Browsing by Author "Kamer, Aaron P."

Now showing 1 - 6 of 6
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    Confronting the US's Highly Uneven State-by-State Distribution of Diagnostic Radiology Residency Positions
    (Elsevier, 2019-11) Mukhtar, Mohsin; Davis, Korbin; Kamer, Aaron P.; Gunderman, Richard B.; Radiology and Imaging Sciences, School of Medicine
    The state-by-state distribution of diagnostic radiology residency positions is important for several reasons. The location in which residents train is positively correlated with their eventual practice location, and states with relatively few residents may have greater difficulty meeting needs for radiology services ( 1 ). The presence of residents can also enrich the educational experiences of other learners such as medical students, but this is less likely to happen when residents are in short supply ( 2 ). Finally, because residency training programs can promote a culture of inquiry, a dearth of residents may undermine intellectual engagement within a professional community ( 3 ).
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    Contrast Leakage Patterns from Dynamic Susceptibility Contrast Perfusion MRI in the Grading of Primary Pediatric Brain Tumors
    (2016) Ho, Chang Y.; Cardinal, Jeremy S.; Kamer, Aaron P.; Lin, Chen; Kralik, Stephen F.; Department of Radiology and Imaging Sciences, IU School of Medicine
    BACKGROUND AND PURPOSE: The pattern of contrast leakage from DSC tissue signal intensity time curves have shown utility in distinguishing adult brain neoplasms, but has limited description in the literature for pediatric brain tumors. The purpose of this study is to evaluate the utility of grading pediatric brain tumors with this technique. MATERIALS AND METHODS: A retrospective review of tissue signal-intensity time curves from 63 pediatric brain tumors with preoperative DSC perfusion MR imaging was performed independently by 2 neuroradiologists. Tissue signal-intensity time curves were generated from ROIs placed in the highest perceived tumor relative CBV. The postbolus portion of the curve was independently classified as returning to baseline, continuing above baseline (T1-dominant contrast leakage), or failing to return to baseline (T2*-dominant contrast leakage). Interobserver agreement of curve classification was evaluated by using the Cohen κ. A consensus classification of curve type was obtained in discrepant cases, and the consensus classification was compared with tumor histology and World Health Organization grade. RESULTS: Tissue signal-intensity time curve classification concordance was 0.69 (95% CI, 0.54–0.84) overall and 0.79 (95% CI, 0.59–0.91) for a T1-dominant contrast leakage pattern. Twenty-five of 25 tumors with consensus T1-dominant contrast leakage were low-grade (positive predictive value, 1.0; 95% CI, 0.83–1.00). By comparison, tumors with consensus T2*-dominant contrast leakage or return to baseline were predominantly high-grade (10/15 and 15/23, respectively) with a high negative predictive value (1.0; 95% CI, 0.83–1.0). For pilomyxoid or pilocytic astrocytomas, a T1-dominant leak demonstrated high sensitivity (0.91; 95% CI, 0.70–0.98) and specificity (0.90, 95% CI, 0.75–0.97). CONCLUSIONS: There was good interobserver agreement in the classification of DSC perfusion tissue signal-intensity time curves for pediatric brain tumors, particularly for T1-dominant leakage. Among patients with pediatric brain tumors, a T1-dominant leakage pattern is highly specific for a low-grade tumor and demonstrates high sensitivity and specificity for pilocytic or pilomyxoid astrocytomas.
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    Institutional Pressure to Reduce Report Turnaround Time Is Damaging the Educational Mission
    (Elsevier, 2017-04) Heitkamp, Darel E.; Kamer, Aaron P.; Koontz, Nicholas A.; Radiology and Imaging Sciences, School of Medicine
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    Radiosurgery dose reduction for brain metastases on immunotherapy (RADREMI): A prospective phase I study protocol
    (Elsevier, 2020) McClelland, Shearwood, III.; Lautenschlaeger, Tim; Zang, Yong; Hanna, Nasser H.; Shiue, Kevin; Kamer, Aaron P.; Agrawal, Namita; Ellsworth, Susannah G.; Rhome, Ryan M.; Watson, Gordon A.; Radiation Oncology, School of Medicine
    Introduction: Up to 20% of patients with brain metastases treated with immune checkpoint inhibitor (ICI) therapy and concomitant stereotactic radiosurgery (SRS) suffer from symptomatic radiation necrosis. The goal of this study is to evaluate Radiosurgery Dose Reduction for Brain Metastases on Immunotherapy (RADREMI) on six-month symptomatic radiation necrosis rates. Methods: This study is a prospective single arm Phase I pilot study which will recruit patients with brain metastases receiving ICI delivered within 30 days before SRS. All patients will be treated with RADREMI dosing, which involves SRS doses of 18 Gy for 0-2 cm lesions, 14 Gy for 2.1-3 cm lesions, and 12 Gy for 3.1-4 cm lesions. All patients will be monitored for six-month symptomatic radiation necrosis (defined as a six-month rate of clinical symptomatology requiring steroid administration and/or operative intervention concomitant with imaging findings consistent with radiation necrosis) and six-month local control. We expect that RADREMI dosing will significantly reduce the symptomatic radiation necrosis rate of concomitant SRS + ICI without significantly sacrificing the local control obtained by the present RTOG 90-05 SRS dosing schema. Local control will be defined according to the Response Assessment in Neuro-Oncology (RANO) criteria. Discussion: This study is the first prospective trial to investigate the safety of dose-reduced SRS in treatment of brain metastases with concomitant ICI. The findings should provide fertile soil for future multi-institutional collaborative efficacy trials of RADREMI dosing for this patient population.
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    Toward Data-Driven Radiology Education—Early Experience Building Multi-Institutional Academic Trainee Interpretation Log Database (MATILDA)
    (Springer, 2016-12) Chen, Po-Hao; Loehfelm, Thomas W.; Kamer, Aaron P.; Lemmon, Andrew B.; Cook, Tessa S.; Kohli, Marc D.; Radiology and Imaging Sciences, School of Medicine
    The residency review committee of the Accreditation Council of Graduate Medical Education (ACGME) collects data on resident exam volume and sets minimum requirements. However, this data is not made readily available, and the ACGME does not share their tools or methodology. It is therefore difficult to assess the integrity of the data and determine if it truly reflects relevant aspects of the resident experience. This manuscript describes our experience creating a multi-institutional case log, incorporating data from three American diagnostic radiology residency programs. Each of the three sites independently established automated query pipelines from the various radiology information systems in their respective hospital groups, thereby creating a resident-specific database. Then, the three institutional resident case log databases were aggregated into a single centralized database schema. Three hundred thirty residents and 2,905,923 radiologic examinations over a 4-year span were catalogued using 11 ACGME categories. Our experience highlights big data challenges including internal data heterogeneity and external data discrepancies faced by informatics researchers.
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    Transitioning to Independent Practice: A Successful Fourth-Year Radiology Resident Curriculum
    (Elsevier, 2017-12) Heitkamp, Darel E.; Ford, Jason M.; Madden, Colleen M.; Smith, Kevin L.; Nartker, Matthew J.; Ponting, John M.; Steenburg, Scott D.; Aaron, Vasantha D.; Kamer, Aaron P.; Radiology and Imaging Sciences, School of Medicine