Christopher Watchman

Christopher Watchman

Associate Professor

Contact Information

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Christopher Watchman, PhD, DABR is a clinical academic medical physicist who serves as the medical physics residency program director in the Department of Radiation Oncology, Banner University Medical Center Tucson. He is a certified by the American Board of Radiology and is an Associate Professor in the Department of Radiation Oncology at the University of Arizona. Dr. Watchman received his bachelor’s degree in physics and Exercise Physiology from Brigham Young University, a master’s degree in physics with an emphasis in Health Physics from Idaho State University and then completed a PhD in medical physics at the University of Florida. Following his doctorate, he joined the Department of Radiation of Oncology at the University of Arizona as a postdoctoral associate and then as a medical physics resident. He then joined the faculty as an assistant professor. During his time in the department, he served as the Director of the Professional Science Degree Program in Medical Physics. He then went to Memorial Sloan Kettering Cancer Center and served as the Education Director for the Department of Medical Physics, where he over saw education and training programs, including their medical physics residency program. He recently returned to the Department of Radiation Oncology at Banner University Medical Center and now serves as the program director for the medical physics residency. Dr. Watchman’s research interests are in medical physics education and training, adaptive therapy, and radiopharmaceutical dosimetry.

Professional memberships or affiliations:

American Association of Physicists in Medicine (AAPM)

American Society of Therapeutic Radiation Oncology (ASTRO)

American College of Radiology (ACR)

Arizona Chapter of American Association of Physicist in Medicine

Society of Directors of Academic Medical Physics Programs

Radiological and Medical Physics Society



Board Certifications: 

American Board of Radiology 

Clinical Practice Sites: 
The University of Arizona Cancer Center - North Campus
Radiation Oncology


University of Arizona, Tucson, AZ
Medical School: 
University of Florida, Gainesville, FL
Master's Degree: 
Idaho State University, Pocatello, ID
Undergraduate School: 
Brigham Young University, Provo, UT


Selected Publications: 

DA Rajon, PW Patton, AP Shah, CJ Watchman, WE Bolch. “Surface Area Overestimation Within 3D Digital Images and Its Consequence for Skeletal Dosimetry”.  Medical Physics 29(5)682-93, 2002.

DA Rajon, DW Jokisch, PW Patton, AP Shah, CJ Watchman, and WE Bolch. “Voxel Effects within Digital Images of Trabecular Bone and Their Consequences on Chord-length Distribution Measurements”. Physics Medicine and Biology 47(10)1741-59, 2002.

DA Rajon, AP Shah, CJ Watchman, JM Brindle, WE Bolch.  “A hyperboloid representation of the bone-marrow interface within 3D NMR images of trabecular bone: applications to skeletal dosimetry”. Physics Medicine and Biology 48(12) 1721-40, 2003.

CJ Watchman, DW Jokisch, PW Patton, DA Rajon, G Sgouros, WE Bolch. “Absorbed Fractions for Alpha Particles in Tissues of Trabecular Bone: Considerations of Marrow Cellularity within the ICRP Reference Male”.  Journal of Nuclear Medicine 46(7)1171-85, 2005.

AP Shah, DW Jokisch, DA Rajon, CJ Watchman, PW Patton, WE Bolch. “Chord Based versus Voxel Based Methods of Electron Transport in Skeletal Dosimetry”.  Medical Physics 32(10)3151-9, 2005

CJ Watchman, VA Bourke, JR Lyon, AE Knowlton, SL Butler, DD Grier, J Wingard, R Braylan, WE Bolch. “Spatial Distribution of Blood Vessels and CD34+ Hematopoietic stem and progenitor Cells within the Marrow Cavities of human cancellous bone”. Journal of Medical Physics 48(4) 645-654, 2007

CJ Watchman, DA Hasenauer, WE Bolch. “Derivation of Skeletal Masses within the Current ICRP Age Series”. Physics Medicine and Biology (52) 3133 2007

JG Hunt, CJ Watchman, WE Bolch. “Calculation of Absorbed Fractions to Human Skeletal Tissues Due to Alpha Particles Using the Monte Carlo and Chord Based Techniques”. Radiation Protection Dosimetry 2007 127(1-4):223-6

WE Bolch, AP Shah, CJ Watchman, DW Jokisch, PW Patton, DA Rajon, M Zankl, N Petoussi-Henss, KF Eckerman. “Skeletal Absorbed Fractions for Electrons and Alpha Particle in the Adult Male – Consideration of a Revised 50-mm Definition of the Bone Endosteum.” Radiation Protection Dosimetry 2007 127(1-4):169-73

LA Ewell, CJ Watchman, K Wharton. “Sulci Density Map to Aid Use of Apparent Diffusion Coefficient for Therapy Evaluation”. Magnetic Resonance Imaging 26 (2008) 20-25

CJ Watchman, RJ Hamilton, B Stea, AJ Mignault. “Patient Positioning Using Implanted Gold Markers with the Novalis Body System in the Thoracic Spine”. Neurosurgery 62:A62-A68, 2008.

