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1.
Nat Commun ; 10(1): 5579, 2019 12 06.
Artigo em Inglês | MEDLINE | ID: mdl-31811120

RESUMO

Although influenza viruses lead to severe illness in high-risk populations, host genetic factors associated with severe disease are largely unknown. As the HLA-A*68:01 allele can be linked to severe pandemic 2009-H1N1 disease, we investigate a potential impairment of HLA-A*68:01-restricted CD8+ T cells to mount robust responses. We elucidate the HLA-A*68:01+CD8+ T cell response directed toward an extended influenza-derived nucleoprotein (NP) peptide and show that only ~35% individuals have immunodominant A68/NP145+CD8+ T cell responses. Dissecting A68/NP145+CD8+ T cells in low vs. medium/high responders reveals that high responding donors have A68/NP145+CD8+ memory T cells with clonally expanded TCRαßs, while low-responders display A68/NP145+CD8+ T cells with predominantly naïve phenotypes and non-expanded TCRαßs. Single-cell index sorting and TCRαß analyses link expansion of A68/NP145+CD8+ T cells to their memory potential. Our study demonstrates the immunodominance potential of influenza-specific CD8+ T cells presented by a risk HLA-A*68:01 molecule and advocates for priming CD8+ T cell compartments in HLA-A*68:01-expressing individuals for establishment of pre-existing protective memory T cell pools.


Assuntos
Linfócitos T CD8-Positivos/imunologia , Antígenos HLA-A/imunologia , Antígenos HLA-A/metabolismo , Vírus da Influenza A/imunologia , Influenza Humana/imunologia , Apresentação de Antígeno , Antígenos Virais/química , Linhagem Celular , Proteção Cruzada , Reações Cruzadas/imunologia , Epitopos de Linfócito T/imunologia , Antígenos HLA-A/química , Antígenos HLA-A/genética , Humanos , Memória Imunológica/imunologia , Vírus da Influenza A Subtipo H1N1/imunologia , Modelos Moleculares , Nucleoproteínas/química , Orthomyxoviridae/genética , Orthomyxoviridae/imunologia , Fragmentos de Peptídeos/química , Fenótipo , Conformação Proteica , Receptores de Antígenos de Linfócitos T alfa-beta/metabolismo , Proteínas do Core Viral/genética
2.
Health Phys ; 112(1): 56-97, 2017 01.
Artigo em Inglês | MEDLINE | ID: mdl-27906788

RESUMO

Individual dose estimates calculated by Dosimetry System 2002 (DS02) for the Life Span Study (LSS) of atomic bomb survivors are based on input data that specify location and shielding at the time of the bombing (ATB). A multi-year effort to improve information on survivors' locations ATB has recently been completed, along with comprehensive improvements in their terrain shielding input data and several improvements to computational algorithms used in combination with DS02 at RERF. Improvements began with a thorough review and prioritization of original questionnaire data on location and shielding that were taken from survivors or their proxies in the period 1949-1963. Related source documents varied in level of detail, from relatively simple lists to carefully-constructed technical drawings of structural and other shielding and surrounding neighborhoods. Systematic errors were reduced in this work by restoring the original precision of map coordinates that had been truncated due to limitations in early data processing equipment and by correcting distortions in the old (WWII-era) maps originally used to specify survivors' positions, among other improvements. Distortion errors were corrected by aligning the old maps and neighborhood drawings to orthophotographic mosaics of the cities that were newly constructed from pre-bombing aerial photographs. Random errors that were reduced included simple transcription errors and mistakes in identifying survivors' locations on the old maps. Terrain shielding input data that had been originally estimated for limited groups of survivors using older methods and data sources were completely re-estimated for all survivors using new digital terrain elevation data. Improvements to algorithms included a fix to an error in the DS02 code for coupling house and terrain shielding, a correction for elevation at the survivor's location in calculating angles to the horizon used for terrain shielding input, an improved method for truncating high dose estimates to 4 Gy to reduce the effect of dose error, and improved methods for calculating averaged shielding transmission factors that are used to calculate doses for survivors without detailed shielding input data. Input data changes are summarized and described here in some detail, along with the resulting changes in dose estimates and a simple description of changes in risk estimates for solid cancer mortality. This and future RERF publications will refer to the new dose estimates described herein as "DS02R1 doses."


