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1.
Radiology ; 287(3): 993-1002, 2018 06.
Artigo em Inglês | MEDLINE | ID: mdl-29558296

RESUMO

Purpose To examine the effect metabolic burden (tumor and/or cardiac myocyte uptake) has on fluorine 18 fluorodeoxyglucose (FDG) distribution in organs and tissues of interest. Materials and Methods Positron emission tomographic (PET)/computed tomographic (CT) scans at the Ann Arbor Veterans Affairs hospital from January to July 2015 were reviewed. A total of 107 scans (50 patients; mean age, 64.3 years ± 13.2 [standard deviation]) had metabolic tissue burden assessed by using total lesion glycolysis (TLG) obtained from autosegmentation of the tumor and/or cardiac tissue. Standardized uptake value (SUV) and subsequent normalized SUV uptake in target organs and tissues were compared with 436 FDG PET/CT scans previously reported in 229 patients as a function of TLG to describe the effect(s) that metabolic burden has on reference tissue (blood pool, liver, and brain) FDG uptake. Subsequent regression by using linear mixed-effects models was used. If the slope of the regression was significantly (P < .05) different than zero, then an effect from TLG was present. Results There was a negative inverse relationship (P < .0001) between FDG uptake within reference tissues (blood pool, liver, and brain) and TLG in comparison to the study population at similar blood glucose levels. This TLG effect was no longer statistically significant (P > .05) when FDG uptake was normalized to a reference tissue (eg, blood pool or liver). Conclusion Metabolic tissue burden can have a significant effect on SUV measurements for PET imaging. This effect can be mitigated by normalizing FDG uptake to a reference tissue. © RSNA, 2018.


Assuntos
Fluordesoxiglucose F18/farmacocinética , Tomografia por Emissão de Pósitrons combinada à Tomografia Computadorizada/métodos , Compostos Radiofarmacêuticos/farmacocinética , Carga Tumoral , Imagem Corporal Total/métodos , Gânglios da Base/metabolismo , Feminino , Fluordesoxiglucose F18/metabolismo , Humanos , Fígado/metabolismo , Masculino , Pessoa de Meia-Idade , Compostos Radiofarmacêuticos/metabolismo , Estudos Retrospectivos
2.
Radiographics ; 36(7): 2154-2169, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-27494386

RESUMO

Frostbite is a localized cold thermal injury that results from tissue freezing. Frostbite injuries can have a substantial effect on long-term limb function and mobility if not promptly evaluated and treated. Imaging plays a critical role in initial evaluation of frostbite injuries and in monitoring response to treatment. A multimodality approach involving radiography, digital subtraction angiography (DSA), and/or multiphase bone scintigraphy with hybrid single photon emission computed tomography (SPECT)/computed tomography (CT) is often necessary for optimal guidance of frostbite care. Radiographs serve as an initial survey of the affected limb and may demonstrate characteristic findings, depending on the time course and severity of injury. DSA is used to evaluate perfusion of affected soft tissues and identify potential targets for therapeutic intervention. Angiography-directed thrombolysis plays an essential role in tissue preservation and salvage in deep frostbite injuries. Multiphase bone scintigraphy with technetium 99m-labeled diphosphonate provides valuable information regarding the status of tissue viability after initial treatment. The addition of SPECT/CT to multiphase bone scintigraphy enables precise anatomic localization of the level and depth of tissue necrosis before its appearance at physical examination and can help uncover subtle findings that may remain occult at scintigraphy alone. Multiphase bone scintigraphy with SPECT/CT is the modality of choice for prognostication and planning of definitive surgical care of affected limbs. Appropriate use of imaging to direct frostbite care can help limit the effects that these injuries have on limb function and mobility. ©RSNA, 2016.


Assuntos
Angiografia Digital/normas , Congelamento das Extremidades/diagnóstico por imagem , Guias de Prática Clínica como Assunto , Radiologia/normas , Tomografia Computadorizada com Tomografia Computadorizada de Emissão de Fóton Único/normas , Tomografia Computadorizada por Raios X/normas , Diagnóstico Diferencial , Humanos , Imagem Multimodal/normas , Traumatismo Múltiplo/diagnóstico por imagem , Osteonecrose/diagnóstico por imagem , Lesões dos Tecidos Moles/diagnóstico por imagem , Estados Unidos
3.
Radiographics ; 33(2): 397-418, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-23479704

RESUMO

Radioiodine imaging has a well-established role in depicting metastatic disease after thyroidectomy in patients with well-differentiated thyroid cancer. Uptake of radioiodine in thyroid metastases depends on expression of sodium-iodide symporter (NIS) by tumor tissues. However, because radioiodine may also accumulate in normal structures and tissues, it is important to distinguish physiologic radioiodine activity from metastatic disease. Furthermore, secretions that contain radioiodine may also simulate pathologic uptake. A spectrum of physiologic distributions, normal variants, and benign mimics of disease have been described in the literature; yet, even when armed with a comprehensive knowledge of these patterns, interpreting radiologists and nuclear physicians may still encounter diagnostic uncertainty. Single-photon emission computed tomography (SPECT) with integrated computed tomography (CT) is a novel technology that, when applied to diagnostic iodine 123 or iodine 131 ((131)I) radioiodine scintigraphy, may accurately localize and help distinguish benign mimics of disease, with the potential to alter the management plan. SPECT/CT is increasingly being used with radioiodine scintigraphy to evaluate patients with thyroid cancer and shows promise for improving imaging specificity and reducing false-positive results.


