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Doctor Profile |
Sylvia S. Hendrix, MD
Central Virginia Radiation Oncologists PC
Dr. Sylvia Hendrix was born in Baltimore. She attended medical school at the University of North Carolina at Chapel Hill, where she was a Morehead Scholar. (Go Heels!) She completed her internship at North Carolina Memorial Hospital and came to Virginia to finish her residency at the University of Virginia. Dr. Hendrix joined Martha Jefferson's Cancer Care Center in 1994. Her clinical interests include intensity modulated radiotherapy and seed implantation for prostate cancer patients, breast cancer, skin cancer, and lung cancer.
Dr. Hendrix dreams of having hobbies someday but is currently busy with 13-year-old twin daughters. Her husband, John Hendrix, is a MOHS surgeon in private practice in Charlottesville.
Martha Jefferson Hospital has recently expanded its services to lung and esophageal patients with the arrival of thoracic surgeon Chris Willms, MD. Radiation oncology is also expanding and now offers respiratory gating for cancer patients who have intrathoracic, upper abdominal, and left-sided breast cancers and are receiving external beam radiotherapy. Respiratory gating synchronizes the patient's respiratory cycle to the simulator (a diagnostic quality CT scan) and a specially equipped linear accelerator. This video-based respiration monitoring system tracks and records the patient's normal breathing pattern. During the planning session, the position of the patient's lower chest is monitored and a 4-D CT scan is obtained, which is indexed to different phases of the respiratory cycle. This CT scan is reviewed by the radiation oncologist and physicists to assess for tumor movement during the entire breath. If there is clinically significant movement, e.g., 5 mm, a segment of the respiration can be earmarked for planning and treatment delivery, i.e., "the gating window." The linear accelerator will "beam on" only when the patient is in the designated portion of the respiratory phase, and therefore the tumor will be within a restricted area which has been evaluated by the 4-D planning CT. Now the precision of 3-D conformal or intensity modulation can be utilized with the advantages of more conformal treatment margins and dose escalation. Although the most significant movement is generally in the superior-inferior direction, displacements in anterior-posterior and left to right are also managed in the planning process.
Patients are coached to breathe regularly. One of the challenges of this process, however, is that many patients have compromised respiratory reserve. Our respiratory gating system, the Varian RPM system, stops treatment on the linear accelerator if variability in the respiratory cycle is encountered, such as with coughing, movement, or even suppression of a cough. Treatment automatically resumes when the normal breathing pattern is restored.