RESUMO
The effects of captopril on effective renal plasma flow and glomerular filtration rate were studied using a noninvasive radioisotopic method on individual kidneys in eight patients with renovascular hypertension and 12 patients with essential hypertension with various renin levels. Four patients with renovascular hypertension had unilateral while three had bilateral renal artery stenosis. The effective renal plasma flow and glomerular filtration rate were determined by using 131I-iodohippurate sodium and 99mTc-diethylenetriamine pentaacetic acid, respectively. Glomerular filtration rate and effective renal plasma flow were significantly reduced in the stenotic kidneys of patients with renovascular hypertension compared with values in nonstenotic kidneys (p less than 0.01). Treatment with captopril, 37.5 to 75 mg/day for 1 to 48 weeks, further reduced the glomerular filtration rate only in stenotic kidneys, and effective renal plasma flow increased in both kidney types. In two of the three renal hypertensive patients with bilateral renal artery stenosis, captopril produced a reversible azotemia that was unrelated to the fall in blood pressure, as evidenced by the lack of azotemia seen after a moderate blood pressure reduction induced by other antihypertensive medications. These results indicate that endogenous angiotensin II is essential in maintaining the glomerular filtration rate in stenotic kidneys and suggest that a reduction in glomerular filtration rate during captopril administration could indicate the presence of renal artery stenosis.
Assuntos
Inibidores da Enzima Conversora de Angiotensina , Hipertensão Renal/tratamento farmacológico , Rim/efeitos dos fármacos , Adulto , Aldosterona/sangue , Captopril/uso terapêutico , Taxa de Filtração Glomerular/efeitos dos fármacos , Humanos , Hipertensão Renal/complicações , Hipertensão Renal/enzimologia , Rim/irrigação sanguínea , Pessoa de Meia-Idade , Ácido Pentético/metabolismo , Fluxo Sanguíneo Regional/efeitos dos fármacos , Obstrução da Artéria Renal/complicações , Renina/sangue , Tecnécio/metabolismo , Pentetato de Tecnécio Tc 99m , Ácido p-Aminoipúrico/metabolismoRESUMO
In a series of 327 patients with primary GI malignancies, the occurrence of hepatic metastases was correctly detected in 70% of 113 cases by focal defects in the radiocolloid scintiscan. Only 1% of false positives were observed among the 214 patients without hepatic metastases. For these patients, the predictive value of the liver scan was 97%, and the overall accuracy, 89%. A composite test formed by disjoining focal radionuclide defects with the combination of elevated CEA and hepatomegaly, or elevated CEA and high alkaline phosphatase activity, exhibited a predictive value of 92% and an overall accuracy of 92%. Formation of such a composite test may be useful for preserving high accuracy when very strict scintigraphic criteria for metastases are employed.
Assuntos
Antígeno Carcinoembrionário/sangue , Neoplasias do Sistema Digestório/patologia , Neoplasias Hepáticas/diagnóstico , Neoplasias Hepáticas/secundário , Fígado/diagnóstico por imagem , Humanos , Neoplasias Hepáticas/sangue , Neoplasias Hepáticas/diagnóstico por imagem , Radioimunoensaio , CintilografiaRESUMO
Nonradiolabeled methylene diphosphonate (MDP) was administered intravenously to CFW Swiss outbred female mice 2 hr prior to i.v. injection of [67Ga]citrate. The dose of MDP ranged from that usually administered for bone scanning (17.9 micrograms/kg) to 1,000 times the usual bone scan dose (17.9 mg/kg). The animals were killed 24 hr after administration of [67Ga]citrate and organ distribution determined as compared to control animals who received no MDP. At MDP doses one to ten times usual bone scan dose, the only organ showing significantly different 67Ga uptake was the lung and this difference in pulmonary uptake was accounted for by incidental pulmonary infection. At MDP doses 100 to 1,000 times usual bone scan dose, significantly altered 67Ga uptake was noted in lung, spleen, kidney, and gastrointestinal tract. The only consistent pattern of association of MDP administered dose and alteration in 67Ga uptake, however, was noted in the spleen where uptake was augmented with increased dose, and the bone where increased MDP dose depressed 67Ga uptake. Even this effect, however, was modest. It is concluded that at usual MDP dose levels used in bone imaging, no significant alterations occur in 67Ga distribution in normal mouse tissue. It is inferred that 67Ga scans performed following bone scans can be interpreted as if both radiopharmaceuticals had been administered separately.
