Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 31
Filtrar
Mais filtros

Base de dados
País/Região como assunto
Tipo de documento
Intervalo de ano de publicação
1.
Cortex ; 155: 46-61, 2022 10.
Artigo em Inglês | MEDLINE | ID: mdl-35964357

RESUMO

The severity of post-stroke aphasia is related to damage to white matter connections. However, neural signaling can route not only through direct connections, but also along multi-step network paths. When brain networks are damaged by stroke, paths can bypass around the damage to restore communication. The shortest network paths between regions could be the most efficient routes for mediating bypasses. We examined how shortest-path bypasses after left hemisphere strokes were related to language performance. Regions within and outside of the canonical language network could be important in aphasia recovery. Therefore, we innovated methods to measure the influence of bypasses in the whole brain. Distinguishing bypasses from all residual shortest paths is difficult without pre-stroke imaging. We identified bypasses by finding shortest paths in subjects with stroke that were longer than the most reliably observed connections in age-matched control networks. We tested whether features of those bypasses predicted scores in four orthogonal dimensions of language performance derived from a principal components analysis of a battery of language tasks. The features were the length of each bypass in steps, and how many bypasses overlapped on each individual direct connection. We related these bypass features to language factors using support vector regression, a technique that extracts robust relationships in high-dimensional data analysis. The support vector regression parameters were tuned using grid-search cross-validation. We discovered that the length of bypasses reliably predicted variance in lexical production (R2 = .576) and auditory comprehension scores (R2 = .164). Bypass overlaps reliably predicted variance in Lexical Production scores (R2 = .247). The predictive elongation features revealed that bypass efficiency along the dorsal stream and ventral stream were most related to Lexical Production and Auditory Comprehension, respectively. Among the predictive bypass overlaps, increased bypass routing through the right hemisphere putamen was negatively related to lexical production ability.


Assuntos
Afasia , Acidente Vascular Cerebral , Afasia/etiologia , Encéfalo , Mapeamento Encefálico , Humanos , Idioma , Imageamento por Ressonância Magnética , Acidente Vascular Cerebral/complicações
2.
Urology ; 152: 117-122, 2021 06.
Artigo em Inglês | MEDLINE | ID: mdl-33556448

RESUMO

OBJECTIVE: To evaluate the outcomes of excision and primary anastomosis (EPA) for radiation-associated bulbomembranous stenoses using a multi-institutional analysis. The treatment of radiation-associated urethral stenosis is typically complex owing to the adverse impact of radiation on adjacent tissue. METHODS: An IRB-approved multi-institutional retrospective review was performed on patients who underwent EPA for bulbomembranous urethral stenosis following prostate radiotherapy. Preoperative patient demographics, operative technique, and postoperative outcomes were abstracted from 1/2007-6/2018. Success was defined as voiding per urethra without the need for endoscopic treatment and a minimum follow-up of 12 months. RESULTS: One hundred and thirty-seven patients from 10 centers met study criteria with a mean age of 69.3 years (50-86), stenosis length of 2.3 cm (1-5) and an 86.9% (119/137) success rate at a mean follow-up 32.3 months (12-118). Univariate Cox regression analysis identified increasing patient age (P = .02), stricture length (P <.0001) and combined modality radiotherapy (P = .004) as factors associated with stricture recurrence while body mass index (P = .79), diabetes (P = .93), smoking (P = .62), failed endoscopic treatment (P = .08) and gracilis muscle use (P = .25) were not. On multivariate analysis, increasing patient age (H.R.1.09, 95%CI 1.01-1.16; P = .02) and stenosis length (H.R.2.62, 95%CI 1.49-4.60; P = .001) remained associated with recurrence. Subsequent artificial urinary sphincter was performed in 30 men (21.9%), of which 25 required a transcorporal cuff and 5 developed cuff erosion. CONCLUSIONS: EPA for radiation-associated urethral stenosis effectively provides unobstructed instrumentation-free voiding. However, increasing stenosis length and age are independently associated with surgical failure. Patients should be counseled that further surgery for incontinence may be necessary.


