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Improving Human Health Through Technical Cooperation
"The IAEA, through its technical cooperation programme, helps countries use nuclear techniques to improve the health of their citizens by facilitating ground-breaking research, providing life-saving equipment and helping states train and retain essential medical staff. The programme supports the needs of health care professionals and technologists, policy makers, regulators, universities and patients. " [+ leia mais]
Colaborador: Laura Natal
Fonte: IAEA
Lançamento do livro Min. Sérgio Rezende
"A Vieira&Lent, a SBPC e o autor convidam para o lançamento do livro: ""MOMENTOS DA CIÊNCIA E TECNOLOGIA NO BRASIL"" de Sérgio Machado Rezende, Ministro da Ciência & Tecnologia"
Colaborador: Cecília Haddad
11th Biennal ESTRO – Conference on Physics and Radiation Technology for Clinical radiotherapy
"organised by ESTRO, the European Society for Therapeutic Radiology & Oncology, from 8 to 12 May 2011 in London, UK. The conference will focus on the major trends and achievements in radiotherapy physics and technology with the major emphasis on education " [+ leia mais]
Colaborador: Cecília Haddad
Evento debaterá plágio e integridade científica
"Estão abertas as inscrições para o First Brazilian Meeting on Research Integrity, Science and Publication Ethics (I Brispe), que acontecerá entre os dias 10 e 16 de dezembro, em instituições do RJ e SP A ideia do evento é reunir pesquisadores brasileiros e estrangeiros de diferentes áreas e estabelecer critérios para avaliação das pesquisas nacionais e os processos de submissão de manuscritos e revisão por pares em periódicos internacionais. O debate envolverá temas como integridade em pesquisa científica, ética e plágio. " [+ leia mais]
Colaborador: Camila de Sales
Fonte: Jornal da Ciência
Simple fractal method of assessment of histological images for application in medical diagnostics
"Nonlinear Biomedical Physics 2010, 4:7doi:10.1186/1753-4631-4-7 We propose new method of assessment of histological images for medical diagnostics. 2-D image is preprocessed to form 1-D landscapes or 1-D signature of the image contour and then their complexity is analyzed using Higuchi|s fractal dimension method. The method may have broad medical application, from choosing implant materials to differentiation between benign masses and malignant breast tumors. " [+ leia mais]
Fonte: Nonlinear Biomedical
Comparison of simple and complex liver intensity modulated radiotherapy
"Radiation Oncology 2010, 5:115doi:10.1186/1748-717X-5-115 Intensity-modulated radiotherapy (IMRT) may allow improvement in plan quality for treatment of liver cancer; however increasing radiation modulation complexity can lead to increased uncertainties and requirements for quality assurance. This study assesses whether target coverage and normal tissue avoidance can be maintained in liver cancer intensity-modulated radiotherapy (IMRT) plans by systematically reducing the complexity of the delivered fluence. " [+ leia mais]
Fonte: Radiation Oncology
Influence of increased target dose inhomogeneity on margins for breathing motion compensation in conformal stereotactic body radiotherapy
"BMC Medical Physics 2008, 8:5doi:10.1186/1756-6649-8-5 Breathing motion should be considered for stereotactic body radiotherapy (SBRT) of lung tumors. Four-dimensional computer tomography (4D-CT) offers detailed information of tumor motion. The aim of this work is to evaluate the influence of inhomogeneous dose distributions in the presence of breathing induced target motion and to calculate margins for motion compensation. " [+ leia mais]
Fonte: BMC Medical Physics
Neutron physics for nuclear reactors, unpublished writings by Enrico Fermi
"Med. Phys. 37, 6500 (2010); doi:10.1118/1.3516223 (2 pages) Neutron physics for nuclear reactors, unpublished writings by Enrico Fermi S. Esposito, Author, O. Pisanti, Author, and Dimitris Mihailidis, Reviewer, Ph.D. " [+ leia mais]
Fonte: Medical Physics
A ABFM está de volta à antiga sede
A diretoria alugou a antiga sede da ABFM, localizada na Rua Brigadeiro Galvão, 262, Campos Eliseos, São Paulo-SP. Em virtude do Congresso Internacional em Porto Alegre de 2011 precisamos receber as inscrições por cartão de crédito e a Cielo, administradora do cartão, faz a vistoria do estabelecimento. Além disso, os Correios exigem comprovante de residência para mantermos a Caixa Postal 72.606. E é importante termos um local para armazenar os documentos da ABFM.