Assuntos
Neoplasias Induzidas por Radiação/mortalidade , Armas Nucleares/estatística & dados numéricos , Exposição à Radiação/estatística & dados numéricos , Radiometria/métodos , Análise de Sobrevida , Sobreviventes/estatística & dados numéricos , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Criança , Pré-Escolar , Confiabilidade dos Dados , Feminino , Humanos , Incidência , Lactente , Recém-Nascido , Japão/epidemiologia , Expectativa de Vida , Masculino , Pessoa de Meia-Idade , Doses de Radiação , Reprodutibilidade dos Testes , Medição de Risco/métodos , Sensibilidade e Especificidade , Adulto Jovem
3.
Radiat Res ; 185(6): 604-15, 2016 06.
Artigo em Inglês | MEDLINE | ID: mdl-27223827

RESUMO

Acute radiation-induced symptoms reported in survivors after the atomic bombings in Hiroshima and Nagasaki have been suspected to be associated with rain that fell after the explosions, but this association has not been evaluated in an epidemiological study that considers the effects of the direct dose from the atomic bombs and other factors. The aim of this study was to evaluate this association using information from a fixed cohort, comprised of 93,741 members of the Life Span Study who were in the city at the time of the bombing. Information on acute symptoms and exposure to rain was collected in surveys conducted by interviewers, primarily in the 1950s. The proportion of survivors developing severe epilation was around 60% at levels of direct radiation doses of 3 Gy or higher and less than 0.2% at levels <0.005 Gy regardless of reported rain exposure status. The low prevalence of acute symptoms at low direct doses indicates that the reported fallout rain was not homogeneously radioactive at a level sufficient to cause a substantial probability of acute symptoms. We observed that the proportion of reported acute symptoms was slightly higher among those who reported rain exposure in some subgroups, however, suggestions that rain was the cause of these reported symptoms are not supported by analyses specific to the known areas of radioactive fallout. Misclassification of exposure and outcome, including symptoms due to other causes and recall bias, appears to be a more plausible explanation. However, the insufficient and retrospective nature of the available data limited our ability to quantify the attribution to those possible causes.


Assuntos
Síndrome Aguda da Radiação/epidemiologia , Armas Nucleares , Chuva , Sobreviventes/estatística & dados numéricos , Adolescente , Adulto , Idoso , Criança , Pré-Escolar , Feminino , Humanos , Lactente , Recém-Nascido , Japão/epidemiologia , Masculino , Pessoa de Meia-Idade , Neoplasias Induzidas por Radiação/etiologia , Exposição à Radiação , Inquéritos e Questionários , Adulto Jovem
4.
Ann ICRP ; 45(1 Suppl): 253-61, 2016 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-26956675

RESUMO

Risks of non-cancer outcomes after exposure to atomic bomb (A-bomb) radiation have been evaluated among the Life Span Study (LSS) cohort and its subcohort, the Adult Health Study (AHS). Information regarding non-cancer outcomes in the LSS is obtained from death certificates. In the AHS, members undergo clinical examinations biennially to determine their health status. Many AHS studies have been limited to participants attending the clinic over a limited period, and therefore have varying degrees of inferential utility; as such, care is required for comparison with the LSS results. Disease structure of non-cancer diseases in Japan has changed over the long follow-up period since the end of World War II. The health status of the A-bomb survivors may be associated with the hardships of living in a devastated city and impoverished country following the prolonged war effort, in addition to the direct effects of radiation exposure. Radiation-related risk of cardiovascular disease may have increased due to radiation-related increased risk of hypertension and other secondary associations, and the risk of atherosclerotic disorders has also been reported recently. These results should be interpreted with caution because of changes in disease definitions over the follow-up period. The radiation-related risk of non-cancer respiratory diseases also appears to have increased over the follow-up period, but the shapes of the dose-response curves have shown little consistency.


Assuntos
Doenças Cardiovasculares/epidemiologia , Armas Nucleares , Doses de Radiação , Exposição à Radiação , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Doenças Cardiovasculares/etiologia , Causas de Morte , Criança , Pré-Escolar , Estudos de Coortes , Feminino , Humanos , Lactente , Recém-Nascido , Japão/epidemiologia , Masculino , Pessoa de Meia-Idade , Sobreviventes/estatística & dados numéricos , Adulto Jovem
5.
Health Phys ; 108(5): 551-6, 2015 May.
Artigo em Inglês | MEDLINE | ID: mdl-25811153

RESUMO

The RERF International Low-Dose Symposium was held on 5-6 December 2013 at the RERF campus in Hiroshima, Japan, to discuss the issues facing the Life Span Study (LSS) and other low-dose studies. Topics included the current status of low-dose risk detection, strategies for low-dose epidemiological and statistical research, methods to improve communication between epidemiologists and biologists, and the current status of radiological studies and tools. Key points made by the participants included the necessity of pooling materials over multiple studies to gain greater insight where data from single studies are insufficient; generating models that reflect epidemiological, statistical, and biological principles simultaneously; understanding confounders and effect modifiers in the current data; and taking into consideration less studied factors such as the impact of dose rate. It is the hope of all participants that this symposium be used as a trigger for further studies, especially those using pooled data, in order to reach a greater understanding of the health effects of low-dose radiation.