Assuntos
Artefatos , Erros de Diagnóstico/prevenção & controle , Aumento da Imagem/métodos , Radioisótopos do Iodo , Neoplasias da Glândula Tireoide/diagnóstico , Tomografia Computadorizada de Emissão de Fóton Único/métodos , Tomografia Computadorizada por Raios X/métodos , Adulto , Idoso , Reações Falso-Positivas , Feminino , Humanos , Radioisótopos do Iodo/farmacocinética , Masculino , Pessoa de Meia-Idade , Especificidade de Órgãos , Compostos Radiofarmacêuticos/farmacocinética , Técnica de Subtração , Neoplasias da Glândula Tireoide/metabolismo , Distribuição Tecidual , Adulto Jovem
4.
J Nucl Med ; 50(5): 823-6, 2009 May.
Artigo em Inglês | MEDLINE | ID: mdl-19372483

RESUMO

UNLABELLED: Human beta-defensin-3 (HBD-3) is an antimicrobial peptide with bactericidal effects on many gram-positive and gram-negative bacteria and some yeast species and, if radiolabeled, might be used to distinguish bacterial infection from sterile inflammation. The goals of the present study were to develop methods for radiolabeling HBD-3 with (99m)Tc and to perform preliminary investigations on (99m)Tc-labeled HBD-3 as a means to evaluate induced infection in an animal model. To this purpose, Staphylococcus aureus-induced infection was used to evaluate the capability of (99m)Tc-HBD-3 to distinguish infection from aseptic inflammation in rats. METHODS: Twenty to 40 microg of recombinant HBD-3 were labeled with (99m)Tc(+) hexa-coordinated with 3 molecules of CO and H(2)O and separated by a column from free (99m)Tc. (99m)Tc-HBD-3 was added to cultures of a bacterial suspension of S. aureus and Escherichia coli to evaluate in vitro antibacterial activity. A bacterial suspension of S. aureus and a carrageenan solution were used to induce infection and sterile inflammation, respectively, in opposite thighs of 9 adult rats. Three separate experiments were performed on groups of 3 rats each. The animals received different doses of (99m)Tc-HBD-3 injected through a cannula into the jugular vein. After sacrifice of the animals, tissue samples were obtained from sites of infection, inflammation, and control muscle (left foreleg) at 1, 3, and 5 h after (99m)Tc-HBD-3 administration. Tissue samples were weighed and then counted in a well-counter. Simultaneously, 1 mL of a standard solution of (99m)Tc-HBD-3 corresponding to each administered dose was counted. RESULTS: (99m)Tc-HBD-3 retained antibacterial activity. Radioactivity in tissue samples from the infected sites was significantly higher than that in samples of either induced inflammation or normal control muscle (ratio, approximately 3:1) at 3 and 5 h after injection, whereas similar radioactivity counts were observed for tissue samples from aseptic inflammation sites and normal control muscle. CONCLUSION: In this investigation, (99m)Tc-HBD-3 retained antibacterial activity and successfully distinguished infection from aseptic inflammation in adult rats.


Assuntos
Modelos Animais de Doenças , Infecções Estafilocócicas/diagnóstico por imagem , Infecções Estafilocócicas/metabolismo , Tecnécio/farmacocinética , beta-Defensinas/farmacocinética , Animais , Sistemas de Liberação de Medicamentos/métodos , Estudos de Viabilidade , Humanos , Masculino , Projetos Piloto , Cintilografia , Compostos Radiofarmacêuticos/farmacocinética , Ratos , Ratos Wistar , Proteínas Recombinantes/farmacocinética , Reprodutibilidade dos Testes , Sensibilidade e Especificidade , beta-Defensinas/genética
5.
Ann Nucl Med ; 23(3): 229-34, 2009 May.
Artigo em Inglês | MEDLINE | ID: mdl-19322512

RESUMO

OBJECTIVE: To evaluate the role of 24 h/4 h uptake ratio (UR) in response to radioiodine-131 ((131)I) therapy in patients with autonomously functioning thyroid nodules (AFTN). METHODS: A total of 1402 consecutive hyperthyroid patients were treated with (131)I, between 1958 and 2005. Therapeutic doses (D) were calculated according to the formula: D = weight of nodule x dose per gram of nodular tissue (q)/24 h (131)I uptake. The ratios of the 24 and 4 h uptake were retrospectively calculated and the patients were grouped according to outcome and q into three groups of UR (< or =1.25; 1.26-1.68; > or =1.69) by means of terziles. RESULTS: Of the 1402 patients, 95 did not respond to (131)I treatment while 93/1307 developed hypothyroidism. Most non-responders (55.8%) had UR < or =1.25, while many hypothyroid patients (66.7%) had UR > or =1.69 (chi (2): P < 0.001). As q increased, the proportion of successfully treated patients increased (level of significance) only in the group with UR < or =1.25; while in the other two terziles, with increasing dose per gram of nodular tissue, the number of successfully treated patients did not increase (level of significance). The cumulative incidence of hypothyroidism was 2.2% at the 1st year after (131)I treatment, increasing to 13.9% at 5 years and 26.2% at 10 years. CONCLUSIONS: The (131)I UR can predict the outcome of (131)I treatment in AFTN and may have utility in modifying treatment in some patients to limit post-radioiodine induced hypothyroidism and treatment failures in order to achieve euthyroidism.


