RESUMO
Cerebrovascular lesions are frequently observed in patients with sickle-cell disease (SCD) and these structural lesions are preceded by insidious perfusion deficits. Our aim was to investigate the presence of brain perfusion deficits in neurologically asymptomatic SCD patients, especially affecting microvessels. For this study, 42 SCD patients [33 sickle-cell anemia (HbSS), 6 sickle hemoglobin C disease (HbSC), and 3 sickle ß-thalassemia disease (HbSß)] with mean hematocrit of 25.1 (±4.85; 15.6-38.5) underwent brain perfusion single photon emission computerized tomography (SPECT) using the tracer (99m)Tc-ECD. Images from SCD patients were compared to images of a healthy control group (29 females and 20 males, mean age 31 ± 8; range 25-49 years). Images underwent voxel-wise comparison of regional tracer uptake using paired t-test to estimate the probability of each voxel to have an increased or decreased tracer uptake. When compared to controls, SCD patients exhibited significantly reduced tracer uptake in basal ganglia and thalami, the anterior frontal region and the watershed region of the temporo-parietal-occipital transition (p < 0.05). Our study showed that neurologically asymptomatic adult SCD patients exhibit a pattern of reduced (99m)Tc-ECD tracer uptake demonstrated by SPECT. Early diagnosis of this cerebral vasculopathy has prognostic implications and can be determinant in considering therapeutic alternatives to avoid increasing brain lesion load and progressive disability.
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OBJECTIVE: Evaluate the efficacy of cumulative doses (CDs) of 131I-iodide therapy (RIT) in differentiated thyroid cancer (DTC). SUBJECTS AND METHODS: The probability of progressive disease according to CDs was evaluated in patients < 45 years old and > 45 years old and correlated to tumor-node-metastasis (TNM), thyroglobulin values, histological types and variants, age, and zduration of the disease. RESULTS: At the end of a follow-up period of 69 ± 56 months, 85 out of 150 DTC patients submitted to fixed doses RIT had no evidence of disease, 47 had stable disease and 18 had progressive disease. Higher CDs were used in the more aggressive variants (p < 0.0001), higher TNM stages (p < 0.0001), and follicular carcinomas (p = 0.0034). Probability of disease progression was higher with CDs > 600 mCi in patients > 45 years old and with CDs > 800 mCi in patients < 45 years. CONCLUSION: Although some patients may still respond to high CDs, the impact of further RIT should be carefully evaluated and other treatment strategies may be warranted.
OBJETIVO: Avaliar a eficácia de doses cumulativas (DCs) da terapia com iodeto-131I (RIT) no câncer diferenciado de tiroide (CDT). SUJEITOS E MÉTODOS: A probabilidade de doença em progressão conforme a DC foi calculada em pacientes com idade < 45 e > 45 anos e correlacionada com o TNM, valores de tiroglobulina sérica, tipos histológicos e variantes, idade e tempo de doença. RESULTADOS: Ao final de um seguimento de 69 ± 56 meses, 85 dos 150 pacientes CDT submetidos a doses fixas de RIT não tinham evidência de doença, 47 tinham doença estável e 18, doença progressiva. DCs mais elevadas foram usadas nas variantes agressivas (p < 0,0001), maior estágio TNM (p < 0,0001) e nos carcinomas foliculares (p = 0,0034). A probabilidade de doença em progressão foi maior com DCs > 600 mCi em pacientes > 45 anos e com DCs > 800 mCi em pacientes < 45 anos. CONCLUSÃO: Apesar de alguns pacientes ainda responderem a altas DCs, o impacto de RITs deve ser cuidadosamente avaliado e outras estratégias terapêuticas devem ser consideradas.
