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1.
Eur J Nucl Med Mol Imaging ; 38(3): 426-35, 2011 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-21057787

RESUMO

PURPOSE: The aim of this study was to determine the impact of the main clinicopathological and biological prognostic factors of breast cancer on (18)F-fluorodeoxyglucose (FDG) uptake. Only women with tumours larger than 20 mm (T2-T4) were included in order to minimize bias of partial volume effect. METHODS: In this prospective study, 132 consecutive women received FDG PET/CT imaging before starting neoadjuvant chemotherapy. Maximum standardized uptake values (SUV(max)) were compared to tumour characteristics as assessed on core biopsy. RESULTS: There was no influence of T and N stage on SUV. Invasive ductal carcinoma showed higher SUV than lobular carcinoma. However, the highest uptake was found for metaplastic tumours, representing 5% of patients in this series. Several biological features usually considered as bad prognostic factors were associated with an increase in FDG uptake: the median of SUV(max) was 9.7 for grade 3 tumours vs 4.8 for the lower grades (p < 0.0001); negativity for oestrogen receptors (ER) was associated with higher SUV (ER+ SUV = 5.5; ER- SUV = 7.6; p = 0.003); triple-negative tumours (oestrogen and progesterone receptor negative, no overexpression of c-erbB-2) had an SUV of 9.2 vs 5.8 for all others (p = 0005); p53 mutated tumours also had significantly higher SUV (7.8 vs 5.0; p < 0.0001). Overexpression of c-erbB-2 had no effect on the SUV value. CONCLUSION: Knowledge of the factors influencing uptake is important when interpreting FDG PET/CT scans. Also, findings that FDG uptake is highest in those patients with poor prognostic features (high grade, hormone receptor negativity, triple negativity, metaplastic tumours) is helpful to determine who are the best candidates for baseline staging.


Assuntos
Neoplasias da Mama/diagnóstico , Neoplasias da Mama/metabolismo , Fluordesoxiglucose F18/metabolismo , Adulto , Idoso , Idoso de 80 Anos ou mais , Transporte Biológico , Neoplasias da Mama/diagnóstico por imagem , Neoplasias da Mama/patologia , Feminino , Humanos , Pessoa de Meia-Idade , Prognóstico , Cintilografia , Carga Tumoral , Proteína Supressora de Tumor p53/metabolismo
2.
Eur J Nucl Med Mol Imaging ; 37(3): 623-34, 2010 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-19946686

RESUMO

BACKGROUND: Parathyroidectomy (PTX), either subtotal or total with forearm autografting, is a well-established treatment for refractory renal hyperparathyroidism (RHPT). However, 20-30% of patients develop persistent or recurrent disease. Obtaining accurate localization before reoperation is difficult. PATIENTS AND METHODS: The study group comprised 21 consecutive adult patients (18 undergoing haemodialysis and 3 with a renal graft) imaged using (99m)Tc-sestamibi/(123)I subtraction scintigraphy. Of the 21 patients, 12 had undergone one previous PTX and the other 9 between two and four parathyroid operations. All patients had symptoms and signs of severe RHPT. The mean serum PTH level was 1,142 pg/ml. (99m)Tc-Sestamibi and (123)I images were recorded simultaneously. Imaging views comprised a planar view of the neck and mediastinum, followed by a magnified pinhole view over the thyroid bed area. If parathyroid ectopy was detected, SPECT or SPECT-CT was performed. The forearm was imaged in case of autograft. RESULTS: Parathyroid scintigraphy was negative in one patient and positive in the other 20 (sensitivity 95.2%). One patient had uptake corresponding to two unresected parathyroid glands. Recurrence at the site of the partially resected gland or autograft was seen in 11 patients. However, six of them had a second (99m)Tc-sestamibi focus corresponding to a supernumerary parathyroid gland. Seven other patients had a supernumerary parathyroid gland as the sole cause of relapse. Three of the supernumerary glands showed major ectopy (intrathyroidal, low mediastinal, undescended within the vagus nerve). One patient had parathyromatosis with multiple parathyroid nodules scattered over the left side of the neck. Reoperation was possible in 13 patients, with no false-positive findings. CONCLUSION: Many patients referred with the hypothesis of hyperplasia of a subtotally resected parathyroid gland or autograft were found to harbour a supernumerary parathyroid gland missed at the initial surgery.


