Time filter

Source Type

Minneapolis, MN, United States

Hayashi N.,Health Science University | Malmin R.L.,Ridgeview Regional Radiation Oncology | Watanabe Y.,420 Delaware St. SE
Journal of Radiation Research

Several tools are used for the dosimetric verification of intensity-modulated arc therapy (IMAT) treatment delivery. However, limited information is available for composite on-line evaluation of these tools. The purpose of this study was to evaluate the dosimetric verification of IMAT treatment plans using a 2D diode array detector (2D array), radiochromic film (RCF) and radiosensitive polymer gel dosimeter (RPGD). The specific verification plans were created for IMAT for two prostate cancer patients by use of the clinical treatment plans. Accordingly, the IMAT deliveries were performed with the 2D array on a gantry-mounting device, RCF in a cylindrical acrylic phantom, and the RPGD in two cylindrical phantoms. After the irradiation, the planar dose distributions from the 2D array and the RCFs, and the 3D dose distributions from the RPGD measurements were compared with the calculated dose distributions using the gamma analysis method (3% dose difference and 3-mm distance-to-agreement criterion), dose-dependent dose difference diagrams, dose difference histograms, and isodose distributions. The gamma passing rates of 2D array, RCFs and RPGD for one patient were 99.5%, 96.5% and 93.7%, respectively; the corresponding values for the second patient were 97.5%, 92.6% and 92.9%. Mean percentage differences between the RPGD measured and calculated doses in 3D volumes containing PTVs were -0.29 ± 7.1% and 0.97 ± 7.6% for the two patients, respectively. In conclusion, IMAT prostate plans can be delivered with high accuracy, although the 3D measurements indicated less satisfactory agreement with the treatment plans, mainly due to the dosimetric inaccuracy in low-dose regions of the RPGD measurements. © 2014 The Author 2014. Published by Oxford University Press on behalf of The Japan Radiation Research Society and Japanese Society for Radiation Oncology. Source

Clark C.J.,University of Minnesota | Borowsky I.W.,University of Minnesota | Salisbury J.,Rainbow Health Initiative | Usher J.,Rainbow Health Initiative | And 5 more authors.
Preventive Medicine

Objective: To examine long-term cardiovascular disease (CVD) risk disparities by sexual identity using a nationally representative sample of young adults in the United States. Methods: Data include participants in wave 4 (2008/09; ages 24-34. years) of the National Longitudinal Study of Adolescent to Adult Health (7087 females; 6340 males). Sexual identity was self-reported (heterosexual, mostly heterosexual, bisexual, mostly homosexual, homosexual) and a Framingham-based prediction model was used to estimate participants' risk of a CVD event over 30. years. Differences in CVD risk by sexual identity, relative to heterosexuals, were calculated with linear regression models adjusted for age, race/ethnicity, education, and financial distress. Results: Average 30-year CVD risk was 17.2% (95% CI: 16.7, 17.7) in males and 9.0% (95% CI: 8.6, 9.3) in females. Compared to heterosexual females, mostly heterosexual (0.8%; 95% CI: 0.2, 1.4) and mostly homosexual females (2.8%; 95% CI: 0.8, 4.9) had higher CVD risk. Bisexual and homosexual females had higher but not statistically significant CVD risk compared to heterosexuals. Among males, differences in CVD risk by sexual identity were not statistically significant. Conclusion: Sexual identity was associated with CVD risk in sexual minority subgroups. Population- and clinic-based prevention strategies are needed to minimize disparities in subsequent disease. © 2015 Elsevier Inc. Source

Abraham J.M.,420 Delaware St. SE | Crespin D.J.,420 Delaware St. SE | Rothman A.J.,University of Minnesota
Journal of Occupational and Environmental Medicine

To investigate the initiation and maintenance of participation in an employer-based wellness program that provides financial incentives for fitness center utilization. Methods: Using multivariate analysis, we investigated how employees' demographics, health status, exercise-related factors, and lifestyle change preferences affect program participation. Results: Forty-two percent of eligible employees participated in the program, and 24% earned a $20 incentive at least once by utilizing a gym eight times or more in a month. On average, participants utilized fitness centers 7.0 months each year and earned credit 4.5 months. Participants' utilization diminished after their first year in the program. Conclusions: Factors associated with initiation and maintenance of fitness center utilization were similar. Declining utilization over time raises concern about the long-run effectiveness of fitness-focused wellness programs. Employers may want to consider additional levers to positively reinforce participation. © 2015 American College of Occupational and Environmental Medicine. Source

