The overexpression of the human epidermal growth factor receptor-2 (HER-2) in 20-25% of human breast cancers was investigated as a target for development of a gold nanoparticle (AuNP) based radiosensitizer for improving the efficacy of neoadjuvant X-radiation therapy of the disease. HER-2 targeted AuNPs were developed by covalently conjugating trastuzumab, a Health Canada approved monoclonal antibody for the treatment of HER-2-overexpressing breast cancer, to 30 nm AuNPs. Trastuzumab conjugated AuNPs were efficiently internalized by HER-2-overexpressing breast cancer cells (as assessed by darkfield microscopy and transmission electron microscopy) and increased DNA damage from X-radiation in these cells by more than 5-fold. To optimize delivery of AuNPs to HER-2-overexpressing tumors, high resolution microSPECT/CT imaging was used to track the in vivo fate of 111In-labelled non-targeted and HER-2 targeted AuNPs following intravenous (i.v.) or intratumoral (i.t.) injection. For i.v. injection, the effects of GdCl3 (for deactivation of macrophages) and non-specific (anti-CD20) antibody rituximab (for blocking of Fc mediated liver and spleen uptake) were studied. It was found that HER-2 targeting via attachment of trastuzumab paradoxically decreased tumor uptake as a result of faster elimination of the targeted AuNPs from the blood while improving internalization in HER-2-positive tumor cells as compared to non-targeted AuNPs. This phenomenon could be attributed to Fc-mediated recognition and subsequent sequestration of trastuzumab conjugated AuNP by the reticuloendothelial system (RES). Blocking of the RES did not increase tumor uptake of either HER-2 targeted or non-targeted AuNPs. Following i.t. injection, our results suggest that Au-NTs redistribute over time and traffick to the liver via the ipsilateral axillary lymph node leading to comparable exposure as seen with i.v. administration. In contrast, targeted AuNPs are bound and internalized by HER-2-overexpressing tumor cells following i.t. injection, with a lower proportion of AuNPs redistributing to normal tissues. In vivo, the combination of HER-2 targeted AuNPs injected i.t. and X-radiation (11 Gy) yielded a 46% decrease in tumor size over a 4 month period in contrast to an 11.5% increase in tumor size for X-radiation treatment alone. Toxicology studies (evaluated through complete blood cell counts, by serum transaminase and creatinine measurements and by monitoring the body weight) demonstrated no apparent normal organ toxicity from the combination of HER-2 targeted AuNPs and X-radiation. These results are promising for the clinical translation of HER-2-targeted AuNPs for radiosensitization of tumors to X-radiation.

The rapid discovery of novel therapeutic agents, targeting the specific mechanism of cancer progression, invasion and angiogenesis, necessitates the development and validation of efficient techniques to assess the therapeutic efficacy of these drugs in vivo. Recently the development of dedicated PET scanners for the imaging of small animals, such as the microPET system (CTI Concorde R4), has allowed for the high-resolution functional and molecular imaging of murine and rodent models of disease. This study, investigates the ability of microPET imaging, using the 18F labelled 2-fluoro-2-deoxyglucose (FDG) PET tracer, to detect the therapeutic efficacy of novel targeted therapies in a rat model of glioma. This technique potentially allows for the rapid and high-throughput assessment of tumour response and evaluation of efficacy of such therapeutic agents in vivo at the pre-clinical stage and will, consequently, facilitate the translation of these novel drugs from the discovery to the clinical phases. / La découverte accélérée de nouvelles molécules thérapeutiques qui ciblent lesmécanismes de progression du cancer tels que l'invasion et l'angiogenèse, nécessite lamise au point et la validation de techniques efficaces qui permettent d'évaluer l'efficacitéthérapeutique de ces agents in vivo. Le développement récent des scanners detomographie à émission de positron (TEP) dédiés à l'imagerie de petits animaux(microPET, CT! Concorde R4), permet aujourd'hui d'obtenir une image fonctionnelle etmoléculaire de haute résolution des modèles rongeurs. Cette étude s'intéresse au potentieldu 18F-2-fluoro-2-deoxyglucose (FDG) en utilisant l'imagerie microPET dansl'évaluation de l'efficacité de nouveaux agents thérapeutiques dans un modèle de gliomechez le. rat. Cette technique pourrait éventuellement mener à une évaluation rapide et àgrande échelle de la réponse tumorale, ainsi que la mesure de l'efficacité d'agentsthérapeutiques in vivo au stade d'étude préclinique. Globalement, cette étude a pour butde faciliter la transition entre la découverte de nouvelles molécules thérapeutiques et leursapplications cliniques.

