Lars A. Ewell, PhD

Assistant Professor, Radiation Oncology

E-Mail Address: 
lewell@email.arizona.edu
Phone Number: 
520-626-5769
Fax: 
520-626-9328
Short Bio: 

Dr. Ewell earned his undergraduate degree in engineering physics and his graduate degree in nuclear physics at the University of Illinois. He received his doctorate in experimental nuclear physics at Iowa State University, and completed residency training in medical physics at the University of Michigan.

Dr. Ewell joined the Department of Radiation Oncology at the Arizona Cancer Center, as assistant professor in 2004. His interests span clinical, research and teaching. He is also interested in issues pertaining to border health. Dr. Ewell is committed to incorporating the latest technological advances in clinical practice, in order to provide patients with innovative treatment options. His research is focused on scattering corrections to therapy and imaging radiation beams and the use of Monte Carlo simulations to aid in such corrections. Dr. Ewell has established an imaging protocol to evaluate the use of magnetic resonance spectroscopy (MRS), also known as chemical shift imaging (CSI), and diffusion weighted MRI (DWMRI) to differentiate between recurrent disease and radiation induced necrosis (RIN) in patients with glioma. Regarding teaching, Dr. Ewell realizes the importance of diffusing knowledge, and enjoys teaching medical physics to radiation therapists, medical residents and other interested parties.

Clinical/Research Information
Member Status: 
Comprehensive Member
Program: 
2. Cancer Imaging
Home Department: 
Radiation Oncology
Academic Title: 
Assistant Professor
Clinical Practice Sites: 
Radiation Oncology Clinic
Selected Publications: 
Ewell L, 'Therapeutic Applications of Monte Carlo Calculations in Nuclear Medicine,' Medical Physics 30(9), 2566, Sept. 2003.
 
Ewell L, Lam K, 'S_p Predictions: Beam Quality and Energy Distribution' SU-GG-PDS-10, Medical Physics 31(6), 1732, June 2004.
 
Vijayakumar N, Ewell L, 'Relationship of Uncertainty in Pixel Intensity to Apparent Diffusion Coefficient Calculation' SU-FF-I-77, Medical Physics 34(6), 2355, June 2007.
 
Ewell L and Vijayakumar N, 'The Dependence of Apparent Diffusion Coefficient on B-values and Voxel Location,' International Journal of Radiation Oncology Biology Physics, 69(3) Supplement 1, S713, 1 November 2007.
 
McDaniels T and Ewell L, 'Method for Determining Apparent Diffusion Coefficient (ADC) Values for Cerebral Lesions from Diffusion Weighted Magnetic Imaging (DWMRI) Examinations,' SU-GG-I-126, Medical Physics 35(6), 2671 June 2008.
 
Ewell L, Watchman C, Wharton K, Sulci density map to aid in use of apparent diffusion coefficient for therapy evaluation. Magn. Reson. Imag. 26 (2008) 20-25.
 
Ewell L, Vijayakumar N, Rodriguez J, Stea B, 'Inferior Brain Lesions Monitored Using Diffusion Weighted Magnetic Resonance Imaging' 2008. Sino-American Network for Therapeutic Radiology and Oncology. August 28-30, Beijing, China.
 
Bhullar A, Ewell L, McDaniels T, Stea B, Metabolic Concentrations and Ratios of Brain Tissue. Frontiers in Medical Research, University Medical Center, Tucson, AZ (2008).
Academic/Professional Information
Residency: 
University of Michigan
Doctorate: 
Iowa State University
Master's Degree: 
University of Illinois
Undergraduate School: 
University of Illinois
Board Certifications: 
  • American Board of Radiology (ABR) in Therapeutic Radiological Physics
Honors: 
  • Nominated to chair American Physical Society session 'Hadron Distributions and Fluctuations' of the Fall 2001 Division of Nuclear Physics meeting in Maui.
  • GAANN fellowship four consecutive years (1991-1995), awarded to the top six graduate students at Iowa State University.