Fonte: Diretoria
O CBFM de 2012 será em Salvador
Em reunião do Conselho Deliberativo do dia 04/12/10 foi escolhido Salvador para ser a cidade sede do Congresso Brasileiro de Física Médica de 2012. Além de Salvador, foram apresentadas propostas de Botucatu e Uberlândia.
Fonte: Diretoria
Proton Therapy
"Proton therapy is a form of radiation treatment that uses beams of protons to deliver more targeted, precise doses than conventional photon beams. More than 50,000 people around the world have been treated with proton therapy. As a result of its success, treatment is emerging from research facilities into regional treatment centers. Varian has a rich history working with the scientific community to advance proton therapy and is a world leader in the manufacturing of medical devices and software for treating cancer. By combining advanced imaging, planning, and state-of-the art proton delivery, we offer clinicians an end-to-end, fully integrated Intensity Modulation Proton Therapy (IMPT) solution at the forefront of cancer therapy options today. Disclaimer The proton therapy device technology described here has not been cleared by the US Food and Drug Administration (""FDA"") for clinical use and is in development. The FDA has a unique set of standards for proton therapy devices because the entire proton therapy facility must be built for the specific device. For these types of devices, the FDA allows proton therapy sponsors to discuss projects with potential customers and to engage in contracts/orders to build proton therapy facilities and /or to purchase proton therapy equipment. However, contracts or other engagements specific to clinical practice are strictly prohibited; that is, no engagements or agreements for patient scheduling or physician group practice to use proton therapy equipment are permitted in advance of FDA clearance. Cyclotron and Energy Selection System The 250 MeV Isochronous Superconducting Cyclotron uses powerful magnetic and electrical fields of alternating polarity to create an accelerated beam of protons. 250 MeV proton therapy energies allow for delivery of dose to deep-seated tumors Continuous and stable proton beam for increased dose delivery rates and precise beam control Excellent reliability due to high beam extraction rate maximizes availability and facilitates preventive maintenance The energy selection system (ESS) adjusts the proton|s beam energy to the amount prescribed in the treatment plan. " [+ leia mais]
Fonte: Varian
Agfa brings TeraRecon’s 3D to IMPAX
"The effects of an agreement signed in the run-up to RSNA 2010 changed the IT approaches of two companies on the exhibit floor, TeraRecon and Agfa HealthCare. One week before the imaging community trekked to Chicago, these two companies cut a deal to make TeraRecon’s thin-client iNtuition an integral part of Agfa’s IMPAX 6 PAC system. Both companies are touting the integrated product at their booths on the RSNA 2010 exhibit floor. Purchasers don’t have to buy TeraRecon’s thin-client system along with IMPAX 6, but with the increasing emphasis on 3D and other advanced visualization techniques, they may feel the need. The value-added reseller agreement with TeraRecon gives IMPAX purchasers a wide range of advanced visualization and decision-support tools for radiology, cardiology, and nuclear medicine applications. Advanced 3D capabilities and automated tools for volume reconstruction and image analysis are a mouse click away as part of a scalable and flexible software license that can be deployed across multiple servers. This license extends to the zero-footprint AquariusWEB viewer, which provides remote access to images, as well as vascular analyses and other quantitative results. And there is an added bonus in that AquariusWEB can connect the user to electronic medical records. The zero-footprint viewer provides an easy way to plug into EMR systems, since it can be launched from a URL referring to the iNtuition server and the patient or study. " [+ leia mais]
Fonte: Agfa
Elekta Axesse e la radioterapia in 6D che distrugge solo le cellule tumorali