Beryllium-7 is a cosmogenic radionuclide produced in the atmosphere through the spallation of nitrogen and oxygen nuclei by cosmic-ray-produced neutrons and protons. It is carried in the atmosphere attached to aerosols and is deposited on land and ocean surfaces by wet and dry deposition processes. Beryllium-7 decays by electron capture to lithium-7 and has a half-life of approximately 53 days. It is a potentially useful radionuclide for studying different natural processes. This thesis presents a collection of scientific papers on the occurrence of beryllium-7 in the natural environment, particularly in the Southeast Queensland region of Australia. It shows the results of experimental measurements and discusses their implications. Overall, this thesis contributes to advancing our understanding of the distribution and behaviour of beryllium-7 in the natural environment and provides a foundation for the development of nuclear techniques for the evaluation of environmental problems.

Thesis (D.Tech.: Radiography)-Dept. of Radiography, Durban Institute of Technology, 2006 xxiii, 166 leaves / The purpose of this study was to evaluate 99mTc- methoxyisobutylisonitrile (MIBI) imaging, in terms of sensitivity and specificity, for non invasively detecting extracutaneous involvement of Kaposi’s sarcoma (KS) and for differentiating pulmonary infection from malignancy in acquired immunodeficiency syndrome (AIDS) patients before and after treatment. Current investigations are invasive.

Within the presented thesis there were collected data of effluents of 14C chemical forms from ventilation stacks of the Unit 1, the Unit 2 and the Auxiliary Building of the Temelin NPP for the period from 2001 to 2006. These data are compared to power of both reactors and concentration of ammonium ions in coolant of the primary circuit of the Unit 1 and Unit 2.

Introdução. Pacientes com insuficiência cardíaca submetidos à ventriculectomia parcial esquerda apresentam melhora na função sistólica do ventrículo esquerdo em repouso, porém continuam apresentando limitação funcional. Objetivo. Para melhor compreender os mecanismos desta limitação funcional, estudamos a função sistólica e diastólica do ventrículo esquerdo em repouso e durante exercício submáximo em pacientes submetidos a ventriculectomia parcial esquerda e em pacientes com insuficiência cardíaca não operados, pareados para capacidade funcional máxima e submáxima. Métodos. Foram estudados 9 pacientes submetidos previamente a ventriculografia parcial esquerda (VPE) e 9 pacientes com insuficiência cardíaca não operados previamente (IC). Todos os pacientes foram submetidos inicialmente a um teste cardiopulmonar para determinação do consumo de oxigênio no limiar anaeróbio (LA) e de pico (VO2 pico). Após, foram estudados através da ventriculografia radioisotópica e analisadas a fração de ejeção (FE) e a taxa máxima de enchimento (TME) do ventrículo esquerdo, em repouso e exercício na intensidade do LA. Resultados. Os grupos apresentaram capacidade funcional semelhante avaliada pelo VO2 pico (VPE: [média ± DP] 13,1 ± 3,3 ml/kg.min; IC: 14,1 ± 3,6 ml/kg.min; P > 0,05) e LA (VPE: 7,9 ± 1.3 ml/kg.min; IC: 8,5 ± 1,6 ml/kg.min; P > 0,05). A frequência cardíaca máxima foi maior no grupo IC em comparação ao grupo da VPE (VPE: 119 ± 20 bpm; IC: 149 ± 21 bpm; P < 0.05) A FE em repouso era mais elevada no grupo VPE (VPE: 40 ± 12 %; IC: 32 ± 9 %; P < 0,0125), entretanto a FE elevou-se do repouso ao LA apenas no grupo IC (VPE: 44 ± 17 %; IC: 39 ± 11 %; P < 0,0125). A TME foi semelhante em repouso (VPE: 1,41 ± 0,55 VDF/s; IC: 1,39 ± 0,55 VDF/s; P > 0,05) e aumentou na intensidade do LA similarmente em ambos os grupos (VPE: 2,28 ± 0,55 VDF/s; IC: 2,52 ± 1,07 VDF/s; P < 0,0125). Conclusão. Pacientes submetidos a ventriculectomia parcial esquerda apresentam uma o limiar anaeróbio (LA) resposta anormal da função sistólica do ventrículo esquerdo ao exercício na intensidade do LA e uma resposta cronotrópica diminuida ao exercício máximo. Essas respostas anormais podem contribuir para a limitada capacidade ao exercício destes pacientes, a despeito da melhora na função ventricular sistólica em