Therapeutic Radiation Oncology

Therapeutic Radiation Oncology has proudly served the metro Atlanta area for more than 30 years. The team of eight highly qualified radiation oncologists staff seven Piedmont Radiation Oncology centers through- out greater Atlanta.

John Giesler, MD, is a senior partner of Therapeutic Radiation Oncology and a certified member of Piedmont’s MD Anderson Cancer Network. He completed his radiation oncology training at the University of Texas MD Anderson Cancer Center.

Diana Santiago, MD, is also a senior partner of Therapeutic Radiation Oncology and serves
as medical director at Piedmont Newnan Hospital Radiation Oncology. Dr. Santiago is a member of Piedmont’s MD Anderson Cancer Network and serves on the board of directors. She completed her medical degree and residency training at the Medical University of South Carolina.

Geetha Rao, MD, serves as medical director at Piedmont Fayette Radiation Oncology. She is on the board of directors for the hospital and is a certified member of the MD Anderson Cancer Network. She graduated from Duke University Medical School and completed residency at the University of Michigan Hospital.

Kim Neisler, MD, serves as medical director at Piedmont Henry Hospital Radiation Oncology. She graduated from the University of Tennessee College of Medicine and completed residency at the Medical University of South Carolina. She
is a certified member of the MD Anderson Cancer Network.

Sasha Wahab, MD, completed his medical degree and residency training at Washington University in St. Louis. He is a certified member of Piedmont’s MD Anderson Cancer Network. He has been published in multiple peer-reviewed journals and has presented his work internationally.