Assuntos
Anastomose Cirúrgica , Lesões por Radiação/cirurgia , Estreitamento Uretral/cirurgia , Fatores Etários , Idoso , Idoso de 80 Anos ou mais , Humanos , Masculino , Pessoa de Meia-Idade , Neoplasias da Próstata/radioterapia , Recidiva , Estudos Retrospectivos , Estreitamento Uretral/etiologia , Esfíncter Urinário Artificial/estatística & dados numéricos
3.
J Gastrointest Surg ; 21(3): 496-505, 2017 03.
Artigo em Inglês | MEDLINE | ID: mdl-27896658

RESUMO

BACKGROUND: The impact of glycemic control in patients with pancreatic cancer treated with neoadjuvant therapy is unclear. METHODS: Glycated hemoglobin (HbA1c) values were measured in patients with localized pancreatic cancer prior to any therapy (pretreatment) and after neoadjuvant therapy prior to surgery (preoperative). HbA1c levels greater than 6.5% were classified as abnormal. Patients were categorized based on the change in HbA1c levels from pretreatment to preoperative: GrpA, always normal; Gr B, worsened; GrpC, improved; and GrpD, always abnormal. RESULTS: Pretreatment HbA1c levels were evaluable in 123 patients; there were 67 (55%) patients in GrpA, 8 (6%) in GrpB, 22 (18%) in GrpC, and 26 (21%) in GrpD. Of the 123 patients, 92 (75%) completed all intended therapy to include surgery; 57 (85%) patients in GrpA, 4 (50%) patients in GrpB, 16 (72%) patients in GrpC, and 15 (58%) patients in GrpD (p = 0.01). Elevated preoperative carbohydrate antigen 19-9 (CA19-9) (OR 0.22;[0.07-0.66]), borderline resectable (BLR) disease stage (OR 0.20;[0.01-0.45]) and abnormal preoperative HbA1c (OR 0.30;[0.11-0.90]) were negatively associated with completion of all intended therapy. Abnormal preoperative HbA1c was associated with a 2.74-fold increased odds of metastatic progression during neoadjuvant therapy (p = 0.08). CONCLUSIONS: Elevated preoperative HbA1c is associated with failure to complete neoadjuvant therapy and surgery and a trend for increased risk of metastatic progression.


Assuntos
Hemoglobinas Glicadas/metabolismo , Neoplasias Pancreáticas/sangue , Neoplasias Pancreáticas/terapia , Idoso , Idoso de 80 Anos ou mais , Antígeno CA-19-9/sangue , Quimiorradioterapia Adjuvante , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Terapia Neoadjuvante , Metástase Neoplásica , Pancreatectomia , Neoplasias Pancreáticas/patologia , Resultado do Tratamento
4.
Pract Radiat Oncol ; 7(2): 126-136, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-28089481

RESUMO

PURPOSE: Local recurrence is a common and morbid event in patients with unresectable pancreatic adenocarcinoma. A more conformal and targeted radiation dose to the macroscopic tumor in nonmetastatic pancreatic cancer is likely to reduce acute toxicity and improve local control. Optimal soft tissue contrast is required to facilitate delineation of a target and creation of a planning target volume with margin reduction and motion management. Magnetic resonance imaging (MRI) offers considerable advantages in optimizing soft tissue delineation and is an ideal modality for imaging and delineating a gross tumor volume (GTV) within the pancreas, particularly as it relates to conformal radiation planning. Currently, no guidelines have been defined for the delineation of pancreatic tumors for radiation therapy treatment planning. Moreover, abdominal MRI sequences are complex and the anatomy relevant to the radiation oncologist can be challenging. The purpose of this study is to provide recommendations for delineation of GTV and organs at risk (OARs) using MRI and incorporating multiple MRI sequences. METHODS AND MATERIALS: Five patients with pancreatic cancer and 1 healthy subject were imaged with MRI scans either on 1.5T or on 3T magnets in 2 separate institutes. The GTV and OARs were contoured for all patients in a consensus meeting. RESULTS: An overview of MRI-based anatomy of the GTV and OARs is provided. Practical contouring instructions for the GTV and the OARs with the aid of MRI were developed and included in these recommendations. In addition, practical suggestions for implementation of MRI in pancreatic radiation treatment planning are provided. CONCLUSIONS: With this report, we attempt to provide recommendations for MRI-based contouring of pancreatic tumors and OARs. This could lead to better uniformity in defining the GTV and OARs for clinical trials and in radiation therapy treatment planning, with the ultimate goal of improving local control while minimizing morbidity.