Assuntos
Hiperparatireoidismo/complicações , Hiperparatireoidismo/diagnóstico por imagem , Nefropatias/complicações , Nefropatias/diagnóstico por imagem , Glândulas Paratireoides/diagnóstico por imagem , Adulto , Idoso , Doença Crônica , Feminino , Seguimentos , Humanos , Hiperparatireoidismo/cirurgia , Nefropatias/cirurgia , Masculino , Pessoa de Meia-Idade , Glândulas Paratireoides/cirurgia , Cintilografia , Recidiva , Sensibilidade e Especificidade
3.
Eur J Nucl Med Mol Imaging ; 37(6): 1095-105, 2010 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-20204358

RESUMO

PURPOSE: Accurate staging of Hodgkin's lymphoma (HL) is necessary in selecting appropriate treatment. Bone marrow trephine biopsy (BMB) is the standard procedure for depicting bone marrow involvement. BMB is invasive and explores a limited part of the bone marrow. (18)F-FDG PET/CT is now widely used for assessing response to therapy in HL and a baseline study is obtained to improve accuracy. The aim of this retrospective analysis was to assess whether routine BMB remains necessary with concomitant (18)F-FDG PET/CT. METHODS: Data from 83 patients (newly diagnosed HL) were reviewed. All patients had received contrast-enhanced CT, BMB and (18)F-FDG PET/CT. Results of BMB were not available at the time of (18)F-FDG PET/CT imaging. RESULTS: Seven patients had lymphomatous involvement on BMB. Four patients had bone involvement on conventional CT (two with negative BMB). All patients with bone marrow and/or bone lesions at conventional staging were also diagnosed on (18)F-FDG PET/CT scan. PET/CT depicted FDG-avid bone/bone marrow foci in nine additional patients. Four of them had only one or two foci, while the other had multiple foci. However, the iliac crest, site of the BMB, was not involved on (18)F-FDG PET/CT. Osteolytic/sclerotic lesions matching FDG-avid foci were visible on the CT part of PET/CT in three patients. MRI ordered in three other patients suggested bone marrow involvement. Interim and/or end-therapy (18)F-FDG PET/CT documented response of FDG-avid bone/bone marrow foci to chemotherapy in every patient. CONCLUSION: (18)F-FDG PET/CT highly improves sensitivity for diagnosis of bone/bone marrow lesions in HL compared to conventional staging.


Assuntos
Medula Óssea/patologia , Osso e Ossos/diagnóstico por imagem , Fluordesoxiglucose F18 , Doença de Hodgkin/patologia , Tomografia por Emissão de Pósitrons , Tomografia Computadorizada por Raios X , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Medula Óssea/diagnóstico por imagem , Criança , Feminino , Doença de Hodgkin/diagnóstico , Doença de Hodgkin/terapia , Humanos , Masculino , Pessoa de Meia-Idade , Estadiamento de Neoplasias , Estudos Retrospectivos , Adulto Jovem
4.
Eur J Nucl Med Mol Imaging ; 36(1): 130-6, 2009 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-18690435

RESUMO

BACKGROUND: We used the Monte Carlo code "CELLDOSE" to assess the dose received by specific target cells from electron emissions in a complex environment. (131)I in a simulated thyroid was used as a model. METHODS: Thyroid follicles were represented by 170 microm diameter spherical units made of a lumen of 150 microm diameter containing colloidal matter and a peripheral layer of 10 microm thick thyroid cells. Neighbouring follicles are 4 microm apart. (131)I was assumed to be homogeneously distributed in the lumen and absent in cells. We firstly assessed electron dose distribution in a single follicle. Then, we expanded the simulation by progressively adding neighbouring layers of follicles, so to reassess the electron dose to this single follicle implemented with the contribution of the added layers. RESULTS: Electron dose gradient around a point source showed that the (131)I electron dose is close to zero after 2,100 microm. Therefore, we studied all contributions to the central follicle deriving from follicles within 12 orders of neighbourhood (15,624 follicles surrounding the central follicle). The dose to colloid of the single follicle was twice as high as the dose to thyroid cells. Even when all neighbours were taken into account, the dose in the central follicle remained heterogeneous. For a 1-Gy average dose to tissue, the dose to colloidal matter was 1.168 Gy, the dose to thyroid cells was 0.982 Gy, and the dose to the inter-follicular tissue was 0.895 Gy. Analysis of the different contributions to thyroid cell dose showed that 17.3% of the dose derived from the colloidal matter of their own follicle, while the remaining 82.7% was delivered by the surrounding follicles. On the basis of these data, it is shown that when different follicles contain different concentrations of (131)I, the impact in terms of cell dose heterogeneity can be important. CONCLUSION: By means of (131)I in the thyroid as a theoretical model, we showed how a Monte Carlo code can be used to map electron dose deposit and build up the dose to target cells in a complex multi-source environment. This approach can be of considerable interest for comparing different radiopharmaceuticals as therapy agents in oncology.