Assuntos
Radioisótopos do Iodo/metabolismo , Radioisótopos do Iodo/uso terapêutico , Nódulo da Glândula Tireoide/metabolismo , Nódulo da Glândula Tireoide/radioterapia , Humanos , Dosagem Radioterapêutica , Estudos Retrospectivos , Nódulo da Glândula Tireoide/patologia , Nódulo da Glândula Tireoide/terapia , Fatores de Tempo , Resultado do Tratamento
6.
Clin Nucl Med ; 44(2): 148-149, 2019 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-30418208

RESUMO

In addition to nuclear cardiac and breast imaging, Tc-sestamibi scintigraphy is often used to localize parathyroid adenomas. F- fluorodeoxyglucose (FDG) PET is heavily utilized in oncology, although its use in identifying parathyroid adenomas is limited. We describe a case of a 57-year-old woman who underwent parathyroid scintigraphy and F-FDG PET/CT in the same week due to hyperparathyroidism and an enlarging breast mass, respectively. A right paratracheal mediastinal mass that otherwise would be suspicious for nodal metastases by CT alone was correctly identified to be an ectopic parathyroid adenoma using a combination of the nuclear medicine studies performed.


Assuntos
Adenoma/diagnóstico por imagem , Neoplasias da Mama/diagnóstico por imagem , Fluordesoxiglucose F18 , Neoplasias Primárias Múltiplas/diagnóstico por imagem , Neoplasias das Paratireoides/diagnóstico por imagem , Tomografia por Emissão de Pósitrons combinada à Tomografia Computadorizada , Tecnécio Tc 99m Sestamibi , Neoplasias da Mama/patologia , Feminino , Humanos , Pessoa de Meia-Idade , Metástase Neoplásica
7.
Am J Clin Oncol ; 42(1): 99-106, 2019 01.
Artigo em Inglês | MEDLINE | ID: mdl-30204613

RESUMO

Painful osseous metastasis resulting from castration-resistant prostate carcinoma is a common clinical problem. Historically, nuclear medicine offered several palliative beta-emitting radiopharmaceuticals targeting the skeleton with the goal of decreasing pain. However, these have largely been replaced by the alpha-emitting agent 223radium (Ra). 223Ra received Food and Drug Administration approval in 2013 for the treatment of metastatic castration-resistant prostate cancer with symptomatic bone metastases without visceral metastases. 223Ra offers an improved therapeutic profile due to its alpha-particle emissions resulting in a relatively higher linear energy transfer and lower particle range compared with beta-emitters. 223Ra also has demonstrated to increase overall survival in patients and to delay adverse skeletal events. Running a successful clinical nuclear therapy program with Ra requires a multidisciplinary team approach and this article suggests an implementation strategy from the authors' institution. Potential new nuclear radiopharmaceuticals still under investigation offering the future possibility of radioligand therapy are also discussed briefly.


Assuntos
Neoplasias Ósseas/secundário , Neoplasias da Próstata/patologia , Radioterapia/métodos , Rádio (Elemento)/efeitos adversos , Rádio (Elemento)/uso terapêutico , Neoplasias Ósseas/radioterapia , Ensaios Clínicos como Assunto , Humanos , Lutécio/uso terapêutico , Masculino , Neoplasias da Próstata/terapia , Neoplasias de Próstata Resistentes à Castração/patologia , Neoplasias de Próstata Resistentes à Castração/terapia , Radioisótopos/efeitos adversos , Radioisótopos/uso terapêutico , Compostos Radiofarmacêuticos/uso terapêutico , Radioterapia/efeitos adversos
8.
Biomed Pharmacother ; 117: 109168, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31334700

RESUMO

Sites of infection and inflammation can be misleading in oncology PET/CT imaging because these areas commonly show 18F-FDG activity. Caution in the interpretation must be taken to avoid the misdiagnosis of malignancy. Utilization of both CT findings as well as patient history can help differentiate benign infectious and inflammatory processes from malignancy, although occasionally additional work-up may be required. This article discusses the mechanism of 18F-FDG uptake in infection and inflammation with illustrative examples.