repouso. / Background. Patients with heart failure who have undergone partial left ventriculectomy improve resting left ventricular systolic function, but maintain limited functional capacity. Objective. In order to better understand the mechanisms associated with this limitation, we studied the systolic and diastolic left ventricular function at rest and during submaximal exercise in patients with previous partial left ventriculectomy and in patients with heart failure who had not been operated, matched for maximal and submaximal exercise capacity. Methods: Nine patients with heart failure who were previously submitted to partial left ventriculectomy (PLV) were compared with a group of 9 patients with heart failure who had not been operated. All patients performed a cardiopulmonary exercise testing with measurement of peak oxygen uptake (VO2 peak) and anaerobic threshold (AT). In a second evaluation, radionuclide left ventriculography was performed to analyze ejection fraction (EF) and peak filling rate (PFR) at rest and during exercise at the intensity corresponding to the AT. Results: Groups presented similar exercise capacity evaluated by VO2peak (PLV: [mean ± SD] 13.1 ± 3.3 mL/Kg.min; HF: 14.1 ± 3.6 mL/Kg.min; P > 0.05) and AT (PLV: 7.9 ± 1.3 mL/Kg.min; HF: 8.5 ± 1.6 mL/Kg.min; P > 0.05). Maximal heart rate was higher in the HF group when compared to the PLV group (PLV: 119 ± 20 bpm; HF: 149 ± 21 bpm; P < 0.05). EF at rest was higher in the PLV group (PLV: 40 ± 12 %; HF: 32 ± 9 %; P < 0.0125), however EF increased from rest to AT only in the HF group (PLV: 44 ± 17 %; HF: 39 ± 11 %; P < 0.0125). PFR was similar at rest (PLV: 1.41 ± 0.55 EDV/sec; HF: 1.39 ± 0.55 EDV/sec; P > 0.05) and increased in both groups at the AT intensity (PLV: 2.28 ± 0.55 EDV/sec; HF: 2.52 ± 1.07 EDV/sec; P < 0,0125). Conclusion: Patients who had partial left ventriculectomy present an abnormal response of left ventricular systolic function to exercise at the AT intensity and an impaired chronotropic response to maximal exercise. These abnormal responses may contribute to the limited exercise capacity of these patients, despite the improvement in resting left ventricular systolic function.

Active Particles at the Temelin NPP, Radiobiological Risks and Protective Precautions The term active particle (AC) was applied on Temelín NPP (ETE) in order to denominate small fragments of high radioactive matters, sized up to 1 millimeter, forming into primary circuit. In accordance with latest available know-how, the ACs major contains corrosion products, that were activated during passing through reactor core. After primary circuit opening, due to carry out outage works, the ACs will spread into ETE radiation controlled area. In proportion to their size, the ACs activity is relative high, so that the ACs can jeopard workers, who will contact them. This jeopardy is namely associated with AC penetration into organism - ingestion or inhalation. The main goal of this dissertation is to determine grounds of ACs occurence in Temelín NPP, to review ACs radiobiological risks and to evaluate procedures and protective aids, used for assurance of workers radiation protection. This dissertation is resuming actual know-how about ACs occured and occuring in Temelín NPP, including suggestions for radiation protection procedures and for protective aids utilization, that are to be used for reduction of above mentioned jeopardy. Next areas are concerned: - analysis of ACs forming and matters composition - description of ACs physical-radiation parameters - identification of main ACs sources in primary circuit - assesment and evaluation of radiobiological jeopardies, associated with ACs occurence in Temelín NPP radiation controlled area - assesment of procedures and protective aids used for protection of workers, who can be endangered by ACs