Assuntos
Osso e Ossos/diagnóstico por imagem , Difosfonatos/farmacologia , Radioisótopos de Gálio , Gálio/metabolismo , Animais , Osso e Ossos/metabolismo , Difosfonatos/administração & dosagem , Relação Dose-Resposta a Droga , Radioisótopos de Gálio/metabolismo , Camundongos , Cintilografia , Medronato de Tecnécio Tc 99m , Distribuição TecidualRESUMO
A 39-yr-old man with an autonomously functioning thyroid carcinoma is presented. Only 17 similar cases have been reported in the literature. The patient had unilateral Graves' ophthalmopathy. He was euthyroid as reflected by normal TSH concentration, whereas the results of a T3 suppression test established the presence of autonomous thyroid function. A thyroid scan with (123)I revealed a hot nodule corresponding to the location of a papillary carcinoma and remained substantially unchanged after T3 administration. The hyperfunction of the carcinoma itself was clearly confirmed by the intense concentration of (131)I within the tumor on microautoradiograms. While a hot nodule on radioiodine scan is unlikely to be malignant, the possibility of carcinoma should not be overlooked.
Assuntos
Carcinoma Papilar/complicações , Doença de Graves/etiologia , Hipertireoidismo/complicações , Neoplasias da Glândula Tireoide/complicações , Adulto , Carcinoma Papilar/diagnóstico por imagem , Carcinoma Papilar/patologia , Humanos , Hipertireoidismo/diagnóstico por imagem , Hipertireoidismo/patologia , Radioisótopos do Iodo , Masculino , Cintilografia , Neoplasias da Glândula Tireoide/diagnóstico por imagem , Neoplasias da Glândula Tireoide/patologiaRESUMO
UNLABELLED: The objective of this study was to clarify the relationship between cardiac sympathetic nervous function (CSNF) and left ventricular (LV) function and perfusion in hypertrophic cardiomyopathy (HCM) and dilated cardiomyopathy (DCM). METHODS: Thirty-eight cases (32 males, 6 females; mean age, 56 +/- 15 y), consisting of 5 healthy control subjects, 15 patients with DCM, and 18 patients with HCM, were studied with (123)I-metaiodobenzylguanidine (MIBG) and (99m)Tc-tetrofosmin SPECT. CSNF was evaluated from cardiac uptake and washout of MIBG, whereas LV perfusion and function were evaluated from tetrofosmin uptake and wall thickening on electrocardiographically gated SPECT. As quantitative parameters of global cardiac MIBG uptake and washout, the heart-to-mediastinum ratio (H/M) and percentage washout were calculated from early and delayed planar images. As quantitative regional parameters, the regional uptake and percentage washout of MIBG were calculated from SPECT images dividing the left ventricle into 12 segments. In the tetrofosmin study, the H/M and LV ejection fraction were calculated as the parameters of global LV perfusion and function. As quantitative regional parameters, the regional uptake and wall thickening were also calculated for the 12 myocardial segments using the quantitative gated SPECT software. Multiple linear regression analysis was performed to investigate the correlations between the parameters from the 2 studies. RESULTS: In DCM and HCM, multiple linear regression analysis of the regional parameters showed significant correlations between LV function and CSNF (P < 0.0001) and between LV perfusion and CSNF (P < 0.0001). According to the partial correlation coefficients, washout and early uptake of MIBG were the most significant factors for predicting LV function and LV perfusion, respectively. CONCLUSION: In cardiomyopathies, CSNF was closely related to LV function. The quantitative parameters of MIBG washout could reflect cardiac functional impairment. Early MIBG uptake might be determined by myocardial perfusion in cardiomyopathies.
