Faculty and Staff

The Department of Radiation Medicine is made up of a diverse group of radiation oncologists, medical physicists, residents, and clinical staff. Get to know more about who'll be assisting during your treatment!

                                                Jump to:  Department leadership   |  Faculty   |   Residents   |   Clinical staff   |   Support staff

Arthur Hung, M.D.

Arthur Hung, M.D.

Arthur Hung, M.D. is interim chair of the Department of Radiation Medicine and associate professor of radiation medicine and associate professor of ophthalmology. Dr. Hung serves as medical director of the Radiation Therapy Training Program. He specializes in genitourinary oncology (treating cancers of the reproductive organs) and soft tissue sarcomas (cancers of the soft tissues of the body), but treats all types of cancer.

Dr. Hung earned undergraduate engineering and history degrees from Rice University before receiving his medical degree from The Ohio State University in 1997. He then completed an internship at St. Joseph’s Hospital in Denver and residency training at M.D. Anderson Cancer Center in Houston. He joined OHSU in 2002 and has clinical affiliations with Hillsboro Medical Center and the VA Portland Health Care System.

Bayouth_John_2017_400x400_PLACEHOLDER

John Bayouth, Ph.D. is the Chief Medical Physicist of the Department of Radiation Medicine. 

Dr. Bayouth earned bachelor's and master's degree from the Kansas State University. He holds a doctoral degree in radiation physics from MD Anderson and completed a research fellowship in radiation physics with MD Anderson. His research interests have been in Radiation-induced changes in pulmonary function and MRI/Image Guided Radiation Therapy.  

Kevin Keen

Kevin Keen is the Department Administrator of the Department of Radiation Medicine. Kevin graduated from the University of Arkansas at Fayetteville with a Bachelor’s of Science in Business Administration. He attended the University of Arkansas for Medical Sciences’ (UAMS) College of Public Health and graduated with a Masters in Health Administration while interning under the campus CFO. He then completed an administrative fellowship at the UAMS Medical Center during which he was fortunate to work on several projects with the leadership of the Rockefeller Cancer Institute. Kevin accepted a position with the Rockefeller Cancer Institute following his fellowship, and for five years worked alongside many incredible leaders, striving to improve access and outcomes for cancer patients in Arkansas. During this time, he was proud to support their Radiation Oncology Center as they achieved ASTRO’s APEx accreditation, opened satellite treatment facilities in underserved areas, and began construction of Arkansas’ first proton therapy center.

Angela Arevalo Smith, M.B.A.

Angela is the Clinical Practice Manager of the Department of Radiation Medicine. She manages the department's patient access services specialists and patient operations. She has bachelor’s degree in business and MBA.  When she is not working, she is busy managing her household, enjoying the PNW, trying to squeeze in a 20 minute workout or planning the next family travel adventure. 

Ellen Huntington, M.B.A., R.T.(R)(ARRT)

Ellen is the Radiation Therapy Manager of the Department of Radiation Medicine. She manages the department's radiation therapists and clinical operations. She received her Bachelor’s degree from Southern Illinois University and her Master’s degree from the University of Cincinnati.  She enjoys being outdoors and spends her time at the beach, cycling, camping and kayaking. 

Marita Keppel

Marita is the Financial Administrator of the Department of Radiation Medicine. She has been at OHSU since 2007, previously serving as Division Manager in the Division of Arthritis & Rheumatic Diseases and Financial Administrator in the Center for Embryonic Cell & Gene Therapy. In her spare time, she enjoys going to the theater, watching the Oregon Symphony, hiking and hanging out with her pup, Duke Ellington.

Michelle Bednar, R.N., B.S.N., O.C.N.

Michelle is the Nurse Manager in Ambulatory Oncology. She serves as nurse manager for all of ambulatory oncology, the nursing team in Department of Radiation Medicine.  As nurse manager she strives to continuously improve patient experience and the quality of clinical care. She received her bachelor’s degree in biology from Centre College in Kentucky and her BSN from Bellarmine University. She enjoys traveling, hiking, and spending time with friends and family.

