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1.
AJNR Am J Neuroradiol ; 42(1): 82-87, 2021 01.
Artigo em Inglês | MEDLINE | ID: mdl-33214183

RESUMO

BACKGROUND AND PURPOSE: T2 signal and FLAIR changes in patients undergoing stereotactic radiosurgery for brain AVMs may occur posttreatment and could result in adverse radiation effects. We aimed to evaluate outcomes in patients with these imaging changes, the frequency and degree of this response, and factors associated with it. MATERIALS AND METHODS: Through this retrospective cohort study, consecutive patients treated with stereotactic radiosurgery for brain AVMs who had at least 1 year of follow-up MR imaging were identified. Logistic regression analysis was used to evaluate predictors of outcomes. RESULTS: One-hundred-sixty AVMs were treated in 148 patients (mean, 35.6 years of age), including 42 (26.2%) pediatric AVMs. The mean MR imaging follow-up was 56.5 months. The median Spetzler-Martin grade was III. The mean maximal AVM diameter was 2.8 cm, and the mean AVM target volume was 7.4 mL. The median radiation dose was 16.5 Gy. New T2 signal and FLAIR hyperintensity were noted in 40% of AVMs. T2 FLAIR volumes at 3, 6, 12, 18, and 24 months were, respectively, 4.04, 55.47, 56.42, 48.06, and 29.38 mL Radiation-induced neurologic symptoms were encountered in 34.4%. In patients with radiation-induced imaging changes, 69.2% had new neurologic symptoms versus 9.5% of patients with no imaging changes (P = .0001). Imaging changes were significantly associated with new neurologic findings (P < .001). Larger AVM maximal diameter (P = .04) and the presence of multiple feeding arteries (P = .01) were associated with radiation-induced imaging changes. CONCLUSIONS: Radiation-induced imaging changes are common following linear particle accelerator-based stereotactic radiosurgery for brain AVMs, appear to peak at 12 months, and are significantly associated with new neurologic findings.


Assuntos
Edema Encefálico/etiologia , Malformações Arteriovenosas Intracranianas/radioterapia , Lesões por Radiação/diagnóstico por imagem , Lesões por Radiação/patologia , Radiocirurgia/efeitos adversos , Adolescente , Adulto , Idoso , Edema Encefálico/diagnóstico por imagem , Criança , Pré-Escolar , Estudos de Coortes , Feminino , Humanos , Imageamento por Ressonância Magnética , Masculino , Pessoa de Meia-Idade , Radiocirurgia/métodos , Estudos Retrospectivos , Resultado do Tratamento
4.
Int J Radiat Oncol Biol Phys ; 55(4): 921-9, 2003 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-12605970

RESUMO

PURPOSE: To examine the ability of standard dose-volume metrics to predict pulmonary function changes as measured by pulmonary function tests (PFTs) in a group of patients with non-small-cell lung cancer treated with nonconventional beam arrangements on a Phase I dose-escalation study. In addition, we wanted to examine the correlation between these metrics. MATERIALS AND METHODS: Forty-three patients received a median treatment dose of 76.9 Gy (range 63-102.9). Eight patients also received induction chemotherapy with cisplatin and vinorelbine. They all had pre- and posttreatment PFTs >/=3 months (median 6.2) after treatment. The volume of normal lung treated to >20 Gy, effective volume, and mean lung dose were calculated for both lungs for all patients. Linear regression analysis was performed to determine whether correlations existed between the metrics and changes in the PFTs. Additionally, the three metrics were compared with each other to assess the degree of intermetric correlation. RESULTS: No correlation was found between the volume of normal lung treated to >20 Gy, effective volume, and mean lung dose and changes in the PFTs. Subgroup analyses of patients without atelectasis before irradiation, Stage I and II disease, or treatment without induction chemotherapy were also performed. Again, no correlation was found between the dose-volume metrics and the PFT changes. The intermetric correlation was good among all three dose-volume metrics. CONCLUSIONS: In this relatively small series of patients, dose-volume metrics that correlate with the risk of pneumonitis did not provide a good model to predict early changes in pulmonary function as measured with PFTs.