Assuntos
Fluordesoxiglucose F18/química , Infecções/diagnóstico por imagem , Inflamação/diagnóstico por imagem , Neoplasias/diagnóstico por imagem , Tomografia por Emissão de Pósitrons combinada à Tomografia Computadorizada , Animais , Fluordesoxiglucose F18/metabolismo , Humanos
9.
Biomed Pharmacother ; 112: 108628, 2019 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-30784923

RESUMO

PURPOSE: Hyperglycemia affects FDG uptake in the brain, potentially emulating Alzheimer's disease in normal individuals. This study investigates global and regional cerebral FDG uptake as a function of plasma glucose in a cohort of patients. METHODS: 120 consecutive male patients with FDG PET/CT for initial oncologic staging (July-Dec 2015) were reviewed. Patients with dementia, cerebrovascular accident, structural brain lesion, prior oncology treatment or high metabolic tumor burden (recently shown affecting brain FDG uptake) were excluded. 53 (24 nondiabetic) eligible patients (age 65.7 ± 2.8 mean ± SE) were analyzed with parametric computer software, MIMneuro™. Regional Z-scores were evaluated as a function of plasma glucose and age using multi variable linear mixed effects models with false discovery analysis adjusting for multiple comparisons. If the regression slope was significantly (p < 0.05) different than zero, hyperglycemia effect was present. RESULTS: There was a negative inverse relationship (p < 0.001) between global brain FDG uptake and hyperglycemia. No regional hyperglycemia effect on uptake were present when subjects were normalized using pons or cerebellum. However, regional hyperglycemia effects were seen (p < 0.047-0.001) when normalizing by the whole brain. No obvious pattern was seen in the regions affected. Age had a significant effect using whole brain normalization (p < 0.04-0.01). CONCLUSIONS: Cortical variation in FDG uptake were identified when subjects were hyperglycemic. However, these variations didn't fit a particular pattern of dementia and the severity of the affect is not likely to alter clinical interpretation.


Assuntos
Glicemia/metabolismo , Encéfalo/metabolismo , Fluordesoxiglucose F18/metabolismo , Hiperglicemia/metabolismo , Tomografia por Emissão de Pósitrons combinada à Tomografia Computadorizada , Compostos Radiofarmacêuticos/metabolismo , Idoso , Encéfalo/diagnóstico por imagem , Humanos , Hiperglicemia/diagnóstico por imagem , Masculino , Estudos Retrospectivos
10.
Radiother Oncol ; 132: 241-249, 2019 03.
Artigo em Inglês | MEDLINE | ID: mdl-30389239

RESUMO

BACKGROUND AND PURPOSE: This study tested the hypotheses that 1) changes in mid-treatment fluorodeoxyglucose (FDG)-positron emission tomography (PET) parameters are predictive of overall survival (OS) and 2) mid-treatment FDG-PET-adapted treatment has the potential to improve survival in patients with non-small cell lung cancer (NSCLC). MATERIAL AND METHODS: Patients with stage I-III NSCLC requiring daily fractionated radiation were eligible. FDG-PET-CT scans were obtained prior to and mid-treatment with radiotherapy at 40-50 Gy. The normalized maximum standardized uptake value (NSUVmax), normalized mean SUV (NSUVmean), PET-metabolic tumor volume (MTV), total lesion glycolysis (TLG), and computed tomography-based gross tumor volume (CT-GTV) were consistently measured for all patients. The primary study endpoint was OS. RESULTS: The study is comprised of 102 patients who received 3-dimensional conformal radiotherapy, among whom 30 patients who received mid-treatment PET-adapted dose escalation radiotherapy. All PET-CT parameters decreased significantly (P < 0.001) mid-treatment, with greater reductions in FDG-volumetric parameters compared to FDG-activity factors. Mid-treatment changes in MTV (P = 0.053) and TLG (P = 0.021) were associated with OS, while changes in NSUVmax, NSUVmean, and CT-GTV were not (all Ps>0.1). Patients receiving conventional radiation (60-70 Gy) with MTV reductions greater than the mean had a median survival of 14 months, compared to those with MTV reductions less than the mean who had a median survival of 22 months. By contrast, patients receiving mid-treatment PET-adapted radiation with MTV reductions greater than the mean had a median survival of 33 months, compared to those with MTV reductions less than the mean who had a median survival of 19 months. Overall, PET-adapted treatment resulted in a 19% better 5-year survival than conventional radiation. CONCLUSION: Changes in mid-treatment PET-volumetric parameters were significantly associated with survival in NSCLC. A greater reduction in the mid-treatment MTV was associated with worse survival in patients treated with standard radiation, but with better survival in patients who received mid-treatment PET-adapted treatment.


