All VCS offices are closed Thursday, November 26 and Friday, November 27. Wishing you and yours a safe and happy holiday!

Gregory S. Sibley, M.D.


Radiation Oncology

Primary Location

10301 Democracy Lane
Fairfax, VA 22030

Phone Number

(703) 934-4450

Gregory S. Sibley, M.D.

Board Certification

American Board of Radiology


University of Chicago


University of Chicago


St. Joseph Mercy Hospital

Medical School

University of Michigan


Dr. Gregory S. Sibley joins Virginia Cancer Specialists after serving as Radiation Oncologist and chair of the Cancer Committee at Sibley Memorial Hospital in Washington, D.C. for 14 years.  Throughout his career, Dr. Sibley has focused on providing the highest quality care in the field of radiation oncology. He has positioned himself as an expert in the multi-disciplinary treatment of cancer and in state-of-the-art radiation treatment planning techniques. Highly active in the medical community, Dr. Sibley is a member of multiple associations, including the American Society of Clinical Oncology and the American Society of Therapeutic Radiation Oncology. Dr. Sibley has authored over 20 peer-reviewed publications, many while on faculty at Duke University Medical Center. Although well-versed in the treatment of multiple cancers, Dr. Sibley has special interest in prostate cancer, having performed over 600 brachytherapy procedures, as well as breast, head and neck, lung, and gastrointestinal cancers. 

In his spare time, Dr. Sibley is an avid hockey player and triathlete.

Physician Awards

Best Doctors 2014

Virginia Living Magazine


Top Doctor 2012

Washingtonian Magazine


Top Doctor 2010

Washingtonian Magazine


Top Doctor 2008

Washingtonian Magazine