Assuntos
Carcinoma Pulmonar de Células não Pequenas/radioterapia , Neoplasias Pulmonares/radioterapia , Pulmão/efeitos da radiação , Idoso , Carcinoma Pulmonar de Células não Pequenas/patologia , Carcinoma Pulmonar de Células não Pequenas/fisiopatologia , Fracionamento da Dose de Radiação , Relação Dose-Resposta à Radiação , Feminino , Humanos , Pulmão/fisiopatologia , Neoplasias Pulmonares/patologia , Neoplasias Pulmonares/fisiopatologia , Masculino , Pessoa de Meia-Idade , Estadiamento de Neoplasias , Pneumonite por Radiação/fisiopatologia , Radiometria , Radioterapia Conformacional , Análise de Regressão , Testes de Função Respiratória
5.
J Clin Oncol ; 19(13): 3219-25, 2001 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-11432889

RESUMO

PURPOSE: As the United States population ages, the increasing prevalence of cancer is likely to result in higher direct medical and nonmedical costs. Although estimates of the associated direct medical costs exist, very little information is available regarding the prevalence, time, and cost associated with informal caregiving for elderly cancer patients. MATERIALS AND METHODS: To estimate these costs, we used data from the first wave (1993) of the Asset and Health Dynamics (AHEAD) Study, a nationally representative longitudinal survey of people aged 70 or older. Using a multivariable, two-part regression model to control for differences in health and functional status, social support, and sociodemographics, we estimated the probability of receiving informal care, the average weekly number of caregiving hours, and the average annual caregiving cost per case (assuming an average hourly wage of $8.17) for subjects who reported no history of cancer (NC), having a diagnosis of cancer but not receiving treatment for their cancer in the last year (CNT), and having a diagnosis of cancer and receiving treatment in the last year (CT). RESULTS: Of the 7,443 subjects surveyed, 6,422 (86%) reported NC, 718 (10%) reported CNT, and 303 (4%) reported CT. Whereas the adjusted probability of informal caregiving for those respondents reporting NC and CNT was 26%, it was 34% for those reporting CT (P <.05). Those subjects reporting CT received an average of 10.0 hours of informal caregiving per week, as compared with 6.9 and 6.8 hours for those who reported NC and CNT, respectively (P <.05). Accordingly, cancer treatment was associated with an incremental increase of 3.1 hours per week, which translates into an additional average yearly cost of $1,200 per patient and just over $1 billion nationally. CONCLUSION: Informal caregiving costs are substantial and should be considered when estimating the cost of cancer treatment in the elderly.


Assuntos
Cuidadores/economia , Efeitos Psicossociais da Doença , Assistência Domiciliar/economia , Neoplasias/economia , Neoplasias/terapia , Atividades Cotidianas , Idoso , Idoso de 80 Anos ou mais , Cuidadores/estatística & dados numéricos , Família/psicologia , Feminino , Assistência Domiciliar/estatística & dados numéricos , Humanos , Masculino , Análise Multivariada , Neoplasias/complicações , Análise de Regressão , Estados Unidos
6.
Rev Sci Tech ; 20(1): 252-64, 2001 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-11288515

RESUMO

Mycobacterium ulcerans infection, or Buruli ulcer, is the third most frequent mycobacterial disease in humans, often causing serious deformities and disability. The disease is most closely associated with tropical wetlands, especially in west and central Africa. Most investigators believe that the aetiological agent proliferates in mud beneath stagnant waters. Modes of transmission may involve direct contact with the contaminated environment, aerosols from water surfaces, and water-dwelling fauna (e.g. insects). Person-to-person transmission is rare. Trauma at the site of skin contamination by M. ulcerans appears to play an important role in initiating disease. Once introduced into the skin or subcutaneous tissue, M. ulcerans multiplies and produces a toxin that causes necrosis. However, the type of disease induced varies from a localised nodule or ulcer, to widespread ulcerative or non-ulcerative disease and osteomyelitis. Although culture of M. ulcerans from a patient was first reported in 1948, attempts to culture the mycobacterium from many specimens of flora and fauna have been unsuccessful. Failure to cultivate this organism from nature may be attributable to inadequate sampling, conditions of transport, decontamination and culture of this fastidious heat-sensitive organism, and to a long generation time relative to that of other environmental mycobacteria. Nevertheless, recent molecular studies using specific primers have revealed M. ulcerans in water, mud, fish and insects. Although no natural reservoir has been found, the possibility that M. ulcerans may colonise microfauna such as free-living amoebae has not been investigated. The host range of experimental infection by M. ulcerans includes lizards, amphibians, chick embryos, possums, armadillos, rats, mice and cattle. Natural infections have been observed only in Australia, in koalas, ringtail possums and a captive alpaca. The lesions were clinically identical to those observed in humans. Mycobacterium ulcerans infection is a rapidly re-emerging disease in some developing tropical countries. The re-emergence may be related to environmental and socioeconomic factors, for example, deforestation leading to increased flooding, and population expansion without improved agricultural techniques, thus putting more people at risk. Eradication of diseases related to these factors is difficult. Whether wild animals have a role in transmission is an important question that, to date, has been virtually unexplored. To address this question, surveys of wild animals are urgently required in those areas in which Buruli ulcer is endemic.