Assuntos
Carcinoma Pulmonar de Células não Pequenas/diagnóstico por imagem , Carcinoma Pulmonar de Células não Pequenas/radioterapia , Neoplasias Pulmonares/diagnóstico por imagem , Neoplasias Pulmonares/radioterapia , Idoso , Carcinoma Pulmonar de Células não Pequenas/patologia , Feminino , Fluordesoxiglucose F18 , Humanos , Neoplasias Pulmonares/tratamento farmacológico , Neoplasias Pulmonares/patologia , Masculino , Pessoa de Meia-Idade , Estadiamento de Neoplasias , Tomografia por Emissão de Pósitrons combinada à Tomografia Computadorizada/métodos , Prognóstico , Estudos Retrospectivos , Carga Tumoral
11.
Biomed Pharmacother ; 62(3): 139-46, 2008 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-17892924

RESUMO

Medullary thyroid carcinoma (MTC) is a rare neuroendocrine tumor originating in the parafollicular cells (C cells) of the thyroid and secretes both calcitonin and carcino-embryonic antigen (CEA). Genetic and biochemical testing allow early pre-clinical identification of familial forms. Sporadic MTC usually presents as a solitary thyroid nodule; the diagnosis can be made preoperatively by fine-needle aspiration or by calcitonin assay, though it is usually established at the time of surgery. In the diagnostic assessment of MTC, nuclear medicine imaging provides its contribution mainly in the post-operative work-up to detect residual/recurrent tumor. For such purpose a number of radiopharmaceuticals, which take advantage of the specific expression of receptors (the somatostatin analogue (111)In-octreotide), hormone transporters (radiolabelled MIBG) or molecular targets (radiolabelled anti-CEA monoclonal antibodies) by MTC lesions are available; these tracers may be used also for the palliative treatment of advanced MTC. Interesting perspectives for MTC imaging are offered by PET radiopharmaceuticals.


Assuntos
Carcinoma Medular/diagnóstico por imagem , Carcinoma Medular/radioterapia , Medicina Nuclear , Compostos Radiofarmacêuticos/uso terapêutico , Neoplasias da Glândula Tireoide/diagnóstico por imagem , Neoplasias da Glândula Tireoide/radioterapia , 3-Iodobenzilguanidina , Animais , Antígeno Carcinoembrionário/imunologia , Humanos , Radioisótopos do Iodo , Tomografia por Emissão de Pósitrons , Somatostatina/análogos & derivados , Somatostatina/farmacologia , Tomografia Computadorizada de Emissão de Fóton Único
12.
Clin Cancer Res ; 13(20): 6049-55, 2007 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-17947467

RESUMO

PURPOSE: Aberrant c-Met expression has been implicated in most types of human cancer. We are developing Met-directed imaging and therapeutic agents. EXPERIMENTAL DESIGN: To seek peptides that bind specifically to receptor Met, the Met-expressing cell lines S114 and SK-LMS-1 were used for biopanning with a random peptide phage display library. Competition ELISA, fluorescence-activated cell sorting analysis, an internalization assay, and a cell proliferation assay were used to characterize a Met-binding peptide in vitro. To evaluate the utility of the peptide as a diagnostic agent in vivo, 125I-labeled peptide was injected i.v. into nude mice bearing s.c. xenografts of the Met-expressing and hepatocyte growth factor (HGF)/scatter factor-expressing SK-LMS-1/HGF, and total body scintigrams were obtained between 1 and 24 h postinjection. RESULTS: One Met-binding peptide (YLFSVHWPPLKA), designated Met-pep1, reacts with Met on the cell surface and competes with HGF/scatter factor binding to Met in a dose-dependent manner. Met-pep1 is internalized by Met-expressing cells after receptor binding. Met-pep1 inhibits human leiomyosarcoma SK-LMS-1 cell proliferation in vitro. In SK-LMS-1 mouse xenografts, tumor-associated activity was imaged as early as 1 h postinjection and remained visible in some animals as late as 24 h postinjection. CONCLUSIONS: Met-pep1 specifically interacts with Met: it is internalized by Met-expressing cells and inhibits tumor cell proliferation in vitro; it is a potential diagnostic agent for tumor imaging.


Assuntos
Regulação Neoplásica da Expressão Gênica , Biblioteca de Peptídeos , Proteínas Proto-Oncogênicas c-met/metabolismo , Animais , Proliferação de Células , Relação Dose-Resposta a Droga , Ensaio de Imunoadsorção Enzimática , Citometria de Fluxo , Fator de Crescimento de Hepatócito/metabolismo , Humanos , Camundongos , Camundongos Nus , Células NIH 3T3 , Transplante de Neoplasias , Peptídeos/química
13.
Nucl Med Commun ; 29(11): 994-8, 2008 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-18836378