Assuntos
3-Iodobenzilguanidina , Cardiomiopatia Dilatada/fisiopatologia , Cardiomiopatia Hipertrófica/fisiopatologia , Circulação Coronária , Coração/inervação , Radioisótopos do Iodo , Compostos Organofosforados , Compostos de Organotecnécio , Compostos Radiofarmacêuticos , Sistema Nervoso Simpático/fisiopatologia , Tomografia Computadorizada de Emissão de Fóton Único , Função Ventricular Esquerda , Adolescente , Adulto , Idoso , Cardiomiopatia Dilatada/diagnóstico por imagem , Cardiomiopatia Hipertrófica/diagnóstico por imagem , Eletrocardiografia , Feminino , Humanos , Masculino , Pessoa de Meia-IdadeRESUMO
Thallium-201 SPECT was performed in 30 patients with suspected lung cancer. Both early and delayed scans demonstrated abnormal accumulation in all of 23 malignant pulmonary lesions including 21 lung cancer and in two of seven benign conditions. There were significant differences in delayed ratio (uptake ratio of the lesion to the normal lung on delayed scan) and retention index (degree of retention in the lesion) between lung cancer and benign conditions, respectively (p less than 0.01, p less than 0.05). The delayed ratio and retention index revealed that adenocarcinoma showed higher 201Tl accumulation than squamous cell carcinoma and small cell carcinoma (p less than 0.05) and 201Tl clearance in squamous cell carcinoma was faster than in the other two (p less than 0.05). Mediastinal involvement was detected in five of seven patients on delayed scans. The smallest lesion depicted was 1.5 cm in diameter. Two false negatives had small metastases less than 1.0 cm in diameter. This method seems to be useful to detect lung cancer, to differentiate malignant from benign lesions, and to evaluate mediastinal involvement from lung cancer.
Assuntos
Neoplasias Pulmonares/diagnóstico por imagem , Radioisótopos de Tálio , Tomografia Computadorizada de Emissão , Adenocarcinoma/diagnóstico por imagem , Idoso , Carcinoma de Células Pequenas/diagnóstico por imagem , Carcinoma de Células Escamosas/diagnóstico por imagem , Feminino , Humanos , Leiomiossarcoma/diagnóstico por imagem , Metástase Linfática/diagnóstico por imagem , Masculino , Neoplasias do Mediastino/diagnóstico por imagem , Neoplasias do Mediastino/secundário , Pessoa de Meia-IdadeRESUMO
The biodistributions of five Tc-99m colloids were compared with the 24-hr distributions of Fe-59 and In-111 in dogs by direct radioassay 1 hr after intravenous injection. One formulation of Tc-99m minmicroaggregated albumin (particle size 30-100 mn), produced the highest marrow concentration, approximately six times that of Tc-99m sulfur colloid, with similar blood, and liver concentrations and a lower splenic uptake. Nevertheless, the best colloid marrow uptake was lower than the 24-hr value for In-11 and much lower than that for Fe-59. The marrow concentration of minimicroaggregated albumin was also higher than that of sulfur colloid in rats at 30 min after injection. The principal disadvantage of Tc-99m antimony sulfide colloid was its slow blood clearance. Clinical evaluation of Tc-99m minimicroaggregated albumin for marrow imaging appears warranted, although its hepatic activity will obscure overlying and immediately adjacent marrow.
Assuntos
Medula Óssea/diagnóstico por imagem , Índio/metabolismo , Radioisótopos de Ferro/metabolismo , Albumina Sérica/metabolismo , Tecnécio/metabolismo , Animais , Medula Óssea/metabolismo , Coloides , Cães , Feminino , Meia-Vida , Fígado/metabolismo , Masculino , Tamanho da Partícula , Radioisótopos/metabolismo , Cintilografia , Ratos , Ratos Endogâmicos , Agregado de Albumina Marcado com Tecnécio Tc 99m , Tecnologia Farmacêutica , Fatores de Tempo , Distribuição TecidualRESUMO
UNLABELLED: Preoperative assessment of residual hepatic functional reserve offers important strategic information for hepatic resection. To predict the postoperative residual liver function, we assessed the value of hepatic 99mTc-diethylenetriamine pentaacetic acid-galactosyl-human serum albumin (99mTc-GSA) clearance estimated by dynamic SPECT analysis. METHODS: We investigated 114 consecutive patients with liver disease, including 55 hepatectomy cases. One minute after injection of 185 MBq 99mTc-GSA, 15 serial dynamic SPECT images were obtained every minute. The initial five sets of SPECT images were analyzed by Patlak plot to estimate the sequential initial hepatic 99mTc-GSA clearance (mL/min) as an index of hepatic function. The sum of hepatic 99mTc-GSA clearance of the segments immune from resection was categorized as predicted residual 99mTC-GSA clearance. In the hepatectomy cases, scintigraphy was performed before and 37 +/- 10 d after the operation. RESULTS: Good correlation was observed between the total hepatic 99mTc-GSA clearance and conventional hepatic function tests: plasma retention rate of iodocyanine green (ICG) at 15 min (ICG R15), r = -0.600, P < 0.0001, n = 94; plasma disappearance rate of ICG (K ICG), r = 0.670, P < 0.0001, n = 83; cholinesterase, r = 0.539, P < 0.0001, n = 121; serum albumin, r = 0.421, P = 0.0001, n = 123; and hepaplastin test, r = 0.456, P < 0.0001, n = 120. There was good correlation between the predicted residual 99mTc-GSA clearance and the postoperative total hepatic 99mTc-GSA clearance in patients who underwent segmentectomy or lobectomy (r = 0.84, P < 0.0001, n = 28) and between the pre- and postoperative total hepatic 99mTc-GSA clearance in patients who underwent subsegmentectomy (r = 0.91, P < 0.0001, n = 25). Five patients who had postoperative complications due to hepatic insufficiency (2 patients died of postoperative hepatic failure within 2 mo after operation) showed significantly lower predicted residual 99mTc-GSA clearance compared with the patients without complications (90.3 +/- 37.2 versus 320.9 +/- 158.8 mL/min; P < 0.005). CONCLUSION: The total hepatic 99mTC-GSA clearance reflected hepatic function. In addition, preoperative predicted residual hepatic 99mTc-GSA clearance was a good indicator of postoperative hepatic function and early prognosis. 99mTc-GSA dynamic SPECT is assumed to be a useful method for determining the surgical strategy in patients with hepatic tumor and especially in patients with hepatic dysfunction.
