scholarly journals Cyclotron production and radiochemical purification of terbium-155 for SPECT imaging

2021 ◽  
Vol 6 (1) ◽  
Author(s):  
C. Favaretto ◽  
Z. Talip ◽  
F. Borgna ◽  
P. V. Grundler ◽  
G. Dellepiane ◽  
...  
Keyword(s):  
Nuclear Reaction ◽  
Photon Emission ◽  
Target Material ◽  
Spect Imaging ◽  
Cell Uptake ◽  
In Vivo Studies ◽  
Matched Pair ◽  
Emission Computed Tomography ◽  
High Chemical ◽  
Chemical Purity

Abstract Background Terbium-155 [T1/2 = 5.32 d, Eγ = 87 keV (32%) 105 keV (25%)] is an interesting radionuclide suitable for single photon emission computed tomography (SPECT) imaging with potential application in the diagnosis of oncological disease. It shows similar decay characteristics to the clinically established indium-111 and would be a useful substitute for the diagnosis and prospective dosimetry with biomolecules that are afterwards labeled with therapeutic radiolanthanides and pseudo-radiolanthanides, such as lutetium-177 and yttrium-90. Moreover, terbium-155 could form part of the perfect “matched pair” with the therapeutic radionuclide terbium-161, making the concept of true radiotheragnostics a reality. The aim of this study was the investigation of the production of terbium-155 via the 155Gd(p,n)155Tb and 156Gd(p,2n)155Tb nuclear reactions and its subsequent purification, in order to obtain a final product in quantity and quality sufficient for preclinical application. The 156Gd(p,2n)155Tb nuclear reaction was performed with 72 MeV protons (degraded to ~ 23 MeV), while the 155Gd(p,n)155Tb reaction was degraded further to ~ 10 MeV, as well as performed at an 18 MeV medical cyclotron, to demonstrate its feasibility of production. Result The 156Gd(p,2n)155Tb nuclear reaction demonstrated higher production yields of up to 1.7 GBq, however, lower radionuclidic purity when compared to the final product (~ 200 MBq) of the 155Gd(p,n)155Tb nuclear reaction. In particular, other radioisotopes of terbium were produced as side products. The radiochemical purification of terbium-155 from the target material was developed to provide up to 1.0 GBq product in a small volume (~ 1 mL 0.05 M HCl), suitable for radiolabeling purposes. The high chemical purity of terbium-155 was proven by radiolabeling experiments at molar activities up to 100 MBq/nmol. SPECT/CT experiments were performed in tumor-bearing mice using [155Tb]Tb-DOTATOC. Conclusion This study demonstrated two possible production routes for high activities of terbium-155 using a cyclotron, indicating that the radionuclide is more accessible than the exclusive mass-separated method previously demonstrated. The developed radiochemical purification of terbium-155 from the target material yielded [155Tb]TbCl3 in high chemical purity. As a result, initial cell uptake investigations, as well as SPECT/CT in vivo studies with [155Tb]Tb-DOTATOC, were successfully performed, indicating that the chemical separation produced a product with suitable quality for preclinical studies.

SPECT Scan in Somatization Disorder Patients: An Exploratory Study of Eleven Cases

2001 ◽  
Vol 35 (3) ◽  
pp. 359-363 ◽  
Author(s):  
Javier Garcia-Campayo ◽  
Concepcion Sanz-Carrillo ◽  
Teresa Baringo ◽  
Concepción Ceballos
Keyword(s):  
Computed Tomography ◽  
Single Photon ◽  
Photon Emission ◽  
Spect Imaging ◽  
The Other ◽  
University Hospital ◽  
Somatization Disorder ◽  
Emission Computed Tomography ◽  
Axis I ◽  
Pain Symptoms