Assuntos
Guerra Nuclear , Sobreviventes , Relação Dose-Resposta à Radiação , Humanos , Japão
6.
Steroids ; 99(Pt A): 49-55, 2015 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-25304359

RESUMO

Epidemiological studies have examined breast cancer risk in relation to sex hormone concentrations measured by different methods: "extraction" immunoassays (with prior purification by organic solvent extraction, with or without column chromatography), "direct" immunoassays (no prior extraction or column chromatography), and more recently with mass spectrometry-based assays. We describe the associations of estradiol, estrone and testosterone with both body mass index and breast cancer risk in postmenopausal women according to assay method, using data from a collaborative pooled analysis of 18 prospective studies. In general, hormone concentrations were highest in studies that used direct assays and lowest in studies that used mass spectrometry-based assays. Estradiol and estrone were strongly positively associated with body mass index, regardless of the assay method; testosterone was positively associated with body mass index for direct assays, but less clearly for extraction assays, and there were few data for mass spectrometry assays. The correlations of estradiol with body mass index, estrone and testosterone were lower for direct assays than for extraction and mass spectrometry assays, suggesting that the estimates from the direct assays were less precise. For breast cancer risk, all three hormones were strongly positively associated with risk regardless of assay method (except for testosterone by mass spectrometry where there were few data), with no statistically significant differences in the trends, but differences may emerge as new data accumulate. Future epidemiological and clinical research studies should continue to use the most accurate assays that are feasible within the design characteristics of each study.


Assuntos
Índice de Massa Corporal , Neoplasias da Mama/etiologia , Estradiol/sangue , Estrona/sangue , Pós-Menopausa/sangue , Testosterona/sangue , Feminino , Humanos , Estudos Prospectivos , Fatores de Risco
7.
Am J Epidemiol ; 177(6): 569-73, 2013 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-23429724

RESUMO

The Life Span Study is a long-term epidemiologic cohort study of survivors of the atomic bombs dropped on Hiroshima and Nagasaki, Japan. In this issue of the Journal, Richardson et al. (Am J Epidemiol. 2013;177(6):562-568) suggest that those who died in the earliest years of follow-up were more likely to have a missing dose of radiation exposure assigned, leading to a bias in the radiation risk estimates. We show that nearly all members of the cohort had shielding information recorded before the beginning of follow-up and that much of the alleged bias that Richardson et al. describe simply reflects the geographic distribution of shielding conditions for which reliable dosimetry was impossible.


Assuntos
Neoplasias Induzidas por Radiação/mortalidade , Armas Nucleares , Doses de Radiação , Sobreviventes , Feminino , Humanos , Masculino
8.
BMJ ; 345: e7093, 2012 Oct 25.
Artigo em Inglês | MEDLINE | ID: mdl-23100333

RESUMO

OBJECTIVE: To investigate the impact of smoking on overall mortality and life expectancy in a large Japanese population, including some who smoked throughout adult life. DESIGN: The Life Span Study, a population-based prospective study, initiated in 1950. SETTING: Hiroshima and Nagasaki, Japan. PARTICIPANTS: Smoking status for 27,311 men and 40,662 women was obtained during 1963-92. Mortality from one year after first ascertainment of smoking status until 1 January 2008 has been analysed. MAIN OUTCOME MEASURES: Mortality from all causes in current, former, and never smokers. RESULTS: Smokers born in later decades tended to smoke more cigarettes per day than those born earlier, and to have started smoking at a younger age. Among those born during 1920-45 (median 1933) and who started smoking before age 20 years, men smoked on average 23 cigarettes/day, while women smoked 17 cigarettes/day, and, for those who continued smoking, overall mortality was more than doubled in both sexes (rate ratios versus never smokers: men 2.21 (95% confidence interval 1.97 to 2.48), women 2.61 (1.98 to 3.44)) and life expectancy was reduced by almost a decade (8 years for men, 10 years for women). Those who stopped smoking before age 35 avoided almost all of the excess risk among continuing smokers, while those who stopped smoking before age 45 avoided most of it. CONCLUSIONS: The lower smoking related hazards reported previously in Japan may have been due to earlier birth cohorts starting to smoke when older and smoking fewer cigarettes per day. In Japan, as elsewhere, those who start smoking in early adult life and continue smoking lose on average about a decade of life. Much of the risk can, however, be avoided by giving up smoking before age 35, and preferably well before age 35.


