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[PMID]:29400037
[Au] Autor:Estêvão R; Duarte H; Lopes F; Fernandes J; Monteiro E
[Ti] Título:Peptide receptor radionuclide therapy in head and neck paragangliomas ­ Report of 14 cases.
[So] Source:Rev Laryngol Otol Rhinol (Bord);136(4):155-8, 2015.
[Is] ISSN:0035-1334
[Cp] País de publicação:France
[La] Idioma:eng
[Ab] Resumo:Background: Peptide receptor radionuclide therapy (PRRT) is a very promising treatment option in neuroendocrine tumours, with good results, but there are only few reports regar­ding its use in paragangliomas. Methods: The authors conduc­ted a retrospective study during the period of May 2011 to February 2014 in an Oncological Centre. Ten patients with jugular-tympanic paragangliomas and four with carotid body paragangliomas were treated with three cycles of Lutetium labelled peptide (177 Lu-DOTATATE). Treatment response was assessed with a PET-CT with 68 Ga-DOTANOC and clinical crite­ria. Results: Ten of the fourteen patients showed a decrea­se in the tumor standard uptake value (SUV) after treat­ment. 90% of patients with Jugulotympanic paraganglio­mas had symptomatic improvement or stabilization. Patients with carotid body paragangliomas and patients with a low uptake of 68 Ga-DOTANOC had a worse response to the treatment. The tumor SUV value was a predictor of treatment response [R= 0,64; F= 8,212; p= 0,014]. Conclusion: Peptide receptor radio­nuclide therapy can be a therapeutic option in selected cases of head and neck paragangliomas.
[Mh] Termos MeSH primário: Neoplasias de Cabeça e Pescoço/radioterapia
Lutécio/uso terapêutico
Paraganglioma/radioterapia
Radioisótopos/uso terapêutico
Compostos Radiofarmacêuticos/uso terapêutico
[Mh] Termos MeSH secundário: Adulto
Idoso
Feminino
Neoplasias de Cabeça e Pescoço/diagnóstico por imagem
Neoplasias de Cabeça e Pescoço/patologia
Seres Humanos
Masculino
Meia-Idade
Paraganglioma/diagnóstico por imagem
Paraganglioma/patologia
Tomografia Computadorizada com Tomografia por Emissão de Pósitrons
Estudos Retrospectivos
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Nm] Nome de substância:
0 (Lutetium-177); 0 (Radioisotopes); 0 (Radiopharmaceuticals); 5H0DOZ21UJ (Lutetium)
[Em] Mês de entrada:1803
[Cu] Atualização por classe:180308
[Lr] Data última revisão:
180308
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:180206
[St] Status:MEDLINE


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[PMID]:27775623
[Au] Autor:Jung SJ; Hong SK; Kwon OK
[Ad] Endereço:Department of Electronics and Computer Engineering, Hanyang University, Seoul 133-791, Korea. sj820831@hanyang.ac.kr.
[Ti] Título:A Readout IC Using Two-Step Fastest Signal Identification for Compact Data Acquisition of PET Systems.
[So] Source:Sensors (Basel);16(10), 2016 Oct 20.
[Is] ISSN:1424-8220
[Cp] País de publicação:Switzerland
[La] Idioma:eng
[Ab] Resumo:A readout integrated circuit (ROIC) using two-step fastest signal identification (FSI) is proposed to reduce the number of input channels of a data acquisition (DAQ) block with a high-channel reduction ratio. The two-step FSI enables the proposed ROIC to filter out useless input signals that arise from scattering and electrical noise without using complex and bulky circuits. In addition, an asynchronous fastest signal identifier and a self-trimmed comparator are proposed to identify the fastest signal without using a high-frequency clock and to reduce misidentification, respectively. The channel reduction ratio of the proposed ROIC is 16:1 and can be extended to 16 × :1 using ROICs. To verify the performance of the two-step FSI, the proposed ROIC was implemented into a gamma photon detector module using a Geiger-mode avalanche photodiode with a lutetium-yttrium oxyorthosilicate array. The measured minimum detectable time is 1 ns. The difference of the measured energy and timing resolution between with and without the two-step FSI are 0.8% and 0.2 ns, respectively, which are negligibly small. These measurement results show that the proposed ROIC using the two-step FSI reduces the number of input channels of the DAQ block without sacrificing the performance of the positron emission tomography (PET) systems.
