1,721,048 research outputs found
Receptor radionuclide therapy of tumors: A road from basic research to clinical applications
No full text..
Yttrium-based therapy for neuroendocrine tumors
No full textPeptide receptor radionuclide therapy with 90Y-peptides is generally well tolerated. Acute side effects are usually mild; some are related to the coadministration of amino acids and others to the radiopeptide itself. Chronic and permanent effects on target organs, particularly kidneys and bone marrow, are generally mild if necessary precautions are taken. The potential risk to kidney and red marrow limits the amount of radioactivity that may be administered. However, when tumor masses are irradiated with adequate doses, volume reduction may be observed. 90Y-octreotide has been the most used radiopeptide in the first 8 to 10 years of experience. © 2014 Elsevier Inc
Current Concepts in (68)Ga-DOTATATE Imaging of Neuroendocrine Neoplasms: Interpretation, Biodistribution, Dosimetry, and Molecular Strategies
No full text(68)Ga-DOTATATE PET/CT provides information on the location of somatostatin receptor-expressing tumors. Integrating this imaging data effectively in patient care requires the clinical history; the histopathology and biomarker information; and the grade, stage, and prior imaging results. Previous therapies and technical aspects of the study should be considered, given their ability to alter the interpretation of the images. This includes physiologic biodistribution of the radiotracer, as well as conditions that engender false-positive results. This article provides a guide to the performance and interpretation of (68)Ga-DOTATATE PET/CT and describes its role in the diagnostic algorithm of neuroendocrine neoplasms and its overall utility in their management
Peptide Receptor Radionuclide Therapy (PRRT)
No full textNeuroendocrine tumors are generally slow growing and are frequently discovered when metastatic spread has occurred. This leaves room for multiple treatments, individualized through a multidisciplinary approach that considers tumor type, extension, and related symptoms. In almost 15 years of academic phase II trials, PRRT with either 90Y-octreotide or 177Lu-octreotate proved to be efficient, with tumor responses in more than 30% of patients, symptom relief and QoL improvement, biomarker reduction, and, ultimately, an impact on survival
Peptide Receptor Radionuclide Therapy for Advanced Neuroendocrine Tumors
No full textNo abstract availabl
Yttrium-labelled peptides for therapy of NET
No full textPeptide receptor radionuclide therapy (PRRT) consists in the systemic administration of a synthetic peptide, labelled with a suitable beta-emitting radionuclide, able to irradiate tumours and their metastases via the internalization through a specific receptor, overexpressed on the cell membrane. After 15 years of experience, we can state that PRRT with 90Y- labelled peptides is generally well tolerated. Acute side effects are usually mild, some of which are related to the co-administration of amino acids, such as nausea. Others are related to the radiopeptide, such as fatigue or the exacerbation of an endocrine syndrome, which rarely occurs in functioning tumours. Chronic and permanent effects on target organs, particularly the kidneys and the bone marrow, are generally mild if the necessary precautions are taken. Currently, the potential risk to kidney and red marrow limits the amount of radioactivity that may be administered. However, when tumour masses are irradiated with adequate doses, volume reduction may be observed. 90Y-octreotide has been the most widely used radiopeptide in the first 8-10 years of experience. Unfortunately, all of the published results derive from different and inhomogeneous phase I/II studies. Hence, a direct comparison is virtually impossible to date. Nevertheless, even with these limitations, objective responses are registered in 10-34% of patients. The optimal timing of 90Y-DOTATOC in the management of somatostatin receptor (SSTR)-positive tumours and the way in which it should be integrated with other treatments have yet to be defined, and prospective phase II/III trials comparing the efficacy and toxicity of different schemes of 90Y-DOTATOC administration are still warranted. © 2011 Springer-Verlag
Neuroendocrine Tumors
No full textNeuroendocrine tumors (NETs) originate from single or clustered neuroendocrine cells, distributed in the gastrointestinal tract, urogenital tract, endocrine, and bronchopulmonary system. NETs account for approximately 2.2% of all malignancies. These slow growing tumors are difficult to localize and often metastatic at diagnosis. Surgery can be curative in only 20% of cases. A syndrome of flushing, diarrhea, sweating, and bronchospasm due to secretion of multiple hormones (carcinoid syndrome) occurs in 20% of patients. Most NETs are sporadic, but occasionally, they may be part of inherited syndromes, known as multiple endocrine neoplasia type 1 and 2 (MEN1 and MEN2). The European Neuroendocrine Tumor Society diagnostic and prognostic stratification criteria are based on histological typing, differentiation, grading, and TNM staging. Immunostaining for the neuroendocrine markers synaptophysin and chromogranin and for the proliferation marker Ki67/MIB1 is mandatory, while immunostaining for hormones, receptors, and other markers is optional. The grading proposal stratifies tumors in G1 (1 mitotic count/10 HPF, Ki67 ⤠2%), G2 (2â20 mitotic counts/10 HPF, Ki67: 3â20%), and G3 (mitotic count >20/10 HPF, Ki67 > 20%). The tumor grading, together with histopathology type and staging, reflects the potential metastatic spread and, therefore, has an impact on the therapy options (surgery, biotherapy, and chemotherapy). CT, MRI, and radionuclide imaging of somatostatin receptor expression or catecholamine uptake is helpful to localize the lesions. Somatostatin receptor imaging utilizes111In-pentetreotide (OctreoScan®), or68Ga-octreotide, while catecholamine uptake is usually imaged with123 I-metaiodobenzylguanidine (131I-MIBG). [18F]FDG PET/CT is less useful than somatostatin/catecholamine receptor imaging. Main indications for radionuclide imaging of NETs are for localization (also as a guide to surgery), for staging, for assessing response to therapy, and for selecting patients for possible therapy with radiolabeled somatostatin analogues or with131I-MIBG. Peptide receptor radionuclide therapy (PRRT) uses high doses of radiolabeled peptides to treat unresectable or metastasized NETs
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
- …