Assuntos
Elétrons , Método de Monte Carlo , Doses de Radiação , Glândula Tireoide/citologia , Glândula Tireoide/efeitos da radiação , Radioisótopos do Iodo , Modelos Biológicos
5.
Int J Radiat Oncol Biol Phys ; 71(3): 695-704, 2008 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-18436392

RESUMO

PURPOSE: To investigate the potential effect of using (18)F-fluorodeoxyglucose positron emission tomography/computed tomography (PET/CT) in the initial assessment of patients with clinical Stage II or III breast cancer. METHODS AND MATERIALS: During 14 consecutive months, 39 patients (40 tumors) who presented with Stage II or III breast cancer on the basis of a routine extension assessment were prospectively included in this study. PET/CT was performed in addition to the initial assessment. RESULTS: In 3 cases, PET/CT showed extra-axillary lymph node involvement that had not been demonstrated with conventional techniques. Two of these patients had hypermetabolic lymph nodes in the subpectoral and infraclavicular regions, and the third had a hypermetabolic internal mammary node. PET/CT showed distant uptake in 4 women. Of these 4 women, 1 had pleural involvement and 3 had bone metastasis. Overall, of the 39 women, the PET/CT results modified the initial stage in 7 (18%). The modified staging altered the treatment plan for 5 patients (13%). It led to radiotherapy in 4 patients (bone metastasis, pleural lesion, subpectoral lymph nodes, and internal mammary nodes) and excision of, and radiotherapy to, the infraclavicular lymph nodes in 1 patient. CONCLUSIONS: PET/CT can provide information on extra-axillary lymph node involvement and can uncover occult distant metastases in a significant percentage of patients. Therefore, initial PET/CT could enable better treatment planning for patients with Stage II and III breast cancer.


Assuntos
Neoplasias da Mama/diagnóstico , Fluordesoxiglucose F18 , Tomografia por Emissão de Pósitrons/métodos , Tomografia Computadorizada por Raios X/métodos , Adulto , Idoso , Idoso de 80 Anos ou mais , Feminino , Humanos , Metástase Linfática , Pessoa de Meia-Idade , Estadiamento de Neoplasias , Compostos Radiofarmacêuticos , Reprodutibilidade dos Testes , Sensibilidade e Especificidade
6.
Thyroid ; 18(4): 469-72, 2008 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-18399770

RESUMO

BACKGROUND: Amiodarone has a high iodine content that can induce persistent iodine excess and may prevent radioiodine (RI) treatment. PATIENT: A 55-year-old obese man had taken amiodarone (200 mg/d) for 3 years and stopped 2 years earlier. He underwent total thyroidectomy for papillary cancer with extrathyroidal extension and a metastatic central lymph node, requiring RI treatment. But iodine overload, with no other documented iodinated drug intake, was found (urinary iodine excretion = 472 microg/24 h; normal < 150 microg/24 h), and persisted 3 months later. Plasma exchanges (PE) were prescribed. INTERVENTIONS AND RESULTS: Eight PE over 4 weeks were needed to eliminate 39,295 nmol of iodine. Urinary iodine excretion and serum iodine concentrations, before PE and after eight sessions were, respectively: 230 and 84 nmol/mmol of creatinine, and 811 and 71 nmol/L, enabling RI treatment (4 GBq (131)I). Post-therapy whole-body scan revealed cervical uptake (0.48% of the total administered dose) corresponding to usual thyroid remnants. Ablation efficacy was confirmed 6 and 24 months later by cervical ultrasonography combined with an undetectable serum thyroglobulin level after recombinant human thyrotropin stimulation. CONCLUSIONS: When spontaneous iodine elimination is too slow to allow RI treatment of high-risk thyroid carcinoma within a reasonable time after thyroidectomy, PE are reliable and effective to overcome iodine overload.