"Una radiochirurgia e una radioterapia che siano in grado di colpire solo i tessuti malati salvaguardando quelli sani: da oggi è possibile grazie alla radioterapia in 6D, attiva per la prima volta in Italia grazie all|ausilio di Elekta Axesse, un macchinaro presentato alle Molinette di Torino in questi giorni. Si tratta di un apparecchio che ospita un lettino in 6D (tre direzioni e tre angoli) che permette al corpo del paziente di assumere l|inclinazione migliore, riducendo pertanto il numero di sedute necessarie alle più comuni terapie tradizionali. Per Umberto Ricardi, direttore del reparto di Radioterapia dell|Ospedale Molinette, ""l|adozione di Elekta Axesse rappresenta un passo di fondamentale importanza per l|ospedale e per tutta la Rete Oncologica Piemonte-Valle d|Aosta, che avrà ora a disposizione un|apparecchiatura dedicata esclusivamente a trattamenti stereotassici, favorendo ulteriormente nel nostro centro lo sviluppo della radioterapia di precisione ad alto gradiente di dose"". " [+ leia mais]
Fonte: Nextme
Dia Nacional de Combate ao Câncer de Pele é lembrado no sábado
"O câncer de pele é causado normalmente pelos raios ultravioletas, que penetram na pele e causam o crescimento descontrolado das células. De acordo com o dermatologista do Hospital Nossa Senhora das Graças, Maurício Sato existem alguns tipos mais comuns da doença que podem ser percebidos. “A alteração da tonalidade de pele, o aparecimento de pintas escuras, marrons ou pretas e feridas que não cicatrizam podem ser os primeiros sinais da doença”, alerta o médico. Apesar de entre os tumores o melanoma ser o tipo mais grave, segundo pesquisa realizada pelo Inca (Instituto Nacional de Câncer), o mais incidente neste ano no Brasil deverá ser o câncer de pele não-melanoma – com 120 mil novos casos. Ainda de acordo com a pesquisa, estima-se para 2010 que ocorram 489.270 tipos de casos de câncer de pele. Para o dermatologista a doença se agrava principalmente no verão, isso se deve a falta de conscientização da população acerca dos riscos da exposição excessiva ao sol, que levou a um aumento de casos da doença nos últimos dez anos. “Criou-se uma falsa ideia de que o uso de filtro solar permite mais tempo de exposição ao sol, mas estudos mostram que a aplicação não tem sido feita corretamente, o que torna essa exposição um perigo para a pele”, alerta. Filtro solar A recomendação é que seja sempre usado o filtro solar de, no mínimo, FPS 15. O produto deve ser aplicado cerca de 2mg/cm², ou seja, uma camada necessária para cobrir a região, sem economia. Deve-se lembrar de passar o produto sempre com, pelo menos, 30 minutos antes da exposição solar e ser reaplicado a cada duas horas. “Estudos mostram que a média utilizada pela população é de 0,5mg/cm², o que é insuficiente”, observa Dr. Maurício. Para os fãs do bronzeado, é preciso mudar os conceitos. Bronzeadores não são recomendados, pois contêm fator de proteção solar inferior a 15 e não protegem a pele da radiação. O bronzeamento artificial feito com as câmaras está na lista de fatores que comprovadamente provocam câncer de pele e o uso está proibido pela Agência Nacional de Vigilância Sanitária (Anvisa) em algumas regiões do país. Crianças O cuidado deve ser maior com as crianças. Elas precisam estar bem protegidas e informadas sobre os riscos da exposição solar. Além do filtro bem aplicado, devem, sempre que possível, ficar na sombra e utilizar chapéus e camisetas. “Já foi constatada menor incidência de câncer de pele em pessoas com menos exposição solar na infância”, comenta. Dr. Sato lembra ainda que proteger-se do sol, além de prevenir o câncer de pele, também impede o envelhecimento precoce, mantendo a pele bonita e jovem por mais tempo. " [+ leia mais]
Fonte: Paranashop.com.br
Líder supremo do Irã tem câncer, diz documento do WikiLeaks
"De acordo com documento datado de agosto de 2009, um empresário da Ásia Central, que não é iraniano mas viaja com frequência a Teerã, ""soube por um dos seus contatos que [o ex-presidente iraniano Ali Akbar] Rafsanjani lhe contou que o líder supremo Ali Khamenei tem leucemia em estágio terminal e pode morrer em poucos meses"". O documento, reproduzido pelo jornal francês ""Le Monde"", foi escrito por um diplomata dos EUA a seus superiores. Rafsanjani, ligado ao movimento opositor reformista iraniano, estaria se preparando para tentar suceder Khamenei no cargo mais importante do Irã. De acordo com o jornal francês, os mais de 250 mil documentos revelados pelo WikiLeaks mostram que os EUA possuem uma rede de informantes no Oriente Médio para relatar o que acontece no Irã. EUA e Irã romperam relações diplomáticas há 30 anos, e atualmente o governo norte-americano lidera o movimento internacional de sanções contra o programa nuclear iraniano, que o país garante ser pacífico. " [+ leia mais]