[Mh] Termos MeSH primário: Tomografia por Emissão de Pósitrons/métodos
[Mh] Termos MeSH secundário: Desenho de Equipamento
Limite de Detecção
Lutécio/química
Silicatos/química
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Nm] Nome de substância:
0 (Silicates); 0 (lutetium orthosilicate); 5H0DOZ21UJ (Lutetium)
[Em] Mês de entrada:1802
[Cu] Atualização por classe:180205
[Lr] Data última revisão:
180205
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:161025
[St] Status:MEDLINE


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[PMID]:28898054
[Au] Autor:Müller C; Farkas R; Borgna F; Schmid RM; Benesová M; Schibli R
[Ad] Endereço:Center for Radiopharmaceutical Sciences ETH-PSI-USZ, Paul Scherrer Institut , 5232 Villigen-PSI, Switzerland.
[Ti] Título:Synthesis, Radiolabeling, and Characterization of Plasma Protein-Binding Ligands: Potential Tools for Modulation of the Pharmacokinetic Properties of (Radio)Pharmaceuticals.
[So] Source:Bioconjug Chem;28(9):2372-2383, 2017 Sep 20.
[Is] ISSN:1520-4812
[Cp] País de publicação:United States
[La] Idioma:eng
[Ab] Resumo:The development of (radio)pharmaceuticals with favorable pharmacokinetic profiles is crucial for allowing the optimization of the imaging or therapeutic potential and the minimization of undesired side effects. The aim of this study was, therefore, to evaluate and compare three different plasma protein binders (PPB-01, PPB-02, and PPB-03) that are potentially useful in combination with (radio)pharmaceuticals to enhance their half-life in the blood. The entities were functionalized with a 1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid (DOTA) chelator via a l-lysine and ß-alanine linker moiety using solid-phase peptide chemistry and labeled with Lu (T = 6.65 days), a clinically established radiometal. The binding capacities of these radioligands and Lu-DOTA were evaluated using human plasma and solutions of human serum albumin (HSA), human α -acid glycoprotein (α -AGP), and human transthyretin (hTTR) by applying an ultrafiltration assay. Lu-DOTA-PPB-01 and Lu-DOTA-PPB-02 bound to a high and moderate extent to human plasma proteins (>90% and ∼70%, respectively), whereas the binding to hTTR was considered negligible (<10%). Lu-DOTA-PPB-03 showed almost complete binding to human plasma proteins (>90%) with a high fraction bound to hTTR (∼50%). Plasma protein binding of the Lu-DOTA complex, which was used as a control, was not observed (<1%). Lu-DOTA-PPB-01 and Lu-DOTA-PPB-02 were both displaced (>80%) from HSA by ibuprofen, specific for Sudlow's binding site II and coherent with the aromatic structures, and >80% by their respective binding entities. Lu-DOTA-PPB-03 was displaced from hTTR by the site-marker l-thyroxine (>60%) and by its binding entity PPB-03* (>80%). All three radioligands were investigated with regard to the in vivo blood clearance in normal mice. Lu-DOTA-PPB-01 showed the slowest blood clearance (T : >15 h) followed by Lu-DOTA-PPB-03 (T : ∼2.33 h) and Lu-DOTA-PPB-02 (T : ∼1.14 h), which was excreted relatively fast. Our results confirmed the high affinity of the 4-(4-iodophenyl)-butyric acid entity (PPB-01) to plasma proteins, while replacement of the halogen by an ethynyl entity (PPB-02) reduced the plasma protein binding significantly. An attractive approach is the application of the transthyretin binder (PPB-03), which shows high affinity to hTTR. Future studies in our laboratory will be focused on the application of these binding entities in combination with clinically relevant targeting agents for diagnostic and therapeutic purposes in nuclear medicine.