Assuntos
Radioisótopos do Iodo/uso terapêutico , Troca Plasmática/métodos , Neoplasias da Glândula Tireoide/radioterapia , Amiodarona/efeitos adversos , Antiarrítmicos/efeitos adversos , Humanos , Iodo/efeitos adversos , Iodo/sangue , Iodo/urina , Radioisótopos do Iodo/efeitos adversos , Metástase Linfática , Masculino , Pessoa de Meia-Idade , Obesidade/complicações , Compostos Radiofarmacêuticos/efeitos adversos , Compostos Radiofarmacêuticos/uso terapêutico , Tireoidectomia , Fatores de Tempo , Resultado do Tratamento
7.
Endocr Relat Cancer ; 14(3): 799-807, 2007 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-17914109

RESUMO

Bone is the second most frequent target of distant metastases in patients with differentiated thyroid cancer, and such forms carry a very poor prognosis. The impact of (131)I therapy in this setting is controversial. We describe the diagnostic circumstances and outcome of patients with bone metastases recently managed in two institutions. Among 921 consecutive thyroid cancer patients who had total thyroidectomy and (131)I ablation between January 2000 and December 2004 and who were subsequently monitored, bone metastases had been diagnosed in 16 patients. In three cases, the bone metastases were non-functioning (negative (131)I uptake) . These patients were treated with surgery and radiotherapy but progressed rapidly. The other 13 patients had functioning (positive (131)I uptake) bone metastases. In five of them, thyroid cancer was revealed by signs of distant involvement (bone pain, n = 4; dyspnea, n = 1). The bone metastases progressed in these five patients, despite local therapy and multiple courses of (131)I. The bone metastases in the remaining eight patients were discovered on the post-surgery (131)I therapy scan. Complementary radiological studies were negative except in one patient in whom one of the metastases (a 5 mm lesion of the right humerus) was visible on magnetic resonance imaging (MRI). Six of these patients showed a good response to (131)I therapy, with (131)I uptake and Tg levels becoming undetectable or showing a sharp fall. One patient refused (131)I therapy; bone metastases became visible on MRI within 1 year and the Tg level rose tenfold. The disease progressed in one patient despite (131)I therapy. Post-surgical (131)I ablation can contribute to early detection of bone metastases at a time when the Tg level may be only moderately elevated, when other radiological studies are negative, and when the disease is potentially curable by (131)I therapy.


Assuntos
Neoplasias Ósseas/diagnóstico , Neoplasias Ósseas/secundário , Carcinoma/diagnóstico , Carcinoma/patologia , Radioisótopos do Iodo , Neoplasias da Glândula Tireoide/diagnóstico , Neoplasias da Glândula Tireoide/patologia , Adolescente , Adulto , Idoso , Neoplasias Ósseas/mortalidade , Carcinoma/mortalidade , Progressão da Doença , Diagnóstico Precoce , Feminino , Seguimentos , Humanos , Masculino , Pessoa de Meia-Idade , Prognóstico , Estudos Retrospectivos , Neoplasias da Glândula Tireoide/mortalidade , Fatores de Tempo
8.
Cancer Biol Ther ; 6(1): 56-61, 2007 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-17172819

RESUMO

We sought to investigate the apoptosis-inducing activities of quercetin, Siamois 1, and Siamois 2 against invasive estrogen-receptor negative MDA-MB 435 cells xenografted in athymic nude mice. This study clearly demonstrated that these compounds exhibited apoptosis-inducing activities in cell culture system. Quercetin (20 microg/mL), Siamois 1 (100 microg/mL), and Siamois 2 (200 microg/mL) can induce apoptotic cell death by 40 +/-5%, 44 +/- 14 %, and 31 +/- 13 %, respectively. Two-fold of IC50 of these compounds were clearly found to induce apoptosis in breast tumor tissue which can be determined by 99mTc-Annexin V scintigraphy and histological staining. This is the first report that the apoptosis-inducing effects of quercetin, Siamois 1 and Siamois 2 on the MDA-MB 435 cell in vitro were effectively extrapolated to the in vivo situation. These compounds might be considered as a simple dietary supplement and with further clinical investigation for their use as a nutrition-based intervention in breast cancer treatment.


Assuntos
Apoptose , Neoplasias da Mama/patologia , Quercetina/análogos & derivados , Quercetina/farmacologia , Animais , Proliferação de Células/efeitos dos fármacos , Humanos , Concentração Inibidora 50 , Camundongos , Camundongos Nus , Ensaios Antitumorais Modelo de Xenoenxerto
10.
Pain ; 47(3): 329-336, 1991 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-1784503