Assuntos
Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Carcinoma Papilar/radioterapia , Radioisótopos do Iodo/administração & dosagem , Neoplasias da Glândula Tireoide/radioterapia , Carcinoma Papilar/metabolismo , Carcinoma Papilar/secundário , Progressão da Doença , Relação Dose-Resposta à Radiação , Métodos Epidemiológicos , Radioisótopos do Iodo/efeitos adversos , Resultado do TratamentoRESUMO
PURPOSE: To assess the impact of [F-18] FDG-PET/CT on the restaging and changing management of patients with malignant melanoma. METHODS: Seventy-eight patients (32 female, 27-83 years) were reviewed. Treatment planning before and after [F-18] FDG-PET/CT scan was evaluated for changes in the management of the disease. Restaging was classified according to the disease extent as follows: local recurrence, locoregional recurrence or distant recurrence. Initial restaging of patients was as follows: local recurrence in 11 patients, locoregional recurrence in 23 patients and distant recurrence in 44 of 78 patients. All the patients were injected with 370 MBq of [F-18] FDG and imaged from the head to feet after 60 min. All the patients fasted for 4-6 h before imaging and blood glucose levels were below 140 mg/dl. Images were taken using a PET/CT scanner (Siemens Biograph). Two nuclear medicine physicians and a radiologist (all experienced in oncology) interpreted the images. RESULTS: In 27% of the patients the management was changed after the [F-18] FDG-PET/CT studies. Upstaging from locoregional recurrence to distant recurrence occurred in a striking 5 of 23 (22%) patients. The sensitivity, specificity and positive and negative predictive values for lesion detection were 95%, and accuracy was 94.9%. There were two false-positive and two false-negative studies. CONCLUSION: [F-18] FDG-PET/CT seems to be a valuable diagnostic tool in restaging and management of patients with malignant melanoma suspected of recurrence especially in patients with locoregional recurrence and distant recurrence.
Assuntos
Fluordesoxiglucose F18 , Melanoma/patologia , Melanoma/terapia , Estadiamento de Neoplasias/métodos , Tomografia por Emissão de Pósitrons , Tomografia Computadorizada por Raios X , Adulto , Idoso , Idoso de 80 Anos ou mais , Feminino , Humanos , Masculino , Melanoma/diagnóstico por imagem , Pessoa de Meia-Idade , Estudos RetrospectivosRESUMO
OBJECTIVE: To evaluate the utility of diuretic dynamic renal scintigraphy (DDRS) with technetium-99m-L,L-ethylenedicysteine ((99m)Tc-EC) in patients with indeterminate or possible false-positive results for urinary obstruction by technetium-99m diethylenetriamine penta-acetic acid ((99m)Tc-DTPA) DDRS. METHODS: A total of 92 patients (63 male; mean age, 16.6 +/- 21.25 years) were studied, with a total of 103 kidneys presenting indeterminate (20/103) or possible false-positive results for obstruction attributable to reduced renal function or severe kidney dilation (83/103) by (99m)Tc-DTPA DDRS (<60% of radiopharmaceutical excreted in 20 minutes-half-time clearance [T(1/2)] >15 minutes). Patients were reimaged after intravenous injection of (99m)Tc-EC, with dynamic images before and after furosemide administration using the same acquisition parameters applied in the previous (99m)Tc-DTPA study. Time interval between (99m)Tc-DTPA and (99m)Tc-EC renograms was 2-64 days. The percentage of excreted material 20 minutes after furosemide was calculated using both radiopharmaceuticals, and were statistically compared using the paired samples t test. RESULTS: The excretion after furosemide injection was 25.3% +/- 18.2% for (99m)Tc-DTPA and 41.2% +/- 26.1% for (99m)Tc-EC, with a statistically significant difference between both radiopharmaceuticals (P <.0001). Using (99m)Tc-EC obstruction was excluded in 36 of 103 kidneys, which excreted >60%. A total of 10 of 83 kidneys (12.0%) with an obstructive pattern by (99m)Tc-DTPA study turned out to be indeterminate by (99m)Tc-EC DDRS. There was an agreement between (99m)Tc-EC and (99m)Tc-DTPA studies in 54 of 83 kidneys with obstructive (65.1%) and in 3 of 20 (15.0%) with indeterminate patterns. CONCLUSIONS: (99m)Tc-EC was more effective than (99m)Tc-DTPA for excluding obstruction, presenting less false-positive and indeterminate results. (99m)Tc-EC can substitute (99m)Tc-DTPA to evaluate patients with urinary tract dilation.