[Mh] Termos MeSH primário: Proteínas Sanguíneas/metabolismo
Lutécio/metabolismo
Compostos Radiofarmacêuticos/metabolismo
[Mh] Termos MeSH secundário: Animais
Feminino
Seres Humanos
Ligantes
Lutécio/química
Lutécio/farmacocinética
Camundongos Endogâmicos BALB C
Pré-Albumina/metabolismo
Ligação Proteica
Radioisótopos/química
Radioisótopos/metabolismo
Radioisótopos/farmacocinética
Compostos Radiofarmacêuticos/química
Compostos Radiofarmacêuticos/farmacocinética
Tomografia Computadorizada com Tomografia Computadorizada de Emissão de Fóton Único/métodos
Tiroxina/metabolismo
Distribuição Tecidual
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Nm] Nome de substância:
0 (Blood Proteins); 0 (Ligands); 0 (Prealbumin); 0 (Radioisotopes); 0 (Radiopharmaceuticals); 5H0DOZ21UJ (Lutetium); Q51BO43MG4 (Thyroxine)
[Em] Mês de entrada:1710
[Cu] Atualização por classe:171009
[Lr] Data última revisão:
171009
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:170913
[St] Status:MEDLINE
[do] DOI:10.1021/acs.bioconjchem.7b00378


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[PMID]:28806773
[Au] Autor:Mezzenga E; D'Errico V; D'Arienzo M; Strigari L; Panagiota K; Matteucci F; Severi S; Paganelli G; Fenwick A; Bianchini D; Marcocci F; Sarnelli A
[Ad] Endereço:Medical Physics Unit, Istituto Scientifico Romagnolo per lo Studio e la Cura dei Tumori (IRST) IRCCS, Meldola, Italy.
[Ti] Título:Quantitative accuracy of 177Lu SPECT imaging for molecular radiotherapy.
[So] Source:PLoS One;12(8):e0182888, 2017.
[Is] ISSN:1932-6203
[Cp] País de publicação:United States
[La] Idioma:eng
[Ab] Resumo:The purpose of this study is to investigate the optimal reference geometry for gamma camera calibration. Yet another question of interest was to assess the influence of the number of 3D Ordered Subsets Expectation Maximization (3D-OSEM) updates on activity quantification for SPECT imaging with 177Lu. The accuracy of 177Lu activity quantification was assessed both in small and in large objects. Two different reference geometries, namely a cylindrical homogeneous phantom and a Jaszczak 16 ml sphere surrounded by cold water, were used to determine the gamma camera calibration factor of a commercial SPECT/CT system. Moreover, the noise level and the concentration recovery coefficient were evaluated as a function of the number of 3D-OSEM updates by using the SPECT/CT images of the reference geometry phantoms and those of a cold Jaszczak phantom with three hot spheres (16ml, 8ml and 4ml), respectively. The optimal choice of the number of 3D-OSEM updates was based on a compromise between the noise level achievable in the reconstructed SPECT images and the concentration recovery coefficients. The quantitative accuracy achievable was finally validated on a test phantom, where a spherical insert composed of two concentric spheres was used to simulate a lesion in a warm background. Our data confirm and extend previous observations. Using the calibration factor obtained with the cylindrical homogeneous phantom and the Jaszczak 16 ml sphere, the recovered activity in the test phantom was underestimated by -16.4% and -24.8%, respectively. Our work has led us to conclude that gamma camera calibration performed with large homogeneous phantom outperforms calibration executed with the Jaszczak 16ml sphere. Furthermore, the results obtained support the assumption that approximately 50 OSEM updates represent a good trade-off to reach convergence in small volumes, meanwhile minimizing the noise level.