Assuntos
Adenocarcinoma/diagnóstico por imagem , Adenocarcinoma/radioterapia , Imageamento por Ressonância Magnética/métodos , Neoplasias Pancreáticas/diagnóstico por imagem , Neoplasias Pancreáticas/radioterapia , Planejamento da Radioterapia Assistida por Computador/métodos , Radioterapia Conformacional , Adenocarcinoma/patologia , Adulto , Idoso , Idoso de 80 Anos ou mais , Humanos , Masculino , Recidiva Local de Neoplasia/diagnóstico por imagem , Estadiamento de Neoplasias , Órgãos em Risco/diagnóstico por imagem , Neoplasias Pancreáticas/patologia , Guias de Prática Clínica como Assunto , Doses de Radiação , Tomografia Computadorizada por Raios X , Carga Tumoral , Adulto Jovem
5.
Case Rep Urol ; 2015: 646784, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-26635991

RESUMO

Excision with primary anastomosis (EPA) urethroplasty is generally the preferred method for short strictures in the bulbar urethra, given its high success rate and low complication rate compared to other surgical interventions. Bleeding is a presumed risk factor for any surgical procedure but perioperative hemorrhage after an EPA requiring hospitalization and/or reintervention is unreported with no known consensus on the best course for management. Through our experience with three separate cases of significant postoperative urethral hemorrhage after EPA, we developed an algorithm for treatment beginning with conservative management and progressing through endoscopic and open techniques, as well as consideration of embolization by interventional radiology. All the three of these cases were managed successfully though they did require multiple interventions. We theorize that younger patients with more robust corpus spongiosum and more vigorous spontaneous erections, patients that have undergone fewer prior urethral procedures and therefore have more prominent vasculature, and those patients managed with a two-layer closure of the ventral urethra without ligation of the transected bulbar arteries are at a higher risk for this complication.

6.
Int J Radiat Oncol Biol Phys ; 29(5): 1095-103, 1994 Jul 30.
Artigo em Inglês | MEDLINE | ID: mdl-8083079

RESUMO

Lymphomas arising within the lacrimal collecting system are rare tumours and unusual causes of lacrimal obstructive symptoms. The presentation, diagnosis, and treatment of this disease in five patients are described, as well as a review of the existing literature. Emphasized in this series is the efficacy of magnetic resonance imaging of these presentations and the importance of irradiation in their treatment.


Assuntos
Doenças do Aparelho Lacrimal/diagnóstico , Doenças do Aparelho Lacrimal/radioterapia , Linfoma/diagnóstico , Linfoma/radioterapia , Adulto , Idoso , Feminino , Humanos , Aparelho Lacrimal/anatomia & histologia , Imageamento por Ressonância Magnética/métodos , Masculino , Pessoa de Meia-Idade
7.
Int J Radiat Oncol Biol Phys ; 28(4): 905-12, 1994 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-8138444

RESUMO

PURPOSE: Total abdominal radiation produces symptoms of nausea, vomiting abdominal cramping and diarrhea. Each of these symptoms is associated with disordered intestinal motility. This article reviews studies of large and small intestinal contractile activity following radiation exposure. METHODS AND MATERIALS: Studies of motility utilize strain gauge transducers surgically implanted on the seromuscular layer of the small intestine. All studies were performed in mixed breed dogs to record the occurrence of normal contractions, giant migrating contractions (GMCs) and retrograde giant contractions (RGCs) before, during and after irradiation (22.5 Gy in 9 fractions at 3 fractions/week). Giant migrating contractions and retrograde giant contractions are infrequent in the healthy state. However, in diseased states, GMCs are associated with abdominal cramps and diarrhea, and RGCs precede vomiting. RESULTS: In fasted animals, fractionated abdominal irradiation dramatically increased the frequency of GMCs, with the incidence peaking after the second dose. The increased frequency of GMCS occurred as early as a few hours after the first radiation fraction, and returned to normal within days of cessation of radiation. RGCs were also significantly increased after abdominal irradiation. The frequency of RGCs was greatest on the first and sixth dose of radiation. Clinically, the dogs developed nausea, vomiting and diarrhea as early as the first day of irradiation. In dogs studied in the fed state, decreased amplitude, duration, and frequency of postprandial contractions occurred. These changes may slow intestinal transit during irradiation. Radiation also produced a striking increase in the frequency of colonic GMCs; these changes in colonic motor activity were associated with diarrhea as early as the second irradiation. CONCLUSION: Changes in GI motility during fractionated irradiation precede the appearance of histopathological lesions in the GI tract. Thus, the symptoms of nausea, vomiting, and diarrhea experienced during radiotherapy (particularly those within the first week) are directly related to changes in bowel motility. It is hoped that further understanding of the etiology of these distressing symptoms will help to guide their treatment.