RESUMO

AIM: To evaluate clinical efficacy of a dual-time acquisition protocol, which included 4 and 20/24-h imaging with antigranulocyte antibody scintigraphy (LeukoScan) combined with semiquantitative analysis in the diagnosis of infection in painful hip prosthesis. METHODS: Sixty-seven consecutive patients with hip prosthesis were enrolled in this research project: 35 females, 32 males, mean age of 56.3 years. All patients had clinical and biochemical suspicious of infection. Each prosthesis had been implanted 3 months to 12 years before enrollment in this study. Twenty-four patients were on antibiotic therapy at the time of scintigraphy. Seven patients had bilateral hip prosthesis, one painful and the other painless: the seven painless prostheses were considered controls. LeukoScan examination was performed both at early (4 h) and delayed (20/24 h) times. The scintigraphic data were assessed both by visual and semiquantitative methods by three experienced nuclear medicine physicians blinded to clinical, laboratory and radiographic results. The uptake was graded visually by a 4-point scale: intense=3, moderate=2, mild=1 and absent=0. The semiquantitative analysis was obtained by a region of interest (ROI) analysis used in the anterior views to measure the ratio between the mean radioactivity in the prosthesis and the background radioactivity in the early and delayed images. An increase in the intensity of uptake of at least one scale-step at visual analysis and 20% at semiquantitative ROI analysis at the dual-time (early vs. delayed) LeukoScan was considered consistent with infection, whereas a stable or decreasing pattern was judged a negative result. Three-phase 99mTc-hydroxymethane diphosphonate bone scan was also performed routinely. Final diagnosis was determined at surgery and/or long-term clinical and imaging follow-up. RESULTS: At visual analysis, sensitivity for both early and delayed imaging was 94%, whereas specificity was 71% for early imaging and 83% for early and delayed imaging approach. At semiquantitative ROI analysis, sensitivity remained 94%, whereas specificity rose slightly to 73% for early imaging and to 90% for early and delayed imaging combined. Of note, four false-positive early scans were diagnosed correctly as negative on delayed imaging showing a decreasing pattern in uptake intensity. Sensitivity and specificity were similar whether patients were on or off antibiotic therapy. CONCLUSION: Our data show that early imaging LeukoScan is highly sensitive in evaluating septic prosthesis, but it is not optimally specific. Although the dual-time LeukoScan is capable of significantly increasing specificity for detecting infection. The semiquantitative ROI analysis further increased the specificity. Concomitant antibiotic treatment did not seem to influence the diagnostic efficacy of LeukoScan scintigraphy in detecting infected hip prosthesis.


Assuntos
Artroplastia do Joelho/efeitos adversos , Infecções Bacterianas/diagnóstico por imagem , Granulócitos/imunologia , Fragmentos Fab das Imunoglobulinas , Articulação do Joelho/diagnóstico por imagem , Compostos Radiofarmacêuticos , Pertecnetato Tc 99m de Sódio , Idoso , Animais , Infecções Bacterianas/imunologia , Infecções Bacterianas/microbiologia , Epitopos , Feminino , Prótese de Quadril/microbiologia , Humanos , Inflamação/diagnóstico por imagem , Articulação do Joelho/imunologia , Articulação do Joelho/microbiologia , Masculino , Camundongos , Pessoa de Meia-Idade , Estudos Prospectivos , Pseudomonas aeruginosa/isolamento & purificação , Cintilografia , Staphylococcus aureus/isolamento & purificação
14.
In Vivo ; 22(4): 513-7, 2008.
Artigo em Inglês | MEDLINE | ID: mdl-18712181

RESUMO

AIM: To evaluate the value of 18F-fluorodeoxy-glucose (FDG) positron emission tomography with computed tomography (PET/CT) in myeloma in patients presenting with a solitary plasmacytoma of bone (SPB). PATIENTS AND METHODS: Fourteen consecutive patients studied since 2006, all having a diagnosis of SPB before PET/CT imaging took part in this study. In 3 patients PET/CT was performed for staging while in the remaining 11 it was used to monitor therapy. PET/CT was performed using a dedicated tomograph 60-90 minutes after intravenous injection of 53 MBq/kg of 18F-FDG and the results were compared to other diagnostic procedures [radiographs and magnetic resonance imaging (MRI)], biopsy, and other available follow-up data. RESULTS: In 8/14 patients, PET/CT scans showed previously unsuspected sites of increased FDG accumulation. In 6/8 patients, FDG uptake was considered pathologic, depicting myeloma involvement in bone, while in the remaining cases, findings were considered incidental and not related to myeloma. PET findings attributed to myeloma were confirmed (i.e. true positives) in 6/6 cases (100%) and in all patients with findings reported as non-pathologic, myeloma was excluded (100% true negatives). CONCLUSION: Our preliminary data in a small number of cases suggests that there are a group of patients with SPB (local disease) in whom FDG PET/CT may detect other unsuspected sites of bone involvement, upstaging the extent of the disease. In these cases, SPB may be a local manifestation of multiple myeloma where other sites of involvement have eluded detection by other less sensitive imaging modalities (i.e. skeletal surveys) or anatomically restricted imaging (i.e., less than total body MR or CT). Finding other sites of involvement have significant implications for appropriate treatment of myeloma.


Assuntos
Neoplasias Ósseas/complicações , Neoplasias Ósseas/diagnóstico por imagem , Mieloma Múltiplo/complicações , Mieloma Múltiplo/diagnóstico por imagem , Plasmocitoma/complicações , Plasmocitoma/diagnóstico por imagem , Adulto , Idoso , Animais , Neoplasias Ósseas/diagnóstico , Feminino , Fluordesoxiglucose F18 , Humanos , Imageamento por Ressonância Magnética/métodos , Masculino , Pessoa de Meia-Idade , Mieloma Múltiplo/diagnóstico , Plasmocitoma/diagnóstico , Tomografia por Emissão de Pósitrons/métodos , Compostos Radiofarmacêuticos , Reprodutibilidade dos Testes , Tomografia Computadorizada por Raios X/métodos
15.
Clin Nucl Med ; 43(1): 73-74, 2018 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-29166335

RESUMO

Hidradenitis suppurativa is an inflammatory disease associated with subcutaneous nodules/abscesses that occur commonly in the axillary, inguinal, and perineal regions. We describe a case of a 64-year-old man presenting for F-FDG PET/CT for staging of a left vocal cord squamous cell carcinoma. The scan showed uptake in the left vocal cord malignancy and multiple hypermetabolic subcutaneous foci in the right axilla, right buttocks, and scalp in known locations of skin lesions related to hidradenitis suppurativa. This case illustrates an unusual inflammatory cause of F-FDG incidental uptake that should not be mistaken for metastases.