[Mh] Termos MeSH primário: Lutécio/química
Radioisótopos/química
Radioterapia
Tomografia Computadorizada de Emissão de Fóton Único/métodos
[Mh] Termos MeSH secundário: Calibragem
Imagens de Fantasmas
Reprodutibilidade dos Testes
Tomografia Computadorizada por Raios X
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Nm] Nome de substância:
0 (Radioisotopes); 5H0DOZ21UJ (Lutetium)
[Em] Mês de entrada:1710
[Cu] Atualização por classe:171009
[Lr] Data última revisão:
171009
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:170815
[St] Status:MEDLINE
[do] DOI:10.1371/journal.pone.0182888


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[PMID]:28732021
[Au] Autor:Chan HS; de Blois E; Morgenstern A; Bruchertseifer F; de Jong M; Breeman W; Konijnenberg M
[Ad] Endereço:Department of Radiology and Nuclear Medicine, Erasmus MC, Rotterdam, The Netherlands.
[Ti] Título:In Vitro comparison of 213Bi- and 177Lu-radiation for peptide receptor radionuclide therapy.
[So] Source:PLoS One;12(7):e0181473, 2017.
[Is] ISSN:1932-6203
[Cp] País de publicação:United States
[La] Idioma:eng
[Ab] Resumo:BACKGROUND: Absorbed doses for α-emitters are different from those for ß-emitters, as the high linear energy transfer (LET) nature of α-particles results in a very dense energy deposition over a relatively short path length near the point of emission. This highly localized and therefore high energy deposition can lead to enhanced cell-killing effects at absorbed doses that are non-lethal in low-LET type of exposure. Affinities of DOTA-DPhe1-Tyr3-octreotate (DOTATATE), 115In-DOTATATE, 175Lu-DOTATATE and 209Bi-DOTATATE were determined in the K562-SST2 cell line. Two other cell lines were used for radiation response assessment; BON and CA20948, with a low and high expression of somatostatin receptors, respectively. Cellular uptake kinetics of 111In-DOTATATE were determined in CA20948 cells. CA20948 and BON were irradiated with 137Cs, 177Lu-DTPA, 177Lu-DOTATATE, 213Bi-DTPA and 213Bi-DOTATATE. Absorbed doses were calculated using the MIRDcell dosimetry method for the specific binding and a Monte Carlo model of a cylindrical 6-well plate geometry for the exposure by the radioactive incubation medium. Absorbed doses were compared to conventional irradiation of cells with 137Cs and the relative biological effect (RBE) at 10% survival was calculated. RESULTS: IC50 of (labelled) DOTATATE was in the nM range. Absorbed doses up to 7 Gy were obtained by 5.2 MBq 213Bi-DOTATATE, in majority the dose was caused by α-particle radiation. Cellular internalization determined with 111In-DOTATATE showed a linear relation with incubation time. Cell survival after exposure of 213Bi-DTPA and 213Bi-DOTATATE to BON or CA20948 cells showed a linear-exponential relation with the absorbed dose, confirming the high LET character of 213Bi. The survival of CA20948 after exposure to 177Lu-DOTATATE and the reference 137Cs irradiation showed the typical curvature of the linear-quadratic model. 10% Cell survival of CA20948 was reached at 3 Gy with 213Bi-DOTATATE, a factor 6 lower than the 18 Gy found for 177Lu-DOTATATE and also below the 5 Gy after 137Cs external exposure. CONCLUSION: 213Bi-DTPA and 213Bi-DOTATATE lead to a factor 6 advantage in cell killing compared to 177Lu-DOTATATE. The RBE at 10% survival by 213Bi-ligand compared to 137Cs was 2.0 whereas the RBE for 177Lu-DOTATATE was 0.3 in the CA20948 in vitro model.