Fonte: Folha
Especialista critica foco no autoexame para prevenir câncer de mama no país
"Secretário-geral da Sociedade Brasileira de Mastologia e pesquisador do Instituto Fernandes Figueira, da Fiocruz, o médico Roberto Vieira critica o foco no autoexame para prevenir mortes por câncer de mama no país. Para ele, é preciso aumentar o investimento no rastreamento por imagem das mamas, capaz de detectar a doença ainda na fase inicial. ""No Brasil, normalmente quem faz o diagnóstico de câncer de mama é a própria mulher. É ela que, apalpando, sente o nódulo e procura o médico. Mas isso não é bom. O bom é quando o país tem um |screening|, um rastreio populacional para a detecção precoce do câncer de mama"", disse ele em entrevista à Folha na semana passada, quando se comemorava a semana nacional de incentivo à saúde mamária. De acordo com Ribeiro, cerca de 60% dos casos de câncer de mama do país são detectados já em estágio avançado, quando o tratamento é mais complexo e o prognóstico, pior. O Inca estima que, em 2010, serão registrados 49,2 mil novos casos da doença no Brasil. Cerca de 10 mil mulheres devem morrer em consequência da doença. ""É importantíssimo que a mulher vá ao médico para que ele possa apalpar a mama e, se for o caso, fazer um exame de imagem. Não adianta jogar isso em cima da paciente, porque às vezes ela não valoriza uma alteração que pode ser um tumor"", afirmou Vieira, lembrando que leva cerca de dez anos para que um nódulo atinja o tamanho de 1 cm. ""Infelizmente, já foi comprovado em grandes trabalho que o autoexame não muda a mortalidade no país."" Ele reconhece, porém, que, na impossibilidade de procurar o médico com regularidade, o autoexame pode cumprir um papel importante. ""Num local em que a pessoa tem que pegar uma canoa e andar cinco horas pelo rio para chegar a um médico, é preciso ter autoexame. A paciente precisa apalpar a mama para conhecê-la."" O especialista disse também que a Sociedade Brasileira de Mastologia continua recomendando a realização periódica de mamografias a partir dos 40 anos de idade, apesar de estudos que questionam a validade da prática. No ano passado, a Força-Tarefa de Serviços Preventivos dos Estados Unidos passou a defender mamografias bianuais apenas para mulheres entre 50 e 74 anos. A avaliação foi de que os danos causados eram maiores do que os benefícios, já que apenas poucos casos eram diagnosticados, enquanto um número elevado de mulheres era submetida à radiação e, em alguns casos, recebia resultados falsos positivos que resultavam em tratamentos desnecessários. ""Aquilo foi uma posição econômica. É claro que fazer screening mamográfico não é barato. Você faz muitas mamografias para às vezes ter um único diagnóstico. Mas, se você comparar com o gasto com quimioterapia, com radioterapia, com cirurgia para metástase cerebral, vai ver que é muito mais barato investir na base, na mamografia"", afirmou. ""Quando o tumor é detectado em estágio inicial, às vezes se cura só com a cirurgia, sem precisar de tanta agressividade terapêutica."" Vieira destacou também a importância de aumentar a conscientização sobre os fatores de risco para a doença, como o sedentarismo, a má alimentação, o tabagismo e o estresse. O risco genético hereditário também é importante: quando há vários casos na mesma família, a recomendação é que os exames sejam iniciados mais cedo. O uso de pílulas anticoncepcionais e a reposição hormonal também costumam ser contraindicados nesses casos, segundo o médico. " [+ leia mais]
Fonte: Folha
Combate ao álcool será prioridade, diz futuro secretário de saúde de SP