Assuntos
Animais Selvagens , Infecções por Mycobacterium não Tuberculosas/veterinária , Mycobacterium ulcerans/isolamento & purificação , África/epidemiologia , Animais , Reservatórios de Doenças , Humanos , Invertebrados/microbiologia , Infecções por Mycobacterium não Tuberculosas/epidemiologia , Infecções por Mycobacterium não Tuberculosas/transmissão , Microbiologia da Água
7.
Infect Immun ; 69(3): 1704-7, 2001 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-11179346

RESUMO

Mycobacterium ulcerans is a slow-growing, acid-fast bacillus that causes chronic necrotizing skin ulcers known as Buruli ulcers. Previously reported information on immunity to this mycobacterium is limited. We examined immune responses to M. ulcerans and M. bovis BCG in patients with M. ulcerans disease and in 20 healthy control subjects (10 tuberculin test positive and 10 tuberculin test negative). Cell-mediated immunity was assessed by stimulating peripheral blood mononuclear cells (PBMC) with whole mycobacteria and then measuring PBMC proliferation and the production of gamma interferon (IFN-gamma). Humoral immunity was assessed by immunoblotting. PBMC from all subjects showed significantly greater proliferation and IFN-gamma production in response to stimulation with living mycobacteria compared with killed cells. However, PBMC from subjects with past or current M. ulcerans disease showed significantly reduced proliferation and production of IFN-gamma in response to stimulation with live M. ulcerans or M. bovis than PBMC from healthy, tuberculin test-positive subjects (P < 0.001) and showed results in these assays comparable to those of tuberculin test-negative subjects (P > 0.2). Serum from 9 of 11 patients with M. ulcerans disease, but no control subject, contained antibodies to M. ulcerans. The results indicate that patients with M. ulcerans infection mount an immune response to M. ulcerans as evidenced by antibody production, but they demonstrate profound systemic T-cell anergy to mycobacterial antigens. These findings may explain some of the distinct clinical and pathological features of M. ulcerans-induced disease.


Assuntos
Infecções por Mycobacterium não Tuberculosas/imunologia , Mycobacterium ulcerans/imunologia , Dermatopatias Bacterianas/imunologia , Úlcera Cutânea/imunologia , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Anticorpos Antibacterianos/sangue , Criança , Anergia Clonal , Humanos , Interferon gama/metabolismo , Ativação Linfocitária , Pessoa de Meia-Idade , Infecções por Mycobacterium não Tuberculosas/etiologia , Mycobacterium bovis/imunologia , Necrose , Dermatopatias Bacterianas/etiologia , Úlcera Cutânea/etiologia
8.
J Clin Oncol ; 19(1): 127-36, 2001 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-11134205

RESUMO

PURPOSE: High-dose radiation may improve outcomes in non-small-cell lung cancer (NSCLC). By using three-dimensional conformal radiation therapy and limiting the target volume, we hypothesized that the dose could be safely escalated. MATERIALS AND METHODS: A standard phase I design was used. Five bins were created based on the volume of normal lung irradiated, and dose levels within bins were chosen based on the estimated risk of radiation pneumonitis. Starting doses ranged from 63 to 84 Gy given in 2.1-Gy fractions. Target volumes included the primary tumor and any nodes >or= 1 cm on computed tomography. Clinically uninvolved nodal regions were not included purposely. More recently, selected patients received neoadjuvant cisplatin and vinorelbine. RESULTS: At the time of this writing, 104 patients had been enrolled. Twenty-four had stage I, four had stage II, 43 had stage IIIA, 26 had stage IIIB, and seven had locally recurrent disease. Twenty-five received chemotherapy, and 63 were assessable for escalation. All bins were escalated at least twice. Although grade 2 radiation pneumonitis occurred in five patients, grade 3 radiation pneumonitis occurred in only two. The maximum-tolerated dose was only established for the largest bin, at 65.1 Gy. Dose levels for the four remaining bins were 102.9, 102.9, 84 and 75.6 Gy. The majority of patients failed distantly, though a significant proportion also failed in the target volume. There were no isolated failures in clinically uninvolved nodal regions. CONCLUSION: Dose escalation in NSCLC has been accomplished safely in most patients using three-dimensional conformal radiation therapy, limiting target volumes, and segregating patients by the volume of normal lung irradiated.