Assuntos
Hepatopatias/diagnóstico por imagem , Compostos Orgânicos , Compostos Radiofarmacêuticos , Agregado de Albumina Marcado com Tecnécio Tc 99m , Pentetato de Tecnécio Tc 99m , Tomografia Computadorizada de Emissão de Fóton Único/métodos , Corantes/metabolismo , Hepatectomia/métodos , Humanos , Hepatopatias/metabolismo , Hepatopatias/cirurgia , Falência Hepática/diagnóstico por imagem , Testes de Função Hepática , Imageamento por Ressonância Magnética , Prognóstico , Agregado de Albumina Marcado com Tecnécio Tc 99m/farmacocinética , Pentetato de Tecnécio Tc 99m/farmacocinética , Fatores de Tempo , Tomografia Computadorizada por Raios X , Resultado do TratamentoRESUMO
Hyperthermia (HT) may increase tumor targeting of a radiolabeled antibody by its effects on tumor vasculature and antigen expression. Expression of a 45-kDa glycoprotein antigen on LS180 colon cancer cells was 2.7-fold enhanced 2 days after heating at 43 degrees C for 1 h. Preferential tumor accumulation of 125I-A7 recognizing this antigen was doubled and the antitumor effect of 131I-A7 was significantly improved by HT. Hyperthermia also increased tumor uptake of an irrelevant antibody but its radioactivity was rapidly cleared. These results indicate that HT increased the initial delivery of an antibody to a tumor by its vascular effect, and radioactivity was retained in tumors by increased specific binding, resulting in a better radioimmunotherapy outcome.
Assuntos
Antígenos de Neoplasias/biossíntese , Neoplasias do Colo/irrigação sanguínea , Neoplasias do Colo/terapia , Hipertermia Induzida , Imunoconjugados/uso terapêutico , Radioimunoterapia , Animais , Anticorpos Monoclonais/farmacocinética , Anticorpos Monoclonais/uso terapêutico , Antígenos de Neoplasias/imunologia , Cromatografia Líquida de Alta Pressão , Terapia Combinada , Feminino , Humanos , Imunoconjugados/farmacocinética , Radioisótopos do Iodo , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Nus , Transplante de Neoplasias , Fatores de Tempo , Distribuição Tecidual , Transplante Heterólogo , Células Tumorais CultivadasRESUMO
Experimentally we investigated the detection of lung cancer with N-isopropyl-p-I-123-iodoamphetamine (I-123 IMP). Various tumors including Lewis lung cancer were used as tumor models. Serial images were obtained. Biodistribution of Lewis lung cancer was performed. In Lewis lung cancer good visualization as in B-16 melanoma and high tumor accumulation were found with IMP. In conclusion, due to its greater accumulation almost equivalent to that in melanotic melanoma, I-123 IMP may have a role in the detection of lung cancer.