"Escolhido pelo governador eleito de São Paulo, Geraldo Alckmin (PSDB), para ocupar a Secretaria de Estado da Saúde, o médico radiologista Giovanni Guido Cerri diz que uma de suas prioridades será o combate ao abuso do álcool. Para traçar as estratégias, ele tem se reunido com especialistas em alcoolismo. Já sabe que o foco será a conscientização nas escolas. Letícia Moreira/Folhapress Giovanni Guido Cerri, escolhido por Geraldo Alckmin para assumir a Secretaria de Estado da Saúde Cerri, 57, é um médico respeitado. Dirige a Faculdade de Medicina da USP, o Icesp (Instituto do Câncer Octavio Frias de Oliveira) e o Centro de Diagnóstico por Imagem do hospital Sírio-Libanês. Não é filiado a partido. É um dos médicos de Dilma Rousseff (PT) -a presidente eleita se tratou de câncer no Sírio e lá faz exames de rotina. |Essa relação deixará SP e o Ministério da Saúde mais próximos|, diz. Folha - Quais serão suas prioridades na secretaria? Giovanni Guido Cerri - A questão da bebida alcoólica será prioritária. O álcool está ligado a doenças, desagregação familiar, acidentes de trânsito e violência urbana. Muitos dirigem alcoolizados, menores de 18 bebem. Há uma permissividade grande. A ideia é aprovar uma lei nos moldes da lei antifumo? Não se trata de criar uma lei seca, mas mostrar o problema à sociedade e liderar a reação. Isso passa pela educação. É por causa da educação que hoje jovens pressionam os pais a parar de fumar e a não desperdiçar água. Nos dois casos, houve uma mudança de pensamento que ainda não ocorreu no álcool. A Saúde trabalhará com a Secretaria da Educação. O sr. pretende fazer alterações na rede de atendimento? Uma necessidade são unidades de câncer regionalizadas. Hoje, um número grande de pacientes se trata em outras cidades, principalmente na capital. Os hospitais ficam sobrecarregados. É preciso criar no interior e litoral unidades de diagnóstico, químio, radioterapia e cirurgias menos complexas. As OSs [organizações sociais privadas] vão continuar dirigindo hospitais estaduais? Não vejo razão para interromper as parcerias. Quando os parceiros são bons, o serviço tem qualidade, o uso da verba pública é fiscalizado e o Estado mantém o controle da política de saúde. Não há inconveniente nas parcerias. O que pensa de um novo imposto federal para a saúde nos moldes da extinta CPMF? Sou contra. Criar tributo é saída fácil e simplista. Com tributo, fica claro que a saúde não é prioridade. Seria prioridade se já estivesse contemplada integralmente nos orçamentos públicos. Todos dizem que a saúde é prioridade, então que redistribuam a verba de outras áreas. Não é fácil, mas é justo. " [+ leia mais]
Fonte: Folha
Prostate Cancer Drug Gets Lukewarm Review
"There is only “moderate’’ evidence that the newly approved prostate cancer drug Provenge helps patients, according to an analysis done for Medicare that was made public on Wednesday. The analysis is part of a controversial review by the Centers for Medicare and Medicaid Services to determine whether to pay for Provenge, which costs $93,000 per patient and extended lives by about four months in clinical trials. Medicare advisers will meet next Wednesday to discuss the drug, which was developed by Dendreon, a Seattle-based biotechnology company. Provenge is the first so-called therapeutic cancer vaccine – meaning it works by training the patient’s immune system to attack the tumor – to win F.D.A. approval. The treatment is made for each patient from his own blood. Sales have been small so far because Dendreon’s manufacturing capacity has been limited. While Medicare generally pays for drugs that are approved by the Food and Drug Administration, its debate over paying for Provenge has raised concerns among some cancer patients, doctors and investors who say the government is sending a warning shot that it will not automatically pay for high-priced medicines. “Not only is C.M.S.’s action contrary to Congress’s intent to ensure beneficiary access to drugs and biologicals used in an anticancer chemotherapeutic regimen, but it threatens to stifle future innovation and cancer research for years to come,’’ Dr. Al B. Benson III, president of the Association of Community Cancer Centers, said in a comment submitted to the Centers for Medicare and Medicaid Services. But others say the health care system cannot afford to continue paying high prices for all therapies, particularly cancer drugs that extend lives by only a few months. With expensive medicines there is already a sort of dual approval system, especially with private insurance companies. First a drug must get F.D.A. approval and then a manufacturer often must go through a lengthy process of persuading insurers to pay for the drug. Medicare is not supposed to consider price when determining whether to cover a drug, however. Some analysts have assumed that Medicare will pay for Provenge when used for the patients specified in the drug’s label – those with advanced prostate cancer that is resistant to