Mammography has been shown to have a significant impact on the early detection of breast cancer. The earlier breast cancer is found, the better the chances that treatment will work. Advances in digital imaging technology have led to even greater detection rates, particularly in women with dense breasts where traditional 2D mammography imaging may be inconclusive. Learn more
At John Muir Health we understand the importance in making an accurate diagnosis of breast cancer in its earliest stages, when it’s most treatable. In the event your care requires additional follow up, we’ve assembled a team of specialists who collaborate with each other and with you on each and every case. Specialists who listen and explain, and are with you every step of the way.
Lisa Brenes, B.A., A.R.R.T., C.R.T (R) (M)
Supervisor of Mammography
Lisa received her Bachelor's Degree in Philosophy from Auburn University before continuing on to Huntsville Hospital to study Radiography and earn her A.R.R.T. licensure. She has been part of the John Muir Health Outpatient Imaging Team since 2008 and currently serves as Supervisor of Mammography in Walnut Creek.
Shellie Campos, M.S.N., R.N., F.N.P.-B.C., A.G.N.-B.C.
Shellie received her Master’s Degree in Nursing and Family Nurse Practitioner Training from Vanderbilt University. She is also certified as an Advanced Genetics Nurse and a Family Nurse Practitioner. Shellie has been with the John Muir Health Cancer Institute since 2010, where her role is to provide Nurse Navigator and Nurse Practitioner services to patients in the High-Risk Cancer Program and several John Muir Health special programs.
Sharon Chan, M.S., C.G.C., M.P.H.
Sharon received her Master’s Degree in Genetic Counseling from California State University at Northridge. She has been with John Muir Health Breast Health Services since 2018.
Sheila Marquez, R.N., M.S.N., C.B.C.N.
Sheila received her Master’s Degree in Nursing from Western Govenors University. She is also certified as a Clinical Research Coordinator and Breast Care Nurse. Sheila has been with John Muir Health since 1998. She contributed ten years each as a Medical-Surgical Nurse and Clinical Research Nurse, and currently serves as the Nurse Navigator for Breast Health Services.
Lesley Martin, M.D.
Dr. Martin completed medical school at University of California, San Francisco. Following medical school, she completed residency training in Internal Medicine at University of California at Davis, where she remained for a fellowship in Hematology/Medical Oncology. Dr. Martin is board certified in Hematology and Medical Oncology by the American Board of Internal Medicine. She specializes in diagnosis and treatment of blood diseases and disorders related to cancer treatment.
Bernadette Tawasha, M.A.
Bernadette is the Office Assistant for the John Muir Health Breast Health Center. Her role is to register patients, collect information upon arrival, and direct patients to their specific service area (Genetic Counseling, High Risk Breast Clinic or Clinical Research). She also obtains insurance authorizations for procedures, schedules appointments and answers questions about the services we offer.
Margo Thelander, M.S., C.G.C.
Margo received her Master's Degree in Genetic Counseling from the University of California in Berkeley, and has been with the John Muir Health Genetic Counseling Program since 2005. She previously had worked at Kaiser Permanente.
Vivian Wing, MD
Director of Medical Imaging
Dr. Wing received her Bachelor's Degree from Northwestern University, and medical degree from Northwestern University Feinberg School of Medicine. She completed her residency and fellowship at the University of California at San Diego. Dr. Wing is Board Certified in Diagnostic Radiology and has been in practice for more than 20 years.
Accredited through the National Accreditation Program for Breast Centers (NAPBC) and American College of Radiology.