1,522 research outputs found

    Contatti e scambi tra la cultura serra d'alto e i vasi a bocca quadrata: Il caso delle Ollette tipo San Martino

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    Il lavoro illustra la distribuzione delle cosiddette ollette San Martino in contesti funerari riconducibili alle culture che si sviluppano durante il V millennio a.C. rispettivamente a Sud e a Nord della penisola italiana. I vasi esaminati, globulari a bocca ristretta e realizzati in ceramica figulina, caratterizzano alcuni corredi funerari della fase più recente della cultura peninsulare di Serra d’Alto, talvolta con connotati di prestigio, e sono presenti anche in diverse sepolture femminili della cultura dei Vasi a Bocca Quadrata in area padana e alpina. L’esatta riproduzione formale del tipo peninsulare e la coerenza dell’uso in contesto funerario rivelano una inattesa condivisione di rituali e di valori simbolici tra due mondi geográficamente distanti

    Change fast or change slow? Late Glacial and Early Holocene cultures in a changing environment at Grotta Continenza, Central Italy

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    This work contextualises the sequence of Grotta Continenza, a cave with a rich sequence of Late Glacial to Early Holocene archaeological levels spanning from the Late Upper Palaeolithic to the Neolithic, within the framework of southern Italy cultural adaptation to environmental change.The sequence is dated by Bayesian modelling of radiocarbon dates and event durations are computed, including hiatuses in sedimentation and gaps in culture development; these data are used in association with sedimentology and soil micromorphology to assess sedimentary models that can explain the environmental change.Techno-typological and behavioural aspects of Late Upper Palaeolithic populations are correlated with environmental change, mostly during Younger Dryas

    Cerenkov and radioluminescence imaging of brain tumor specimens during neurosurgery

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    We presented the first example of Cerenkov luminescence imaging (CLI) and radioluminescence imaging (RLI) of human tumor specimens. A patient with a brain meningioma localized in the left parietal region was injected with 166 MBq of 90Y-DOTATOC the day before neurosurgery. The specimens of the tumor removed during surgery were imaged using both CLI and RLI using an optical imager prototype developed in our laboratory. The system is based on a cooled electron multiplied charge coupled device coupled with an f 150.95 17-mm C-mount lens. We showed for the first time the possibility of obtaining CLI and RLI images of fresh human brain tumor specimens removed during neurosurgery

    Impact of SPECT corrections on 3D-dosimetry for TARE

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    Purpose: Many centers aim to plan liver transarterial radioembolization (TARE) with dosimetry, even without CT-based attenuation correction (AC), or with unoptimized scatter correction (SC) methods. This work investigates the impact of presence vs absence of such corrections, and limited spatial resolution, on 3D dosimetry for TARE. Methods: Three voxelized phantoms were derived from CT images of real patients with different body sizes. Simulations of 99mTc-SPECT projections were performed with the SIMIND code, assuming three activity distributions in the liver: uniform, inside a "liver's segment," or distributing multiple uptaking nodules ("nonuniform liver"), with a tumoral liver/healthy parenchyma ratio of 5:1. Projection data were reconstructed by a commercial workstation, with OSEM protocol not specifically optimized for dosimetry (spatial resolution of 12.6 mm), with/without SC (optimized, or with parameters predefined by the manufacturer; dual energy window), and with/without AC. Activity in voxels was calculated by a relative calibration, assuming identical microspheres and 99mTc-SPECT counts spatial distribution. 3D dose distributions were calculated by convolution with 90Y voxel S-values, assuming permanent trapping of microspheres. Cumulative dose-volume histograms in lesions and healthy parenchyma from different reconstructions were compared with those obtained from the reference biodistribution (the "gold standard," GS), assessing differences for D95%, D70%, and D50% (i.e., minimum value of the absorbed dose to a percentage of the irradiated volume). γ tool analysis with tolerance of 3%/13 mm was used to evaluate the agreement between GS and simulated cases. The influence of deep-breathing was studied, blurring the reference biodistributions with a 3D anisotropic gaussian kernel, and performing the simulations once again. Results: Differences of the dosimetric indicators were noticeable in some cases, always negative for lesions and distributed around zero for parenchyma. Application of AC and SC reduced systematically the differences for lesions by 5%–14% for a liver segment, and by 7%–12% for a nonuniform liver. For parenchyma, the data trend was less clear, but the overall range of variability passed from −10%/40% for a liver segment, and −10%/20% for a nonuniform liver, to −13%/6% in both cases. Applying AC, SC with preset parameters gave similar results to optimized SC, as confirmed by γ tool analysis. Moreover, γ analysis confirmed that solely AC and SC are not sufficient to obtain accurate 3D dose distribution. With breathing, the accuracy worsened severely for all dosimetric indicators, above all for lesions: with AC and optimized SC, −38%/−13% in liver's segment, −61%/−40% in the nonuniform liver. For parenchyma, D50% resulted always less sensitive to breathing and sub-optimal correction methods (difference overall range: −7%/13%). Conclusions: Reconstruction protocol optimization, AC, SC, PVE and respiratory motion corrections should be implemented to obtain the best possible dosimetric accuracy. On the other side, thanks to the relative calibration, D50% inaccuracy for the healthy parenchyma from absence of AC was less than expected, while the optimization of SC was scarcely influent. The relative calibration therefore allows to perform TARE planning, basing on D50% for the healthy parenchyma, even without AC or with suboptimal corrections, rather than rely on nondosimetric methods