Introdução. Pacientes com insuficiência cardíaca submetidos à ventriculectomia parcial esquerda apresentam melhora na função sistólica do ventrículo esquerdo em repouso, porém continuam apresentando limitação funcional. Objetivo. Para melhor compreender os mecanismos desta limitação funcional, estudamos a função sistólica e diastólica do ventrículo esquerdo em repouso e durante exercício submáximo em pacientes submetidos a ventriculectomia parcial esquerda e em pacientes com insuficiência cardíaca não operados, pareados para capacidade funcional máxima e submáxima. Métodos. Foram estudados 9 pacientes submetidos previamente a ventriculografia parcial esquerda (VPE) e 9 pacientes com insuficiência cardíaca não operados previamente (IC). Todos os pacientes foram submetidos inicialmente a um teste cardiopulmonar para determinação do consumo de oxigênio no limiar anaeróbio (LA) e de pico (VO2 pico). Após, foram estudados através da ventriculografia radioisotópica e analisadas a fração de ejeção (FE) e a taxa máxima de enchimento (TME) do ventrículo esquerdo, em repouso e exercício na intensidade do LA. Resultados. Os grupos apresentaram capacidade funcional semelhante avaliada pelo VO2 pico (VPE: [média ± DP] 13,1 ± 3,3 ml/kg.min; IC: 14,1 ± 3,6 ml/kg.min; P > 0,05) e LA (VPE: 7,9 ± 1.3 ml/kg.min; IC: 8,5 ± 1,6 ml/kg.min; P > 0,05). A frequência cardíaca máxima foi maior no grupo IC em comparação ao grupo da VPE (VPE: 119 ± 20 bpm; IC: 149 ± 21 bpm; P < 0.05) A FE em repouso era mais elevada no grupo VPE (VPE: 40 ± 12 %; IC: 32 ± 9 %; P < 0,0125), entretanto a FE elevou-se do repouso ao LA apenas no grupo IC (VPE: 44 ± 17 %; IC: 39 ± 11 %; P < 0,0125). A TME foi semelhante em repouso (VPE: 1,41 ± 0,55 VDF/s; IC: 1,39 ± 0,55 VDF/s; P > 0,05) e aumentou na intensidade do LA similarmente em ambos os grupos (VPE: 2,28 ± 0,55 VDF/s; IC: 2,52 ± 1,07 VDF/s; P < 0,0125). Conclusão. Pacientes submetidos a ventriculectomia parcial esquerda apresentam uma o limiar anaeróbio (LA) resposta anormal da função sistólica do ventrículo esquerdo ao exercício na intensidade do LA e uma resposta cronotrópica diminuida ao exercício máximo. Essas respostas anormais podem contribuir para a limitada capacidade ao exercício destes pacientes, a despeito da melhora na função ventricular sistólica em repouso. / Background. Patients with heart failure who have undergone partial left ventriculectomy improve resting left ventricular systolic function, but maintain limited functional capacity. Objective. In order to better understand the mechanisms associated with this limitation, we studied the systolic and diastolic left ventricular function at rest and during submaximal exercise in patients with previous partial left ventriculectomy and in patients with heart failure who had not been operated, matched for maximal and submaximal exercise capacity. Methods: Nine patients with heart failure who were previously submitted to partial left ventriculectomy (PLV) were compared with a group of 9 patients with heart failure who had not been operated. All patients performed a cardiopulmonary exercise testing with measurement of peak oxygen uptake (VO2 peak) and anaerobic threshold (AT). In a second evaluation, radionuclide left ventriculography was performed to analyze ejection fraction (EF) and peak filling rate (PFR) at rest and during exercise at the intensity corresponding to the AT. Results: Groups presented similar exercise capacity evaluated by VO2peak (PLV: [mean ± SD] 13.1 ± 3.3 mL/Kg.min; HF: 14.1 ± 3.6 mL/Kg.min; P > 0.05) and AT (PLV: 7.9 ± 1.3 mL/Kg.min; HF: 8.5 ± 1.6 mL/Kg.min; P > 0.05). Maximal heart rate was higher in the HF group when compared to the PLV group (PLV: 119 ± 20 bpm; HF: 149 ± 21 bpm; P < 0.05). EF at rest was higher in the PLV group (PLV: 40 ± 12 %; HF: 32 ± 9 %; P < 0.0125), however EF increased from rest to AT only in the HF group (PLV: 44 ± 17 %; HF: 39 ± 11 %; P < 0.0125). PFR was similar at rest (PLV: 1.41 ± 0.55 EDV/sec; HF: 1.39 ± 0.55 EDV/sec; P > 0.05) and increased in both groups at the AT intensity (PLV: 2.28 ± 0.55 EDV/sec; HF: 2.52 ± 1.07 EDV/sec; P < 0,0125). Conclusion: Patients who had partial left ventriculectomy present an abnormal response of left ventricular systolic function to exercise at the AT intensity and an impaired chronotropic response to maximal exercise. These abnormal responses may contribute to the limited exercise capacity of these patients, despite the improvement in resting left ventricular systolic function.