RESUMO

Five patients with central post-stroke pain (CPSP) accepted to be studied according to the following paradigm: a single photon emission computerized tomography (SPECT) using [123I]N-isopropyl-iodoamphetamine (IMP) was made in each patient 20 min following i.v. injection of IMP; during this time, the patients were stimulated in order to reproduce their spontaneous pain. Of the five patients, two had CPSP with hyperpathia following a stroke (with a lesion on CT scan involving the thalamo-cortical pathway in one and involving the thalamus in the other); two had CPSP following a stroke in the middle cerebral artery area, without hyperpathia; and the last patient suffered pain from algodystrophia following a fracture of the wrist. In the two cases with hyperpathia, SPECT demonstrated a contralateral relative hyperactivity in a central region corresponding to the thalamic area. This was not observed in the three other patients. In the two patients with hyperpathia, a second SPECT scan with stimulation of the contralateral pain-free arm did not demonstrate any hyperactivity in the thalamic area. These results suggest that a thalamic neuronal hyperactivity may characterize some hyperpathic syndromes and, in accordance with our previous results obtained in the rat, that the loss of inhibition on medial thalamic neurons may be a main feature of hyperpathia following certain cerebral stroke syndromes.


Assuntos
Dor/diagnóstico por imagem , Dor/fisiopatologia , Tálamo/diagnóstico por imagem , Tálamo/fisiopatologia , Idoso , Transtornos Cerebrovasculares/complicações , Transtornos Cerebrovasculares/diagnóstico por imagem , Transtornos Cerebrovasculares/fisiopatologia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Dor/etiologia , Tomografia Computadorizada de Emissão de Fóton Único , Tomografia Computadorizada por Raios X
11.
J Nucl Med ; 44(9): 1394-401, 2003 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-12960182

RESUMO

UNLABELLED: In vitro studies have demonstrated that (99m)Tc-methoxyisobutylisonitrile ((99m)Tc-MIBI) is a transport substrate of multidrug resistance (MDR)-related proteins. The aim of this clinical study was to evaluate whether (99m)Tc-MIBI scintigraphy was a functional imaging tool for in vivo detection of multidrug resistance-associated protein (MRP) expression in osteosarcoma and to investigate the role of MRP and (99m)Tc-MIBI imaging to predict the clinical outcome. We also examined whether the scintigraphic parameters would help to distinguish the functional capacity of P-glycoprotein (Pgp) and MRP. METHODS: Twenty-four patients with a diagnosis of osteosarcoma were studied before neoadjuvant chemotherapy. Tumor-to-background ratios of both early (10 min) and delayed (1 h) images and the percentage washout rate (WR%) of (99m)Tc-MIBI were calculated. Immunohistochemical analysis of MRP and Pgp was performed on biopsy specimens, and the response to preoperative chemotherapy was assessed by histopathologic examination. RESULTS: Fifteen of 24 osteosarcoma samples in our series (62.5%) showed significant expression of MRP. The level of MRP expression was significantly correlated with the WR% of (99m)Tc-MIBI (r = 0.58, P = 0.003), and the WR% of (99m)Tc-MIBI was significantly faster in patients with high MRP expression than in those with a low MRP score (P = 0.007). The clearance rate of (99m)Tc-MIBI was significantly slower in tumor samples with negative or low expression of both Pgp and MRP (16% +/- 6.2%) when compared with osteosarcomas with high expression of both proteins (31.7% +/- 8.7%) (P = 0.001). There was not a significant difference between the WR% of (99m)Tc-MIBI in tumors with coexpression of both proteins and in tumors with high expression of either Pgp or MRP. Both the rate of MRP expression and the WR% of (99m)Tc-MIBI were significantly correlated with response rate. CONCLUSION: Our results suggest that the WR% of (99m)Tc-MIBI is correlated with MRP expression. Both the WR% of (99m)Tc-MIBI and MRP expression are correlated with therapy response. (99m)Tc-MIBI can be used as a general probe for functional imaging of both Pgp and MRP; however, it is not capable of differentiating the functional status of either MDR-related glycoprotein.


Assuntos
Membro 1 da Subfamília B de Cassetes de Ligação de ATP/metabolismo , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Proteínas Associadas à Resistência a Múltiplos Medicamentos/metabolismo , Osteossarcoma/diagnóstico por imagem , Osteossarcoma/metabolismo , Tecnécio Tc 99m Sestamibi , Adolescente , Adulto , Idoso , Biomarcadores Tumorais/análise , Biomarcadores Tumorais/metabolismo , Neoplasias Ósseas/diagnóstico por imagem , Neoplasias Ósseas/tratamento farmacológico , Neoplasias Ósseas/metabolismo , Criança , Feminino , Neoplasias Femorais/diagnóstico por imagem , Neoplasias Femorais/tratamento farmacológico , Neoplasias Femorais/metabolismo , Humanos , Úmero/diagnóstico por imagem , Úmero/efeitos dos fármacos , Úmero/metabolismo , Masculino , Taxa de Depuração Metabólica , Pessoa de Meia-Idade , Osteossarcoma/tratamento farmacológico , Valor Preditivo dos Testes , Cintilografia , Compostos Radiofarmacêuticos/farmacocinética , Estatística como Assunto , Tecnécio Tc 99m Sestamibi/farmacocinética , Resultado do Tratamento
13.
Neurosci Lett ; 355(3): 185-8, 2004 Jan 30.
Artigo em Inglês | MEDLINE | ID: mdl-14732462