Assuntos
Carcinoma Pulmonar de Células não Pequenas/radioterapia , Fracionamento da Dose de Radiação , Neoplasias Pulmonares/radioterapia , Radioterapia Conformacional , Adulto , Idoso , Idoso de 80 Anos ou mais , Carcinoma Pulmonar de Células não Pequenas/mortalidade , Carcinoma Pulmonar de Células não Pequenas/patologia , Intervalo Livre de Doença , Relação Dose-Resposta à Radiação , Feminino , Humanos , Neoplasias Pulmonares/mortalidade , Neoplasias Pulmonares/patologia , Masculino , Pessoa de Meia-Idade , Pneumonia/etiologia , Radioterapia Conformacional/efeitos adversos , Taxa de Sobrevida , Estados Unidos/epidemiologia
9.
Int J Radiat Oncol Biol Phys ; 48(3): 629-33, 2000 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-11020557

RESUMO

PURPOSE: To study the significance, in terms of overall and cause-specific survival, of biochemical failure after conformal external-beam radiation therapy (RT) for prostate cancer. METHODS AND MATERIALS: Of the 1844 patients in the Radiation Oncology prostate cancer database, 718 were deemed eligible. Patients excluded were those with N1 or M1 disease, those treated after radical prostatectomy, those who received hormone therapy before radiation therapy, and those who died, failed clinically, or had no PSA response in the first 6 months after RT. Patients included were required to have a minimum of 2 post-RT PSAs separated by at least 1 week. Biochemical relapse was defined as 3 consecutive PSA rises. This resulted in 154 patients with biochemical failure. Survival was calculated from the third PSA elevation. The rate of rise of PSA was calculated by fitting a regression line to the four rising PSAs on a ln PSA vs. time plot. RESULTS: There were 41 deaths among the 154 patients with failure in 23 of the 41 due to prostate cancer. The overall survival after failure was 58% at 5 years, while the cause-specific failure was 73% at 5 years. Among the 154 failures, several factors were evaluated for an association with overall survival: age at failure, pre-RT PSA, PSA at second rise, PSA nadir, time from RT to failure, time to nadir, Gleason score, T-stage, and rate of rise, both from the nadir and from the beginning of the rise. None of these factors were significantly associated with an increased risk of death. As expected, the group of patients with biochemical failure have significantly worse prognostic factors than those without biochemical failure: median pre-RT PSA 15.9 vs. 9.0 (p < 0.001), and Gleason score of 7 or greater for 48% of subjects vs. 40% (p = 0.1). Relative PSA rise and slope of ln PSA vs. time were associated with cause-specific mortality (p < 0.001 and p = 0.007, respectively). CONCLUSION: Overall survival after conformal radiotherapy for prostate cancer remains high 5 years after biochemical failure. This high survival rate occurs even though the group of patients with biochemical failure has worse than average adverse preradiation prognostic factors. Thus, although biochemical failure can identify patients who have recurrent disease after RT, the ultimate relationship between this endpoint and death remains to be better defined.


Assuntos
Antígeno Prostático Específico/sangue , Neoplasias da Próstata/radioterapia , Idoso , Humanos , Masculino , Recidiva Local de Neoplasia/sangue , Recidiva Local de Neoplasia/mortalidade , Neoplasias da Próstata/sangue , Neoplasias da Próstata/mortalidade , Radioterapia Conformacional , Recidiva , Taxa de Sobrevida , Fatores de Tempo
10.
Neurosurgery ; 47(1): 123-8; discussion 128-30, 2000 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-10917355

RESUMO

OBJECTIVE: To prospectively demonstrate the safety and efficacy of stereotactic radiosurgery for arteriovenous malformations (AVMs) of the brain with a linear accelerator fitted with a multileaf collimator. METHODS: A novel radiosurgery system was developed at the University of Michigan Medical Center with a standard multileaf collimator and a computer-controlled radiotherapy system. Data were accumulated prospectively on all patients undergoing treatment with this system since treatment began in 1995. RESULTS: Thirty-six patients with 37 AVMs have undergone treatment to date. At more than 3 years since treatment, 15 of 16 AVMs with a volume of less than 10 cc were proven to be obliterated by angiography or magnetic resonance imaging, and one was considered a treatment failure. At more than 24 months since therapy, all four AVMs with a volume of 10 to 25 cc were obliterated. Four patients with AVMs with a volume of more than 25 cc have undergone staged therapy, treating the entire volume to 10 Gy twice, but none has been followed long enough to demonstrate a final outcome. There were four transient and no permanent complications. CONCLUSION: Our early data indicate that stereotactic radiosurgery of cerebral AVMs with a linear accelerator and a multileaf collimator is safe and effective. Large AVMs may be especially suitable for this mode of therapy. Staged treatment of very large AVMs seems to be a promising addition to standard treatment, but longer follow-up is necessary to confirm that complete obliteration can be achieved.


