the number of radiopharmaceutical production facilities have been estimated to be growing worldwide. During the process of production and/or patient administration of radiopharmaceuticals, an amount of these radionuclides might become airborne and escape into the environment. Therefore, the analysis of radionuclide concentration in the air released to the stack is a very important issue to evaluate the dose to the population living around the plant. To this end, sampling and measurement of radionuclide concentration in air released through the stack of a Nuclear Medicine Center (NMC), provided with a c…
Chernobyl Clean-Up Workers: 17 Years of Follow-Up in Latvia
2005
About 5000 Latvian inhabitants took part at clean up works after accident on Chernobyl Nuclear Power Plant during 1986–1991. Clinical follow-up programme showed that clean-up workers having higher morbidity rate compare to the general population with prevalence of poly–symptomatic sicknesses caused by depression of immune system. Dose reconstruction made by Electron Paramagnetic Resonance (EPR) indicated underestimation of officially documented doses by factor 2-10. Blood measurement performed by Inductively Coupled Plasma Mass Spectrometry (ICP MS) indicated elevated concentration of lead, cadmium and thorium. It was assumed that toxic compounds, physical stress, incorporated long-lived ra…
Alpha emitting nuclides in nuclear medicine theranostics.
2021
Theranostic applications with radio-isotopes currently are rapidly progressing and expand nuclear medicine application in clinical routine. Alpha emitting isotopes, in particular, have long been hypothesized to achieve relevant advances for the treatment of malignancies. Here, an overview of their properties and the knowledge of radiobiology is reviewed in view of clinical translation. Clinical evidence of radiopharmaceuticals based on alpha emitters is summarized with a focus on recent developments for treatment of metastasized castration resistant prostate cancer.Theranostische Anwendungen mit Radioisotopen machen derzeit rasche Fortschritte und erweitern den Einsatz der Nuklearmedizin in…
Processing of Generator-Produced 68Ga for Medical Application
2007
The (68)Ge/(68)Ga generator provides an excellent source of positron-emitting (68)Ga. However, newly available "ionic" (68)Ge/(68)Ga radionuclide generators are not necessarily optimized for the synthesis of (68)Ga-labeled radiopharmaceuticals. The eluates have rather large volumes, a high concentration of H(+) (pH of 1), a breakthrough of (68)Ge, increasing with time or frequency of use, and impurities such as stable Zn(II) generated by the decay of (68)Ga, Ti(IV) as a constituent of the column material, and Fe(III) as a general impurity.We have developed an efficient route for the processing of generator-derived (68)Ga eluates, including the labeling and purification of biomolecules. Prec…
Isoltrap pins down masses of exotic nuclides
2005
The mass of radionuclides contribute to a variety of fundamental studies including tests of the weak interaction and the Standard Model. The limits of mass measurements of exotic nuclides have been extended considerably by the Penning-trap mass spectrometer ISOLTRAP at the ISOLDE facility at CERN. Recent ISOLTRAP measurements are summarized and current technical improvements are outlined.
Robustness of PET Radiomics Features: Impact of Co-Registration with MRI
2021
Radiomics holds great promise in the field of cancer management. However, the clinical application of radiomics has been hampered by uncertainty about the robustness of the features extracted from the images. Previous studies have reported that radiomics features are sensitive to changes in voxel size resampling and interpolation, image perturbation, or slice thickness. This study aims to observe the variability of positron emission tomography (PET) radiomics features under the impact of co-registration with magnetic resonance imaging (MRI) using the difference percentage coefficient, and the Spearman’s correlation coefficient for three groups of images: (i) original PET, (ii) PET after co-…
Increased exercise ejection fraction and reversed remodeling after long-term treatment with metoprolol in congestive heart failure: a randomized, str…
2003
Background: the effects of long-term administration of β-blockers on left ventricular (LV) function during exercise in patients with ischemic heart disease (IHD) and idiopathic dilated cardiomyopathy (DCM) are controversial. Patients and methods: patients with stable congestive heart failure (CHF) (New York heart association [NYHA] class II and III) and ejection fraction (EF) ≤0.40 were randomized to metoprolol, 50 mg t.i.d. or placebo for 6 months. Patients were divided into two groups: ischemic heart disease (IHD) and idiopathic dilated cardiomyopathy (DCM). The mean EF was 0.29 in both groups and 92% were taking angiotensin-converting enzyme (ACE) inhibitors. In the IHD group, 84% had su…
Resonant laser–SNMS for spatially resolved and element selective ultra-trace analysis of radionuclides
2018
The newly developed resonant laser–SNMS system at the IRS Hannover combines the high spatial and decent mass resolution of a TOF-SIMS instrument with the element-selective process of resonant laser ionization. This setup was characterized by use of synthetic uranium, plutonium and technetium samples to prepare and demonstrate the performance for measurements on environmental samples. The laser–SNMS system will be applied for the detection, visualization and ultra-trace analysis of radionuclide containing nanoparticles in environmental samples with strongly reduced or even completely omitted chemical preparation. The necessary suppression of isobaric contamination was demonstrated as well as…
TH-C-AUD A-08: Evaluation of Electronic Equilibrium Conditions Near Brachytherapy Sources
2008
Purpose: For high‐energy photon‐emitting brachytherapysources such as 60 Co , 137 Cs , 192 Ir , and 169 Yb , the main contribution of the systematic uncertainty in the dose distributions near the sources is understanding of electronic equilibrium and the contribution of β‐rays due to radioactive disintegration. Thus, it is important to study these effects in detail to accurately depict dose distributions near these brachytherapysources. This work studies the relative importance of β‐ray contributions to total dose (β + γ + x‐ray), and feasibility of using the approximation “collision kerma equals dose in electronic equilibrium conditions.” Method and Materials:Characteristics of kerma and d…
Prophylaxis of radiogenic sialadenitis and mucositis by coumarin/troxerutine in patients with head and neck cancer--a prospective,randomized, placebo…
2001
To study the efficacy of coumarin/troxerutine for the protection of salivary glands and mucosa during irradiation. Design: Prospective, randomized, placebo-controlled, double-blind trial. Setting: University hospital, Germany. Patients: 48 patients who had radiotherapy to the head and neck. Main outcome measures: Salivary gland scintigraphy and acute side-effects of radiotherapy (Radiation Therapy Oncology Group (RTOG) score). Results: 23 patients (11 experimental, 12 placebo) completed the study. The global efficacy measure combining scintigraphy and RTOG score favoured the experimental arm (P= 0.07). The RTOG score showed significantly fewer acute side-effects of radiation in the experime…