RESUMO

Patterns of leukoaraiosis were analyzed on both T2-weighted fast fluid-attenuated inversion-recovery and 3D T1-weighted sequences in 23 community-dwelling older subjects with mild cognitive impairment. Mobility assessment had allowed their classification into higher and lower mobility groups (P<0.0001). Lower mobility appeared correlated with frontal subependymal lesions (P=0.0005). The absence of marked ventriculomegaly, any thick caps, deep white matter lesions curved along the ventricles bodies, large deep white matter lesions, deep grey matter leukoaraiosis was an hallmark of the higher mobility group (P<0.0001). High resolution MRI demonstrated regular patterns of the subependymal lesions and detected perivascular distribution in other forms of leukoaraiosis. It suggests that the underlying mechanism of mobility decline in the elderly may be impairment of cerebrospinal fluid dynamics with cerebral small vessel disease.


Assuntos
Encéfalo/patologia , Transtornos Cognitivos/diagnóstico , Imageamento por Ressonância Magnética/métodos , Transtornos das Habilidades Motoras/diagnóstico , Bainha de Mielina/patologia , Idoso , Transtornos Cognitivos/líquido cefalorraquidiano , Transtornos Cognitivos/patologia , Feminino , Humanos , Masculino , Transtornos das Habilidades Motoras/líquido cefalorraquidiano , Transtornos das Habilidades Motoras/patologia
14.
Nucl Med Biol ; 31(5): 575-81, 2004 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-15219275

RESUMO

Neuropilins (NRP) are receptors of angiogenic vascular endothelial growth factor (VEGF). Their overexpression was correlated with tumor angiogenesis and growth suggesting that their specific targeting could provide a new marker of tumor progression. Here, we observed in vitro that new (99m)Tc-labeled derivative of anti-VEGF heptapeptide, ATWLPPR, binds to NRP1 but not to NRP2. Our radiotracer is stable up to 24 h in human serum and in cysteine challenge. But, its too low affinity and too fast extraction indicate further improvement to give a successful imaging of tumor in vivo.


Assuntos
Neoplasias da Mama/diagnóstico por imagem , Neoplasias da Mama/metabolismo , Neuropilina-1/metabolismo , Peptídeos/farmacocinética , Fator A de Crescimento do Endotélio Vascular/antagonistas & inibidores , Fator A de Crescimento do Endotélio Vascular/metabolismo , Animais , Linhagem Celular Tumoral , Feminino , Humanos , Marcação por Isótopo/métodos , Masculino , Taxa de Depuração Metabólica , Camundongos , Camundongos Nus , Neuropilina-1/química , Especificidade de Órgãos , Peptídeos/síntese química , Peptídeos/química , Ligação Proteica , Cintilografia , Compostos Radiofarmacêuticos/química , Compostos Radiofarmacêuticos/farmacocinética , Ratos , Reprodutibilidade dos Testes , Sensibilidade e Especificidade , Tecnécio/química , Tecnécio/farmacologia , Distribuição Tecidual
15.
Anticancer Res ; 22(1A): 251-6, 2002.
Artigo em Inglês | MEDLINE | ID: mdl-12017298

RESUMO

BACKGROUND: Resistance mediated by the MultiDrug Resistance protein (P-glycoprotein and MRP1), results in energy-dependent efflux of drugs and 99mTc-MIBI from the cells. The goal of our investigation was to evaluate the capacity of PAK-104P to lower multidrug resistance by decreasing substrate efflux. MATERIALS AND METHODS: 99mTc-MIBI accumulation was quantified in the leukaemia cell line which expresses the P-glycoprotein (K562/R) or not (K562/S) and the small lung cancer cell line which expresses MRP1 (GLC4/R) or not (GLC4/S). Three experimental protocols were used: 1). cells were treated with increasing concentrations of PAK-104P; 2). the plasma membrane potential was lowered; 3). intracellular reduced glutathione (GSH) was depleted. RESULTS: Exposure of cells to 5 microM PAK-104P affected 99mTc-MIBI accumulation as follow: 1). no effect on K562 cell lines; 2). increased 8-fold in GLC4/R; 3). enhanced in GLC4 after GSH concentration and transmembrane potential reduction. CONCLUSION: Assessed by 99mTc-MIBI, PAK-104P modulated MRP1 activity by the decrease of intracellular GSH concentration.