Assuntos
Expectativa de Vida/tendências , Fumar/mortalidade , Adulto , Idoso , Causas de Morte/tendências , Feminino , Humanos , Japão/epidemiologia , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , Fatores de Risco , Fatores Sexuais , Abandono do Hábito de Fumar/estatística & dados numéricos , Taxa de Sobrevida , Adulto Jovem
9.
Radiat Res ; 178(1): 86-98, 2012 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-22631857

RESUMO

Among the Life Span Study (LSS) of Atomic-bomb survivors, recent estimates showed that unspecified bladder cancer had high radiation sensitivity with a notably high female-to-male excess relative risk (ERR) per radiation dose ratio and were the only sites for which the ERR did not decrease with attained age. These findings, however, did not consider lifestyle factors, which could potentially confound or modify the risk estimates. This study estimated the radiation risks of the most prevalent subtype of urinary tract cancer, urothelial carcinoma, while accounting for smoking, consumption of fruit, vegetables, alcohol and level of education (a surrogate for socioeconomic status). Eligible study subjects included 105,402 (males = 42,890) LSS members who were cancer-free in 1958 and had estimated radiation doses. Members were censored due to loss of follow-up, incident cancer of another type, death, or the end of calendar year 2001. Surveys (by mail or clinical interview) gathered lifestyle data periodically for 1963-1991. There were 63,827 participants in one or more survey. Five hundred seventy-three incident urothelial carcinoma cases occurred, of which 364 occurred after lifestyle information was available. Analyses were performed using Poisson regression methods. The excess relative risk per weighted gray unit (the gamma component plus 10 times the neutron component, Gy(w)) was 1.00 (95% CI: 0.43-1.78) but the risks were not dependent upon age at exposure or attained age. Lifestyle factors other than smoking were not associated with urothelial carcinoma risk. Neither the magnitude of the radiation ERR estimate (1.00 compared to 0.96), nor the female-to-male (F:M) ERR/Gy(w) ratio (3.2 compared to 3.4) were greatly changed after accounting for all lifestyle factors. A multiplicative model of gender-specific radiation and smoking effects was the most revealing though there was no evidence of significant departures from either the additive or multiplicative joint effect models. Among the LSS cohort members with doses greater than 0.005 Gy(w) (average dose 0.21 Gy(w)), the attributable fraction of urothelial carcinoma due to radiation was 7.1% in males and 19.7% in females. Among current smokers, the attributable fraction of urothelial carcinoma due to smoking was 61% in males and 52% in females. Relative risk estimates of smoking risk were approximately two for smokers compared to nonsmokers. After adjustment for lifestyle factors, gender-specific radiation risks and the F:M ERR/Gy(w), the ratios of excess urothelial carcinoma risk were similar to the estimates without adjusting for lifestyle factors. Smoking was the primary factor responsible for excess urothelial carcinoma in this cohort. These findings led us to conclude that the radiation risk estimates of urothelial carcinoma do not appear to be strongly confounded or modified by smoking, consumption of alcohol, fruits, or vegetables, or level of education.


Assuntos
Estilo de Vida , Neoplasias Induzidas por Radiação/etiologia , Guerra Nuclear , Sobreviventes , Neoplasias da Bexiga Urinária/etiologia , Adulto , Estudos de Coortes , Feminino , Humanos , Japão , Masculino , Risco , Fumar/efeitos adversos
10.
Ann Oncol ; 23(7): 1894-8, 2012 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-22147734