Assuntos
Iofetamina , Neoplasias Pulmonares/diagnóstico , Compostos Radiofarmacêuticos , Animais , Humanos , Radioisótopos do Iodo , Iofetamina/farmacocinética , Neoplasias Pulmonares/metabolismo , Masculino , Melanoma Experimental/metabolismo , Camundongos , Camundongos Endogâmicos C57BL , Compostos Radiofarmacêuticos/farmacocinética , Distribuição TecidualRESUMO
PURPOSE: The feasibility of radioimmunotherapy (RAIT) combined with 5-fluorouracil (5-FU) was examined in colon cancer xenografts. The mode of interaction of the two treatments was also investigated. METHODS: Mice bearing human colon cancer were treated with a combination of 4.63 MBq (L-RAIT) or 9.25 MBq (H-RAIT) (131)I-A7, an IgG1 against 45-kDa glycoprotein, and 5-FU at a dose of 30 mg kg(-1)day(-1) for 5 days. Myelotoxicity was monitored by blood cell counts and intestinal toxicity was assessed by the dosimetry. The results were compared with those of a single-modality therapy. RESULTS: The combination of 5-FU with H-RAIT enhanced the antitumor effect, improving the tumor quadrupling time from 25.3 +/- 9.59 days to 31.3 +/- 8.32 days (P < 0.05) and inducing tumor regression in 7 out of 10 mice, compared to 3 out of 9 mice treated with H-RAIT alone. The efficacy of L-RAIT was also improved by the combination. Analysis of the dose/response relationship showed an additive interaction of the two modalities. The combination of 5-FU with RAIT induced slightly more severe myelotoxicity than a single-modality treatment, but blood cell counts recovered similarly. Dose estimation suggested that RAIT does not increase the intestinal toxicity of 5-FU. CONCLUSION: The combination of two modalities would be feasible for the treatment of colon cancer, increasing antitumor effect with minor effect on toxicity.
Assuntos
Neoplasias do Colo/tratamento farmacológico , Neoplasias do Colo/radioterapia , Fluoruracila/uso terapêutico , Radioimunoterapia , Animais , Anticorpos Monoclonais/efeitos adversos , Anticorpos Monoclonais/farmacocinética , Anticorpos Monoclonais/uso terapêutico , Contagem de Células Sanguíneas/efeitos dos fármacos , Neoplasias do Colo/patologia , Terapia Combinada , Relação Dose-Resposta a Droga , Ensaios de Seleção de Medicamentos Antitumorais , Estudos de Viabilidade , Feminino , Fluoruracila/efeitos adversos , Humanos , Imunoconjugados/efeitos adversos , Imunoconjugados/uso terapêutico , Radioisótopos do Iodo , Camundongos , Camundongos Nus , Transplante de Neoplasias , Fatores de Tempo , Distribuição Tecidual , Resultado do Tratamento , Células Tumorais CultivadasRESUMO
This study was undertaken to find optimum period of hypertensive treatment for the improvement of tumor targeting of 111In-labeled monoclonal antibody. Angiotensin II was infused into tumor-bearing mice at an infusion rate of 2.0 micrograms/kg/min determined by the dose-finding study. The infusion was continued for up to 72 h, and biodistribution of 111In-DTPA-A7, a murine IgG1, was observed 72 h postinjection. Tumor-to-nontumor ratios were best improved with the infusion for 0.5-3 h. However, with the longer infusion, the effect deteriorated by the increase of nontumor uptakes, and body-weight loss became remarkable. It could be concluded that hypertensive treatment for a short period could be safely performed to benefit targeting of radiolabeled monoclonal antibody.
Assuntos
Angiotensina II/farmacologia , Anticorpos Monoclonais , Hipertensão/metabolismo , Radioisótopos de Índio , Radioimunodetecção , Animais , Anticorpos Monoclonais/farmacocinética , Feminino , Hipertensão/induzido quimicamente , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Nus , Distribuição TecidualRESUMO
Induced hypertension with angiotensin II (AT-II) and the inhibition of kininase with enalapril maleate may increase the tumor targeting of radiolabeled monoclonal antibodies (MAbs). We previously found that short-period infusion of 2.0 microg/kg/min of AT-II enhanced tumor targeting of MAb without an impact on normal tissue distribution. In this study, we aimed to optimize the manipulation with these agents, and examine the possible mechanism of their effects on MAb distribution. Effect of the manipulation on tissue circulation was assessed in mice bearing colon cancer xenografts by 201Tl and 99mTc-human serum albumin (HSA) as markers of tissue blood flow and tissue blood volume and/or vascular permeability. A dose finding study of enalapril ranging from 3 to 300 microg showed that 30 microg of enalapril in combination with AT-II infusion produced the best improvement in tumor uptake of 99Tc-HSA without altering 201Tl distribution, suggesting that the increase of vascular permeability was caused by enalapril. AT-II infusion for longer than 1 h affected renal blood flow and caused subcutaneous edema. Tumor uptake of (111)In-A7, a murine IgG1, was 1.62-fold improved 72 h postinjection (P < 0.001) and intratumoral distribution became uniform with 2.0 microg/kg/min of AT-II for 1 h and 30 microg of enalapril. Vessels in manipulated tumors were distended even 48 h after the cessation of AT-II infusion. In conclusion, it was suggested that persistent distension of tumor vessels and the increase of diffusive extravasation of MAb caused by short-period-induced hypertension and inhibition of bradykinin degradation produced favorable effect for the MAb distribution in tumors.