hormone-deprivation therapy but who are experiencing no or minimal symptoms. The Medicare review might be more designed to limit off-label use of the expensive drug, such as for patients who already have symptoms. The review for Medicare said there was insufficient evidence to judge whether Provenge would work if used off-label. The F.D.A. declined to approve Provenge in 2007, setting off protests by patients and Dendreon investors. After Dendreon completed another trial, which reaffirmed a survival advantage for the drug, Provenge was approved this April. But the analysis for Medicare said that there were issues in how the trials were designed that made it difficult to assess how effective Provenge really was. One big issue was that the placebo used in the control arm was not really inert. Robyn Karnauskas, a biotechnology analyst at Deutsche Bank, said in a note to clients Wednesday that the assessment of moderate evidence in support of Provenge boded well for reimbursement. “Historically, moderate means that CMS will reimburse the product for its on-label indication,’’ she wrote. Dendreon’s shares rose more than 5 percent in trading after the close of the market. The assessment was done by a technology evaluation group at the Blue Cross and Blue Shield Association under contract to the government’s Agency for Healthcare Research and Quality. " [+ leia mais]
Fonte: NYTimes
Cancer Patients, Lost in a Maze of Uneven Care
"The first doctor gave her six months to live. The second and third said chemotherapy would buy more time, but surgery would not. A fourth offered to operate. Skip to next paragraph Six Killers Cancer This series examines the leading causes of illness and death in the United States: heart disease, cancer, stroke, chronic obstructive pulmonary disease, diabetes and Alzheimer’s. Previous Articles in the Series » Expert Q&A Readers’ Questions About Cancer Dr. Richard Wender, president of the American Cancer Society, is answering readers| questions. Multimedia Graphic Leading Causes of Cancer Deaths Graphic Related Obstacles to Care: Doing Battle With the Insurance Company in a Fight to Stay Alive (July 29, 2007) What You Should Know: Push Hard for the Answers You Require (July 29, 2007) Expert Q&A: Cancer (July 28, 2007) Enlarge This Image Rob Mattson for The New York Times Gordon Hendrickson of Albuquerque won a long legal fight with his insurance company after it refused to cover his live-saving treatment for pancreatic cancer in Houston. Karen Pasqualetto had just given birth to her first child last July when doctors discovered she had colon cancer. She was only 35, and the disease had already spread to her liver. The months she had hoped to spend getting to know her new daughter were hijacked by illness, fear and a desperate quest to survive. For the past year, she and her relatives have felt lost, fending for themselves in a daunting medical landscape in which they struggle to make sense of conflicting advice as they race against time in hopes of saving her life. “It’s patchwork, and frustrating that there’s not one person taking care of me who I can look to as my champion,” Ms. Pasqualetto said recently in a telephone interview from her home near Seattle. “I don’t feel I have a doctor who is looking out for my care. My oncologist is terrific, but he’s an oncologist. The surgeon seems terrific, but I found him through my own diligence. I have no confidence in the system.” It was a sudden immersion in the scalding realities of life with cancer. This year, there will be more than 1.4 million new cases of cancer in the United States, and 559,650 deaths. Only heart disease kills more people. Cancer, more than almost any other disease, can be overwhelmingly complicated to treat. Patients are often stunned to learn that they will need not just one doctor, but at least three: a surgeon and specialists in radiation and chemotherapy. Diagnosis and treatment require a seemingly endless stream of appointments. Doctors do not always agree, and patients may find that at the worst time in their lives, when they are ill, frightened and most vulnerable, they also have to seek second opinions on biopsies and therapy, fight with insurers and sort out complex treatment options. The decisions can be agonizing, in part because the quality of cancer care varies among doctors and hospitals, and it is difficult for