RESUMO

BACKGROUND: The evidence for a role of tobacco smoking, alcohol drinking, and body mass index (BMI) in the etiology of small intestine cancer is based mainly on case-control studies from Europe and United States. SUBJECTS AND METHODS: We harmonized the data across 12 cohort studies from mainland China, Japan, Korea, Singapore, and Taiwan, comprising over 500,000 subjects followed for an average of 10.6 years. We calculated hazard ratios (HRs) for BMI and (only among men) tobacco smoking and alcohol drinking. RESULTS: A total of 134 incident cases were observed (49 adenocarcinoma, 11 carcinoid, 46 other histologic types, and 28 of unknown histology). There was a statistically non-significant trend toward increased HR in subjects with high BMI [HR for BMI>27.5 kg/m2, compared with 22.6-25.0, 1.50; 95% confidence interval (CI) 0.76-2.96]. No association was suggested for tobacco smoking; men drinking>400 g of ethanol per week had an HR of 1.57 (95% CI 0.66-3.70), compared with abstainers. CONCLUSIONS: Our study supports the hypothesis that elevated BMI may be a risk factor for small intestine cancer. An etiologic role of alcohol drinking was suggested. Our results reinforce the existing evidence that the epidemiology of small intestine cancer resembles that of colorectal cancer.


Assuntos
Adenocarcinoma/etiologia , Consumo de Bebidas Alcoólicas/efeitos adversos , Índice de Massa Corporal , Neoplasias Intestinais/etiologia , Fumar/efeitos adversos , Adenocarcinoma/epidemiologia , Idoso , Ásia/epidemiologia , Estudos de Coortes , Feminino , Humanos , Neoplasias Intestinais/epidemiologia , Masculino , Pessoa de Meia-Idade , Modelos de Riscos Proporcionais
11.
Clin Cancer Res ; 3(9): 1547-55, 1997 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-9815842

RESUMO

Preclinical studies have demonstrated that recombinant IFN-alpha (rIFN-alpha) can enhance the tumor associated glycoprotein 72 (TAG-72) on tumors. To determine whether rIFN-alpha could enhance TAG-72 expression in vivo in patients, 15 women with breast cancer were randomized to receive daily injections of rIFN-alpha (3 x 10(6) units/m2 for 14 days) beginning on day 1 (group 1 = 7 patients) or on day 6 (group 2 = 8 patients). On day 3, all patients received a 10-20-mCi tracer dose of 131I-CC49, a high-affinity murine monoclonal antibody reactive against TAG-72, followed by a therapy dose of 60-75 mCi/m2 of 131I-CC49 on day 6. Whole body and single-photon emission computed tomography scans along with whole blood pharmacokinetics were performed following tracer and treatment phases. Hematological toxicity was considerable; reversible grade 3-4 neutropenia and thrombocytopenia was observed in 12 of 15 patients. Twelve of 14 patients tested developed human antimouse antibodies 3-6 weeks after treatment. For group 1 patients, whole blood residence time increased significantly between that predicted from the tracer doses and therapy doses (42.6 +/- 4.7 versus 51.5 +/- 4.8 h, respectively; P < 0.01). The calculated radiation absorbed dose to red marrow from therapy compared to tracer activity was also significantly higher for this group (1.25 +/- 0.35 versus 1. 07 +/- 0.26 cGy/mCi; P < 0.05). Treatment with rIFN-alpha was found to enhance TAG-72 expression in tumors from patients receiving rIFN-alpha (group 1) by 46 +/- 19% (P < 0.05) compared to only 1.3 +/- 0.95% in patients not initially receiving IFN (group 2). The uptake of CC49 in tumors was also significantly increased in rIFN-alpha-treated patients. One partial and two minor tumor responses were seen. In summary, rIFN-alpha treatment altered the pharmacokinetics and tumor uptake of 131I-CC49 in patients at the expense of increased toxicity.


Assuntos
Anticorpos Monoclonais/farmacocinética , Antígenos de Neoplasias/imunologia , Antineoplásicos/farmacologia , Neoplasias da Mama/metabolismo , Glicoproteínas/imunologia , Imunoconjugados/farmacocinética , Interferon-alfa/farmacologia , Radioisótopos do Iodo/farmacocinética , Radioimunoterapia , Adulto , Animais , Anticorpos Anti-Idiotípicos/biossíntese , Anticorpos Monoclonais/efeitos adversos , Anticorpos Monoclonais/uso terapêutico , Especificidade de Anticorpos , Antígenos de Neoplasias/biossíntese , Antígenos de Neoplasias/genética , Antineoplásicos/administração & dosagem , Antineoplásicos/uso terapêutico , Medula Óssea/efeitos da radiação , Neoplasias da Mama/diagnóstico por imagem , Neoplasias da Mama/imunologia , Neoplasias da Mama/radioterapia , Terapia Combinada , Esquema de Medicação , Feminino , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Glicoproteínas/biossíntese , Glicoproteínas/genética , Humanos , Imunoconjugados/efeitos adversos , Imunoconjugados/uso terapêutico , Interferon alfa-2 , Interferon-alfa/administração & dosagem , Interferon-alfa/uso terapêutico , Radioisótopos do Iodo/efeitos adversos , Radioisótopos do Iodo/uso terapêutico , Metástase Linfática/radioterapia , Camundongos , Pessoa de Meia-Idade , Metástase Neoplásica , Neutropenia/induzido quimicamente , Proteínas Recombinantes , Trombocitopenia/induzido quimicamente , Distribuição Tecidual , Tomografia Computadorizada de Emissão de Fóton Único , Resultado do Tratamento
12.
Cancer Res ; 55(23 Suppl): 5925s-5928s, 1995 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-7493372