Faculty

Aaron Grossberg, M.D., Ph.D.
Aaron Grossberg, M.D., Ph.D.
Blair Murphy MD
Blair Murphy M.D.
Josh Walker, M.D., Ph.D.
Josh Walker, M.D., Ph.D.
Kiri Cook, MD
Kiri Cook, M.D.
Michael Marietta
Michael Marietta, M.D.
Nima Nabavizadeh, M.D.
Nima Nabavizadeh, M.D.
Pehr Hartvigson, M.D.
Pehr Hartvigson, M.D.
Randy Moore DO
Randy Moore, D.O.
Reid Thompson, M.D., Ph.D.
Reid Thompson, M.D., Ph.D.
Sylvia K. Gosline, M.D.
Sylvia K. Gosline, M.D.
Timur Mitin, M.D., Ph.D.
Timur Mitin, M.D., Ph.D.
Christopher Aguilera, M.S.
Christopher Aguilera, M.S.
Junan Zhang, Ph.D.
Junan Zhang, Ph.D.
Faculty_ Malcolm Heard
Malcolm Heard, Ph.D.
Monica Kishore, M.S.
Monica Kishore, M.S.
Faculty_Stephanie Junell
Stephanie Junell, Ph.D.

Residents

Carl Post, M.D.

Dr. Post is a chief resident (PGY-5) in the Department of Radiation Medicine. He received a medical degree from University of Nebraska College of Medicine and a bachelor’s degree in biochemistry from University of Nebraska-Lincoln. He completed his internship year at Presence Saint Francis Hospital in Evanston, Illinois.

Hans Kim, M.D.

Dr. Kim is a chief resident (PGY-5)  in the Department of Radiation Medicine. He received a medical degree from State University of New York Upstate Medical University, a bachelor’s degree in chemistry from University of Pennsylvania, and a degree in biology and chemistry from Ajou University in South Korea. He completed his internship year at OHSU's Department of Surgery in Portland, Oregon.

Mohammad Hissourou III, M.D.

Dr. Hissourou is a chief resident (PGY-5) in the Department of Radiation Medicine. He received his medical degree from Icahn School of Medicine at Mount Sinai. In addition to her medical degree, Dr. Hissourou holds an undergraduate from Columbia College-Columbia University in biology and an undergraduate - SUNY Stony Brook University in biology. He completed his internship year at Northwell Health.

Jehan Yahya, M.D.

Dr. Yahya is a PGY-4 resident in the Department of Radiation Medicine. She received her medical degree from Oregon Health and Science University and completed her internship year  at Henry Ford Hospital in Detroit, Michigan. In addition to her medical degree, Dr. Yahya has a bachelor’s degree in biology and Hispanic studies, as well as a minor in chemistry from Lewis and Clark College in Portland.

Kim Ohaegbulam, M.D., Ph.D.

Dr. Ohaegbulam is a PGY-4 resident in the Department of Radiation Medicine. He received his medical degree (M.D./Ph.D.) from Albert Einstein College of Medicine and completed his internship year in medicine at Hofstra/Northwell in Forest Hills, New York. In addition to his medical degree, Dr. Ohaegbulam has a bachelor’s degree in biomedical science from the University of South Florida and a master’s degree in biomedical science from the Albert Einstein College of Medicine.

Cymon Kersch, M.D., Ph.D.

Dr. Kersch is a PGY-2 resident with the Department of Radiation Medicine. She received her medical degree (M.D./Ph.D.) from Oregon Health and Science University and completed her preliminary internship at Providence Portland Medical Center. In addition to her medical degree, Dr. Kersch has an undergraduate degree from University of Puget Sound in molecular and cellular biology, a graduate from Texas A&M University in entomology.

Jason Burton, M.D., Ph.D.

Dr. Burton is a PGY-2 resident with the Department of Radiation Medicine. He received his medical degree (M.D./Ph.D.) from University of Texas Rio Grande Valley School of Medicine and completed his internship year preliminary year at Dartmouth Hitchcock Medical Center. In addition to his medical degree, Dr. Burton has two undergraduate degrees, one from Dixie State University and one from Brigham Young University in biophysics. He also received a graduate degree from Baylor College of Medicine in integrative molecular and biomedical sciences.

Ana Dieguez, M.S.

Ms. Dieguez is a PGY-2 medical physics resident. She received her bachelor of science in physics from the Universidad del Valle de Guatemala and her master of science in medical physics from Louisiana State University.

Elizabeth Park, M.S.

Ms. Park is a PGY-1 medical physics resident with the Department of Radiation Medicine. She received a bachelor of science in nuclear engineering, minoring in mathematics and physics, from Missouri University of Science and Technology and was granted the distinction of magna cum laude. She earned her master of science in medical physics from Louisiana State University in 2022.

Clincal staff

Marquam Hill

Bonnie Luedloff

Bonnie is lead radiation therapist and serves as a member of the Student Advisory Committee. She has been part of the OHSU team since 2003 and was part of the team to treat the first patient in Kohler Pavilion.  She enjoys hiking the Pacific Northwest with family, friends and her black lab Lucy.