even the most educated patients to be sure they are receiving the best treatment. “Let the buyer beware” is harsh advice to give a cancer patient, but it often applies. Excellent care is out there, but people are often on their own to find it. Patients are told they must be their own advocates, but few know where to begin. “Here it is, a country with such a great health system, with so many different breakthroughs in treatment, but even though we know things that work, not everybody who could benefit gets them,” said Dr. Nina A. Bickell, an associate professor of health policy and medicine at the Mount Sinai medical school in Manhattan. Death rates from cancer have been dropping for about 15 years in the United States, but experts say far too many patients receive inferior care. Mistakes in care can be fatal with this disease, and yet some people do not receive enough treatment, while others receive too much or the wrong kind. " [+ leia mais]
Fonte: NYTimes
CT Scans Cut Lung Cancer Deaths, Study Finds
"Annual CT scans of current and former heavy smokers reduced their risk of death from lung cancer by 20 percent, a huge government-financed study has found. Even more surprising, the scans seem to reduce the risks of death from other causes as well, suggesting that the scans could be catching other illnesses. Enlarge This Image Claudia Henschke Suspicious nodules that may indicate lung cancer can be seen in a CT scan of the lung (above), but not in an X-ray (below). Multimedia Back Story With Gardiner Harris Enlarge This Image The findings represent an enormous advance in cancer detection that could potentially save thousands of lives annually, although at considerable expense. Lung cancer will claim about 157,000 lives this year, more than the deaths from colorectal, breast, pancreatic and prostate cancers combined. Most patients discover their disease too late for treatment, and 85 percent die from it. No screening method had proved effective at reducing mortality from the disease. Four randomized controlled trials done during the 1970s showed that chest X-rays, while they helped catch cancers at an earlier stage, had no effect on overall death rates. Since then, researchers have suggested that CT scans — which use coordinated X-rays to provide three-dimensional views — could detect lung tumors at an even earlier stage than X-rays. “This is the first time that we have seen clear evidence of a significant reduction in lung cancer mortality with a screening test in a randomized controlled trial,” said Dr. Christine Berg of the National Cancer Institute. Cancer doctors and others predicted that the study’s results would soon lead to widespread use of CT scans, in particular for older smokers, who have a one in 10 chance of contracting lung cancer. “These people are worried about lung cancer, and now there is an opportunity to offer them something,” said Dr. Mary Reid, an associate professor of oncology at the Roswell Park Cancer Institute in Buffalo. But health officials involved in the study refused to endorse widespread screening of current or former smokers, saying more analysis of the study’s results is needed to further identify who benefited most. Such an analysis is months away. And they pointed out that the study offers no reassurance about the safety of smoking or the advisability of CT scans for younger smokers or nonsmokers. “No one should come away from this thinking that it’s now safe to continue to smoke,” said Dr. Harold E. Varmus, director of the National Cancer Institute. Patients wishing to get a CT lung screen will most likely have to pay the roughly $300 charge themselves, since few insurers pay for such scans unless an illness is suspected. The federal Medicare program will soon reconsider paying for such screens, a Medicare official said. The study, called the National Lung Screening Trial, was conducted by the American College of Radiology Imaging Network and the cancer institute. It involved more than 53,000 people ages 55 to 74 who had smoked at least 30 pack-years — one pack a day for 30 years or two packs a day for 15 years. Ex-smokers who had quit within the previous 15 years were included in the group. Each was given either a standard chest X-ray or a low-dose CT scan at the start of the trial and then twice more over the next two years. Participants were followed for up to five