VA Bourke, CJ Watchman, JD. Reith, M Jorgensen, A Dieudonnè, and WE. Bolch. “Spatial Gradients of Blood Vessels and Hematopoietic Stem and Progenitor Cells Within the Marrow Cavities of the Human Skeleton.”  Blood 114(19) 4077-80, 2009.

DA Pafundi, C Lee, CJ Watchman, VA Bourke, J Arnis, N Shagina, J Harrison, T Fell, WE Bolch. “An Image Based Skeletal Tissue Model for the ICRP Reference Newborn.”  Physics Medicine and Biology 54(14):4497-531 2009

CJ Watchman, WE Bolch. “Absorbed Fractions for Alpha Particles in Tissues of Cortical Bone”. Physics Medicine and Biology 54 (2009) 6009-6027

Hadad, K, Ganapol, BD, Hamilton, RJ, Watchman, CJ, & Xu, Y. “Dose assessment to heart and lungs in HDR breast brachytherapy”. Transactions of the American Nuclear Society. (Vol. 101, pp. 1097-1099) 2009

Hadad, K., Ganapol, B. D., Hamilton, R., & Watchman, C.  “Dose verification for accelerated partial breast irradiation". American Nuclear Society - International Conference on Mathematics, Computational Methods and Reactor Physics 2009, M and C 2009. (Vol. 2, pp. 1371-1381) 2009

NP Nguyen, M Ceizyk, P Vos, V Vinh-Hung, R Davis, A Desai, D Abraham, SP Krafft, S Jang, CJ Watchman, LA Ewell, RJ Hamilton, L Smith-Raymond.  “Effectiveness of Image Guided-Radiotherapy for Laryngeal Sparing in Head and Neck Cancer”. Oral Oncology (2010) 46(4) 283-6

NP Nguyen, SP Krafft, P Vos, V Vinh-Hung, M Ceizyk, SJ Jang, A Desai, D Abrahm, LA Ewell, CJ Watchman, RJ Hamilton, BH Jo, U Karlsson, L Smith-Raymond. “Feasibility of Tomotherapy for Graves’ Opthalmopathy.” Strahlentherapi und Onkologie 187(9)568-574 2011.

A Bhullar, CJ Watchman. “The Effective Depth of Cylindrical Ionization Chambers in Water for Clinical Proton Beams”.  Physics Medicine and Biology Physics Medicine and Biology 57(1) 273 2012.

RF Hobbs, H Song, CJ Watchman, WE Bolch, AK Aksnes, T Ramdahl, GD Flux, G Sgouros. “Bone Marrow Toxicity Considerations from 223Ra Alpha-emitter Radiopharmaceutical Therapy.” Physics Medicine and Biology 57 3207 (2012).

CJ Watchman, C Cheng, JM Galvin, JD Fontenot, S Jiang, FF Yin.  “ACR-AAPM Technical Standard for Medical Physics Performance Monitoring of Image-Guided Radiation Therapy (IGRT) (Resolution 36)”. 2014 

CJ Watchman, MA Pacella, MC Schell, JD Fontenot, JA Garret, DC Pavord.  “ACR-AAPM Technical Standard for the Performance of Radiation Oncology Physics for External Beam Therapy” (Resolutions 52). 2015

D Mandair, Q Ho, B Wertheim, G Johnson, D Roe, CJ Watchman, S Yi. “Comparison of Two Thermoplastic Mask Systems in Daily Volumetric Image Guided Radiation Therapy for Head and Neck Cancers.”  Biomedical Physics & Engineering Express, 4(2018) 055007.

MA. Pacella, JP Masten, DL Schofield, CJ Watchman. “ACR–AAPM Practice Parameter On The Expert Witness in Medical Physics (VSC/BOD),, Revised 2018 (CSC/BOC).

Mirzapour M, Hadad K, Faghihi R, Hamilton, RJ, Watchman CJ. “Fast Monte-Carlo Photon Transport Employing GPU Based Parallel Computation.” IEEE Transactions on Radiation and Plasma Medical Sciences, DOI: 10.1109/TRPMS.2020.2972202 Vol 4 Iss 4 Pg 450-460, 2020.

PH Halverson, JL Johnson, HM Lincoln, CJ Watchman, C Clift, D DiCostanzo, K Moore, L Olsen. “ACR-AAPM Technical Standard For External-Beam Radiation Therapy Treatment Planning” 2021 (CSC/BOC).