[Mh] Termos MeSH primário: Absorção de Radiação
Bismuto
Lutécio
Octreotida/análogos & derivados
Octreotida/farmacologia
Radioisótopos
Compostos Radiofarmacêuticos
Receptores de Somatostatina/metabolismo
[Mh] Termos MeSH secundário: Linhagem Celular Tumoral
Sobrevivência Celular/efeitos da radiação
Relação Dose-Resposta à Radiação
Seres Humanos
Cinética
Transferência Linear de Energia
Modelos Biológicos
Método de Monte Carlo
Compostos Organometálicos/administração & dosagem
Compostos Organometálicos/farmacologia
Radioisótopos/administração & dosagem
Radioisótopos/farmacocinética
Radiometria
Compostos Radiofarmacêuticos/administração & dosagem
Compostos Radiofarmacêuticos/farmacocinética
[Pt] Tipo de publicação:COMPARATIVE STUDY; JOURNAL ARTICLE
[Nm] Nome de substância:
0 (Organometallic Compounds); 0 (Radioisotopes); 0 (Radiopharmaceuticals); 0 (Receptors, Somatostatin); 0 (somatostatin receptor subtype 2, human); 5H0DOZ21UJ (Lutetium); RWM8CCW8GP (Octreotide); U015TT5I8H (Bismuth)
[Em] Mês de entrada:1710
[Cu] Atualização por classe:171002
[Lr] Data última revisão:
171002
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:170722
[St] Status:MEDLINE
[do] DOI:10.1371/journal.pone.0181473


  6 / 700 MEDLINE  
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[PMID]:28663195
[Au] Autor:Fendler WP; Rahbar K; Herrmann K; Kratochwil C; Eiber M
[Ad] Endereço:Department of Molecular and Medical Pharmacology, David Geffen School of Medicine at UCLA, Los Angeles, California wfendler@mednet.ucla.edu.
[Ti] Título:Lu-PSMA Radioligand Therapy for Prostate Cancer.
[So] Source:J Nucl Med;58(8):1196-1200, 2017 Aug.
[Is] ISSN:1535-5667
[Cp] País de publicação:United States
[La] Idioma:eng
[Ab] Resumo:Lu-prostate-specific membrane antigen (PSMA) radioligand therapy (RLT) using inhibitors of PSMA is a novel therapeutic option in patients with metastatic castration-resistant prostate cancer. The current literature suggests that this therapy is well tolerated and effective. On the basis of clinical need and current evidence, the therapy is being implemented in a growing number of centers worldwide. Here, we review important aspects of Lu-PSMA RLT, including patient stratification, the therapy protocol, concomitant medication, and follow-up, to inform medical staff involved in the RLT and care of patients with metastatic castration-resistant prostate cancer.
[Mh] Termos MeSH primário: Antígenos de Superfície/metabolismo
Glutamato Carboxipeptidase II/metabolismo
Lutécio/uso terapêutico
Neoplasias da Próstata/metabolismo
Neoplasias da Próstata/radioterapia
Radioisótopos
Radioterapia/métodos
[Mh] Termos MeSH secundário: Seres Humanos
Masculino
Radioterapia/efeitos adversos
Segurança
[Pt] Tipo de publicação:JOURNAL ARTICLE; REVIEW
[Nm] Nome de substância:
0 (Antigens, Surface); 0 (Radioisotopes); 5H0DOZ21UJ (Lutetium); EC 3.4.17.21 (Glutamate Carboxypeptidase II); EC 3.4.17.21 (glutamate carboxypeptidase II, human)
[Em] Mês de entrada:1708
[Cu] Atualização por classe:170825
[Lr] Data última revisão:
170825
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:170701
[St] Status:MEDLINE
[do] DOI:10.2967/jnumed.117.191023


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[PMID]:28423546
[Au] Autor:Maisonial-Besset A; Witkowski T; Navarro-Teulon I; Berthier-Vergnes O; Fois G; Zhu Y; Besse S; Bawa O; Briat A; Quintana M; Pichard A; Bonnet M; Rubinstein E; Pouget JP; Opolon P; Maigne L; Miot-Noirault E; Chezal JM; Boucheix C; Degoul F
[Ad] Endereço:INSERM, U 1240, 63005 Clermont-Ferrand, France.