years. There were 354 lung cancer deaths among those who received CT scans and 442 among those who got X-rays. The $250 million study, which began in 2002, was paid for by the cancer institute and carried out at 33 sites. Its preliminary results were announced days after an independent monitoring board determined that the benefits of CT scans were strong enough to stop the trial. The study will be published in the coming months. The study found that for every 300 people who were screened, one person lived who would otherwise have died during the study. But one-quarter of those given CT scans were found to have anomalies, nearly all of which were benign. These false signals generally led to more worry, more CT scans and sometimes to lung biopsies and thoracic surgery. “There are economic, medical and psychological consequences of finding these abnormalities,” Dr. Varmus said. Deaths due to all causes declined by 7 percent among study participants who received CT scans, suggesting the tests helped to detect other life-threatening diseases besides lung cancer. Dr. Claudia Henschke, a clinical professor of radiology at Mount Sinai Medical Center and a longtime advocate for use of CT to screen for lung cancer, said the study was likely to have underestimated the benefits of CT scans because participants were screened only three times. Had the screening continued for 10 years, as many as 80 percent of lung cancer deaths could have been averted, she said. Dr. Henschke’s research has been controversial because of its statistical methods and its financing, which included money from a tobacco company. She earns royalties from makers of CT machines. “What we also have found is that low-dose CT scan gives information on cardiovascular disease, emphysema” and other pulmonary diseases, Dr. Henschke said. “Those are the three big killers of older people. There is just tremendous potential.” But Dr. Edward F. Patz Jr., professor of radiology at Duke who helped devise the study, said he was far from convinced that a thorough analysis would show that widespread CT screening would prove beneficial in preventing most lung cancer deaths. Dr. Patz said that the biology of lung cancer has long suggested that the size of cancerous lung tumors tells little about the stage of the disease. “If we look at this study carefully, we may suggest that there is some benefit in high-risk individuals, but I’m not there yet,” Dr. Patz said. Since 46 million people in the United States smoke and tens of millions more once smoked, a widespread screening program could cost billions annually. Any further refinement of those most at risk could reduce those costs. Low-dose CT scans expose patients to about the same radiation levels as mammograms. Little is known about how the cumulative risks of years of such scans would balance the benefits. The study’s results could have both legal and political consequences. Suits against tobacco companies have sought to force cigarette makers to pay for annual CT screens of former smokers. But with the science uncertain, those claims have so far been rebuffed. Congress has diverted some research money to create pilot CT lung screening programs, diversions that may gain momentum now. Some Obama administration officials argued during the debate on the health care law that patients’ health was often harmed by getting too many tests and procedures that, if reduced, would improve health while reducing costs. This study suggests that, at least in lung cancer, spending more on tests saves lives. Laurie Fenton, president of the Lung Cancer Alliance, which has lobbied for widespread CT lung screening, said the debate about the advisability of such scans is now over. “The challenge now shifts from proving the efficacy of the method to developing the proper quality standards, infrastructure and guidelines to bring this needed benefit to those at high risk for the disease — now,” Ms. Fenton said. But Dr. Peter B. Bach, a pulmonologist at Memorial Sloan-Kettering Cancer Center in New York, said no one should rush out and get a CT scan yet because further analysis will better define whom the screening helped. “Very soon we’ll have an answer about who should be screened and how frequently,” Dr. Bach said, “but we don’t have that answer today.” " [+ leia mais]
Fonte: NYTimes
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