Radiation Oncology Expert Dr. Zimmerman Leads Cancer Care
Feb 18, 2026
Adventist Health White Memorial is pleased to welcome Dr. Robert Zimmerman as medical director of radiation oncology at the Cecilia Gonzalez De La Hoya Cancer Center. Dr. Zimmerman brings three decades of experience in radiation oncology, with a focus on combining clinical expertise with compassionate, patient-centered care.
Serving adults ages 18 and older, Dr. Zimmerman provides radiation therapy for many cancer diagnoses, including breast cancer, prostate cancer, and brain tumors, as well as select non-cancerous conditions when appropriate.
He is board-certified by the American Board of Radiology (ABR).
Patients can expect a calming, supportive approach — from the first visit. A cancer diagnosis can bring uncertainty, stress, and fear — especially when patients are hearing about unfamiliar treatments. Dr. Zimmerman believes one of the most important parts of his role is helping patients feel informed and supported, reducing anxiety around cancer and treatments that may feel intimidating at first.
He is committed to taking time with each patient to explain the recommended plan, answer questions clearly, and help patients and families feel confident about what comes next.
Dr. Zimmerman’s philosophy aligns with Adventist Health’s whole-person mission. In his own words, he’s “made for a more supportive and comprehensive care experience,” and he emphasizes teamwork — partnering with Adventist Health’s cancer experts to provide high-quality care and guide patients throughout their cancer treatment journey.
Dr. Zimmerman earned his undergraduate degree at the University of California, Los Angeles, and completed medical school at UCLA School of Medicine, where he was recognized by the American Osteopathic Association. He then completed residency training in radiation oncology at UCLA.
Most recently, he served as a staff radiation oncologist with the UCLA Department of Radiation Oncology. He also held a national leadership role in radiation oncology at Carelon Medical Benefits Management, a subsidiary of Elevance Health — experience that further strengthened his focus on evidence-based care, clinical guidelines, and decision support.
Born in Glendale and raised in Agoura Hills, Dr. Zimmerman is proud to care for his Southern California community. He is fluent in Spanish, helping more patients communicate comfortably during treatment.
