Meet Our Providers

Nathan Cannon MD

Nathan Cannon, MD

Nathan Cannon, MD attended Saint Louis University School of Medicine where he completed medical school and a PhD in Molecular Microbiology and Immunology. He then completed residency at the University of of Texas Southwestern where he continued researching the safety and efficacy of stereotactic radiation therapy for cancers of the brain, lung and kidney. Dr. Cannon chose to pursue radiation oncology to help people who were facing a difficult and life changing challenge with far-reaching consequences for themselves and their families. He believes that patients should feel empowered in their decisions. The patients he works with are the most rewarding part of his job.

Brian Chang MD

Brian K Chang, MD

Dr. Brian Chang is a board-certified radiation oncologist who joined Radiation Oncology Associates in 2007 after completing his residency in radiation oncology at the University of Texas Southwestern Medical Center, where he served as Chief resident for two years.  Dr. Chang has written a number of first author publications in peer reviewed journals and a textbook chapter on topics ranging from Hodgkin’s Lymphoma and locally advanced lung cancer to stereotactic radiosurgery and stereotactic body radiation therapy, in collaboration with the leaders in those respective fields of radiation oncology.  He has also served as an expert reviewer of radiosurgery publications for the American Journal of Clinical Oncology.  Dr. Chang is the Principal Investigator of Radiation Therapy Oncology Group (RTOG) trials in Fort Wayne, the leading clinical trials group in Radiation Oncology, where he feels he can make a real difference in the battle against cancer by offering access to the most cutting edge therapies to the patients in the region in his continual efforts to improve their survival and quality of life.

Dr. Chang’s clinical areas of interest and expertise include High Dose Rate (HDR) Brachytherapy for gynecological and breast cancers, IMRT, intracranial radiosurgery, Stereotactic Body Radiation Therapy (SBRT), and combined modality therapy.      

Nathan Comsia, MD

Nathan Comsia, MD

Dr. Comsia, an experienced radiation oncologist, comes to ROA from Loyola University's Department of Radiation Oncology where he served as Co-Chief Resident. Prior to residency, Dr. Comsia was extensively involved in ground-breaking medical research that included studies on radiation therapy sponsored by the American Cancer Society.

Dr. Comsia is a member in ASTRO (American Society for Radiation Oncology), RSNA (Radiological Society of North America), ABS (American Brachytherapy Society), and CRS (Chicago Radiological Society).

Mark Ranck, MD

Mark Ranck, MD

Dr. Mark Ranck joined Radiation Oncology Associates in 2013. He received his medical degree from the Virginia Commonwealth University School of Medicine located in Richmond, Virginia. He then completed a residency in Radiation Oncology in the Department of Radiation and Cellular Oncology at the University of Chicago, where he served as Chief Resident. Dr. Ranck has traveled extensively both domestically and internationally to gain advanced training in radiation oncology technologies and has made dedicated efforts in international outreach and the promotion of global health efforts in the field of oncology. He is also interested in scientific research and how this will help further the practice of medicine and improve outcomes for patients. He has presented research at several national meetings, authored numerous articles for peer-reviewed journals covering topics as diverse as the use of stereotactic body radiation therapy (SBRT) to preclinical models used in the study of head and neck cancer. For this work, he was awarded a Radiological Society of North America Resident/Fellow Research Award in 2013.

Wesley Russell, MD

Wesley Russell, MD

Dr. Russell joined Radiation Oncology Associates in 2013. Dr. Russell received his medical degree from Washington University School of Medicine in St. Louis, Missouri and completed his training as Chief Resident in Radiation Oncology at Rush University Medical Center in Chicago, Illinois. Dr. Russell has held multiple leadership positions in professional organizations and community outreach programs and has received numerous academic awards and distinctions.

Charles Vu, MD

Charles Vu, MD

Dr. Charles Vu received his undergraduate degree from Princeton University, where he graduated magna cum laude and Phi Beta Kappa. He received his M.D. degree from Stony Brook University in New York and completed his residency at William Beaumont Hospital in Michigan, where he served as chief resident. He has published research on prostate and lung cancers in peer-reviewed journals and presented research on breast and gynecologic malignancies at national conferences. During residency, he received grant funding for his research applying artificial intelligence to radiation oncology. Dr. Vu believes that each patient’s cancer journey is unique, with its own challenges and intricacies. The patients and the individualized care that he can provide with radiation are what drives Dr. Vu’s passion for his field.

Zhigang Yuan, MD

Zhigang Yuan, MD

Dr. Zhigang Yuan received his medical degree from Florida State University College of Medicine and completed his residency in Radiation Oncology at Moffitt Cancer Center in Tampa, Florida. He also holds a PhD in Cancer Biology with specific interest in integrating individual tumor biology into the application of radiation therapy. He was involved in clinical research and novel clinical trial development, especially utilizing radiomics, genomics and the combination of radiation and immunotherapy. His research has led to many publications and presentations at national conferences. He strives to bring new treatment modalities into clinics with the effort to personalize radiation therapy tailored to each individual patient, and the tumor biology to improve clinical outcomes.

Melanie Pequignot, MPAS, PA-C

Melanie Pequignot, MPAS, PA-C

Melanie, a northeast Indiana native, joined the practice in 2020. 

She received her CNA certificate in 2003 and worked in Assisted Living and Inpatient Neurology settings until 2007. Attending the University of St. Francis in Fort Wayne, Melanie received her Masters of Science in Physician Assistant Studies in 2009.
 
Her experience in the field of Oncology includes:

  • Interventional Radiology/Interventional Oncology with Indiana Radiology Partners at IU Hospital in Indianapolis from 2009-2012.
  • Gynecologic Oncology/Surgical Oncology in Fort Wayne from 2012-2020.
  • Melanie is an active member of the  American Academy of Physician Assistants (AAPA) and Indiana Academy of Physician Assistants (IAPA).
Rebecca Brown, AANP, FNP-C

Rebecca Brown, AANP, FNP-C

Becca, a Fort Wayne native, is the newest member of the ROA staff, joining the practice in 2022. 

She began her healthcare career as a phlebotomist in 1998.  She became a medical laboratory scientist in 2002 and worked in the inpatient laboratory before transitioning into management in an outpatient setting.  She received her nursing degree in 2007 where she has worked in preoperative, post-operative, and PACU in the hospital setting, as well as orthopedics, and has experience in nursing management.  She received her MSN in Nursing Administration at Ball State University and her post Masters FNP at the University of Southern Indiana.  After completing her NP certification, she spent 3 years in surgical oncology prior to joining ROA.  

Becca is an active member of American Association of Nurse Practitioners (AANP), Coalition of Advanced Practice Nurses of Indiana (CAPNI), and Junior League of Fort Wayne.