Assuntos
Gastroenteropatias/etiologia , Motilidade Gastrointestinal/efeitos da radiação , Radioterapia/efeitos adversos , Animais , Cães , Mucosa Gástrica/efeitos da radiação , Mucosa Intestinal/efeitos da radiação , Complexo Mioelétrico Migratório/efeitos da radiação
8.
Int J Radiat Oncol Biol Phys ; 31(3): 651-60, 1995 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-7852132

RESUMO

PURPOSE: Confirmation of the efficacy of orbital irradiation in Graves' ophthalmopathy is needed due to the unpredictable natural history of the disease, the variation in individual clinical presentations, the contribution of other simultaneous treatments, and the lack of controlled studies using objective criteria to classify and assess response over time. Orbital echography before and at select intervals following orbital irradiation is proposed as an objective parameter of tissue response to orbital irradiation over time. METHODS AND MATERIALS: From January, 1983 to September, 1993, 55 patients with progressive Graves' ophthalmopathy underwent 20 Gy retrobulbar irradiation. On retrospective review, standardized orbital echography was performed randomly prior to irradiation in 37 of the 55 patients to assess the acoustic characteristics of the extraocular muscles and to quantitate their individual and summed diameters. Twenty-one patients had at least one follow-up echographic evaluation at random intervals of 0 to 27.5 months following completion of irradiation. Twelve patients received steroids before or during irradiation, which were tapered in proximity to completion of radiation. Follow-up ranged from 2 to 65 months with the majority followed at least 6 months (18 patients). RESULTS: Of the 21 patients with serial studies, 18 showed an interval decrease in individual and summed muscle size over time and return of symmetry. Interval improvement was documented as early as the 1 month follow-up study, with continued improvement seen during the 3-9-month studies, with stability typically achieved within 12 months. One patient had further changes between the 21 and 27.5 month follow-up studies. Exacerbation of disease was, however, echographically demonstrated in three patients at 6.5, 8.5, and 13 months. Follow-up studies in two of these patients again revealed improvement, one following tapered steroids. The third patient required orbital decompression. CONCLUSION: Objective parameters of response are needed to document both the immediate and long-term outcome of orbital irradiation on the course of Graves' ophthalmopathy and confirm its efficacy. Serial echography is proposed as a new technique for providing parameters to judge response.


Assuntos
Doença de Graves/radioterapia , Músculos Oculomotores/efeitos da radiação , Órbita/efeitos da radiação , Seguimentos , Doença de Graves/diagnóstico por imagem , Humanos , Músculos Oculomotores/diagnóstico por imagem , Órbita/diagnóstico por imagem , Estudos Retrospectivos , Ultrassonografia
9.
Surgery ; 128(4): 520-30, 2000 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-11015084

RESUMO

BACKGROUND: Cell cycle arrest after DNA damage is partly mediated through the transcriptional activation of p21(WAF1) by the p53 tumor suppressor gene. p21(WAF1) and p53 are both critical in maintaining cell cycle control in response to DNA damage from radiation or chemotherapy. Therefore, we examined the role of p21(WAF1) and p53 in the determination of outcome for patients who receive radiation and/or chemotherapy for pancreatic cancer. METHODS: p21(WAF1) and p53 protein expression were determined (with the use of immunohistochemistry) in specimens from 90 patients with pancreatic cancer. Forty-four patients underwent surgical resection, and 46 patients had either locally unresectable tumors (n = 9 patients) or distant metastases (n = 37 patients). Seventy-three percent of the patients who underwent resection and 63% of the patients who did not undergo resection received radiation and/or chemotherapy. RESULTS: p21(WAF1) expression was present in 48 of 86 tumors (56%) and was significantly (P<.05) associated with advanced tumor stage. Median survival among patients with resected pancreatic cancer who received adjuvant chemoradiation with p21(WAF1)-positive tumors was significantly longer than in patients with no p21(WAF1) staining (25 vs. 11 months; P = .01). Fifty of 89 tumors (56%) stained positive for p53 protein. p53 overexpression was associated with decreased survival in patients who did not undergo resection. CONCLUSIONS: Normal p21(WAF1) expression may be necessary for a beneficial response to current adjuvant chemoradiation protocols for pancreatic cancer. Alternate strategies for adjuvant therapy should be explored for patients with pancreatic cancer who lack functional p21(WAF1).