Assuntos
Malformações Arteriovenosas Intracranianas/cirurgia , Radiocirurgia/instrumentação , Adolescente , Adulto , Idoso , Criança , Humanos , Pessoa de Meia-Idade , Estudos Prospectivos
11.
Appl Environ Microbiol ; 66(8): 3206-13, 2000 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-10919771

RESUMO

We recently described the use of PCR to identify the environmental source of Mycobacterium ulcerans during an outbreak of ulcerative disease that occurred in a localized region of southeast Australia. The PCR used was based on amplification of the M. ulcerans-specific insertion sequence, IS2404. In this study we developed a new test that is a substantial improvement over the original PCR method in terms of sensitivity, reliability, and ease of use. In the new method magnetic bead sequence capture-PCR is used to detect two M. ulcerans sequences (IS2404 and IS2606) and total mycobacterial 16S ribosomal DNA. We used sequence capture-PCR to test water and plant material collected over a 12-month period during 1998 and 1999 from sites near the centers of two distinct foci of M. ulcerans infections. A golf course irrigation system in one area and a small shallow lake in another area repeatedly were PCR positive for M. ulcerans. Nearby sites and sites unrelated to the endemic areas were negative. Based on the PCR data, a most-probable-number method was used to estimate the concentration of M. ulcerans cells in positive samples from both regions. This procedure resulted in average concentrations of 0.5 cell per 100 ml of water and 40 cells per 100 g of detritus. Loss of the PCR signal coincided with a decrease in ulcerative disease in each area. These results provide further evidence that M. ulcerans may be transmitted from a point environmental source and demonstrate the utility of magnetic bead sequence capture-PCR for identification of nonculturable microbial pathogens in the environment.


Assuntos
Microbiologia Ambiental , Infecções por Mycobacterium não Tuberculosas/microbiologia , Mycobacterium ulcerans/classificação , Reação em Cadeia da Polimerase/métodos , Elementos de DNA Transponíveis , DNA Bacteriano/análise , DNA Bacteriano/genética , DNA Ribossômico/análise , DNA Ribossômico/genética , Doenças Endêmicas , Genes de RNAr , Humanos , Separação Imunomagnética/métodos , Dados de Sequência Molecular , Infecções por Mycobacterium não Tuberculosas/epidemiologia , Mycobacterium ulcerans/genética , Mycobacterium ulcerans/isolamento & purificação , Plantas/microbiologia , RNA Ribossômico 16S/genética , Análise de Sequência de DNA , Vitória/epidemiologia , Microbiologia da Água
12.
Int J Radiat Oncol Biol Phys ; 47(2): 461-7, 2000 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-10802374