Introdução. Pacientes com insuficiência cardíaca submetidos à ventriculectomia parcial esquerda apresentam melhora na função sistólica do ventrículo esquerdo em repouso, porém continuam apresentando limitação funcional. Objetivo. Para melhor compreender os mecanismos desta limitação funcional, estudamos a função sistólica e diastólica do ventrículo esquerdo em repouso e durante exercício submáximo em pacientes submetidos a ventriculectomia parcial esquerda e em pacientes com insuficiência cardíaca não operados, pareados para capacidade funcional máxima e submáxima. Métodos. Foram estudados 9 pacientes submetidos previamente a ventriculografia parcial esquerda (VPE) e 9 pacientes com insuficiência cardíaca não operados previamente (IC). Todos os pacientes foram submetidos inicialmente a um teste cardiopulmonar para determinação do consumo de oxigênio no limiar anaeróbio (LA) e de pico (VO2 pico). Após, foram estudados através da ventriculografia radioisotópica e analisadas a fração de ejeção (FE) e a taxa máxima de enchimento (TME) do ventrículo esquerdo, em repouso e exercício na intensidade do LA. Resultados. Os grupos apresentaram capacidade funcional semelhante avaliada pelo VO2 pico (VPE: [média ± DP] 13,1 ± 3,3 ml/kg.min; IC: 14,1 ± 3,6 ml/kg.min; P > 0,05) e LA (VPE: 7,9 ± 1.3 ml/kg.min; IC: 8,5 ± 1,6 ml/kg.min; P > 0,05). A frequência cardíaca máxima foi maior no grupo IC em comparação ao grupo da VPE (VPE: 119 ± 20 bpm; IC: 149 ± 21 bpm; P < 0.05) A FE em repouso era mais elevada no grupo VPE (VPE: 40 ± 12 %; IC: 32 ± 9 %; P < 0,0125), entretanto a FE elevou-se do repouso ao LA apenas no grupo IC (VPE: 44 ± 17 %; IC: 39 ± 11 %; P < 0,0125). A TME foi semelhante em repouso (VPE: 1,41 ± 0,55 VDF/s; IC: 1,39 ± 0,55 VDF/s; P > 0,05) e aumentou na intensidade do LA similarmente em ambos os grupos (VPE: 2,28 ± 0,55 VDF/s; IC: 2,52 ± 1,07 VDF/s; P < 0,0125). Conclusão. Pacientes submetidos a ventriculectomia parcial esquerda apresentam uma o limiar anaeróbio (LA) resposta anormal da função sistólica do ventrículo esquerdo ao exercício na intensidade do LA e uma resposta cronotrópica diminuida ao exercício máximo. Essas respostas anormais podem contribuir para a limitada capacidade ao exercício destes pacientes, a despeito da melhora na função ventricular sistólica em repouso. / Background. Patients with heart failure who have undergone partial left ventriculectomy improve resting left ventricular systolic function, but maintain limited functional capacity. Objective. In order to better understand the mechanisms associated with this limitation, we studied the systolic and diastolic left ventricular function at rest and during submaximal exercise in patients with previous partial left ventriculectomy and in patients with heart failure who had not been operated, matched for maximal and submaximal exercise capacity. Methods: Nine patients with heart failure who were previously submitted to partial left ventriculectomy (PLV) were compared with a group of 9 patients with heart failure who had not been operated. All patients performed a cardiopulmonary exercise testing with measurement of peak oxygen uptake (VO2 peak) and anaerobic threshold (AT). In a second evaluation, radionuclide left ventriculography was performed to analyze ejection fraction (EF) and peak filling rate (PFR) at rest and during exercise at the intensity corresponding to the AT. Results: Groups presented similar exercise capacity evaluated by VO2peak (PLV: [mean ± SD] 13.1 ± 3.3 mL/Kg.min; HF: 14.1 ± 3.6 mL/Kg.min; P > 0.05) and AT (PLV: 7.9 ± 1.3 mL/Kg.min; HF: 8.5 ± 1.6 mL/Kg.min; P > 0.05). Maximal heart rate was higher in the HF group when compared to the PLV group (PLV: 119 ± 20 bpm; HF: 149 ± 21 bpm; P < 0.05). EF at rest was higher in the PLV group (PLV: 40 ± 12 %; HF: 32 ± 9 %; P < 0.0125), however EF increased from rest to AT only in the HF group (PLV: 44 ± 17 %; HF: 39 ± 11 %; P < 0.0125). PFR was similar at rest (PLV: 1.41 ± 0.55 EDV/sec; HF: 1.39 ± 0.55 EDV/sec; P > 0.05) and increased in both groups at the AT intensity (PLV: 2.28 ± 0.55 EDV/sec; HF: 2.52 ± 1.07 EDV/sec; P < 0,0125). Conclusion: Patients who had partial left ventriculectomy present an abnormal response of left ventricular systolic function to exercise at the AT intensity and an impaired chronotropic response to maximal exercise. These abnormal responses may contribute to the limited exercise capacity of these patients, despite the improvement in resting left ventricular systolic function.