Assuntos
Adenocarcinoma/radioterapia , Adenocarcinoma/cirurgia , Ciclinas/biossíntese , Neoplasias Pancreáticas/radioterapia , Neoplasias Pancreáticas/cirurgia , Adenocarcinoma/metabolismo , Adenocarcinoma/mortalidade , Idoso , Biomarcadores Tumorais/análise , Biomarcadores Tumorais/biossíntese , Terapia Combinada , Inibidor de Quinase Dependente de Ciclina p21 , Ciclinas/análise , Feminino , Humanos , Imuno-Histoquímica , Masculino , Pessoa de Meia-Idade , Análise Multivariada , Pancreatectomia , Neoplasias Pancreáticas/metabolismo , Neoplasias Pancreáticas/mortalidade , Prognóstico , Modelos de Riscos Proporcionais , Análise de Sobrevida , Proteína Supressora de Tumor p53/análise , Proteína Supressora de Tumor p53/biossíntese
10.
Surgery ; 124(4): 663-9, 1998 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-9780986

RESUMO

BACKGROUND: Reports of improved survival rates for patients with resected adenocarcinoma of the pancreas coincide with the adoption of adjuvant chemoradiation protocols. The impact of nodal micrometastases demonstrated by molecular assays and adjuvant therapy on survival of patients with stage I pancreatic cancer has not been adequately assessed. METHODS: A retrospective analysis of postoperative chemoradiation on survival in 61 patients undergoing resection of pancreatic adenocarcinomas from 1984 to 1997 was performed. Archival tumors and regional nodes from 25 patients with stage I cancers were tested for a Kiras oncogene mutation using polymerase chain reaction and analysis for restriction fragment length polymorphisms (PCR/RFLP). RESULTS: Adjuvant chemoradiation was associated with improved survival for stage I (P < .01), but not stage III, disease. Seventeen (68%) of 25 patients with stage I disease tested had evidence of mutant Kiras in one or more regional nodes. Survival did not differ for patients with molecular micrometastases. Six of 17 (35%) patients with micrometastases received adjuvant chemoradiation and had improved survival (P < .05). CONCLUSIONS: The majority of patients with stage I pancreatic cancer have PCR/RFLP evidence of lymph node micrometastases. Adjuvant chemoradiation improves survival in these patients by treating micrometastases not detected by histology. Adjuvant chemoradiation should be used for patients with stage I pancreatic cancers.


Assuntos
Adenocarcinoma/patologia , Adenocarcinoma/terapia , Neoplasias Pancreáticas/patologia , Neoplasias Pancreáticas/terapia , Adenocarcinoma/mortalidade , Idoso , Quimioterapia Adjuvante , Feminino , Humanos , Metástase Linfática , Masculino , Pessoa de Meia-Idade , Neoplasias Pancreáticas/mortalidade , Mutação Puntual , Reação em Cadeia da Polimerase , Polimorfismo de Fragmento de Restrição , Proteínas Proto-Oncogênicas p21(ras)/genética , Radioterapia Adjuvante , Estudos Retrospectivos , Taxa de Sobrevida
11.
J Am Med Inform Assoc ; 3(4): 270-2, 1996.
Artigo em Inglês | MEDLINE | ID: mdl-8816349

RESUMO

This case study details the set-up and implementation of the PathNet autocoder (Cerner Corporation) in a busy anatomic pathology laboratory. After initial start-up, procedures were developed to improve the system's performance. Four classes of software coding errors were identified, and an index was developed to measure the number of cases between errors (CBE). Through modifications in the program, the CBE increased sharply by the end of the six-month study period. During the last three months of the study, the efficiency of case retrieval was tested by comparing manual and electronic methods on the same reference cases. This demonstrated significant time saving and removed the variability of manual coding. The technique employed in this study may assist other institutions seeking to implement such a coding system within their respective environments.


Assuntos
Sistemas de Informação em Laboratório Clínico , Armazenamento e Recuperação da Informação , Serviço Hospitalar de Patologia , Software , Vocabulário Controlado , Humanos , Garantia da Qualidade dos Cuidados de Saúde , Controle de Qualidade , Validação de Programas de Computador
12.
Urology ; 31(2): 125-8, 1988 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-3341096

RESUMO

The daily variation of serum levels of prostatic acid phosphatase (PAP) determined by the Roy enzymatic method was investigated in 10 patients with metastatic prostatic cancer and in 10 patients without prostatic disease. Duplicate serum samples were obtained from all patients on the same day at 8 AM, 12 PM, 4 PM, and 8 PM. Statistical analysis of the mean PAP levels at the four sampling times in both groups of patients demonstrated no evidence of circadian or diurnal rhythmic variation. Prostate cancer patients did show significantly greater variability in daily PAP than patients without prostatic disease, although a distinct pattern of secretion was not observed in either group. These results underscore the potential inaccuracy of the use of single determination of serum PAP as a parameter of response in patients with metastatic prostatic cancer and in the staging of patients with clinically localized prostatic malignancy. Evaluation of trends of PAP levels over time, however, continues to play a major role in the assessment and management of patients with prostatic carcinoma.