RESUMO

PURPOSE: To accurately assess the cost-effectiveness of treatment with external beam radiation, it is necessary to have accurate estimates of its cost. One of the most common methods for estimating technical costs has been to convert Medicare charges into costs using Medicare Cost-to-Charge Ratios (CCR). More recently, health care organizations have begun to invest in sophisticated cost-accounting systems (CAS) that are capable of providing procedure-specific cost estimates. The purpose of this study was to examine whether these competing approaches result in similar cost estimates for four typical courses of external beam radiation therapy (EBRT). METHODS AND MATERIALS: Technical costs were estimated for the following treatment courses: 1) a palliative "simple" course of 10 fractions using a single field without blocks; 2) a palliative "complex" course of 10 fractions using two opposed fields with custom blocks; 3) a curative course of 30 fractions for breast cancer using tangent fields followed by an electron beam boost; and 4) a curative course of 35 fractions for prostate cancer using CT-planning and a 4-field technique. Costs were estimated using the CCR approach by multiplying the number of units of each procedure billed by its Medicare charge and CCR and then summing these costs. Procedure-specific cost estimates were obtained from a cost-accounting system, and overall costs were then estimated for the CAS approach by multiplying the number of units billed by the appropriate unit cost estimate and then summing these costs. All costs were estimated using data from 1997. The analysis was also repeated using data from another academic institution to estimate their costs using the CCR and CAS methods, as well as the appropriate relative value units (RVUs) and conversion factor from the 1997 Medicare Fee Schedule to estimate Medicare reimbursement for the four treatment courses. RESULTS: The estimated technical costs for the CCR vs. CAS approaches for the four treatment courses were as follows: palliative "simple" $1,285 vs. $1,195; palliative "complex" $2,345 vs. $1,769; curative breast $6,757 vs. $4,850; and curative prostate $9,453 vs. $7,498. Accordingly, the CCR estimates were 8%, 33%, 39%, and 26% higher than the CAS cost estimates, respectively. The primary cause of the difference between the estimates was the daily cost of delivering a "complex" treatment. In fact, if corrected the difference between the estimates fell to 0%, 1%, 4%, and 0%, respectively. Similar results were observed for both methods when the analysis was repeated using data from another academic institution. Medicare reimbursement was also slightly lower than, but remarkably close to, the costs estimated by the CAS approach. CONCLUSIONS: For "complex" treatment courses, which represent the vast majority of external beam treatments, technical costs estimated using the CCR approach appear to be significantly higher than those estimated using procedure-specific cost estimates. Because cost-effectiveness analyses of radiation therapy tend to be sensitive to the cost of treatment, the use of higher costs will result in radiation therapy appearing less cost-effective.


Assuntos
Análise Custo-Benefício , Radioterapia/economia , Medicare/economia , Cuidados Paliativos/economia , Mecanismo de Reembolso , Estados Unidos
13.
J Clin Microbiol ; 38(4): 1482-7, 2000 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-10747130

RESUMO

Two high-copy-number insertion sequences, IS2404 and IS2606, were recently identified in Mycobacterium ulcerans and were shown by Southern hybridization to possess restriction fragment length polymorphism between strains from different geographic origins. We have designed a simple genotyping method that captures these differences by PCR amplification of the region between adjacent copies of IS2404 and IS2606. We have called this system 2426 PCR. The method is rapid, reproducible, sensitive, and specific for M. ulcerans, and it has confirmed previous studies suggesting a clonal population structure of M. ulcerans within a geographic region. M. ulcerans isolates from Australia, Papua New Guinea, Malaysia, Surinam, Mexico, Japan, China, and several countries in Africa were easily differentiated based on an array of 4 to 14 PCR products ranging in size from 200 to 900 bp. Numerical analysis of the banding patterns suggested a close evolutionary link between M. ulcerans isolates from Africa and southeast Asia. The application of 2426 PCR to total DNA, extracted directly from M. ulcerans-infected tissue specimens without culture, demonstrated the sensitivity and specificity of this method and confirmed for the first time that both animal and human isolates from areas of endemicity in southeast Australia have the same genotype.


Assuntos
Elementos de DNA Transponíveis , Infecções por Mycobacterium não Tuberculosas/microbiologia , Mycobacterium ulcerans/classificação , Reação em Cadeia da Polimerase/métodos , Genótipo , Humanos , Mycobacterium ulcerans/genética , Sensibilidade e Especificidade
14.
J Clin Oncol ; 18(2): 287-95, 2000 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-10637242

RESUMO

PURPOSE: Electron-beam boosts (EBB) are routinely added after conservative surgery and tangential radiation therapy (TRT) for early-stage breast cancer. We performed an incremental cost-utility analysis to evaluate their cost-effectiveness. METHODS: A Markov model examined the impact of adding an EBB to TRT from a societal perspective. Outcomes were measured in quality-adjusted life years (QALYs). On the basis of the Lyon trial, the EBB was assumed to reduce local recurrences by approximately 2% at 10 years but to have no impact on survival. Patients' utilities were used to adjust for quality of life. Given the small absolute benefit of the EBB, baseline utilities were assumed to be the same with or without it, an assumption evaluated by Monte Carlo simulation. Direct medical, time, and travel costs were considered. RESULTS: Adding the EBB led to an additional cost of $2,008, an increase of 0.0065 QALYs and, therefore, an incremental cost-effectiveness ratio of over $300,000/QALY. In a sensitivity analysis, the ratio was moderately sensitive to the efficacy and cost of the EBB and highly sensitive to patients' utilities for treatment without it. Even if patients do value a small risk reduction, the mean cost-effectiveness ratio estimated by the Monte Carlo simulation remains high, at $70,859/QALY (95% confidence interval, $53,141 to $105,182/QALY). CONCLUSION: On the basis of currently available data, the cost-effectiveness ratio for the EBB is well above the commonly cited threshold for cost-effective care ($50,000/QALY). The EBB becomes cost-effective only if patients place an unexpectedly high value on the small absolute reduction in local recurrences achievable with it.