Vydra J.,420 Delaware St. SE | Shanley R.M.,Masonic Cancer Center | George I.,420 Delaware St. SE | Ustun C.,420 Delaware St. SE | And 2 more authors.
Clinical Infectious Diseases

Background. Enterococci are an important cause of healthcare-associated infections. We retrospectively analyzed risk factors and outcome of vancomycin-resistant enterococci (VRE) and vancomycin-sensitive enterococci (VSE) infections.Methods.Seven hundred fifty-two patients who received hematopoietic stem cell transplants from 2004 through 2008 at the University of Minnesota were included.Results.Ninety-three patients had enterococcal bloodstream infection (BSI) during the first year after transplant. Vancomycin resistance was observed in 66 and 31 of isolates in adults and children, respectively. Cumulative incidence of VRE and VSE bacteremia was 6.6 (95 confidence interval [CI], 4.8-8.4) and 5.7 (95 CI, 4.0-7.4), respectively. Colonization with VRE before or after transplant was a risk factor for VRE bacteremia (odds ratio [OR], 3.3 [95 CI, 1.3-8.3] and 7.0 [95 CI, 4.0-14.8], respectively). Delay in engraftment increased the incidence of VRE bacteremia from 4.5 (95 CI, 2.9-6.6) if engrafted before day 21 and to 15 (95 CI, 3.2-38) if engrafted between days 36 and 42. In adults, mortality 30 days after infection was 38 for both VRE (95 CI, 25-54) and VSE cases (95 CI, 21-62). The hazard ratio for all-cause mortality up to 1 year after transplant was 4.2 (95 CI, 3.1-6.9) and 2.7 (95 CI, 1.4-5.1) for patients with VRE and VSE BSIs, respectively, compared to patients without enterococcal BSI. In pediatric patients, mortality 30 days after VRE and VSE bacteremia was 20 (95 CI, 5.4-59) and 4.5 (95 CI,. 6-28), respectively.Conclusion.High rates of vancomycin resistance and association of enterococcal infections with significant mortality warrant further efforts to optimize prevention and management of these infections. © 2012 The Author. Source

Andersen B.M.,420 Delaware St. SE | SantaCruz K.S.,Laboratory Medicine and Pathology | Schutten M.M.,University of Minnesota | Meints J.P.,Laboratory Medicine and Pathology | And 8 more authors.
Cancer Research

Malignant and atypical meningiomas are resistant to standard therapies and associated with poor prognosis. Despite progress in the treatment of other tumors with therapeutic vaccines, this approach has not been tested preclinically or clinically in these tumors. Spontaneous canine meningioma is a clinically meaningful but underutilized model for preclinical testing of novel strategies for aggressive human meningioma. We treated 11 meningioma-bearing dogs with surgery and vaccine immunotherapy consisting of autologous tumor cell lysate combined with toll-like receptor ligands. Therapy was well tolerated, and only one dog had tumor growth that required intervention, with a mean follow up of 585 days. IFN-g-elaborating T cells were detected in the peripheral blood of 2 cases, but vaccine-induced tumor-reactive antibody responses developed in all dogs. Antibody responses were polyclonal, recognizing both intracellular and cell surface antigens, and HSP60 was identified as one common antigen. Tumor-reactive antibodies bound allogeneic canine and human meningiomas, showing common antigens across breed and species. Histologic analysis revealed robust infiltration of antibody-secreting plasma cells into the brain around the tumor in posttreatment compared with pretreatment samples. Tumor-reactive antibodies were capable of inducing antibody-dependent cell-mediated cytotoxicity to autologous and allogeneic tumor cells. These data show the feasibility and immunologic efficacy of vaccine immunotherapy for a large animal model of human meningioma and warrant further development toward human trials. Cancer Res; 73(10); 2987-97. © 2013 AACR. Source

Discover hidden collaborations