Objective: There are no previous studies using single photon emission computed tomography (SPECT) scans in somatization disorder (SD) patients. The aim of this paper is to assess SPECT imaging abnormalities in SD patients and study any relation to laterality. Method: Eleven SD patients from the Somatization Disorder Unit of Miguel Servet University Hospital, Zaragoza, Spain, not fulfilling criteria for any other psychiatric disorder and showing normal computed tomography (CT) and magnetic resonance imaging (MRI) images were studied with SPECT. Patients with DSM-IV axis I comorbidity were ruled out because it has been demonstrated that SPECT scans can show abnormalities in patients with depression and anxiety disorders. The technique used for SPECT was 99mTc-D,1,hexamethylpropyleneamide- oxime (99mTc-HMPAO) in four patients and 99mTc-bicisate in the other seven. The SPECT scans were evaluated without knowledge of clinical data and entirely by visual inspection. Results: Seven out of 11 (63.6%) SD patients showed hypoperfusion in SPECT imaging. In four cases there was hypoperfusion in the non-dominant hemisphere and the predominance of pain symptoms took place in the contralateral hemibody. In the other three patients hypoperfusion was bilateral. The anatomical regions affected were cerebellum (four cases), frontal and prefrontal areas (three cases), temporoparietal areas (two cases) and the complete hemisphere (one case). Conclusions: A proportion of SD patients may present hypoperfusion in SPECT images, uni- or bilaterally, in different brain areas. Possible aetiological explanations for this finding are discussed. Controlled studies are necessary to confirm or refute this hypothesis.

Functional Neuroimaging: A Transformative Tool for Integrative Psychiatry

2018 ◽  
Author(s):  
Abass Alavi ◽  
Andrew B. Newberg
Keyword(s):  
Psychiatric Disorders ◽  
Functional Neuroimaging ◽  
Single Photon ◽  
Cerebral Metabolism ◽  
Photon Emission ◽  
Spect Imaging ◽  
Emission Computed Tomography ◽  
Positron Emission ◽  
Integrative Psychiatry ◽  
Integrative Therapies

Functional neuroimaging with positron emission tomography (PET), single photon emission computed tomography (SPECT), and functional magnetic resonance imaging (fMRI) can be highly useful in the evaluation and management of patients with psychiatric disorders. PET and SPECT imaging typically evaluate cerebral metabolism and blood flow, respectively, and can determine patterns associated with different disorders such as depression or schizophrenia. PET and SPECT imaging can also evaluate neurotransmitter changes such as dopamine or serotonin associated with different psychiatric disorders. fMRI is an excellent tool for studying the effects of psychiatric disorders on specific brain processes related to cognition and mood. fMRI activations studies allow researchers to present various stimuli to a subject in order to determine how the brain reacts and whether psychiatric disorders are associated with different brain reactivity patterns. Functional neuroimaging with PET, SPECT, and fMRI can be highly useful in the investigation of the mechanism of action of integrative therapies for psychiatric disorders.

scholarly journals 99mTc-3PRGD2 SPECT Predicts the Outcome of Endostar and Cisplatin Therapy in Xenograft Animals

Dose-Response ◽  
2019 ◽  
Vol 17 (4) ◽  
pp. 155932581988254
Author(s):  
Wei Sun ◽  
Guifu He ◽  
Mingming Zhang ◽  
Yi Zhao ◽  
Hongmei Yu ◽  
...  
Keyword(s):  
Single Photon ◽  
Antiangiogenic Therapy ◽  
Photon Emission ◽  
Xenograft Model ◽  
Treated Group ◽  
Spect Imaging ◽  
Emission Computed Tomography ◽  
Histopathological Analysis ◽  
Photon Emission Computed Tomography ◽  
Cisplatin Therapy

Aims: Our study was designed to investigate the usefulness of 99mTc-3PRGD2 single-photon emission computed tomography (SPECT) for noninvasively monitoring the response of integrin αvβ3 expression to antiangiogenic treatment with endostar and cisplatin in xenograft animals. Methods: 99mTc-3PRGD2 SPECT imaging was performed at days 0, 7, 14, and 21. Tumors were harvested at all imaging time points for Western blotting and histopathological analysis. Result: In 99mTc-3PRGD2 SPECT imaging, the radioactivity accumulation of NaCl group rised gradually in the first half and dispersed on day 21 due to the necrosis of the tumor. While the radioactivity accumulation of treated groups gradually decreased throughout the course. The downtrend of tumor to nontumor ratio in endostar-treated group was more remarkable than cisplatin-treated group. The expression of intergrin αvβ3 of treated groups was lower than NaCl group from day 14. The expression of intergrin αvβ3 of endostar-treated group was significantly lower than cisplatin-treated group from baseline onward. Conclusion: It’s demonstrated that the 99mTc-3PRGD2 could noninvasively visualize and semiquantify tumor angiogenesis in the xenograft model and monitor the response to the antiangiogenic therapy of endostar and cisplatin effectively. It also can predict the outcome of endostar and cisplatin therapy in xenograft animals.

scholarly journals Single photon emission-computed tomography (SPECT) for functional investigation of the proximal tubule in conscious mice

