432 research outputs found

    On voxel-by-voxel accumulated dose for prostate radiation therapy using deformable image registration.

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    Since delivered dose is rarely the same with planned, we calculated the delivered total dose to ten prostate radiotherapy patients treated with rectal balloons using deformable dose accumulation (DDA) and compared it with the planned dose. The patients were treated with TomoTherapy using two rectal balloon designs: five patients had the Radiadyne balloon (balloon A), and five patients had the EZ-EM balloon (balloon B). Prostate and rectal wall contours were outlined on each pre-treatment MVCT for all patients. Delivered fractional doses were calculated using the MVCT taken immediately prior to delivery. Dose grids were accumulated to the last MVCT using DDA tools in Pinnacle3 TM (v9.100, Philips Radiation Oncology Systems, Fitchburg, USA). Delivered total doses were compared with planned doses using prostate and rectal wall DVHs. The rectal NTCP was calculated based on total delivered and planned doses for all patients using the Lyman model. For 8/10 patients, the rectal wall NTCP calculated using the delivered total dose was less than planned, with seven patients showing a decrease of more than 5% in NTCP. For 2/10 patients studied, the rectal wall NTCP calculated using total delivered dose was 2% higher than planned. This study indicates that for patients receiving hypofractionated radiotherapy for prostate cancer with a rectal balloon, total delivered doses to prostate is similar with planned while delivered dose to rectal walls may be significantly different from planned doses. 8/10 patients show significant correlation between rectal balloon anterior-posterior positions and some VD values

    Chest Swelling and Fever in an Intravenous Drug User

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    This case report describes a sternoclavicular infection in an IV drug user. The history and physical exam suggested an abscess. In the emergency department (ED) the patient refused incision and drainage but did consent to simple needle aspiration. Subsequent culture of the aspirate revealed Pseudomonas aeruginosa. He was admitted for IV antibiotics. After admission, a bone scan suggested the presence of osteomyelitis. The patient refused operative débridement, but ultimately did consent to bedside incision and drainage. By day five, the fever had resolved and the patient signed out AMA. He was given a prescription for Ciprofloxacin. The patient had an unscheduled follow up in the ED five months later for an unrelated heroin overdose. Physical examination demonstrated complete resolution of the infection

    Encapsulation of FITC to monitor extracellular pH: a step towards the development of red blood cells as circulating blood analyte biosensors

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    A need exists for a long-term, minimally-invasive system to monitor blood analytes. For certain analytes, such as glucose in the case of diabetics, a continuous system would help reduce complications. Current methods suffer significant drawbacks, such as low patient compliance for the finger stick test or short lifetime (i.e., 3–7 days) and required calibrations for continuous glucose monitors. Red blood cells (RBCs) are potential biocompatible carriers of sensing assays for long-term monitoring. We demonstrate that RBCs can be loaded with an analyte-sensitive fluorescent dye. In the current study, FITC, a pH-sensitive fluorescent dye, is encapsulated within resealed red cell ghosts. Intracellular FITC reports on extracellular pH: fluorescence intensity increases as extracellular pH increases because the RBC rapidly equilibrates to the pH of the external environment through the chloride-bicarbonate exchanger. The resealed ghost sensors exhibit an excellent ability to reversibly track pH over the physiological pH range with a resolution down to 0.014 pH unit. Dye loading efficiency varies from 30% to 80%. Although complete loading is ideal, it is not necessary, as the fluorescence signal is an integration of all resealed ghosts within the excitation volume. The resealed ghosts could serve as a long-term (>1 to 2 months), continuous, circulating biosensor for the management of diseases, such as diabetes

    Linguistics

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    Contains table of contents for Section 4, an introduction and abstracts for three doctoral dissertations

    Minority-carrier mobility enhancement in p+ InGaAs lattice matched to InP

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    Minority electron mobilities in pf-In0.ssGac4, As have been measured with the zero field time-of-flight technique. The room-temperature (297 K) minority electron mobilities for p+-In,, 53Gac47A~ doped 0.9 and 3.1 x 10” cmm3 are found to be 2900 and 3300 cm* V-’ s-l, respectively. These are the first measurements to demonstrate enhancement in minority-carrier mobility as doping is increased for heavily doped Ines3Gae.4+s. This enhancement in mobility as doping is increased is similar to that observed in p+-GaAs, which has been attributed to reductions in plasmon and carrier-carrier scattering between minority electrons and majority holes

    Evidence-based Surgical Competency Outcomes from the Clinical Readiness Program

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    Objectives: 1) Evaluate the value and strength of a competency framework for identifying and measuring performance requirements for expeditionary surgeons; 2) Verify psychometric integrity of assessment instrumentation for measuring domain knowledge and skills; 3) Identify gaps in knowledge and skills capabilities using assessment strategies; 4) Examine shared variance between knowledge and skills outcomes, and the volume and diversity of routine surgical practice. Background: Expeditionary military surgeons provide care for patients with injuries that extend beyond the care requirements of their routine surgical practice. The readiness of these surgeons to independently provide accurate care in expeditionary contexts is important for casualty care in military and civilian situations. Identifying and closing performance gap areas are essential for assuring readiness. Methods: We implemented evidence-based processes for identifying and measuring the essential performance competencies for expeditionary surgeons. All assessment instrumentation was rigorously examined for psychometric integrity. Performance outcomes were directly measured for expeditionary surgical knowledge and skills and gap areas were identified. Knowledge and skills assessment outcomes were compared, and also compared to the volume and diversity of routine surgical practice to determine shared variance. Results: Outcomes confirmed the integrity of assessment instrumentation and identified significant performance gaps for knowledge and skills in the domain. Conclusions: Identification of domain competencies and performance benchmarks, combined with best-practices in assessment instrumentation, provided a rigorous and defensible framework for quantifying domain competencies. By identifying and implementing strategies for closing performance gap areas, we provide a positive process for assuring surgical competency and clinical readiness