Assuntos
Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Neoplasias do Colo/irrigação sanguínea , Neoplasias do Colo/terapia , Radioimunoterapia/métodos , Angiotensina II/administração & dosagem , Inibidores da Enzima Conversora de Angiotensina/administração & dosagem , Animais , Anticorpos Monoclonais/farmacocinética , Autorradiografia , Enalapril/administração & dosagem , Extravasamento de Materiais Terapêuticos e Diagnósticos , Feminino , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Nus , Albumina Sérica/metabolismo , Radioisótopos de Tálio/farmacocinética , Distribuição Tecidual , Transplante HeterólogoRESUMO
Local hyperthermia (HT) may enhance the efficacy of radioimmunotherapy (RIT). However, the optimal timing of HT relative to administration of antibody is unknown. Human colon cancer xenografts (290 +/- 26 mm3) were treated with 4.63 MBq 131I-A7 monoclonal antibody (MAb) anti-Mr 45,000 glycoprotein antigen on colorectal cancer, and HT at 43 degrees C for 1 h was administered at: (A), 2 days after the 131I-A7 injection at the maximum 131I-A7 tumor accumulation (radiation); (B), soon after the 131I-A7 injection aiming to increase the tumor accumulation of 131I-A7 due to HT vascular effects; or (C), 2 days before the 131I-A7 injection in an attempt at injecting 131I-A7 when increased antigen expression could be expected. Specific growth delay (SGD) of tumors was calculated as (Tqtreat-Tqcontrol)/Tqcontrol where Tq was tumor quadrupling time. The biodistribution and intratumoral distribution of 131I-A7 were investigated to explore the mechanism of tumor response among the different HT regimens. HT alone produced some antitumor effect (SGD 1.90 +/- 0.26), which was less effective than RIT (3.11 +/- 0.50). HT soon after 131I-A7 RIT (B) significantly enhanced RIT efficacy (6.57 +/- 0.51, p < 0.0001) whereas neither HT at 2 days after RIT (A) nor at 2 days before RIT (C) did so. Biodistribution study revealed that HT soon after RIT (B) increased the tumor radiation absorbed dose by a factor of 2.4, while HT after RIT (A) did not increase radiation dose and HT before RIT (C) decreased it. Radioluminograms of tumor sections indicated that HT soon after RIT (B) improved the uniformity of 131I-A7 distribution whereas HT after RIT (A) did not and HT before RIT (C) diminished the uniformity of A7 distribution. In conclusion, the best therapeutic efficacy was obtained when HT was combined soon after the initiation of RIT with 131I-A7. The increased tumor radiation absorbed dose and the uniform intratumoral distribution of 131I-A7 were important factors underlying this improvement, and the additive cytotoxicity of HT is suspected to some extent. HT-induced radiosensitization of tumor was not apparent in this model when HT was given 2 days after 131I-A7 MAb.
Assuntos
Neoplasias Colorretais/radioterapia , Hipertermia Induzida , Imunoconjugados/uso terapêutico , Radioimunoterapia , Compostos Radiofarmacêuticos/uso terapêutico , Animais , Anticorpos Monoclonais/uso terapêutico , Neoplasias Colorretais/imunologia , Feminino , Humanos , Imunoconjugados/farmacocinética , Radioisótopos do Iodo/uso terapêutico , Camundongos , Camundongos Endogâmicos BALB C , Modelos Animais , Transplante de Neoplasias , Radioimunoterapia/métodos , Compostos Radiofarmacêuticos/farmacocinéticaRESUMO
201Tl single photon emission computed tomography (SPECT) was evaluated in 170 patients suspected of having a malignant pulmonary lesion greater than 20 mm in diameter on the surgical specimen. Delayed SPECT (at 3 h after injection) visualized all of the 147 malignant pulmonary lesions and 16 of the 23 (69.6%) benign pulmonary lesions, and generally exhibited the lesion more clearly than the early SPECT images (at 15 min after injection). There was no significant difference in delayed ratio (uptake ratio of the lesion to the normal lung on delayed scan) among the various histological groups except between the adenocarcinoma and large cell carcinoma groups (P < 0.05), and no difference was noted between the malignant and benign lesions. However, in retention index (degree of retention in the lesion) a significant difference was noted between the malignant and benign lesions (P < 0.01), although there was no significant difference in this index among malignant different histology groups. These results indicate that this method is useful for visualizing malignant pulmonary lesions greater than 20 mm in diameter to exclude the possibility of malignancy in the lesions when no abnormal 201Tl accumulation is observed. When the lesion shows abnormal 201Tl accumulation, the retention index seems to help differentiate malignant from benign lesions.