Assuntos
Fosfatase Ácida/sangue , Neoplasias Ósseas/secundário , Carcinoma/secundário , Próstata/metabolismo , Neoplasias da Próstata/enzimologia , Adulto , Idoso , Carcinoma/enzimologia , Carcinoma/metabolismo , Ritmo Circadiano , Humanos , Masculino , Próstata/enzimologia , Neoplasias da Próstata/metabolismo
13.
Med Decis Making ; 19(1): 49-57, 1999.
Artigo em Inglês | MEDLINE | ID: mdl-9917020

RESUMO

PURPOSE: To compare three decision making techniques using a common clinical problem. METHODS: Two recently developed methods, the analytic hierarchy process (AHP) and the analytic network process (ANP), were compared with a Markov process in the evaluation of the optimal post-lumpectomy treatment strategy for an elderly woman with a mammographically detected, nonpalpable early-stage breast cancer. The following treatment alternatives were considered: observation, radiation, tamoxifen, combination radiation and tamoxifen, and simple mastectomy. All three decision methods incorporated patient preferences. RESULTS: The models agreed on the ranking of the preferred treatment, radiation and tamoxifen, but there were variations in the rankings of the other treatment choices. Individual differences between the three models were uncovered. The Markov process provided estimates of quality-adjusted life expectancy and distribution of health events. Both AHP and ANP required less development time than the Markov process. CONCLUSION: All three methods may be useful tools to the clinician in analyzing complex medical problems. The Markov is the most labor-intensive method but provides detailed results, whereas the AHP and the ANP give only rank orders of the alternatives. The most important considerations in choosing between these methods are time to project completion and the detail of information sought.


Assuntos
Neoplasias da Mama/terapia , Tomada de Decisões , Modelos Teóricos , Antineoplásicos/uso terapêutico , Terapia Combinada , Feminino , Humanos , Cadeias de Markov , Mastectomia , Métodos , Tamoxifeno/uso terapêutico
14.
Med Decis Making ; 16(2): 178-83, 1996.
Artigo em Inglês | MEDLINE | ID: mdl-8778536

RESUMO

Numerous decision-making tools exist to assist physicians in diagnosis management. However, the accuracy of available clinical information is often ambiguous or unknown and current analytical models do not explicitly incorporate judgementally defined information. A model encompassing both physician judgment and probability analysis was developed to accommodate such data. A problem requiring sequential diagnostic testing was structured utilizing the analytic hierarchy process (AHP). The case presented involved a patient complaining of upper abdominal pain who, after initial evaluation, did not need immediate surgery. Physicians were faced with identifying the optimal sequence of diagnostic testing. The criteria used for test selection included minimizing risk, patient discomfort, and cost of testing and maximizing diagnostic capability. Although at the onset the "best" test choice was unknown, the clinical picture indicated four test alternatives: upper gastrointestinal series (GI), abdominal ultrasonography (US), abdominal computed tomography (CT), and upper gastrointestinal endoscopy (END). Based upon the relative preferences of the criteria utilized, the AHP analysis indicated that upper GI series was the optimal first test. Given a negative test, posterior probabilities were calculated using Bayes' theorem, resulting in a new estimate of diagnostic capability. The AHP analysis was reiterated, identifying abdominal ultrasonography as the optimal second test. This analysis may be repeated as many times as necessary. Sensitivity analysis demonstrated that changing criteria preferences may alter the choice of tests and/or their sequence.


Assuntos
Dor Abdominal/etiologia , Técnicas de Apoio para a Decisão , Diagnóstico por Imagem/estatística & dados numéricos , Dor Abdominal/economia , Teorema de Bayes , Análise Custo-Benefício , Diagnóstico por Imagem/economia , Humanos , Masculino , Pessoa de Meia-Idade , Probabilidade , Sensibilidade e Especificidade
15.
Med Decis Making ; 15(2): 138-42, 1995.
Artigo em Inglês | MEDLINE | ID: mdl-7783574

RESUMO

A survey of 53 university and community hospitals revealed that 73% of the institutions had no standard policy for the replacement of triple-lumen catheters (TLCs). Since the maintenance of a TLC in place for a prolonged period may lead to infectious complications, it appeared warranted that standards of management be developed. A decision-tree model was constructed for evaluating the optimal time for changing a TLC that would minimize infection. Cost estimates and health effects at three-, five-, and ten-day change intervals were considered for catheter insertion and complications resulting from such insertion. The results suggested that prophylactic catheter changes should occur no later than every five days, provided that there are no signs of infection. However, sensitivity analysis of several variables suggested that individual institutions should establish policy timing changes based upon careful interpretation of their own data. A model was developed to assist in determining the optimal time to change a TLC based upon such data.