Assuntos
Neoplasias da Mama/radioterapia , Custos de Cuidados de Saúde , Radioterapia/economia , Adulto , Idoso , Neoplasias da Mama/economia , Neoplasias da Mama/cirurgia , Análise Custo-Benefício , Elétrons/uso terapêutico , Feminino , Humanos , Metástase Linfática , Cadeias de Markov , Mastectomia Segmentar , Pessoa de Meia-Idade , Recidiva Local de Neoplasia/economia , Recidiva Local de Neoplasia/prevenção & controle , Anos de Vida Ajustados por Qualidade de Vida
15.
Semin Radiat Oncol ; 9(3): 287-91, 1999 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-10378968

RESUMO

With the publication of two randomized trials showing an improvement in overall survival after the use of postmastectomy radiation therapy, interest in the use of radiation therapy in this setting has been rekindled. These results are in contrast to those reported in the most recent meta-analysis of the Early Breast Cancer Trialists' Collaborative Group, in which a statistically significant survival benefit was not detected. Although evidence of a survival benefit was sufficient in the past for an intervention to gain acceptance, payers are increasingly interested in knowing whether its use is also cost-effective. This article briefly reviews the methods used in performing cost-effectiveness analyses, summarizes the results of one published and a second preliminary cost-effectiveness analysis of postmastectomy radiation therapy, and highlights several areas for future research.


Assuntos
Neoplasias da Mama/radioterapia , Neoplasias da Mama/cirurgia , Mastectomia , Radioterapia Adjuvante/economia , Análise Custo-Benefício , Feminino , Humanos , Anos de Vida Ajustados por Qualidade de Vida
16.
Med Dosim ; 24(1): 13-9, 1999.
Artigo em Inglês | MEDLINE | ID: mdl-10100160

RESUMO

Over a period of approximately 3 years, our institution has implemented and refined a system of Stereotactic Radiosurgery (SRS) which utilizes the standard multi leaf collimator (MLC) of the Scanditronix MM50 Racetrack Microtron and treats in an arrangement of segmental "pseudo-arcs." This system employs a commercial BRW based stereotactic frame which is mounted to the treatment table. With the exception of the table-mounted frame hardware there have been no modifications to the treatment machine to accommodate these treatments. By use of standard evaluation parameters (e.g., treatment time, planning time, dose conformance and dose heterogeneity ratios) this system compares quite favorably with reported data from institutions treating SRS with either a GammaKnife or a standard linear accelerator with tertiary collimators.


Assuntos
Encéfalo/cirurgia , Radiocirurgia/métodos , Encéfalo/diagnóstico por imagem , Neoplasias Encefálicas/diagnóstico por imagem , Neoplasias Encefálicas/cirurgia , Humanos , Malformações Arteriovenosas Intracranianas/diagnóstico por imagem , Malformações Arteriovenosas Intracranianas/cirurgia , Radiocirurgia/instrumentação , Planejamento da Radioterapia Assistida por Computador , Tomografia Computadorizada por Raios X
17.
Pathology ; 31(4): 431-3, 1999 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-10643021

RESUMO

We report on the rare finding of pituitary tissue, including both adenohypophysis and neurohypophsis, in a mature cystic teratoma of the ovary removed from a 26 year old female at the time of cesarean section. Immunocytochemistry of the ectopic anterior pituitary component showed pregnancy-related changes that have previously only been described in pituitaries obtained at autopsy.


Assuntos
Coristoma/patologia , Neoplasias Ovarianas/patologia , Adeno-Hipófise , Neuro-Hipófise , Complicações Neoplásicas na Gravidez/patologia , Teratoma/patologia , Hormônio Adrenocorticotrópico/metabolismo , Adulto , Coristoma/metabolismo , Feminino , Proteína Glial Fibrilar Ácida/metabolismo , Hormônio do Crescimento/metabolismo , Humanos , Técnicas Imunoenzimáticas , Neoplasias Ovarianas/metabolismo , Gravidez , Complicações Neoplásicas na Gravidez/metabolismo , Prolactina/metabolismo , Teratoma/metabolismo
18.
J Clin Oncol ; 16(3): 1022-9, 1998 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-9508186