Assuntos
Fluordesoxiglucose F18 , Hidradenite Supurativa/diagnóstico por imagem , Hidradenite Supurativa/metabolismo , Tomografia por Emissão de Pósitrons combinada à Tomografia Computadorizada , Pele/metabolismo , Carcinoma de Células Escamosas/diagnóstico por imagem , Carcinoma de Células Escamosas/metabolismo , Carcinoma de Células Escamosas/patologia , Diagnóstico Diferencial , Hidradenite Supurativa/patologia , Humanos , Masculino , Pessoa de Meia-Idade , Metástase Neoplásica , Pele/diagnóstico por imagem
16.
Artigo em Inglês | MEDLINE | ID: mdl-30505461

RESUMO

OBJECTIVE: To evaluate the success rate of therapeutic administration of a single calculated 131I activity for eliminating hyperthyroidism due to Graves' disease. METHODS AND MATERIALS: Patients with Graves' hyperthyroidism underwent pinhole thyroid imaging, 24-h radioactive iodine uptake (RAIU) measurements and clinical examination and received a calculated 131I activity of 0.2 mCi per estimated gram of thyroid tissue, adjusted for the 24-h RAIU. The goal of RAI treatment was to achieve hypothyroidism within 3-6 months of 131I administration. Response to RAI therapy was assessed at 7 weeks and 3 months by clinical and biochemical follow-up. RESULTS: The study included 316 hyperthyroid patients with Graves' disease (F238:M78, mean age 42.1 ± 16 y, 4-94). 179 patients (56.6%) had no prior therapeutic intervention (treatment-naive patients), whereas 6 patients had prior thyroid surgery, and 131 (41.5%) had been treated with anti-thyroid medications.The mean estimated thyroid gland size was 50.2 g ± 18, range 15-100. Mean RAIU was 0.57 ± 0.17 (normal 0.07-0.30). RAI doses ranged from 5 to 70 mCi (mean dose = 18.1 mCi). Successful treatment of hyperthyroidism at our institution was obtained after a single therapeutic 131-I activity administration in 295 of 316 (93.3%) patients. Multivariate logistic regression analysis demonstrated that failure of 131I therapy was associated with previous PTU therapy (p <  0.001).The mean response time after successful RAI therapy was 110.2 days, with cumulative response of 25% at 61 days, 50% by 84 days and 75% by 118 days after radioiodine administration. The mean time to respond for those on prior PTU medications was 297 days compared to 116 days for those on MMI and 109 days for those not previously treated with antithyroid medications. In patients with persistent hyperthyroidism, failure of RAI therapy was documented in 16 patients (76.2%) within (less than) one year after 131I administration and in 5 patients (23.8%) more than one year after initial therapy, considered late failure. CONCLUSION: Successful 131I therapy for Graves' hyperthyroidism with a single calculated dose can be achieved in the majority (> 90%) of patients, adjusting for the thyroid size and 24 h uptake measurement.

17.
Am J Clin Oncol ; 41(5): 513-518, 2018 05.
Artigo em Inglês | MEDLINE | ID: mdl-27322696

RESUMO

OBJECTIVES: The extent of whether staging by fluorodeoxyglucose positron-emission tomography (PET) impacts outcomes in American Veterans with stage I-III non-small-cell lung cancer (NSCLC) is unknown. We investigated impact of fluorodeoxyglucose PET staging and age-adjusted comorbidities (AACs) on management and survival of NSCLC in this group. MATERIALS AND METHODS: We performed a retrospective review to identify with NSCLC who underwent initial PET scan and received care at the Ann Arbor Veterans Hospital between 2005 and 2010. Survival outcomes were estimated by Kaplan-Meier methods, quantile regressions, and Cox proportional hazards models, after accounting for age at diagnosis, sex, AAC, and initial treatment. RESULTS: The number of PET scans increased from 0 in 2005 to 66 in 2010. There were 170 men, 4 women, median age 64 years. Median AAC score was 4. In CS I (n=54), initial PET upstaged 5 patients. Median survival for no change in PET stage was 27.43 versus 67 months for upstaged patients (P=0.034). For CS II (n=15), initial PET scan upstaged 1 patient. Median survival for no change in PET stage was 16.53 versus 2.8 months for upstaged patient (P=0.335). For CS III (n=104), PET scan upstaged 20 patients. Median survival for no change in PET stage was 13.3 versus 3.8 months for upstaged patients (P=0.016). CONCLUSIONS: PET scans resulted in upstaging in 15% in CS I-III NSCLC. AAC scores dictated therapy decisions and outcomes more than PET staging. Veterans had lower 5-year survival rates (26.3%, 15.8%/13.4%) compared with 53% and 27% in age/sex/time-period matched SEER data for stage I-II/III NSCLC.