RESUMO

The IFNs, alpha and gamma, have been shown to enhance the tumor-associated glycoprotein (TAG-72) on adenocarcinoma cells in vitro and in mice with human breast cancer xenografts, resulting in improved targeting of monoclonal antibody CC49. To determine the effect of IFN-alpha on biodistribution and tumor uptake of 131I-labeled CC49, patients with metastatic breast cancer were randomized to either receive or not receive IFN-alpha (3 million units daily for 14 days) by s.c. injection. Three days after beginning IFN-alpha, all patients received 10-20 mCi of 131I-CC49 (specific activity, 16.7 mCi/mg) i.v. Total-body Anger camera scans, along with total-body blood and plasma pharmacokinetics, were performed. Tumor biopsies were taken in all patients before and 48 h after IFN-alpha treatment. There were no significant differences in number of metastases imaged or whole-body, blood and plasma pharmacokinetics between IFN-alpha-treated and untreated patients. Quantitative immunohistochemistry on biopsy specimens from IFN-alpha-treated patients demonstrated a significant increase in mean +/- SEM TAG-72 expression (45.7 +/- 19.4%) compared to patients that were not given IFN-alpha (1.3 +/- 0.95%; P < 0.05). Although slight increases in the percent injected dose of 131I-CC49 in tumor occurred after IFN-alpha-treatment, the changes were not significant at the P < 0.05 level. These data suggest that IFN-alpha may be useful in enhancing TAG-72 antigen expression in vivo in humans, despite modest improvement in tumor uptake of CC49, possibly because of limited tumor access or other unknown factors.


Assuntos
Adenocarcinoma/tratamento farmacológico , Anticorpos Monoclonais/farmacocinética , Antígenos de Neoplasias/biossíntese , Neoplasias da Mama/tratamento farmacológico , Interferon-alfa/farmacologia , Radioisótopos do Iodo/uso terapêutico , Adenocarcinoma/diagnóstico por imagem , Adenocarcinoma/imunologia , Anticorpos Monoclonais/uso terapêutico , Antígenos de Neoplasias/imunologia , Neoplasias da Mama/diagnóstico por imagem , Neoplasias da Mama/imunologia , Feminino , Humanos , Metástase Neoplásica , Radioimunodetecção
13.
Med Phys ; 22(10): 1637-43, 1995 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-8551988

RESUMO

The majority of radiation absorbed dose estimates for radioimmunotherapy (RIT) with I-131 labeled antibodies have been calculated based on in vivo quantitation of activity using the conjugate view approach with planar Anger camera images. Scatter and septal penetration events contributed by a small fraction of high-energy photons emitted by I-131 with an energy exceeding 600 KeV lead to a significant degradation of I-131 images acquired with an Anger camera, which blurs the images of uptake sites and complicates the definition of background regions. The objective of this study was to evaluate a triple energy window (TEW) subtraction method that has been used to remove these interfering events from I-131 images. In the method, a primary photopeak image for I-131 is obtained after sequential subtraction of septal penetration and scatter events by using scatter multipliers derived from a photopeak window and two adjacent scatter window images. Qualitative improvement in image contrast was demonstrated with this technique, together with more accurate and reproducible quantitation for I-131 in the organs of an abdominal phantom. This TEW scatter subtraction method can be used to provide more precise dosimetry estimates for radionuclide therapy and RIT with I-131.


Assuntos
Radioisótopos do Iodo/uso terapêutico , Imagens de Fantasmas , Radioimunoterapia/métodos , Abdome , Humanos , Matemática , Modelos Teóricos , Radioimunoterapia/instrumentação , Cintilografia/instrumentação , Cintilografia/métodos , Dosagem Radioterapêutica , Espalhamento de Radiação
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