MARCOS ROBERTO TAVARES

(Fonte: Lattes)
Índice h a partir de 2011
9
Projetos de Pesquisa
Unidades Organizacionais
Instituto Central, Hospital das Clínicas, Faculdade de Medicina
LIM/28 - Laboratório de Cirurgia Vascular e da Cabeça e Pescoço, Hospital das Clínicas, Faculdade de Medicina

Resultados de Busca

Agora exibindo 1 - 2 de 2
  • article 35 Citação(ões) na Scopus
    Comparison of Ga-68 PET/CT to Other Imaging Studies in Medullary Thyroid Cancer: Superiority in Detecting Bone Metastases
    (2018) CASTRONEVES, Luciana Audi; COURA FILHO, George; FREITAS, Ricardo Miguel Costa de; SALLES, Raphael; MOYSES, Raquel Ajub; LOPEZ, Rossana Veronica Mendoza; PEREIRA, Maria Adelaide Albergaria; TAVARES, Marcos Roberto; JORGE, Alexander Augusto de Lima; BUCHPIGUEL, Carlos Alberto; HOFF, Ana Oliveira
    Context: Persistent disease after surgery is common in medullary thyroid cancer (MTC), requiring lifelong radiological surveillance. Staging workup includes imaging of neck, chest, abdomen, and bones. A study integrating all sites would be ideal. Despite the established use of gallium-68 (Ga-68) positron emission tomography (PET)/CT with somatostatin analogues in most neuroendocrine tumors, its efficacy is controversial in MTC. Objective: Evaluate the efficacy of Ga-68 PET/CT in detecting MTC lesions and evaluate tumor expression of somatostatin receptors (SSTRs) associated with Ga-68 PET/CT findings. Methods: Prospective study evaluating 30 patients with MTC [group 1 (n = 16), biochemical disease; group 2 (n = 14), metastatic disease]. Patients underwent Ga-68 PET/CT, bone scan, CT and ultrasound of the neck, CT of the chest, CT/MRI of the abdomen, and MRI of the spine. Ga-68 PET/CT findings were analyzed by disease site as positive or negative and as concordant or discordant with conventional studies. Sensitivity and specificity were calculated using pathological or cytological analysis or unequivocal identification by standard imaging studies. Immunohistochemical analysis of SSTRs was compared with Ga-68 PET/CT findings. Results: In both groups, Ga-68 PET/CT was inferior to currently used imaging studies except for bone scan. In group 2, Ga-68 PET/CT sensitivities were 56%, 57%, and 9% for detecting neck lymph nodes, lung metastases, and liver metastases, respectively, and 100% for bone metastases, superior to the bone scan (44%). Expression of SSTRs, observed in 44% of tumors, was not associated with Ga-68-DOTATATE uptake. Conclusions: Ga-68 PET/CT does not provide optimal whole-body imaging as a single procedure in patients with MTC. However, it is highly sensitive in detecting bone lesions and could be a substitute for a bone scan and MRI.
  • article
    Does the Intensity of IGG4 Immunostaining Have a Correlation with the Clinical Presentation of Riedel's Thyroiditis?
    (2018) SIMOES, C. A.; TAVARES, M. R.; ANDRADE, N. M. M.; UEHARA, T. M.; DEDIVITIS, R. A.; CERNEA, C. R.
    Riedel's thyroiditis (RT) represents one type of IgG4-related thyroid disease (IgG4RTD) and the diagnosis involves quantitative immunohistochemistry showing dense lymphoplasmacellular inflammatory infiltrate consisting of IgG4- positive plasma cells with storiform fibrosis and obliterative phlebitis. We report a case of RT with progressive enlargement of the anterior neck, severe dysphagia, odynophagia, and dyspnea. The patient underwent surgical decompression of the airway, protection tracheotomy, and gastrostomy for nutritional intake 6 months after first symptoms. Complete resolution occurred after surgical treatment combined with prednisolone. Immunostaining revealed IgG4-positive plasma cells 12/HPF (high-power field) and the IgG4/IgG ratio 25%, values that were disproportionate to the intensity of the patient's symptoms. As to this case and the few cases described and analyzed in the literature, our impression is that there is no relation between the intensity of symptoms in RT with the total number of IgG4positive plasma cells and the IgG4/IgG ratio, but more studies are needed.