Analysis of focused laser differential interferometry.

A computational method for predicting the output of a focused laser differential interferometer (FLDI) given an arbitrary density field is presented. The method is verified against analytical predictions and experimental data. The FLDI simulation software is applied to the problem of measuring Mack-mode wave packets in a hypervelocity boundary layer on a 5° half-angle cone. The software is shown to complement experiments by providing the necessary information to allow quantitative density fluctuation magnitudes to be extracted from experimental measurements.

Effects of estrogen on congnition mood, and degenerative brain diseases.

OBJECTIVE: To review research findings on the effects of estrogen on cognition, mood, memory, and degenerative brain disease in women. DATA SOURCES: English-language journal articles published primarily since 1995, retrieved from a MEDLINE search and from bibliographies of selected reviews. STUDY SELECTION: Investigational studies, clinical trials, and review articles examining the effects of estrogen on the central nervous system. DATA SYNTHESIS: Although scientific study of the brain is in its infancy, numerous studies indicate that estrogen is essential to optimal brain function. Estrogen has been shown to increase cerebral blood flow, act as an antiinflammatory agent, enhance activity at neuronal synapses, and exert direct neuroprotective and neurotrophic effects on brain tissue. Through these varied mechanisms, estrogen strongly influences mood and cognition, and the decline of this hormone at menopause can produce significant emotional and cognitive problems in women. CONCLUSION: Pharmacists can educate women about the various mood and memory changes that can occur during perimenopause and how estrogen replacement therapy may lead to improvements in brain function. The potential use of estrogen replacement therapy to reduce the risk of Alzheimer's disease and ease the symptoms of Parkinson's disease could have a profound effect on women, their families, and society as a whole.

Decision analysis for the cost-effective management of recurrent colorectal cancer.

OBJECTIVE: To determine whether the use of [(18)F]2-fluoro-2-deoxyglucose positron emission tomography (FDG PET) in addition to computed axial tomography (CT) is helpful in managing recurrent colorectal cancer (CRC). SUMMARY BACKGROUND DATA: There is no consensus on a management algorithm for CRC. However, when recurrence is suspected, CT is generally used for further evaluation and staging of disease. METHODS: The authors used decision trees based on theoretical models to assess the cost-effectiveness of a CT + FDG PET strategy for the diagnosis and management of recurrent CRC compared with a CT-alone strategy. These theoretical models focus on patients with hepatic recurrence who are potentially curable through surgical hepatic resection. The population entering the decision trees consisted of patients with CRC who had undergone surgical resection of their primary CRC and who were suspected of having recurrence based on elevated levels of carcinoembryonic antigen. RESULTS: The CT + FDG PET strategy was found to be cost-effective for managing patients with elevated carcinoembryonic antigen levels who were candidates for hepatic resection. The CT + FDG PET strategy was higher in mean cost by $429 per patient but resulted in an increase in the mean life expectancy of 9.527 days per patient. CONCLUSIONS: These results show, through rigorous decision tree analysis, the potential cost-effectiveness of FDG PET in the management of recurrent CRC. The decision trees can be used to model various features of the management of recurrent CRC, including the cost-effectiveness of other newly emerging technologies.

A review of the literature for whole-body FDG PET in the management of patients with melanoma.

BACKGROUND: A review and meta-analysis of the literature on the use of 2-[18F]fluoro-2-deoxy-D-glucose (FDG) positron emission tomography (PET) in the detection of recurrent melanoma was conducted. The goals were to evaluate the quality of data reporting and to determine the overall values for the sensitivity and specificity of whole body FDG PET and management changes. METHODS: Guidelines to evaluate reporting within articles were formulated based on the United States medical payer source criteria for assessing studies reporting information on the utilization of new medical technology. A meta-analysis was conducted using methodology described in the peer reviewed literature. RESULTS: Our MEDLINE PLUS search resulted in a universe of 89 total articles. Within these 89, 19 were categorized in our targeted content area of which 13 were selected for analysis in our targeted subset, with the remaining 70 covering 24 different related content areas. Five of 13 (38%) articles in the target subset reported data which was adequate for incorporation into modeling objectives based on PET sensitivity and specificity values, with 1 of 13 (8%) in the same target subset reporting data adequate for modeling based on change-in-management data. Through a meta-analysis of the 13 target articles we determined, within a 95% confidence level, an overall sensitivity of 92% (95% confidence level 88.41%-95.82%) and an overall specificity of 90% (95% confidence level 83.26%-96.05%) as calculated by number of lesions, for FDG PET detecting recurrent melanoma throughout the whole body. Furthermore, limited data available for change-in-management suggests an overall FDG PET directed change-in-management value of 22%. CONCLUSIONS: Our review suggests that improvements can be made to more effectively report the results of these FDG PET studies. The overall values determined through the meta-analysis indicate the potential benefits of using FDG PET as a diagnostic/management tool. Furthermore, these values should prove useful to assessing the cost effectiveness of utilizing FDG PET in the management of recurrent melanoma.

A meta-analysis of the literature for whole-body FDG PET detection of recurrent colorectal cancer.