2010 ◽  
Vol 298 (2) ◽  
pp. F454-F460 ◽  
Author(s):  
François Jouret ◽  
Stéphan Walrand ◽  
Kleber S. Parreira ◽  
Pierre J. Courtoy ◽  
Stanislas Pauwels ◽  
...  
Keyword(s):  
Computed Tomography ◽  
Proximal Tubule ◽  
Knockout Mice ◽  
Single Photon ◽  
Photon Emission ◽  
Spect Imaging ◽  
Emission Computed Tomography ◽  
Single Photon Emission ◽  
Single Photon Emission Computed ◽  
Photon Emission Computed Tomography

Noninvasive analysis of renal function in conscious mice is necessary to optimize the use of mouse models. In this study, we evaluated whether single photon emission-computed tomography (SPECT) using specific radionuclear tracers can be used to analyze changes in renal proximal tubule functions. The tracers included 99mTC- dimercaptosuccinic acid (99mTc-DMSA), which is used for cortex imaging; 99mTc-mercaptoacetyltriglycine (99mTc-MAG3), used for dynamic renography; and 123I-β2-microglobulin, which monitors receptor-mediated endocytosis. 99mTc-DMSA SPECT imaging was shown to delineate the functional renal cortex with a ∼1-mm spatial resolution and accumulated in the cortex reaching a plateau 5 h after injection. The cortical uptake of 99mTc-DMSA was abolished in Clcn5 knockout mice, a model of proximal tubule dysfunction. Dynamic renography with 99mTc-MAG3 in conscious mice demonstrated rapid extraction from blood, renal accumulation, and subsequent tubular secretion. Anesthesia induced a significant delay in the 99mTc-MAG3 clearance. The tubular reabsorption of 123I-β2-microglobulin was strongly impaired in the Clcn5 knockout mice, with defective tubular processing and loss of the native tracer in urine, reflecting proximal tubule dysfunction. Longitudinal studies in a model of cisplatin-induced acute tubular injury revealed a correlation between tubular recovery and 123I-β2-microglobulin uptake. These data show that SPECT imaging with well-validated radiotracers allows in vivo investigations of specific proximal tubule functions in conscious mice.

scholarly journals Filtering in SPECT Image Reconstruction

2011 ◽  
Vol 2011 ◽  
pp. 1-14 ◽  
Author(s):  
Maria Lyra ◽  
Agapi Ploussi
Keyword(s):  
Image Processing ◽  
Image Quality ◽  
Single Photon ◽  
Photon Emission ◽  
Spect Imaging ◽  
Emission Computed Tomography ◽  
Clinical Role ◽  
Tomographic Images ◽  
Reconstruction Software ◽  
The Times

Single photon emission computed tomography (SPECT) imaging is widely implemented in nuclear medicine as its clinical role in the diagnosis and management of several diseases is, many times, very helpful (e.g., myocardium perfusion imaging). The quality of SPECT images are degraded by several factors such as noise because of the limited number of counts, attenuation, or scatter of photons. Image filtering is necessary to compensate these effects and, therefore, to improve image quality. The goal of filtering in tomographic images is to suppress statistical noise and simultaneously to preserve spatial resolution and contrast. The aim of this work is to describe the most widely used filters in SPECT applications and how these affect the image quality. The choice of the filter type, the cut-off frequency and the order is a major problem in clinical routine. In many clinical cases, information for specific parameters is not provided, and findings cannot be extrapolated to other similar SPECT imaging applications. A literature review for the determination of the mostly used filters in cardiac, brain, bone, liver, kidneys, and thyroid applications is also presented. As resulting from the overview, no filter is perfect, and the selection of the proper filters, most of the times, is done empirically. The standardization of image-processing results may limit the filter types for each SPECT examination to certain few filters and some of their parameters. Standardization, also, helps in reducing image processing time, as the filters and their parameters must be standardised before being put to clinical use. Commercial reconstruction software selections lead to comparable results interdepartmentally. The manufacturers normally supply default filters/parameters, but these may not be relevant in various clinical situations. After proper standardisation, it is possible to use many suitable filters or one optimal filter.