    Dosimetry optimization system and integrated software (DOSIS) : a comparison against Fluka code results over a standard phantom

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    Trabajo presentado en el X Latin American Symposium on Nuclear Physics and Applications (X LASNPA), 1-6 diciembre 2013. Montevideo, Uruguay.Actually, dual-imaging facilities allow obtainance of both mass and activity patient-specific distributions perfectly correlated, which are important to improve dose distributions estimations and radioimmunotherapy treatment planifications accuracy. Calculus methods at voxel level require both quantitative and qualitative validation to obtain improvements in patient-specific dosimetry. The present work presents advances on the development of a novel computational tool dedicated to 3D patient-specific dosimetry at voxel level; and its results analysis and visualization. With the aim of providing a dosimetric tool for planar and tridimensional methods at voxel level, as well as the development of a platform based on fullstochastic methods for α-, β- and γ-emitters used in radiopharmaceutical applications. DOSIS is based on the Boltzmann radiation transport equation to realize energy delivering calculations. Procedures for 2D and 3D dosimetry have been designed tacking into accont established formalism and standards on MIRD Pamphlets. Anatomic and metabolic images, and dose maps resulting of this calculus are analysed and procesed by a special developed and designed software. DOSIS has been preliminary validated on some standard clinic cases in comparison whith other standard procedures used commonly in radionuclide treatments, showing great accordance on its results and a friendly user usability. Finally, a dose calculation over a standard phantom is performed using DOSIS calculation code and FLUKA, validating the radiation transport code of DOSIS.publishedVersionFil: Pérez, Pedro Antonio. Universidad Nacional de Córdoba. Facultad de Matemática, Astronomía y Física; Argentina.Fil: Pérez, Pedro Antonio. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Física Enrique Gaviola; Argentina.Fil: Pérez, Pedro Antonio. Universidad Nacional de Córdoba. Laboratorio de Investigación e Instrumentación en Física Aplicada a la Medicina e Imágenes por Rayos X; Argentina.Fil: Pérez, Pedro Antonio. Universidad Nacional de Río Cuarto. Facultad de Ciencias Exactas, Físico-Químicas y Naturales. Departamento de Física; Argentina.Fil: Botta, Francesca. European Institute of Oncology; Italia.Fil: Cremonesi, Marta. European Institute of Oncology; Italia.Fil: Ferrari, Mahila. European Institute of Oncology; Italia.Fil: Guerriero, Francesco. European Institute of Oncology; Italia.Fil: Malano, Francisco Mauricio. Universidad Nacional de Córdoba. Facultad de Matemática, Astronomía y Física; Argentina.Fil: Malano, Francisco Mauricio. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Física Enrique Gaviola; Argentina.Fil: Malano, Francisco Mauricio. Universidad Nacional de Córdoba. Laboratorio de Investigación e Instrumentación en Física Aplicada a la Medicina e Imágenes por Rayos X; Argentina.Fil: Pedroli, Guido. European Institute of Oncology; Italia.Fil: Scarinci, Ignacio Emanuel. Universidad Nacional de Córdoba. Laboratorio de Investigación e Instrumentación en Física Aplicada a la Medicina e Imágenes por Rayos X; Argentina.Fil: Valente, Mauro Andrés. Universidad Nacional de Córdoba. Facultad de Matemática, Astronomía y Física; Argentina.Fil: Valente, Mauro Andrés. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Física Enrique Gaviola; Argentina.Fil: Valente, Mauro Andrés. Universidad Nacional de Córdoba. Laboratorio de Investigación e Instrumentación en Física Aplicada a la Medicina e Imágenes por Rayos X; Argentina.Física Atómica, Molecular y Química (física de átomos y moléculas incluyendo colisión, interacción con radiación, resonancia magnética, Moessbauer Efecto.