[Ti] Título:Tetraspanin 8 (TSPAN 8) as a potential target for radio-immunotherapy of colorectal cancer.
[So] Source:Oncotarget;8(13):22034-22047, 2017 Mar 28.
[Is] ISSN:1949-2553
[Cp] País de publicação:United States
[La] Idioma:eng
[Ab] Resumo:Tetraspanin 8 (TSPAN8) overexpression is correlated with poor prognosis in human colorectal cancer (CRC). A murine mAb Ts29.2 specific for human TSPAN8 provided significant efficiency for immunotherapy in CRC pre-clinical models. We therefore evaluate the feasability of targeting TSPAN8 in CRC with radiolabeled Ts29.2. Staining of tissue micro-arrays with Ts29.2 revealed that TSPAN8 espression was restricted to a few human healthy tissues. DOTA-Ts29.2 was radiolabeled with 111In or 177Lu with radiochemical purities >95%, specific activity ranging from 300 to 600 MBq/mg, and radioimmunoreactive fractions >80%. The biodistribution of [111In]DOTA-Ts29.2 in nude mice bearing HT29 or SW480 CRC xenografts showed a high specificity of tumor localization with high tumor/blood ratios (HT29: 4.3; SW480-TSPAN8: 3.9 at 72h and 120h post injection respectively). Tumor-specific absorbed dose calculations for [177Lu]DOTA-Ts29.2 was 1.89 Gy/MBq, establishing the feasibility of using radioimmunotherapy of CRC with this radiolabeled antibody. A significant inhibition of tumor growth in HT29 tumor-bearing mice treated with [177Lu]DOTA-Ts29.2 was observed compared to control groups. Ex vivo experiments revealed specific DNA double strand breaks associated with cell apoptosis in [177Lu]DOTA-Ts29.2 treated tumors compared to controls. Overall, we provide a proof-of-concept for the use of [111In/177Lu]DOTA-Ts29.2 that specifically target in vivo aggressive TSPAN8-positive cells in CRC.
[Mh] Termos MeSH primário: Anticorpos Monoclonais/uso terapêutico
Neoplasias Colorretais/patologia
Neoplasias Colorretais/terapia
Radioisótopos de Índio/uso terapêutico
Lutécio/uso terapêutico
Radioimunoterapia
Tetraspaninas/antagonistas & inibidores
[Mh] Termos MeSH secundário: Animais
Anticorpos Monoclonais/farmacocinética
Neoplasias Colorretais/diagnóstico por imagem
Neoplasias Colorretais/metabolismo
Feminino
Seres Humanos
Imunoconjugados/imunologia
Radioisótopos de Índio/farmacocinética
Lutécio/farmacocinética
Camundongos
Camundongos Endogâmicos BALB C
Camundongos Nus
Terapia de Alvo Molecular
Compostos Radiofarmacêuticos/farmacocinética
Compostos Radiofarmacêuticos/uso terapêutico
Distribuição Tecidual
Ensaios Antitumorais Modelo de Xenoenxerto
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Nm] Nome de substância:
0 (Antibodies, Monoclonal); 0 (Immunoconjugates); 0 (Indium Radioisotopes); 0 (Radiopharmaceuticals); 0 (TSPAN8 protein, human); 0 (Tetraspanins); 5H0DOZ21UJ (Lutetium)
[Em] Mês de entrada:1710
[Cu] Atualização por classe:171013
[Lr] Data última revisão:
171013
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:170421
[St] Status:MEDLINE
[do] DOI:10.18632/oncotarget.15787


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[PMID]:28333041
[Au] Autor:Conti M; Eriksson L; Rothfuss H; Sjoeholm T; Townsend D; Rosenqvist G; Carlier T
[Ad] Endereço:Siemens Healthcare Molecular Imaging, Knoxville, United States of America.