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Cisteína/análogos & derivados , Pelve Renal , Compostos de Organotecnécio , Compostos Radiofarmacêuticos , Pentetato de Tecnécio Tc 99m , Obstrução Ureteral/diagnóstico por imagem , Adolescente , Adulto , Idoso , Criança , Pré-Escolar , Dilatação Patológica , Reações Falso-Positivas , Feminino , Humanos , Lactente , Masculino , Pessoa de Meia-Idade , Cintilografia , Adulto JovemRESUMO
OBJECTIVE: Evaluate the efficacy of cumulative doses (CDs) of 131I-iodide therapy (RIT) in differentiated thyroid cancer (DTC). SUBJECTS AND METHODS: The probability of progressive disease according to CDs was evaluated in patients < 45 years old and > 45 years old and correlated to tumor-node-metastasis (TNM), thyroglobulin values, histological types and variants, age, and zduration of the disease. RESULTS: At the end of a follow-up period of 69 ± 56 months, 85 out of 150 DTC patients submitted to fixed doses RIT had no evidence of disease, 47 had stable disease and 18 had progressive disease. Higher CDs were used in the more aggressive variants (p < 0.0001), higher TNM stages (p < 0.0001), and follicular carcinomas (p = 0.0034). Probability of disease progression was higher with CDs > 600 mCi in patients > 45 years old and with CDs > 800 mCi in patients < 45 years. CONCLUSION: Although some patients may still respond to high CDs, the impact of further RIT should be carefully evaluated and other treatment strategies may be warranted.
Assuntos
Carcinoma Papilar/radioterapia , Radioisótopos do Iodo/administração & dosagem , Neoplasias da Glândula Tireoide/radioterapia , Carcinoma Papilar/metabolismo , Carcinoma Papilar/secundário , Progressão da Doença , Relação Dose-Resposta à Radiação , Métodos Epidemiológicos , Feminino , Humanos , Radioisótopos do Iodo/efeitos adversos , Masculino , Pessoa de Meia-Idade , Resultado do TratamentoRESUMO
Although autoimmune thyroid disease (AITD) is frequent in Turner's syndrome (TS), followup studies are scant, and there are none regarding subclinical thyroiditis. We investigated thyroid function and morphology in 17 patients with TS (mean age 14.6 years) with transient and asymptomatic variations of TSH and/or thyroid hormones. Our 2-year follow-up included measurements of TSH, free T4, T3 and TPO and Tg antibodies, ultrasound (US) (first and last evaluations) and scintigraphy (first evaluation). Thyroid volume was evaluated relative to the patients' stature. Fourteen had abnormal hormones, including four with hypothyroidism and one with hyperthyroidism, ten had positive antibodies, and all had abnormalities on US; uptake was normal in 14/16. Abnormal hormones were independent of antibodies, number of US findings, age, time of disease and volume. At the end of the follow-up, antibodies were associated with a high number of abnormal US features, particularly heterogeneous texture. Our results indicate that recurring thyroid hormone variations in TS are due to chronic AITD.
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Glândula Tireoide/fisiopatologia , Tireoidite Autoimune/fisiopatologia , Síndrome de Turner/fisiopatologia , Adolescente , Autoanticorpos/sangue , Estatura , Criança , Pré-Escolar , Seguimentos , Humanos , Cintilografia , Testes de Função Tireóidea , Glândula Tireoide/diagnóstico por imagem , Hormônios Tireóideos/sangue , Tireoidite Autoimune/diagnóstico por imagem , Síndrome de Turner/sangue , Ultrassonografia , Adulto JovemRESUMO
BACKGROUND: To achieve a more specific method to estimate the real size of breast cancer, we have developed a method to fuse magnetic resonance imaging (MRI) and scintimammography (SM) images. The aim of this study was to assess the feasibility of this method and to evaluate its accuracy to measure the size of breast cancer compared with MRI alone, mammography, and clinical examination, employing pathologic size as the gold standard. METHODS: Twenty consecutive breast cancer women at stages IIA-IIIA, scheduled for mastectomies, underwent SM with (99m)Tc-sestamibi and MRI with gadolinium 2-10 days before surgery. All patients had had recent mammographies and were examined clinically. Software was developed in visual language to perform the fusion between MRI and SM images and tumor measurements (MRI/SM). The tumor size, in 3 diameters (anteroposterior, longitudinal, and transverse), for each examination was correlated with pathological measurements using linear regression. RESULTS: The MRI/SM technique was successfully performed in all patients, and the principal tumor was measured by this method. The MRI/SM cancer measurements correlated better with pathology than MRI, mammography, and clinical exam in all diameters analyzed (r = 0.88, 0.81, 0.81; SE = 0.11, 0.14, 0.11 in anteroposterior, longitudinal, and transverse diameters, respectively). CONCLUSIONS: The MRI/SM is a feasible technique and appears to be more accurate than other examinations (MRI alone, mammography, and clinical exam) to measure breast cancer size.