Assuntos
Adenocarcinoma/diagnóstico por imagem , Carcinoma Pulmonar de Células não Pequenas/diagnóstico por imagem , Carcinoma de Células Pequenas/diagnóstico por imagem , Carcinoma de Células Escamosas/diagnóstico por imagem , Neoplasias Pulmonares/diagnóstico por imagem , Radioisótopos de Tálio , Tomografia Computadorizada de Emissão de Fóton Único , Idoso , Feminino , Humanos , Masculino , Pessoa de Meia-IdadeRESUMO
201Tl SPECT was performed to detect mediastinal involvement in 80 patients with lung cancer who underwent surgery within a week after the SPECT study. Out of 29 patients with mediastinal involvement 16 (55%) were positive on the 201Tl early scan at 15 min postinjection and 22 (76%) were positive on the delayed scan at 3 h. These metastatic lymph nodes tended to be visualized much better on the delayed scan. In all patients with true positive results on the delayed scan, the mediastinal lymph nodes were plural, with a lesion of more than 14 mm in size. Seven false negative cases were found to have metastatic lesions less than 12 mm in size. Both the early and delayed scans showed false positive accumulation in six of 51 patients without mediastinal involvement (specificity 88%). Thus the overall accuracy for the delayed scan was 84%. The 201Tl delayed SPECT is thought to be a good noninvasive method for assessing mediastinal lymph node metastases from lung cancer.
Assuntos
Neoplasias Pulmonares , Metástase Linfática/diagnóstico por imagem , Neoplasias do Mediastino/diagnóstico por imagem , Radioisótopos de Tálio , Tomografia Computadorizada de Emissão de Fóton Único/métodos , Idoso , Estudos de Avaliação como Assunto , Reações Falso-Negativas , Feminino , Humanos , Masculino , Neoplasias do Mediastino/secundário , Pessoa de Meia-IdadeRESUMO
The objective of this study was to investigate clinical utility of a graphical method for estimating liver uptake and blood retention of 99mTc-DTPA-galactosyl human serum albumin (99mTc-GSA; DTPA is diethylenetriaminepentaacetic acid) using dynamic single photon emission computed tomography (SPECT) data. When considering the kinetics of 99mTc-GSA, if it is assumed that (1) 99mTc-GSA distributes only between blood and liver, and (2) no metabolism of 99mTc-GSA occurs during the observation period, a plot of liver counts versus cardiac blood pool counts should, theoretically, be a straight line. From the slope and y intercept of a regression line, coefficients for converting count based liver and blood pool data to the per cent injected dose (%ID) can be calculated. The applicability of this method was tested on dynamic SPECT data from 30 patients with liver dysfunction. To validate this method, plasma concentrations (%ID/ml plasma) at 6, 15 and 30 min after the injection were estimated by this method and compared with the measured ones. To investigate the clinical significance of the per cent liver uptake, the value obtained by this method was compared with the results of conventional liver function tests, including serum albumin, the hepaplastin test, prothrombin time and indocyanine green clearance. In every data set, a plot of liver counts to cardiac blood pool counts was fitted well by a straight line (P<0.00001). Estimated plasma concentrations by this method showed good correlation with the measured ones at 6, 15 and 30 min after the injection (r=0.748, 0.838, 0.875, respectively; P<0.0001). The liver uptake determined by this method showed good correlation with the results of conventional hepatic function tests (P<0.002). The graphical method could provide an accurate estimate of %ID of 99mTc-GSA in blood without the need for blood sampling. The liver uptake determined by this method could be a simple but useful quantitative indicator of hepatic function.