    Towards a Radio-guided Surgery with β\beta^{-} Decays: Uptake of a somatostatin analogue (DOTATOC) in Meningioma and High Grade Glioma

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    A novel radio guided surgery (RGS) technique for cerebral tumors using β\beta^{-} radiation is being developed. Checking the availability of a radio-tracer that can deliver a β\beta^{-} emitter to the tumor is a fundamental step in the deployment of such technique. This paper reports a study of the uptake of 90Y labeled (DOTATOC) in the meningioma and the high grade glioma (HGG) and a feasibility study of the RGS technique in these cases.Comment: 21 pages, 5 figure

    EANM dosimetry committee recommendations for dosimetry of 177Lu-labelled somatostatin-receptor- and PSMA-targeting ligands

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    The purpose of the EANM Dosimetry Committee is to provide recommendations and guidance to scientists and clinicians on patient-specific dosimetry. Radiopharmaceuticals labelled with lutetium-177 (177Lu) are increasingly used for therapeutic applications, in particular for the treatment of metastatic neuroendocrine tumours using ligands for somatostatin receptors and prostate adenocarcinoma with small-molecule PSMA-targeting ligands. This paper provides an overview of reported dosimetry data for these therapies and summarises current knowledge about radiation-induced side effects on normal tissues and dose-effect relationships for tumours. Dosimetry methods and data are summarised for kidneys, bone marrow, salivary glands, lacrimal glands, pituitary glands, tumours, and the skin in case of radiopharmaceutical extravasation. Where applicable, taking into account the present status of the field and recent evidence in the literature, guidance is provided. The purpose of these recommendations is to encourage the practice of patient-specific dosimetry in therapy with 177Lu-labelled compounds. The proposed methods should be within the scope of centres offering therapy with 177Lu-labelled ligands for somatostatin receptors or small-molecule PSMA.</p

    Eleven-year experience with the avidin-biotin pretargeting system in glioblastoma: Toxicity, efficacy and survival

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    Background: The 3-step avidin-biotin pretargeting approach is applied in patients with recurrent glioblastoma (GBM), using biotinylated anti-tenascin monoclonal antibody as the first step of pretargeting followed by avidin and 90Ybiotin. Methods: The present study reviews objective response and overall survival rates in 502 glioblastoma patients treated with 3-step radioimmunotherapy in our institute from December 1994 to December 2005. Patients underwent standard treatment before receiving Pretargeted Antibody-Guided Radionuclide Therapy with 90Y-biotin (PAGRIT ®). Results: Of the 502 patients, 272 (54%) were evaluable for response and 375 (75%) for overall survival. 174 patients (64%) continued to progress after PAGRIT ®, 77 (28%) obtained disease stabilization, and 21 (8%) showed objective tumor regression. Survival of the 375 evaluable patients was 98.4% at 6 months, 79.2% at 12 months, 51.7% at 18 months, and 30.7% at 24 months after the first cycle of PAGRIT ®. All 375 received 3-step PAGRIT ® at recurrence of GBM. The median survival time from diagnosis was 19 months. Conclusion: The results from this retrospective analysis suggest that 90Y-biotin PAGRIT ® interferes with the progression of glioblastoma, prolonging survival in a larger number of patients. Our analysis forms the basis for further prospective trials, where radioimmunotherapy, which is known to be more effective in minimal residual disease, could be offered immediately after surgery. © Grana et al.; Licensee Bentham Open
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