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Neoplasias da Mama/diagnóstico , Carcinoma Ductal de Mama/diagnóstico , Aumento da Imagem/métodos , Processamento de Imagem Assistida por Computador/métodos , Imageamento Tridimensional/métodos , Imageamento por Ressonância Magnética/métodos , Mamografia/métodos , Cintilografia/métodos , Adulto , Idoso , Mama/patologia , Neoplasias da Mama/patologia , Neoplasias da Mama/cirurgia , Carcinoma Ductal de Mama/patologia , Carcinoma Ductal de Mama/cirurgia , Estudos de Viabilidade , Feminino , Humanos , Mastectomia , Pessoa de Meia-Idade , Estadiamento de Neoplasias , Projetos Piloto , Sensibilidade e Especificidade , Software , Tecnécio Tc 99m SestamibiRESUMO
Patients with Turner syndrome (TS) frequently exhibit transient, recurrent and asymptomatic variations of TSH and/or thyroid hormones (TH). This work was carried out to evaluate thyroid function and structure in patients with TS who had had such variations in hormone concentrations. Our sample comprised 24 patients, 17 less than 20-years old. Evaluation included serum levels of TSH, free T4, total T3, TPO and Tg autoantibodies, thyroid ultrasound (US) and scintigraphy with 99mTc-pertechnetate. Thirteen patients had abnormal TSH and/or TH levels; 23 exhibited US features compatible with chronic thyroid disorder, particularly thyromegaly (established according to volume expected for stature) and heterogeneous echogenicity. Uptake was normal in 21 cases and tracer distribution was homogeneous in 22. The finding of abnormal hormone concentrations was independent of age, length of time since the first similar finding, thyroid autoantibodies, number of abnormalities at US and abnormal scintigraphic findings. Patients aged more than 20 years had higher frequency of thyroid antibodies and heterogeneous echogenicity, and thyroid volume was significantly correlated to length of time since detection of the first hormone variation, indicating progressive thyroid disease. These results suggest that subclinical thyroid dysfunction in TS is due to chronic autoimmune thyroid disease.
Assuntos
Autoanticorpos/sangue , Glândula Tireoide/fisiopatologia , Hormônios Tireóideos/sangue , Tireoidite Autoimune/diagnóstico por imagem , Tireotropina/sangue , Síndrome de Turner/fisiopatologia , Adolescente , Adulto , Criança , Pré-Escolar , Feminino , Humanos , Lactente , Cintilografia , Compostos Radiofarmacêuticos , Pertecnetato Tc 99m de Sódio , Síndrome , Testes de Função Tireóidea , Glândula Tireoide/diagnóstico por imagem , Tiroxina/sangue , Tri-Iodotironina/sangue , UltrassonografiaRESUMO
UNLABELLED: PET with (18)F-FDG has been considered of limited value for detection of bladder cancer because of the urinary excretion of the tracer. The purpose of this study was to investigate the role of PET/CT in the detection and restaging of bladder cancer using furosemide and oral hydration to remove the excreted (18)F-FDG from the bladder. METHODS: Seventeen patients with bladder cancer (11 without cystectomy, 6 with total cystectomy and urinary diversion) underwent (18)F-FDG PET/CT from head to the upper thighs 60 min after the intravenous injection of 370 MBq of (18)F-FDG. Additional pelvic images were acquired 1 h after the intravenous injection of furosemide and oral hydration. PET/CT findings were confirmed by MRI, cystoscopy, or biopsy. RESULTS: PET/CT was able to detect bladder lesions in 6 of 11 patients who had not undergone cystectomy. These images changed the PET/CT final reading in 7 patients: Recurrent bladder lesions were detected in 6 patients, pelvic lymph node metastases in 2 patients, and prostate metastasis in 1. This technique overcame the difficulties posed by the urinary excretion of (18)F-FDG. Hypermetabolic lesions could be easily detected by PET and precisely localized in the bladder wall, pelvic lymph nodes, or prostate by CT. Seven of 17 patients (41%) were upstaged only after delayed pelvic images. CONCLUSION: Detection of locally recurrent or residual bladder tumors can be dramatically improved using (18)F-FDG PET/CT with delayed images after a diuretic and oral hydration.