Introdução - Grande parte das cintilografias das paratiróides realizadas antes da primeira cirurgia (paratiroidectomia) resulta negativa, podendo sugerir uma inadequação na solicitação do exame. Objetivo - Desenvolver e comparar dois modelos matemáticos baseados em teoria de conjuntos fuzzy e regressão logística para tomada de decisão na realização de cintilografia das paratiróides, a partir de valores séricos de Cálcio (Ca) e Paratormônio (PTH). Métodos - Da base de registros de cintilografia de paratiróides realizadas no Centro de Medicina Diagnóstica Fleury, em São Paulo, foram identificados 194 pacientes (grupo desenvolvimento) que no período de janeiro de 2000 a dezembro de 2004 tinham Ca e PTH séricos medidos. Foram desenvolvidos dois modelos matemáticos, um deles baseado em regressão logística e o outro em teoria de conjuntos fuzzy, com a finalidade de definir uma medida de indicação para a realização do exame cintilográfico. O desempenho dos modelos foi comparado utilizando curvas ROC pelo teste de Hanley e McNeil. Utilizou-se o grupo teste de 139 pacientes registrados de 2005 a 2006 para avaliar os modelos e verificar sua acurácia. Resultados - No grupo desenvolvimento, a área sob a curva ROC do modelo de regressão logística foi de 0,86 (IC 95%: 0,81-0,91) e do modelo fuzzy foi 0,89 (IC 95%: 0,84-0,93), avaliadas como estatisticamente distintas (p=0,026). O modelo fuzzy se destacou como particularmente útil porque, ao contrário do modelo logístico, mostrou capacidade de utilizar informações de PTH em intervalo em que os valores de Ca mostraram-se pouco discriminantes. No grupo teste, a área para o modelo logístico foi de 0,89 (IC 95%: 0,83-0,95) e para o modelo fuzzy foi de 0,91 (IC 95%: 0,85-0,96) (p=0,128). Conclusões - O modelo fuzzy apresentou desempenho igual ou superior ao modelo de regressão logística. O modelo matemático baseado em teoria de conjuntos fuzzy, no contexto deste estudo, obteve desempenho mais adequado do que o modelo baseado em regressão logística como método para decisão da realização de cintilografia das paratiróides. Por pertinente, destaque-se que, resultado de um exercício metodológico, inferências sobre o comportamento do objeto podem ser impróprias, dada a não representatividade populacional dos dados. / Introduction - A great number of parathyroid scintigraphies performed before the first surgery (parathyroidectomy) results negative suggesting an inadequate use of this test. Objective - The aim of this study was to develop and compare two mathematical models based on logistic regression analysis and fuzzy sets theory to select patients to be submitted to parathyroid scintigraphy based on serum calcium and parathormone values. Methods - From the data registrered on parathyroid scintigrafy database from Fleury - Medical Diagnostic Center, São Paulo, within the period between January 2000 to December 2004, 194 patients with available serum calcium and parathormone were identified. Two mathematical models based on logistic regression analysis and fuzzy sets theory were developed to recognize patients for parathyroid scintigraphy on the basis of laboratorial exams. The logistic regression model was developed using SPSS and the fuzzy model using MatLab. The performances of the models were compared using ROC curves with the test of Hanley e McNeil. The accuracies of both models were also analyzed and compared using a new database (test database) of 139 parathyroid scintigraphies performed between 2005 and 2006. Results - The performances of the models were statistically different (p=0.026). The area under the ROC curves were 0.86 (CI 95%: 0.81-0.91) for the logistic regression model and 0.89 (CI 95%: 0.84-0.93) for the fuzzy model. As an advantage over the logistic model, the latter has shown the ability to draw decision from parathormone information within a not discriminating interval of calcium values. In the test database the ROC area for the logistic regression model the ROC curve area was 0.89 (CI 95%: 0.83-0.95) and for the fuzzy model was 0.91 (CI 95%: 0.85-0.96) (p=0.128). Conclusions - The mathematical model based on fuzzy sets theory fared better than the logistic model in decision making for scintigraphy indication. Nevertheless, one should take heed that inferences should be kept to what concerns model comparison and not the parathyroid scintigraphy itself, once the data analysed was not representative of any population.