Assuntos
Membro 1 da Subfamília B de Cassetes de Ligação de ATP/antagonistas & inibidores , Carcinoma de Células Pequenas/metabolismo , Óxidos P-Cíclicos/farmacologia , Resistência a Múltiplos Medicamentos/fisiologia , Neoplasias Pulmonares/metabolismo , Ácidos Nicotínicos/farmacologia , Compostos Radiofarmacêuticos , Tecnécio Tc 99m Sestamibi , Membro 1 da Subfamília B de Cassetes de Ligação de ATP/metabolismo , Carcinoma de Células Pequenas/diagnóstico por imagem , Carcinoma de Células Pequenas/tratamento farmacológico , Membrana Celular/efeitos dos fármacos , Membrana Celular/metabolismo , Membrana Celular/fisiologia , Glutationa/metabolismo , Humanos , Células K562/efeitos dos fármacos , Células K562/metabolismo , Neoplasias Pulmonares/diagnóstico por imagem , Neoplasias Pulmonares/tratamento farmacológico , Potenciais da Membrana/efeitos dos fármacos , Cintilografia , Compostos Radiofarmacêuticos/farmacocinética , Tecnécio Tc 99m Sestamibi/farmacocinética
16.
Clin Nucl Med ; 29(4): 251-4, 2004 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-15096973

RESUMO

The authors report a patient with persistent left knee pain after traumatic injury. The initial bone scan seemed to confirm a valgus stress knee injury. The final diagnosis, however, was focal inflammation of the knee ligaments (enthesopathy) related to ankylosing spondylitis. The diagnostic procedure and the results of other imaging modalities are presented. The bone scan findings are discussed.


Assuntos
Artralgia/diagnóstico , Artralgia/etiologia , Erros de Diagnóstico , Articulação do Joelho/diagnóstico por imagem , Espondiloartropatias/complicações , Espondiloartropatias/diagnóstico por imagem , Adulto , Traumatismos em Atletas/complicações , Traumatismos em Atletas/diagnóstico , Traumatismos em Atletas/diagnóstico por imagem , Diagnóstico Diferencial , Humanos , Traumatismos do Joelho/diagnóstico , Traumatismos do Joelho/diagnóstico por imagem , Traumatismos do Joelho/etiologia , Masculino , Radiografia , Cintilografia , Espondiloartropatias/diagnóstico
17.
Presse Med ; 33(4): 270-6, 2004 Feb 28.
Artigo em Francês | MEDLINE | ID: mdl-15029020

RESUMO

The key to prognosis. Initial staging and early recurrence diagnosis are key parameters in the treatment and outcome of testicular cancer. Initial staging. It is difficult using conventional modalities, which can miss node involvement and are non-specific since enlargement does not rhyme with involvement. 18FDG PET improves the accuracy of initial staging. Residual mass and recurrences. Existence of residual mass or enhancement of its Volume in the presence of an otherwise beneficial chemotherapy is difficult to manage. Several studies have demonstrated the value of 18FDG imaging in such cases. As for follow-up whole body 18FDG can prevent multiple diagnostic imaging and can diagnose recurrences with greater diagnostic accuracy than with other imaging modalities.


Assuntos
Seminoma/diagnóstico por imagem , Neoplasias Testiculares/diagnóstico por imagem , Tomografia Computadorizada de Emissão , Adolescente , Adulto , Diagnóstico Diferencial , Fluordesoxiglucose F18 , Seguimentos , Humanos , Metástase Linfática/diagnóstico por imagem , Imageamento por Ressonância Magnética , Masculino , Pessoa de Meia-Idade , Metástase Neoplásica/diagnóstico por imagem , Recidiva Local de Neoplasia/diagnóstico por imagem , Prognóstico , Compostos Radiofarmacêuticos , Estudos Retrospectivos , Seminoma/diagnóstico , Seminoma/tratamento farmacológico , Seminoma/mortalidade , Neoplasias Testiculares/diagnóstico , Neoplasias Testiculares/tratamento farmacológico , Neoplasias Testiculares/mortalidade , Fatores de Tempo , Tomografia Computadorizada por Raios X , Ultrassonografia
18.
Cancer Biother Radiopharm ; 26(1): 135-40, 2011 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-21355785