Assuntos
Adenocarcinoma/mortalidade , Carcinoma Pulmonar de Células não Pequenas/mortalidade , Carcinoma de Células Escamosas/mortalidade , Neoplasias Pulmonares/mortalidade , Tomografia por Emissão de Pósitrons/métodos , Adenocarcinoma/diagnóstico por imagem , Adenocarcinoma/patologia , Adenocarcinoma/terapia , Idoso , Idoso de 80 Anos ou mais , Carcinoma Pulmonar de Células não Pequenas/diagnóstico por imagem , Carcinoma Pulmonar de Células não Pequenas/patologia , Carcinoma Pulmonar de Células não Pequenas/terapia , Carcinoma de Células Escamosas/diagnóstico por imagem , Carcinoma de Células Escamosas/patologia , Carcinoma de Células Escamosas/terapia , Terapia Combinada , Comorbidade , Gerenciamento Clínico , Feminino , Fluordesoxiglucose F18 , Seguimentos , Humanos , Neoplasias Pulmonares/diagnóstico por imagem , Neoplasias Pulmonares/patologia , Neoplasias Pulmonares/terapia , Masculino , Pessoa de Meia-Idade , Estadiamento de Neoplasias , Compostos Radiofarmacêuticos , Estudos Retrospectivos , Taxa de Sobrevida , Estados Unidos
19.
Clin Nucl Med ; 32(6): 440-4, 2007 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-17515749

RESUMO

BACKGROUND AND AIM: Papillary thyroid carcinoma (PTC) is universally regarded as a curable malignancy with a favorable prognosis. However, a minority of patients may present, or subsequently develop, locoregional and distant metastases that may adversely affect survival. The value of the various staging methods is complicated by different approaches to diagnostic, therapeutic and follow-up strategies. We aimed at assessing the prognostic factors and survival rate in a large cohort of patients treated and followed up in the same center. MATERIALS AND METHODS: A total of 1858 patients with PTC operated on by the same surgeon, and followed in the same center over a period of 35 years, were included. Total thyroidectomy was performed in the majority of patients after I-131 diagnostic scans and thyroglobulin assays. When the latter 2 were positive, therapy with I-131 was given. Follow-up was performed periodically and further therapy doses were administered when necessary. All patients were maintained on life-long thyroxine. RESULTS: Ninety-three patients (5%) developed evidence of locoregional or distant metastases after an average follow-up period of 7.9 years (range 1.53-30.5 years). Univariate analysis showed all variables (except for gender) to be significantly correlated with disease recurrence and survival. Multivariate analysis showed 4 variables to be significant and independent prognostic factors: patient age at first treatment, extent of disease, extent of surgery, and the presence of I-131 positive metastases. DISCUSSION AND CONCLUSION: Our data agree with other scoring systems in that patient age at first treatment and the extent of disease are significant and independent prognostic factors. However, and at variance with other methods, we found that the extent of primary surgery and the presence of I-131 positive or negative metastases have similar prognostic significance. In high risk patients, total thyroidectomy and lymphadenectomy followed by I-131 treatment and TSH-suppressive hormonal therapy are recommended.


Assuntos
Adenocarcinoma Papilar/terapia , Neoplasias da Glândula Tireoide/terapia , Adenocarcinoma Papilar/patologia , Adulto , Análise de Variância , Distribuição de Qui-Quadrado , Terapia Combinada , Feminino , Humanos , Complicações Intraoperatórias , Radioisótopos do Iodo/uso terapêutico , Masculino , Pessoa de Meia-Idade , Metástase Neoplásica , Recidiva Local de Neoplasia , Estadiamento de Neoplasias , Complicações Pós-Operatórias , Prognóstico , Modelos de Riscos Proporcionais , Taxa de Sobrevida , Neoplasias da Glândula Tireoide/patologia , Tireoidectomia , Tiroxina/administração & dosagem
20.
Pediatr Infect Dis J ; 36(12): e353-e355, 2017 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-28806281

RESUMO

Ventilator-associated pneumonia represents one of the most common nosocomial infections in neonatal intensive care units, increasing morbidity and mortality and associated costs. The authors report the case of a neonatal patient with ventilator-associated pneumonia secondary to Chryseobacterium indologenes and a review of the literature. The most effective empiric treatment for C. indologenes infection remains unclear due to limited data in the literature, and therefore, therapy should be adjusted in accordance with the result of the susceptibility profile.


Assuntos
Chryseobacterium , Infecções por Flavobacteriaceae , Pneumonia Associada à Ventilação Mecânica , Antibacterianos/uso terapêutico , Eletrocardiografia , Humanos , Recém-Nascido , Unidades de Terapia Intensiva Neonatal , Masculino , Tomografia Computadorizada por Raios X
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