[Ti] Título:Characterization of Lu background in LSO-based PET scanners.
[So] Source:Phys Med Biol;62(9):3700-3711, 2017 May 07.
[Is] ISSN:1361-6560
[Cp] País de publicação:England
[La] Idioma:eng
[Ab] Resumo:LSO and LYSO are today the most common scintillators used in positron emission tomography. Lutetium contains traces of Lu, a radioactive isotope that decays ß with a cascade of γ photons in coincidence. Therefore, Lutetium-based scintillators are characterized by a small natural radiation background. In this paper, we investigate and characterize the Lu radiation background via experiments performed on LSO-based PET scanners. LSO background was measured at different energy windows and different time coincidence windows, and by using shields to alter the original spectrum. The effect of radiation background in particularly count-starved applications, such as Y imaging, is analysed and discussed. Depending on the size of the PET scanner, between 500 and 1000 total random counts per second and between 3 and 5 total true coincidences per second were measured in standard coincidence mode. The LSO background counts in a Siemens mCT in the standard PET energy and time windows are in general negligible in terms of trues, and are comparable to that measured in a BGO scanner of similar size.
[Mh] Termos MeSH primário: Radiação de Fundo
Lutécio/química
Tomografia por Emissão de Pósitrons/instrumentação
Radioisótopos/química
[Mh] Termos MeSH secundário: Fótons
Tomografia por Emissão de Pósitrons/normas
Compostos Radiofarmacêuticos
Radioisótopos de Ítrio
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Nm] Nome de substância:
0 (Radioisotopes); 0 (Radiopharmaceuticals); 0 (Yttrium Radioisotopes); 5H0DOZ21UJ (Lutetium)
[Em] Mês de entrada:1710
[Cu] Atualização por classe:171017
[Lr] Data última revisão:
171017
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:170324
[St] Status:MEDLINE
[do] DOI:10.1088/1361-6560/aa68ca


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[PMID]:28327464
[Au] Autor:Derenzo SE
[Ad] Endereço:Molecular Biophysics and Integrated Bioimaging Division, Lawrence Berkeley National Laboratory, Berkeley, CA, United States of America.
[Ti] Título:Monte Carlo simulations of time-of-flight PET with double-ended readout: calibration, coincidence resolving times and statistical lower bounds.
[So] Source:Phys Med Biol;62(9):3828-3858, 2017 May 07.
[Is] ISSN:1361-6560
[Cp] País de publicação:England
[La] Idioma:eng
[Ab] Resumo:This paper demonstrates through Monte Carlo simulations that a practical positron emission tomograph with (1) deep scintillators for efficient detection, (2) double-ended readout for depth-of-interaction information, (3) fixed-level analog triggering, and (4) accurate calibration and timing data corrections can achieve a coincidence resolving time (CRT) that is not far above the statistical lower bound. One Monte Carlo algorithm simulates a calibration procedure that uses data from a positron point source. Annihilation events with an interaction near the entrance surface of one scintillator are selected, and data from the two photodetectors on the other scintillator provide depth-dependent timing corrections. Another Monte Carlo algorithm simulates normal operation using these corrections and determines the CRT. A third Monte Carlo algorithm determines the CRT statistical lower bound by generating a series of random interaction depths, and for each interaction a set of random photoelectron times for each of the two photodetectors. The most likely interaction times are determined by shifting the depth-dependent probability density function to maximize the joint likelihood for all the photoelectron times in each set. Example calculations are tabulated for different numbers of photoelectrons and photodetector time jitters for three 3 × 3 × 30 mm scintillators: Lu SiO :Ce,Ca (LSO), LaBr :Ce, and a hypothetical ultra-fast scintillator. To isolate the factors that depend on the scintillator length and the ability to estimate the DOI, CRT values are tabulated for perfect scintillator-photodetectors. For LSO with 4000 photoelectrons and single photoelectron time jitter of the photodetector J = 0.2 ns (FWHM), the CRT value using the statistically weighted average of corrected trigger times is 0.098 ns FWHM and the statistical lower bound is 0.091 ns FWHM. For LaBr :Ce with 8000 photoelectrons and J = 0.2 ns FWHM, the CRT values are 0.070 and 0.063 ns FWHM, respectively. For the ultra-fast scintillator with 1 ns decay time, 4000 photoelectrons, and J = 0.2 ns FWHM, the CRT values are 0.021 and 0.017 ns FWHM, respectively. The examples also show that calibration and correction for depth-dependent variations in pulse height and in annihilation and optical photon transit times are necessary to achieve these CRT values.