RESUMO

BACKGROUND AND AIM: In internal radiotherapy, the variable distribution of target receptors within the tumoral tissue, and the variable ranges of electrons may be responsible for a heterogeneous dose distribution at the cellular level. The aim of the present study was to use Monte Carlo simulations to assess (131)I electron dose in a model of heterogeneous tumor containing multiple clusters of cancer cells, targeted by (131)I-labeled molecules. METHODS: The model consisted of 150-µm-diameter spherical tumor cell clusters, in which (131)I was homogeneously distributed. Clusters were placed 24 µm apart, separated by septa of nonradioactive connective tissue. The electron dose distribution to tumor cells in a single cluster was first assessed. Then was assessed the dose increase to these targets after adding multiple layers of neighboring clusters (total number of clusters = 15,624). RESULTS: Dose distribution within a single isolated cluster follows a decreasing gradient, the dose for the outermost cell layer being about half that at the center. When radioactive neighbors were added, the dose to the central cluster increased. The most important contribution was given by the nearest neighbors, whereas the contribution from neighbors beyond a distance of 1 mm was only for 5% of the final dose. If the central cluster was unlabeled, the absorbed dose to the outermost cell layer of this cluster was reduced by 27%, and that at the center by 45%. CONCLUSIONS: The electron cross-dose of (131)I falls rapidly as a function of distance and becomes negligible after just 1 mm. Small clusters of tumor cells that are not radiolabeled may receive a very small dose. Therefore, in internal radiotherapy it is important to aim at targeting tumor cells as homogeneously as possible, rather than relying on the cross-dose to achieve a therapeutic effect.


Assuntos
Isótopos de Iodo/farmacologia , Modelos Biológicos , Neoplasias/radioterapia , Simulação por Computador , Elétrons , Isótopos de Iodo/química , Método de Monte Carlo , Neoplasias/patologia , Radiometria/métodos , Dosagem Radioterapêutica
19.
J Nucl Med ; 52(3): 405-14, 2011 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-21321267

RESUMO

Axillary node status is a major prognostic factor in early breast cancer. Staging with sentinel node biopsy (SNB) leads to a substantial reduction in surgical morbidity. Recent multiinstitutional studies revealed SNB false-negative rates ranging from 5.5% to 16.7%, higher than the target (<5%) set by the 2005 guidelines of the American Society of Clinical Oncology. These alarming data point to the necessity of optimization. Dual mapping with radiotracer and blue dye, combining 2 different injection sites, and routinely using lymphoscintigraphy may improve accuracy. Factors associated with decreased sensitivity, such as prior excisional biopsy or neoadjuvant chemotherapy, should be recognized. The use of SNB in situations with a high prevalence of node positivity (large tumor, multifocality) is controversial. The risk of missed disease after negative SNB ranges from 1% to 4% in patients with T1 tumor and up to 15% in patients with T3. With peritumoral injection, internal mammary drainage is seen in about 20% of cases. Patients combining internal mammary drainage with a positive axillary sentinel node have close to a 50% probability of internal mammary involvement. Lymphoscintigraphy might thus be helpful in selecting patients for whom internal mammary radiation has a high benefit-to-risk ratio.


Assuntos
Neoplasias da Mama/diagnóstico por imagem , Neoplasias da Mama/mortalidade , Linfonodos/diagnóstico por imagem , Mastectomia/mortalidade , Neoplasias da Mama/cirurgia , Feminino , Humanos , Metástase Linfática , Prognóstico , Cintilografia , Medição de Risco , Fatores de Risco , Biópsia de Linfonodo Sentinela/métodos , Análise de Sobrevida , Taxa de Sobrevida , Resultado do Tratamento
20.
PET Clin ; 6(1): 9-25, 2011 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-27156352

RESUMO

Sentinel node status is the most powerful prognostic factor in patients with early-stage melanoma. This review discusses several issues of clinical interest and technical points for an optimized sentinel node biopsy (SNB) procedure. The role of fluorodeoxyglucose positron emission tomography/computed tomography is clearly established in patients with suspicion of locoregional or distant recurrence of melanoma before any surgical decision. However, its role at initial staging or follow-up of patients with localized disease or with positive SNB is less clear. Further research and efforts should focus on identifying which groups of patients are at specific high risk of early distant recurrence.

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