UNLABELLED: A meta-analysis of the literature for the use of FDG PET in the detection of recurrent colorectal cancer (CRC) was conducted to evaluate the quality of the reported studies. Overall values for the sensitivity and specificity of whole-body FDG PET and an overall FDG PET-directed percentage change in management were also determined through this analysis. METHODS: Guidelines to evaluate the articles were formulated on the basis of the U.S. medical payer source criteria for assessing studies that report information on usage of new medical technology. A metaanalysis was conducted using methodology described in the peer-reviewed literature. RESULTS: On the basis of the guidelines established for our review, the availability of necessary information for assessing the reliability of the FDG PET data for diagnosing recurrent CRC was less than ideal. Through a meta-analysis of 11 articles, we determined, within a 95% confidence level, an overall sensitivity of 97% (95% confidence level, 95%-99%) and an overall specificity of 76% (95% confidence level, 64%-88%) for FDG PET detecting recurrent CRC throughout the whole body. Furthermore, through pooling of the change-in-management data, an overall FDG PET-directed change in management was calculated to be 29% (95% confidence level, 25%-34%). CONCLUSION: Our review suggests that improvements can be made to more effectively report the results of these FDG PET studies. The overall values determined through the meta-analysis indicate the potential benefits of using FDG PET as a diagnostic or management tool. Furthermore, these values should prove to be useful to assess the cost-effectiveness of using FDG PET in the management of patients with recurrent CRC.

Current strategies for prevention, detection, and treatment of ovarian cancer.

OBJECTIVE: To review the prevalence, etiology, risk factors, diagnosis, and treatment of ovarian cancer. DATA SOURCES: English-language journal articles retrieved from a MEDLINE search from 1990 to the present, and selected references retrieved from the bibliographies of those articles. STUDY SELECTION: Clinical trials and pertinent review articles that discussed the detection, prevention, and clinical management of ovarian cancer. DATA SYNTHESIS: Although relatively uncommon, ovarian cancer is the leading cause of mortality from gynecologic cancer. Because most ovarian cancers are not detected until the disease has metastasized beyond the ovary, the 5-year survival rate for all cases is only 50%. Pharmacists can educate women about strategies that can reduce ovarian cancer risk, especially the use of oral contraceptives. To aid in earlier detection, pharmacists also should be aware of the nonspecific symptoms that can be associated with the disease, and refer women with suggestive symptoms to their physicians for further evaluation. Treatment usually consists of hysterectomy with debulking surgery to remove as much tumor as possible, followed by chemotherapy, for which the current gold standard is cisplatin and paclitaxel. CONCLUSION: Pharmacist-provided education can help women reduce their risk of ovarian cancer. As integral members of the health care team, pharmacists also can optimize the efficacy and tolerability of chemotherapeutic regimens; assist with palliative care for nausea, vomiting, and pain; and serve as a resource for patient information and support.

Analytical decision model for the cost-effective management of solitary pulmonary nodules.

PURPOSE AND METHODS: Multiple strategies are currently being used to manage patients who present with indeterminate solitary pulmonary nodules (SPN). We have used decision-analysis models to assess the cost-effectiveness of various strategies for the diagnosis and management of SPN. Four decision strategies were compared: a wait and watch strategy, a surgery strategy, a computed tomography (CT)-based strategy, and a CT-plus-positron emission tomography (PET) strategy. An incremental cost-effectiveness ratio (ICER) was used to compare all strategies to the wait and watch strategy. RESULTS: A CT-plus-PET strategy was the most cost-effective over a large pretest likelihood (probability of having a malignant nodule), with a range of 0.12 to 0.69. Furthermore, within this likelihood range, the potential cost savings of using the CT-plus-PET strategy over the CT strategy ranged from $91 to $2,200 per patient. This translates to a yearly national savings of approximately $62.7 million. CONCLUSION: Decision-analysis modeling indicates the potential cost-effectiveness of [18F]2-fluoro-2-deoxy-D-glucose (FDG)-PET in the management of SPN. Furthermore, the decision trees developed can be used to model various features of the management of SPN, including modeling the cost-effectiveness of other newly emerging technologies.

MD@: a physician-friendly decision analysis tool.

The cost-effective use of medical resources is increasingly important in justifying strategies for medical diagnosis and management. Although some software is available to help with decision analysis, it can be difficult to use these tools for medical applications. We have developed a prototype package for modeling various medical decision strategies, which can be used with a Macintosh or Windows-based personal computer. The system is graphically based, intuitive, and user-friendly. The user constructs decision trees for comparing alternative strategies for diagnosis and management. Selecting blocks from a library, the user sets mean values for variables such as prevalence, sensitivity, specificity, cost, morbidity, and mortality. The system then generates the probabilities of various pathways, using Bayesian analysis, without requiring the user to enter equations. It displays the best strategy in terms of a particular criterion and, when appropriate, performs sensitivity analysis.

Exenteration as palliation for patients with advanced pelvic malignancy.

OBJECTIVE: To examine the place of pelvic exenteration in the palliation of advanced and recurrent pelvic tumours. PATIENTS AND METHODS: The notes of patients referred for palliative exenteration were reviewed retrospectively. Fourteen patients (three men, mean age 52 years, and 11 women, mean age 61 years) with a variety of pelvic tumours associated with severe symptoms, had a laparotomy with a view to pelvic exenteration and 10 underwent total or anterior exenteration. RESULTS: Eight patients achieved excellent or good palliation based on survival and quality of life assessment, and two received no benefit. Four of eight patients were alive and apparently free of tumour at a mean of 17 months after surgery. Four were alive, symptom-free but with evidence of malignancy at a mean of 19 months. Two patients who received no benefit died at 2 and 7 months after surgery. The planned exenteration was abandoned in four patients; three of these four patients were dead at a mean of 13 months and one was alive at 12 months. CONCLUSION: Our results confirm that with careful selection and appropriate multi-specialty care, aggressive pelvic surgery is of value in the palliation of some tumours.