Elsbeth Allanketner

Elsbeth is a radiation therapist. She has lived in Portland, Oregon since 2000. In her free time, she enjoys spending time with her family, gardening, and hiking.

Jillian Bacon

Jillian is a radiation therapist. She received her training at OHSU and Oregon State University. Jillian is from Pocatello, Idaho and enjoys sampling new foods and trying new restaurants. She also loves watching the Portland Trailblazers win (go ‘zers!).

JoAnne Reasoner

JoAnne is a radiation therapist. She received her bachelor’s degree in Radiation Therapy from OHSU. Joanne was previously a vet tech for eight years. In her free time, she enjoys travelling with her husband and three dogs, as well as dog training and cooking.

Julia Ryan

Julia is a radiation therapist who specializing in simulation. She received her bachelor’s degree in Radiation Therapy from OHSU. Her hobbies include camping, gardening, and spending time with her partner and dogs.

Linette Chapman

Linette is a radiation therapist.  She began working in radiation medicine in 2007 and joined the team permanently in 2008.  She loves to globe trot, go to the beach, and hang out with friends/family.

Ramon Sison

Ramon is a radiation therapist. He received his bachelor’s degree in Radiation Therapy from OHSU in 2003. In his earlier days, he worked as a karaoke dj.

Rebecca Botaitis

Rebecca is a lead radiation therapist.  She has received degrees from Oregon State University and OHSU. Rebecca is a native of the Pacific Northwest and enjoys hiking outdoors in all weather, reading books, making crafts and traveling the world.

Beaverton

Hilary Dekker

Hilary is a radiation therapist based at the Beaverton Cancer Clinic.

Linea O'Brien

Linea is a radiation therapist. She is based at the Beaverton Cancer Clinic. Linea graduated from OHSU's radiation therapy program in 2009 and became a member of the team shortly after. She enjoys helping and caring for patients, as well as the technical challenges of working with the machines. In her free time, she enjoys playing video games and board games, watching movies, and spending time with her friends, family, and cats.

Marquam Hill

Alexis Graf, B.S.N.

Alexis is a registered nurse. She has been with OHSU since 2003, working part-time in radiation medicine and previously the transplant department. Her favorite part of being a nurse is the opportunity to build relationships with those that she serves. In her free time, she enjoys running, camping, spending time with her four boys.

Amy Budwill, B.S.N.

Amy is a registered nurse. She studied Anthropology and Global Health at University of Washington, and received her BSN from OHSU. Amy is originally from Seattle, Washington and in her free time she enjoys traveling and hiking.

Angel Franklin, B.S.N.

Angel is a registered nurse. She received a Bachelor’s degree in Nursing from Washington State University and has always had a passion for the Oncology nursing field. Angel has always lived in the Pacific Northwest and enjoys spending time with her family and traveling

Litti K. Bledsoe, B.S.N.

Litti is a registered nurse. She enjoying spending time with her husband and two daughters and loves exploring the outdoors when the weather is nice.

Maggie Rising, R.N., J.D., Ph.D.

Maggie is a part-time resource registered nurse. She also holds faculty appointments at PCC and UP. She loves outdoor activities, exercise, yard work, music, theater, reading and learning more about others. She's the proud mom of 2 grown boys (in their twenties) and lives with her 2 spoiled dogs and ancient kitty.

Swastika “Tika” Weigel, B.S.N.

Tika is a registered nurse. She and radiation medicine in 2018 and has been a part of OHSU since her first job at 16 years old. Tika was raised here in Portland Oregon and in her free time she loves to volunteer in the community, travel and spend time outdoors with her husband and puppy.

Beaverton

Jennifer Lockhart, R.N.

Jennifer is a registered nurse and an oncology certified nurse. She is based at the Beaverton Cancer Clinic. She joined Radiation Medicine in 2007. Jennifer is an active member in ONS Mt Hood Chapter, American Society for Radiation Oncology, and an active participant in unit-based nursing practice committee. During her time off she enjoys taking care of her family, cooking, and outdoor activities.

Marquam Hill

Amy Longsdon M.S., RT(R)(T), C.M.D.

Amy is a certified medical dosimetrist who joined OHSU in 2018.  She enjoys playing a role in caring for our patients by collaborating with her colleagues to solve challenging treatment planning cases.  In her free time she loves hiking and backpacking with her husband and their two dogs

Barbara Agrimson C.M.D., R.T. (R)(T)

Barb is a certified medical dosimetrist and serves as clinical coordinator of the OHSU Radiation Therapy Program. She has previous experience as a radiation therapist. In her free time, she enjoys spending time with her husband and two daughters at the Oregon Coast.