Relationship of gastric emptying and volume changes after a solid meal in humans

2005 ◽  
Vol 289 (2) ◽  
pp. G261-G266 ◽  
Author(s):  
Duane D. Burton ◽  
H. Jae Kim ◽  
Michael Camilleri ◽  
Debra A. Stephens ◽  
Brian P. Mullan ◽  
...  
Keyword(s):  
Gastric Emptying ◽  
Volume Change ◽  
Single Photon ◽  
Photon Emission ◽  
Gastric Volume ◽  
Spect Imaging ◽  
Emission Computed Tomography ◽  
Planar Imaging ◽  
Solid Meal ◽  
3 Dimensional

Noninvasive imaging has been developed to measure gastric volumes. The relationship between gastric emptying and volume postprandially is unclear. The aims were to 1) develop a 3-dimensional (3D) single photon emission-computed tomography (SPECT) method to simultaneously measure gastric volume and emptying postprandially, 2) describe the course of gastric volume change during emptying of the meal, and 3) assess a 3D method measuring gastric emptying. In 30 healthy volunteers, we used 111In-planar and 99mTc-SPECT imaging to estimate gastric emptying and volume after a radiolabeled meal. A customized analysis program of SPECT imaging assessed gastric emptying. A Bland-Altman plot assessed the performance of the new SPECT analysis compared with planar analysis. Gastric volume postprandially exceeds the fasting volume plus meal volume. The course of volume change and gastric emptying differ over time. Higher differences in volumes exist relative to fasting plus residual meal volumes at 15 min (median 763 vs. 568 ml, respectively, P < 0.001), 1 h (median 632 vs. 524 ml, P < 0.001), and 2 h (median 518 vs. 428 ml, P < 0.02), in contrast to similar volumes at 3 h (median 320 vs. 314 ml, P = 0.85). Analysis of SPECT imaging accurately measures gastric emptying compared with planar imaging with median differences of 1% (IQR −2.25 to 2.0) at 1 h, 1% (−3.25 to 2.25) at 2 h, and −2.5% (−4 to 0) at 3 h. Gastric volume exceeds meal volume during the first 2 postprandial hours, and simultaneous measurements of gastric volume and emptying can be achieved with a novel 3D SPECT method.

scholarly journals Difficulties of Diagnostics of Obstructive Coronary Artery Lesions in Patients with Stable Ischemic Heart Disease and Possibilities of Single-Photon Emission Computed Tomography

Kardiologiia ◽  
2019 ◽  
Vol 59 (1) ◽  
pp. 28-35
Author(s):  
A. N. Sumin ◽  
E. V. Korok ◽  
A. A. Korotkevitch ◽  
E. N. Kachurina ◽  
A. N. Kokov ◽  
...  
Keyword(s):  
Coronary Artery ◽  
Single Photon ◽  
Photon Emission ◽  
Spect Imaging ◽  
Emission Computed Tomography ◽  
Single Photon Emission ◽  
Single Photon Emission Computed ◽  
Group 2 ◽  
Photon Emission Computed Tomography ◽  
Group 1

Purpose: to assess diagnostic capabilities of single-photon emission computed tomography (SPECT) in the detection of obstructive coronary artery (CA) lesions, depending on the meeting appropriate use criteria. Materials and Methods: We used in this retrospective analysis data from 107 patients with previously diagnosed ischemic heart disease (IHD) or in need to exclude it, who were hospitalized in inpatient departments of the Research Institute for Complex Issues of Cardiovascular Diseases in the period from 2012 to 2015. All patients underwent coronary angiography (CAG) and SPECT (the time interval between the studies did not exceed 3 months) for detection of hemodynamically significant CA stenoses. Patients were distributed into two groups according SPECT imaging appropriateness score: group 1–88 patients with score 7–9 (in whom SPECT imaging was appropriate), group 2–19 patients with score 1–6 (in whom SPECT imaging was uncertain, possibly appropriate, or inappropriate. Results. Clinical signs and symptoms of angina pectoris were predominantly found in group 1 patients (p=0.499). Asymptomatic patients were more likely to be found in group 2 (p<0.001). Group 1 patients commonly had high pretest probability (PTP) (over 90 %, p<0.001), whereas group 2 patients commonly had low PTP (5–10 %, p<0.001). Mean PTP was 77 and 58 % in groups 1 and 2, respectively (p=0.003). According to positive SPECT imaging, significant CA lesions were more often found in group 1 compared to group 2 (31.8 and 10.5 %, respectively, p=0.060). Two- and three-vessel disease prevailed in group 1 (25 % and 14.7 %) according the analysis of prevalence and location of hemodynamically significant CA lesions, although the data did not reach statistical significance (p=0.057 and p=0.073). Stenoses >70 % were more commonly detected in group 1, compared to group 2: in anterior descending artery 52.3 vs. 5.3 % (p<0.001), circumflex artery 35.2 vs. 10.5 %; (p=0.034), right coronary artery 34.1 vs. 10.5 % (p=0.041). The sensitivity in both groups was rather low (40 % vs. 25 %), whereas specificity was 83 % in group 1 and 93 % in group 2. Conclusion. According to clinical examination, patients with IHD and indications for SPECT imaging more often had obstructive CA lesions (63.6 %), than patients with questionable or no indications (21.1 %). However, rate of positive findings during stress tests with SPECT imaging was low in both groups and did not differ significantly (p=0.06). Despite high specificity of SPECT imaging, its sensitivity was low in both groups.