[Mh] Termos MeSH primário: Tomografia por Emissão de Pósitrons/métodos
Dosímetros de Radiação/normas
Contagem de Cintilação/instrumentação
[Mh] Termos MeSH secundário: Calibragem
Elétrons
Funções Verossimilhança
Lutécio/efeitos da radiação
Método de Monte Carlo
Fótons
Distribuição Aleatória
Contagem de Cintilação/métodos
Contagem de Cintilação/normas
Compostos de Silício/efeitos da radiação
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Nm] Nome de substância:
0 (Silicon Compounds); 0 (dilutetium silicon pentaoxide); 5H0DOZ21UJ (Lutetium)
[Em] Mês de entrada:1710
[Cu] Atualização por classe:171017
[Lr] Data última revisão:
171017
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:170323
[St] Status:MEDLINE
[do] DOI:10.1088/1361-6560/aa6862


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[PMID]:28303694
[Au] Autor:Emmett L; Willowson K; Violet J; Shin J; Blanksby A; Lee J
[Ad] Endereço:University of New South Wales, Sydney, NSW, Australia.
[Ti] Título:Lutetium PSMA radionuclide therapy for men with prostate cancer: a review of the current literature and discussion of practical aspects of therapy.
[So] Source:J Med Radiat Sci;64(1):52-60, 2017 Mar.
[Is] ISSN:2051-3909
[Cp] País de publicação:United States
[La] Idioma:eng
[Ab] Resumo:Prostate-specific membrane antigen (PSMA) is a receptor on the surface of prostate cancer cells that is revolutionising the way we image and treat men with prostate cancer. New small molecule peptides with high-binding affinity for the PSMA receptor have allowed high quality, highly specific PET imaging, in addition to the development of targeted radionuclide therapy for men with prostate cancer. This targeted therapy for prostate cancer has, to date, predominately used Lutetium 177 (Lu) labelled PSMA peptides. Early clinical studies evaluating the safety and efficacy of Lu PSMA therapy have demonstrated promising results with a significant proportion of men with metastatic prostate cancer, who have already failed other therapies, responding clinically to Lu PSMA. This review discusses the practical issues of administering Lu PSMA, and gives an overview of the findings from currently published trials in regards to treatment response rates, expected toxicities and safety.
[Mh] Termos MeSH primário: Antígenos de Superfície/metabolismo
Glutamato Carboxipeptidase II/metabolismo
Lutécio/uso terapêutico
Neoplasias da Próstata/metabolismo
Neoplasias da Próstata/radioterapia
Radioterapia/métodos
[Mh] Termos MeSH secundário: Seres Humanos
Masculino
Radioterapia/efeitos adversos
Dosagem Radioterapêutica
Segurança
[Pt] Tipo de publicação:JOURNAL ARTICLE; REVIEW
[Nm] Nome de substância:
0 (Antigens, Surface); 5H0DOZ21UJ (Lutetium); EC 3.4.17.21 (Glutamate Carboxypeptidase II); EC 3.4.17.21 (glutamate carboxypeptidase II, human)
[Em] Mês de entrada:1704
[Cu] Atualização por classe:170425
[Lr] Data última revisão:
170425
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:170318
[St] Status:MEDLINE
[do] DOI:10.1002/jmrs.227



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