RESUMO

PURPOSE: To examine the cost-effectiveness of radiation therapy following conservative surgery for early-stage breast cancer. METHODS: Using a Markov model, a cost-utility analysis was performed to compare a strategy of radiation therapy versus no radiation therapy in a hypothetical cohort of 60-year-old women following conservative surgery. Local recurrence, distant recurrence, and survival rates used in the model were derived from randomized trial data. Utilities for the nonmetastatic health states were collected from actual patients. Direct medical costs were estimated using data from a single institution. Transportation and time costs were also estimated. Years of life, quality-adjusted life-years (QALYs), costs, and incremental cost/QALY over a 10-year time horizon were calculated by the model for each strategy. RESULTS: The addition of radiation therapy results in a cost increase of $9,800 per patient, no change in life expectancy, and an increase of 0.35 QALYs per patient, which leads to an incremental cost-effectiveness ratio of $28,000/QALY, which is well below $50,000/QALY, a commonly cited threshold for cost-effective care. Sensitivity analysis shows the ratio to be heavily influenced by the cost of radiation therapy and the quality-of-life benefit that results from decreased risk of local recurrence. CONCLUSION: Radiation therapy following conservative surgery is cost-effective compared with other accepted medical interventions. This study illustrates the importance of considering an intervention's effect on quality of life, as well as survival in defining cost-effectiveness.


Assuntos
Neoplasias da Mama/radioterapia , Radioterapia Adjuvante/economia , Neoplasias da Mama/economia , Neoplasias da Mama/cirurgia , Análise Custo-Benefício , Feminino , Humanos , Cadeias de Markov , Mastectomia/economia , Probabilidade , Anos de Vida Ajustados por Qualidade de Vida , Radioterapia/economia , Taxa de Sobrevida
19.
Appl Environ Microbiol ; 63(10): 4135-8, 1997 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-9327583

RESUMO

Mycobacterium ulcerans is an environmental bacterium which causes chronic skin ulcers. Despite significant epidemiological evidence to suggest that water is the source of infection, the organism has never been identified in the environment. Environmental water samples were collected from a small town in which an outbreak of 29 cases had occurred in a 3-year period. These were examined by mycobacterial culture and PCR amplification. Similar to previous studies, M. ulcerans was not cultured from the water samples. However, five samples were positive for M. ulcerans by PCR. These samples were collected from a swamp and a golf course irrigation system within the outbreak area. This is the first time that M. ulcerans has been demonstrated to be present in the environment and supports the postulated epidemiology of disease due to this organism.


Assuntos
Surtos de Doenças , Infecções por Mycobacterium não Tuberculosas/epidemiologia , Mycobacterium ulcerans/isolamento & purificação , Úlcera Cutânea/epidemiologia , Microbiologia da Água , DNA Bacteriano/genética , DNA Bacteriano/isolamento & purificação , Humanos , Mycobacterium ulcerans/genética , Mycobacterium ulcerans/patogenicidade , Reação em Cadeia da Polimerase , Vitória/epidemiologia
20.
Pathology ; 29(3): 317-9, 1997 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-9271026

RESUMO

This paper describes humoral hypercalcemia of malignancy (HHM) associated with squamous cell carcinoma (SCC) of the breast and its association with assayed levels of parathyroid hormone related protein (PTHrP). A 57-year-old woman presented with locally advanced SCC of the breast. The diagnosis was supported by serum analysis and histological and immunohistochemical findings. She was initially treated with chemotherapy to reduce the tumor bulk but developed symptomatic hypercalcemia after on course. The hypercalcemia was effectively treated with intravenous amino hydroxy propildene diphosphonate. Subsequently the tumor progressed despite multimodality therapy and was associated with recurrent hypercalcemia. The patient died nine months after presentation.


Assuntos
Neoplasias da Mama/patologia , Carcinoma de Células Escamosas/patologia , Hipercalcemia/etiologia , Proteínas de Neoplasias/biossíntese , Hormônio Paratireóideo/biossíntese , Biossíntese de Proteínas , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Neoplasias da Mama/complicações , Neoplasias da Mama/tratamento farmacológico , Neoplasias da Mama/metabolismo , Carcinoma de Células Escamosas/complicações , Carcinoma de Células Escamosas/tratamento farmacológico , Carcinoma de Células Escamosas/metabolismo , Progressão da Doença , Humanos , Técnicas Imunoenzimáticas , Masculino , Pessoa de Meia-Idade , Proteína Relacionada ao Hormônio Paratireóideo
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