Compton-camera-based SPECT for thyroid cancer imaging

2020 ◽  
pp. 1-14
Author(s):  
Hengyong Yu ◽  
Ge Wang
Keyword(s):  
Computed Tomography ◽  
Thyroid Cancer ◽  
Detection Efficiency ◽  
Single Photon ◽  
Photon Emission ◽  
Resolution Enhancement ◽  
Spect Imaging ◽  
Emission Computed Tomography ◽  
Compton Camera ◽  
Study Results

Thyroid cancer is the most common type of endocrine-related cancer and the most common cancer in young women. Currently, single photon emission computed tomography (SPECT) and computed tomography (CT) are used with radioiodine scintigraphy to evaluate patients with thyroid cancer. The gamma camera for SPECT contains a mechanical collimator that greatly compromises dose efficiency and limits diagnostic sensitivity. Fortunately, the Compton camera is emerging as an ideal approach for mapping the distribution of radiopharmaceuticals inside the thyroid. In this preliminary study, based on the state-of-the-art readout chip Timepix3, we investigate the feasibility of using Compton camera for radiotracer SPECT imaging in thyroid cancer. A thyroid phantom is designed to mimic human neck, the mechanism of Compton camera-based event detection is simulated to generate realistic list-mode data, and a weighted back-projection method is developed to reconstruction the original distribution of the emission source. Study results show that the Compton camera can improve the detection efficiency for two or higher orders of magnitude comparing with the conventional gamma cameras. The thyroid gland regions can be reconstructed from the Compton camera measurements in terms of radiotracer distribution. This makes the Compton-camera-based SPECT imaging a promising modality for future clinical applications with significant benefits for dose reduction, scattering artifact reduction, temporal resolution enhancement, scan throughput increment, and others.

scholarly journals Dual Imaging Gold Nanoplatforms for Targeted Radiotheranostics

Materials ◽  
2020 ◽  
Vol 13 (3) ◽  
pp. 513 ◽  
Author(s):  
Francisco Silva ◽  
António Paulo ◽  
Agnès Pallier ◽  
Sandra Même ◽  
Éva Tóth ◽  
...  
Keyword(s):  
Cancer Cells ◽  
Cellular Uptake ◽  
Photon Emission ◽  
Spect Imaging ◽  
Emission Computed Tomography ◽  
Bimodal Imaging ◽  
Biodistribution Studies ◽  
T1 And T2 ◽  
T2 Mri

Gold nanoparticles (AuNPs) are interesting for the design of new cancer theranostic tools, mainly due to their biocompatibility, easy molecular vectorization, and good biological half-life. Herein, we report a gold nanoparticle platform as a bimodal imaging probe, capable of coordinating Gd3+ for Magnetic Resonance Imaging (MRI) and 67Ga3+ for Single Photon Emission Computed Tomography (SPECT) imaging. Our AuNPs carry a bombesin analogue with affinity towards the gastrin releasing peptide receptor (GRPr), overexpressed in a variety of human cancer cells, namely PC3 prostate cancer cells. The potential of these multimodal imaging nanoconstructs was thoroughly investigated by the assessment of their magnetic properties, in vitro cellular uptake, biodistribution, and radiosensitisation assays. The relaxometric properties predict a potential T1- and T2- MRI application. The promising in vitro cellular uptake of 67Ga/Gd-based bombesin containing particles was confirmed through biodistribution studies in tumor bearing mice, indicating their integrity and ability to target the GRPr. Radiosensitization studies revealed the therapeutic potential of the nanoparticles. Moreover, the DOTA chelating unit moiety versatility gives a high theranostic potential through the coordination of other therapeutically interesting radiometals. Altogether, our nanoparticles are interesting nanomaterial for theranostic application and as bimodal T1- and T2- MRI / SPECT imaging probes.

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