Assuntos
Cateterismo Venoso Central/efeitos adversos , Cateteres de Demora/efeitos adversos , Árvores de Decisões , Cateterismo Venoso Central/economia , Cateteres de Demora/economia , Análise Custo-Benefício , Hospitais Comunitários , Hospitais Universitários , Humanos , Controle de Infecções/métodos , Inquéritos e Questionários , Fatores de Tempo
16.
Med Decis Making ; 18(2): 213-9, 1998.
Artigo em Inglês | MEDLINE | ID: mdl-9566454

RESUMO

PURPOSE: To evaluate the post-lumpectomy treatment of a nonpalpable, stage I, T1b tumor, mammographically detected, in a 74-year-old woman without comorbidities. METHODS: A Markov process, through 120 monthly cycles, was used to model patient progression through a treatment program, employing literature data and a health-outcome utility. Treatments considered were: observation; radiation totaling 5,000 cGy over six weeks; tamoxifen, 20 mg/day, for five years; simple mastectomy; and radiation therapy plus tamoxifen. Health states included absence of disease (NED), loco-regional recurrence, distant metastasis, age-sex-race (ASR)-adjusted death, cancer mortality, treatment complications, and post-mastectomy death. Transition probabilities were established from the literature. Health-state utilities were determined from the responses of health care professionals to a basic reference gamble. RESULTS: Quality-adjusted life years (QALYs) were determined to be 8.19 for radiation plus tamoxifen, decreasing to 8.04 for mastectomy, a difference of only a 0.15 years (1.8 months). Sensitivity analysis, however, showed relative stability in the ranking among treatment options. CONCLUSION: Although the model showed little difference between QALYs with the treatments, the combination of radiation and tamoxifen provides the optimal therapy for this case.


Assuntos
Idoso , Antineoplásicos Hormonais/uso terapêutico , Neoplasias da Mama/cirurgia , Árvores de Decisões , Mastectomia Segmentar , Seleção de Pacientes , Anos de Vida Ajustados por Qualidade de Vida , Tamoxifeno/uso terapêutico , Neoplasias da Mama/tratamento farmacológico , Neoplasias da Mama/radioterapia , Terapia Combinada , Feminino , Nível de Saúde , Humanos , Cadeias de Markov , Prognóstico , Sensibilidade e Especificidade , Resultado do Tratamento
17.
Am J Clin Oncol ; 16(5): 424-43, 1993 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-8213626

RESUMO

There has been a recent resurgence of interest in implementing brachytherapy in the management of nasopharyngeal carcinoma, not only as treatment for recurrent disease, where it has secured a notable role, but also as an elective boost following external beam irradiation in an attempt to improve local control. Examination of the use of nasopharyngeal brachytherapy over nearly the last century may provide guidance for such endeavors and encourage further evolution of these techniques. Throughout this interval, ingenuity has prevailed in attempts to treat a secluded anatomical site which has been difficult to access, explore, and implant in an acceptable manner.


Assuntos
Braquiterapia , Neoplasias Nasofaríngeas/radioterapia , Braquiterapia/instrumentação , Braquiterapia/métodos , Humanos
18.
Am J Clin Oncol ; 24(5): 522-9, 2001 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-11586108

RESUMO

Proton magnetic resonance spectroscopy (MRS) may be a useful tool in both the initial diagnosis of cervical carcinoma and the subsequent surveillance after radiation therapy, particularly when other standard diagnostic methods are inconclusive. Single voxel magnetic resonance (MR) spectral data were acquired from 8 normal volunteers, 16 patients with cervical cancer before radiation therapy, and 18 patients with cervical cancer after radiation therapy using an external pelvic coil at a 1.5-T on a Signa system. The presence or absence of various resonances within each spectrum was evaluated for similarities within each patient group and for spectral differences between groups. Resonances corresponding to lipid and creatine dominated the spectrum for the eight normal volunteers without detection of a choline resonance. Spectra from 16 pretreatment patients with biopsy-proven cervical cancer revealed strong resonances at a chemical shift of 3.25 ppm corresponding to choline. Data acquired from the 18 posttreatment setting studies was variable, but often correlated well with the clinical findings. Biopsy confirmation was obtained in seven patients. H1 MRS of the cervix using a noninvasive pelvic coil consistently demonstrates reproducible spectral differences between normal and neoplastic cervical tissue in vivo. However, signal is still poor for minimal disease recurrence. Further study is needed at intervals before, during, and after definitive irradiation with biopsy confirmation to validate the accuracy of MRS in distinguishing persistence or recurrence of disease from necrosis and fibrosis.


