Zachary Robinett

Weber State University, Ogden, Utah, United States

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Publications (3)3.46 Total impact

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    ABSTRACT: To compare long-term quality-of-life outcomes in vestibular schwannoma patients managed with observation, microsurgery, or stereotactic radiation. ross-sectional survey with retrospective chart review. Tertiary care center. The Penn Acoustic Neuroma Quality of Life (PANQOL) survey was mailed to 600 patients treated for vestibular schwannoma. Patients were separated by treatment and subsequently subdivided by years of follow-up (0-5, 6-10, and >10 years). Composite quality-of-life (cQOL) scores and subscores for hearing, balance, facial nerve, pain, anxiety, energy, and general health were calculated. Scores were compared among treatment groups as a whole, among treatment groups at each time interval, and within treatment groups over time using a 2-tailed analysis of variance and paired t test. The survey return rate was 49%, and the mean follow-up was 7.9 years. The only significant difference in cQOL occurred at 0 to 5 years, where stereotactic radiation scores were better than both microsurgery and observation (P = .009). No significant differences were detected in cQOL after 5 years. Within the radiation group, cQOL was significantly lower at 6 to 10 years than at 0 to 5 years (P = .013). At no point was cQOL for stereotactic radiation less than that for observation or microsurgery. Long-term (>5 years) quality-of-life outcomes measured by the PANQOL in vestibular schwannoma patients show no significant differences between stereotactic radiation, observation, and microsurgical intervention. Studies are needed to fully evaluate very-long-term QOL for patients with vestibular schwannoma.
    Otolaryngology Head and Neck Surgery 03/2014; · 1.73 Impact Factor
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    ABSTRACT: Objective To compare 3-D segmented volumetric analysis of vestibular schwannomas (VS) with traditional linear tumor measurement on serial magnetic resonance imaging (MRI) studies to assess volume and growth rates. Study Design Case series with retrospective chart review. Setting Tertiary care medical center. Methods This analysis identified 24 VS patients clinically followed with serial gadolinium enhanced images. Maximum linear dimensions (MLD) were obtained from gadolinium-contrasted T1 sequences from 3 serial MRI scans per RECIST guidelines. MLD was cubed (MLD(3)) and orthogonal analysis (OA) was carried out to provide volumetric estimates for comparison with segmented data. Segmented volumetric analysis (SVA) was performed with semi-automated 3-D conformal procedure. Tumor volume, percentage change in volume, and interval percentage change were compared using paired 2-tailed t tests. Results The average interval between MRIs was 2.6 years. Volume estimates differed significantly between SVA and OA and MLD(3) at all intervals. Linear growth measurements averaged 0.5 mm/y (5.4%). Volumetric growth was 50 mm(3)/y (22.8%) with SVA, 110 mm(3)/y (19.6%) with OA, and 210 mm(3)/y (14.4%) with MLD(3) estimates. Differences between MLD and both MLD(3) and SVA were significant, but significance between MLD(3) and SVA was only identified in interval analysis. Progression was identified in 75% more patients with SVA than OA, MLD(3), or MLD. Conclusions VS assume complex configurations. Linear measurements inaccurately estimate tumor volume and growth compared with segmented analysis. SVA is a useful clinical tool that accurately assesses tumor volume. Use of outcomes such as tumor volume and percentage of volume change may be more sensitive in assessing tumor progression compared with linear measurements.
    Otolaryngology Head and Neck Surgery 05/2012; 147(4):737-43. · 1.73 Impact Factor
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    ABSTRACT: Each year the United States population receives an estimated 12 to 14 million units of packed red blood cells (RBCs) and whole blood. It is estimated that 33% of transfusions associated with trauma are with unmatched type O RBCs (UORBC). UORBCs have been proven effective and relatively safe however, by masking RBC surface antigens the risk of transfusion reaction may be further decreased. It is, therefore, important to evaluate and validate the stability of antigen masked RBCs, which may play a part in avoiding transfusion reactions. These antigen-masked RBCs would be regularly subjected to abnormal in vivo conditions commonly associated with massive transfusion such as lactic acidosis, bacteremia, and in vitro irradiation, which is frequently used to sterilize and decrease T Lymphocyte counts in RBC units before transfusion. This study compared two methods of masking RBC antigens by PEGylation: maleimide-PEGylation and cyanuric chloride-PEGylation. RBC PEGylation effectively masks the Rh(D) antigen and PEG-RBC bond stability was evaluated by comparison of pre and post exposure agglutination with anti-D sera. While the stability of maleimide-PEG-RBCs remained unaffected, the cyanuric chloride-PEG-RBCs remained stable in the bacteremia and irradiation studies, but critical concentrations of lactic acid caused dePEGylation. Further studies are warranted to ensure in vivo stability.
    Clinical laboratory science: journal of the American Society for Medical Technology 01/2011; 24(4):227-32.