    Effect of Midtreatment PET/CT-Adapted Radiation Therapy With Concurrent Chemotherapy in Patients With Locally Advanced Non–Small-Cell Lung Cancer

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    IMPORTANCE Our previous studies demonstrated that tumors significantly decrease in size and metabolic activity after delivery of 45 Gy of fractionated radiatiotherapy (RT), and that metabolic shrinkage is greater than anatomic shrinkage. This study aimed to determine whether 18F-fludeoxyglucose–positron emission tomography/computed tomography (FDG-PET/CT) acquired during the course of treatment provides an opportunity to deliver higher-dose radiation to the more aggressive areas of the tumor to improve local tumor control without increasing RT-induced lung toxicity (RILT), and possibly improve survival. OBJECTIVE To determine whether adaptive RT can target high-dose radiation to the FDG-avid tumor on midtreatment FDG-PET to improve local tumor control of locally advanced non–small-cell lung cancer (NSCLC). DESIGN, SETTING, AND PARTICIPANTS A phase 2 clinical trial conducted at 2 academic medical centers with 42 patients who had inoperable or unresectable stage II to stage III NSCLC enrolled from November 2008, to May 2012. Patients with poor performance, more than 10% weight loss, poor lung function, and/or oxygen dependence were included, providing that the patients could tolerate the procedures of PET scanning and RT. INTERVENTION Conformal RT was individualized to a fixed risk of RILT (grade >2) and adaptively escalated to the residual tumor defined on midtreatment FDG-PET up to a total dose of 86 Gy in 30 daily fractions. Medically fit patients received concurrent weekly carboplatin plus paclitaxel followed by 3 cycles of consolidation. MAIN OUTCOMES AND MEASURES The primary end point was local tumor control. The trial was designed to achieve a 20% improvement in 2-year control from 34% of our prior clinical trial experience with 63 to 69 Gy in a similar patient population. RESULTS The trial reached its accrual goal of 42 patients: median age, 63 years (range, 45–83 years); male, 28 (67%); smoker or former smoker, 39 (93%); stage III, 38 (90%). Median tumor dose delivered was 83 Gy (range, 63–86 Gy) in 30 daily fractions. Median follow-up for surviving patients was 47 months. The 2-year rates of infield and overall local regional tumor controls (ie, including isolated nodal failure) were 82% (95% CI, 62%–92%) and 62% (95% CI, 43%–77%), respectively. Median overall survival was 25 months (95% CI, 12–32 months). The 2-year and 5-year overall survival rates were 52% (95% CI, 36%–66%) and 30% (95% CI, 16%–45%), respectively. CONCLUSIONS AND RELEVANCE Adapting RT-escalated radiation dose to the FDG-avid tumor detected by midtreatment PET provided a favorable local-regional tumor control. The RTOG 1106 trial is an ongoing clinical trial to validate this finding in a randomized fashion. TRIAL REGISTRATION clinicaltrials.gov Identifier: NCT0119052

    Analysis of cardiac symptoms preceding cardiac arrest

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    Prodromal symptoms and cardiac history were examined in 227 patients with coronary artery disease who were successfully resuscitated after out-of-hospital cardiac arrest. Cardiac arrest was sudden--with either no symptoms or symptoms for less than 1 hour--in 71% of the patients. Nonsudden death--death occurring after more than 1 hour of symptoms--occurred in 29% of the patients. A history of cardiovascular disease was present in 85% of patients with sudden cardiac arrest and in 83% with nonsudden arrest. Cardiac arrest occurred without symptoms in 38% of the patients with sudden cardiac arrest and was the first expression of coronary artery disease in 4% of the entire study group. This study indicates that cardiac arrest usually occurs with symptoms and almost always in the setting of a history of cardiovascular disease.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/25967/1/0000033.pd

    The effect of bystander CPR on survival of out-of-hospital cardiac arrest victims

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    The effect of bystander cardiopulmonary resuscitation (CPR) was studied in 2142 emergency medical service (EMS) cardiac arrest runs. When bystander CPR was administered to cardiac arrest victims, 22.9% of the victims survived until they were admitted to the hospital and 11.9% were discharged alive. In comparison, the statistics for cardiac arrest victims who did not receive bystander CPR were 14.6% and 4.7%, respectively (p < 0.001). A critical factor in patient survival was the amount of time that elapsed before the EMS personnel arrived and administered CPR. Patients who received bystander CPR were more likely to have ventricular fibrillation when the EMS arrived. Other factors relating to patient survival were the location of the victim at the time of the cardiac arrest and the age of the victim. Understanding these factors is important in developing community strategies to treat patients with cardiac arrest out of hospital.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/25928/1/0000491.pd
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