Assuntos
Algoritmos , Hepatopatias/diagnóstico por imagem , Hepatopatias/metabolismo , Agregado de Albumina Marcado com Tecnécio Tc 99m/farmacocinética , Pentetato de Tecnécio Tc 99m/farmacocinética , Tomografia Computadorizada de Emissão de Fóton Único/métodos , Adulto , Idoso , Feminino , Humanos , Fígado/diagnóstico por imagem , Fígado/metabolismo , Hepatopatias/diagnóstico , Testes de Função Hepática , Masculino , Pessoa de Meia-Idade , Técnica de Diluição de Radioisótopos , Compostos Radiofarmacêuticos/sangue , Compostos Radiofarmacêuticos/farmacocinética , Reprodutibilidade dos Testes , Sensibilidade e Especificidade , Índice de Gravidade de Doença , Estatística como Assunto , Agregado de Albumina Marcado com Tecnécio Tc 99m/sangue , Pentetato de Tecnécio Tc 99m/sangueRESUMO
The uptake and retention of single photon tracers in irradiated tumour cells was observed in an attempt at the early evaluation of the effect of radiation. T24 human bladder cancer cells were exposed to a single dose of 10 Gy or 20 Gy or a fractionated dose of 10 Gy (2 Gy for 5 days). The uptake of 201Tl chloride, 99Tcm-sestamibi and 99Tcm-tetrofosmin was observed by incubating in vitro for 60 min. The retention of the tracers was observed at 60 min after changing the incubation medium for a tracer-free medium. Uptake per culture well of all tracers in the cells exposed to 20 Gy declined as viable cell number decreased, but uptake per cell increased progressively. Uptake per cell of all tracers in the cells exposed to either a single dose or a fractionated dose of 10 Gy also increased, while a delay in growth was observed. The retention of these tracers decreased during this period and recovered thereafter. A binding assay with purified human leukocytes indicated that assessment with 99Tcm-sestamibi and 99Tcm-tetrofosmin is influenced by inflammatory cells. In conclusion, the effect of radiation may be underestimated if assessed by tracer uptake alone because of the increase in tracer uptake in viable irradiated cells. Observation of the retention of tracers may provide additional information.
Assuntos
Leucócitos/diagnóstico por imagem , Leucócitos/efeitos da radiação , Compostos Radiofarmacêuticos , Neoplasias da Bexiga Urinária/diagnóstico por imagem , Neoplasias da Bexiga Urinária/radioterapia , Humanos , Técnicas In Vitro , Compostos Organofosforados , Compostos de Organotecnécio , Tecnécio Tc 99m Sestamibi , Tálio , Radioisótopos de Tálio , Tomografia Computadorizada de Emissão de Fóton Único , Células Tumorais CultivadasRESUMO
A 31-year-old woman visited an out-patient clinic, because of low-grade fever and general fatigue. She was referred to our hospital and admitted for examination of an abnormal shadow which had been found on the chest radiograph. She had experienced faint right lateral chest pain several times on the deep inspirations. Chest radiography showed a mass shadow with calcification in the right lower lung field on the mediastinal side. Chest radiographic computed tomography showed a 6x6 cm tumor in the right lung field. There were low-density areas with septae inside the tumor. Bone scintigraphy showed extremely high uptake of (99m)Tc-HMDP in the tumor. After surgical resection and pathological examination, we concluded that the tumor was an extensively calcified benign hemangioma of the diaphragm.
Assuntos
Calcinose/diagnóstico , Diafragma/diagnóstico por imagem , Hemangioma/diagnóstico , Adulto , Calcinose/metabolismo , Feminino , Hemangioma/metabolismo , Humanos , Radiografia , Cintilografia , Medronato de Tecnécio Tc 99m/metabolismoRESUMO
A 67-year-old man presented with malaise and marked anemia. A diagnostic workup revealed severe pancytopenia on a complete blood count and diffuse sclerotic change in the axial skeleton on a plain abdominal radiograph. Bone metastases being suspected from these findings, bone scintigraphy was performed. The bone scan demonstrated uniformly increased skeletal activity with faint soft-tissue activity. The findings of the bone scan, however, appeared atypical of the super scan caused by diffuse bone metastases, without any decrease in radioactivities of the appendicular skeleton and kidneys. Bone marrow scintigraphy with In-111 chloride demonstrated central marrow failure and peripheral expansion, which indicated the possibility of myelophthisis. The patient underwent bone marrow biopsy, which revealed replacement of the bone marrow by metastatic adenocarcinoma. Further examinations detected the primary lesion in the prostate. In this case, the findings of the bone scan were insufficient for the super scan, and might be categorized as a sub-super scan. It would be important to recognize this incomplete form of super scan as a rare scintigraphic pattern of diffuse bone marrow metastases.