Chhipo Sath, M.S., C.M.D.

Chhipo is a certified medical dosimetrist.  He completed his graduate studies here at OHSU in 2010 and joined the treatment planning team in 2019. He enjoys teaching and working closely with students and residents in Radiation Oncology, Medical Physics and Radiation Therapy programs. In his free time he loves traveling, hiking and playing with his nieces and nephews.

Debra Monaco C.M.D., R.T. (R)(T)

Debbie is certified medical dosimetrist.  She has been certified since 1992.  She is a native Oregonian who enjoys the outdoors.  She likes to hike, camp, kayak and play with her huskies.

Lori Willette C.M.D., B.S.R.T. (R)(T)

Lori is a certified medical dosimetrist.  She joined OHSU in 2016 and enjoys getting to work closely with other members of the medical team, the technical challenges of treatment planning, and playing a part in caring for patients. In her free time she loves traveling and glamping with her husband and 2 boys.

Steve Rhodes, B.S. R.T.(T),C.M.D.

Steve is a certified medical dosimetrist. He first started working at OHSU in 2004 as a radiation therapist before becoming a dosimetrist in 2007.  Prior to his career in radiation medicine, Steve was a secondary school science teacher for 4 years. In his free time, he likes to travel, workout, and walk the dogs.

Beaverton

George Soriano

George is a medical assistant and paramedic. He is originally from El Paso, Texas. In his free time, he enjoys grilling, playing the guitar, favorite sport watching baseball (go Dodgers!).

Emily York

Peter Bennett, L.C.S.W.

Peter is a licensed clinical social worker (LCSW) and has oncology social work certification (OSW-C). He received a master's degree in Social Work from Portland State University and holds bachelor's degree degrees in history and French from the University of Michigan. He aims to help people in cancer treatment with a range of assistance, from practical support to counseling and referrals to local support resources. Peter enjoys spending time with his family and in exploring the beauty of the natural world. 

Susan Hedlund, M.S.W., L.C.S.W., O.S.W-C.

Susan is a licensed clinical social worker (LCSW) and certified oncology social work. She received master's degree in social work from Portland State University and a bachelor's degree from University of California. Susan has been an oncology social worker for over 30 years and specializes in the development and provision of psychosocial support services for people with cancer and their loved ones. She currently supervises adult oncology social workers at OHSU and coordinate wellness offerings of yoga, mindfulness-based stress reduction, exercise, massage, and retreats for people with cancer.

Katherine Bagwell, R.D., L.D.

Katherine is a registered and licensed dietitian. She works with patients who have breast, lung, sarcoma, blood cancer, melanomas, brain tumors, and head and neck cancers. Learn more about cancer nutrition services.

Angie Rademacher, N.D., L.Ac., R.N.

Angie is a naturopathic doctor specializing in acupuncture with a special interest in oncology. She holds a doctorate in naturopathic medicine, a master's degree in oriental medicine, and a bachelor's degree of nursing. Learn more about Dr. Rademacher's work.

Support staff

Marquam Hill

Megan Johnson

Megan is a patient access specialist (PAS). She graduated from Oregon State University with a degree in Human Development and Family Sciences. Megan is originally from California and enjoys spending time with family, photography, and traveling.

Rachel Gray

Rachel is a patient access specialist (PAS) in the Department of Radiation Medicine.

Beaverton

Tammy Zell

Tammy is a patient access specialist (PAS). She is based at the Beaverton Cancer Clinic. Tammy is originally from South Dakota and has been living in Oregon for since 2000. In her free time, she enjoys spending time with her daughter, watching the Blazers and other sports, and going to the movies.

Cassidy Tyre

Cassidy is the HR Coordinator supporting the Department of Radiation Medicine. She has received a bachelor’s degree in psychology and human development from Washington State University in Vancouver, Washington. Cassidy is originally from Tennessee, but has been living in Washington for over 13 years now. In her free time, she enjoys spending time with her family and friends, traveling, shopping, and telling dad jokes.

Margaret Hutchins

Margaret is the administrative assistant for the Department of Radiation Medicine. Her passions outside of work include a multitude of outdoor sports such as outrigger canoeing, softball, or snowshoeing. Alongside her love of nature, she can also be found in her home studio, drinking coffee, listening to vinyl, and working on large scale paintings. 

Rebecca Bowen

Rebecca is the administrative assistant for the physics divisionShe loves the Pacific Northwest and has lived here since the age of four. She has a degree in communication studies and a degree in American history. In her free time, she enjoys practicing Irish dance, eating too much ice cream, providing obscure history facts during trivia, and traveling.

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