Assuntos
Espectroscopia de Ressonância Magnética , Neoplasias do Colo do Útero/diagnóstico , Adulto , Feminino , Humanos , Pessoa de Meia-Idade , Neoplasias do Colo do Útero/patologia , Neoplasias do Colo do Útero/radioterapia
19.
Hosp Pharm ; 22(9): 871-6, 1987 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-10312222

RESUMO

The amount of i.v. drugs wasted in our centralized i.v. admixture program was initially identified as a problem in 1982. The i.v. drug waste in 1982 was approximately $72,000, which represented 8.8% of the total i.v. drug budget. The i.v. admixture workload had also increased 35% from 1980 to 1982. The pharmacy department decided to approach the i.v. drug waste and increased workload problem by purchasing premixed i.v. solutions. The objective of this study was to evaluate whether premixed i.v. solutions are cost effective by decreasing both drug waste and i.v. preparation time. In addition, pharmacy standardized the doses of various i.v. drugs and instituted an on-call card system for the ordering of selected drug by nursing. By using the above methods, the pharmacy department was able to absorb an additional 37% increase in workload from 196,418 units in 1982 to 269,176 units in 1985. Also, pharmacy was able to reduce the i.v. drug waste from 8.8% of the i.v. budget in 1982, to 2.35% of the 1985 i.v. budget. Both of these goals was achieved without additional staff.


Assuntos
Eficiência , Infusões Intravenosas/economia , Sistemas de Medicação no Hospital/economia , Gestão de Recursos Humanos , Admissão e Escalonamento de Pessoal , Serviço de Farmácia Hospitalar/organização & administração , Análise Custo-Benefício , Hospitais com mais de 500 Leitos , Minnesota
20.
J Gastrointest Surg ; 18(11): 2016-25, 2014 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-25227638

RESUMO

BACKGROUND: Pancreatectomy with venous reconstruction (VR) for pancreatic cancer (PC) is occurring more commonly. Few studies have examined the long-term patency of the superior mesenteric-portal vein confluence following reconstruction. METHODS: From 2007 to 2013, patients who underwent pancreatic resection with VR for PC were classified by type of reconstruction. Patency of VR was assessed using surveillance computed tomographic imaging obtained from date of surgery to last follow-up. RESULTS: VR was performed in 43 patients and included the following: tangential resection with primary repair (7, 16%) or saphenous vein patch (9, 21%); segmental resection with splenic vein division and either primary anastomosis (10, 23%) or internal jugular vein interposition (8, 19%); or segmental resection with splenic vein preservation and either primary anastomosis (3, 7%) or interposition grafting (6, 14%). All patients were instructed to take aspirin after surgery; low molecular weight heparin was not routinely used. An occluded VR was found in four (9%) of the 43 patients at a median follow-up of 13 months; median time to detection of thrombosis in the four patients was 72 days (range 16-238). CONCLUSIONS: Pancreatectomy with VR can be performed with high patency rates. The optimal postoperative pharmacologic therapy to prevent thrombosis requires further investigation.


Assuntos
Veias Mesentéricas/cirurgia , Pancreatectomia/métodos , Neoplasias Pancreáticas/cirurgia , Veia Porta/cirurgia , Grau de Desobstrução Vascular/fisiologia , Procedimentos Cirúrgicos Vasculares/métodos , Idoso , Estudos de Coortes , Feminino , Seguimentos , Humanos , Estimativa de Kaplan-Meier , Masculino , Pessoa de Meia-Idade , Pancreatectomia/efeitos adversos , Neoplasias Pancreáticas/mortalidade , Neoplasias Pancreáticas/patologia , Complicações Pós-Operatórias/mortalidade , Complicações Pós-Operatórias/fisiopatologia , Complicações Pós-Operatórias/terapia , Procedimentos de Cirurgia Plástica/métodos , Estudos Retrospectivos , Medição de Risco , Análise de Sobrevida , Resultado do Tratamento
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA