The Stanford Cyberknife Program Team


Steven Chang, MD
Co-Medical Director, Cyberknife Radiosurgery Program
Professor of Neurosurgery

Dr. Steven Chang received his medical degree from Stanford University. He completed his neurosurgical training at Stanford with a focus on stereotactic radiosurgery, cerebrovascular disease, and brain and spinal tumors. He is recognized as an expert in Cyberknife radiosurgery and surgical resection of brain tumors. Dr. Chang is a research interest in neurogenetics and protenomics.

John Adler, MD
Emeritus Faculty, Neurosurgery

John Adler received his undergraduate, medical and neurosurgical education at Harvard University. In the midst of his training he performed a one year fellowship at the Karolinska Institute, alongside Lars Leksell, the neurosurgeon who conceptualized radiosurgery and created the Gamma Knife. Upon moving to Stanford, Dr. Adler invented the CyberKnife. Through this invention Dr. Adler is credited with creating the broad field of image guided radiation targeting (IGRT), which today defines the most advanced form of therapeutic radiation. His clinical focus involves neuro oncology, while his current research interest centers around the use of precision radiation to treat psychiatric disorders.

Navjot Chaudhary, MD, FRCSC
Clinical Assistant Professor of Neurosurgery

Nav Chaudhary, MD, FRCSC, is a Clinical Assistant Professor of Neurosurgery. She received her medical degree from McMaster University in Hamilton, Canada. Dr. Chaudhary completed her neurosurgery residency at the University of Western Ontario in London, Canada and fellowships in Spine Neurosurgery and Cyberknife Radiosurgery at Stanford University School of Medicine.

She works primarily in CyberKnife Neurosurgery at the Stanford Cancer Center, predominantly treating patients with brain and spine tumors, brain and spine arteriovenous malformations, and trigeminal neuralgia.

Her research interests include surgical outcomes. She has co-authored several papers relating to spine conditions, vascular malformations, and brain tumor management.

Atman Desai, MD
Clinical Assistant Professor of Neurosurgery

Atman Desai, MD, MA, is Director of Neurosurgical Spinal Oncology and Clinical Assistant Professor of Neurosurgery at Stanford University Medical Center. Dr. Desai received his medical degree from the University of Cambridge. He completed his residency in Neurological Surgery at Dartmouth-Hitchcock Medical Center and a fellowship in Spinal Oncology and Complex Spinal Reconstruction at Johns Hopkins Hospital. He focuses on the surgical treatment of spinal tumors, spinal degenerative disease and spinal deformity, and has particular interest in computer-assisted and minimally invasive surgical approaches.

Robert Dodd, MD, PhD
Associate Professor of Neurosurgery and of Radiology

Dr. Dodd received his medical degree from the Stanford University School of Medicine, where he also earned a PhD in Neurosciences from the Department of Neurobiology. His neurosurgery training also took place at Stanford, where he recently completed an endovascular fellowship. His research interests have been in cerebral blood vessel reactivity and stroke.

Dr. Dodd's clinical interests include endovascular and microsurgical treatment of intracranial aneurysms and arteriovenous malformations; percutaneous and surgical interventions for both extracranial and intracranial carotid artery occlusive disease; and minimally invasive neurosurgery though the use of neuroendoscopy and keyhole approaches.

Griffith Harsh, MD
Professor of Neurosurgery and, by courtesy, of Otolaryngology-Head and Neck Surgery at the Stanford University Medical Center

Griff Harsh, MD, MA, MBA, is Professor of Neurological Surgery and Associate Dean for Education (CME) at the Stanford University School of Medicine. He directs the Stanford Brain Tumor Center and the Neurosurgery Residency Training Program. His research focuses on innovative treatments and the molecular biology of tumors of the brain, pituitary gland, and skull base.

Melanie G Hayden Gephart, MD
Associate Professor of Neurosurgery

Dr. Melanie Hayden Gephart is an adult brain tumor neurosurgeon and scientist. She performs complex brain tumor surgery and stereotactic radiosurgery, specializing in primary and metastatic brain tumors. Dr. Hayden Gephart also runs a basic science laboratory focused on improving our understanding and treatment of malignant brain tumors.

Gordon Li, MD
Associate Professor of Neurosurgery

Gordon Li completed his neurosurgical training at Stanford and is an expert in the treatment of adult brain tumors.  His laboratory studies the biology of brain tumors with the goal of developing novel therapeutics for the treatment of malignant brain tumors and translating that research into clinical trials. His clinical interests include improving surgical techniques for brain tumor surgery, immunotherapy for the treatment of glioblastoma, and novel uses for stereotactic radiosurgery.

Jon Park, MD, FRCSC
Professor of Neurosurgery

Dr. Park has extensive clinical practice at Stanford in outpatient minimally invasive spine surgery involving spine disc disease, degenerative spinal disorders and compression fractures. He also has special clinical interest in reconstruction of complex spine traumas and treatment of spinal tumors using Cyberknife Radiosurgery.

Dr. Park's research interest includes non-fusion dynamic spinal stabilization, artificial disc technologies, and regenerative spinal technologies.

Dr. Park completed his neurosurgical residency from the world renowned Montreal Neurological Institute. After completing a spine fellowship at UCLA, he was an Assistant Professor of Neurosurgery at the University of Washington prior to joining Stanford faculty.

John Ratliff, MD, FACS
Professor of Neurosurgery

Dr. Ratliff received his medical degree from Tulane University. He is fellowship trained in complex spinal reconstructive surgery and completed a research fellowship in neural regeneration and peripheral nerve repair at the National Institutes of Neurological Disorders and Stroke at the National Institutes of Health. His area of research focuses upon outcomes assessment in spine surgery; his areas of clinical focus are primary and metastatic spinal tumors, spinal reconstruction procedures, and spinal radiosurgery.

Radiation Oncology

Scott G. Soltys, MD
Associate Professor of Radiation Oncology (Radiation Therapy)
Co-Medical Director, Cyberknife Radiosurgery Program

Dr. Scott Soltys earned his medical degree from the University of Michigan, completing his residency in Radiation Oncology at Stanford University. His clinical and research interests focus on the development of new treatments involving radiotherapy and radiosurgery for tumors of the brain and spine, as well as functional disorders such as trigeminal neuralgia. His current clinical trials are investigating how to optimize the radiosurgical treatment of patients with large brain metastases and how to improve the quality of life of patients receiving radiotherapy for Glioblastoma Multiforme (GBM).

Daniel Chang, MD
Professor of Radiation Oncology (Radiation Therapy)

Dr. Chang specializes in the treatment of gastrointestinal malignancies. He is interested in developing stereotactic body radiotherapy for tumors of the liver, both primary and metastatic and in developing functional imaging as a means of determining treatment response with radiation. In addition, he is interested in developing image-guided radiotherapy to improve radiation delivery for GI cancers to reduce toxicity and improve disease outcome.

Maximilian Diehn, MD, PhD
Associate Professor of Radiation Oncology

Sarah Donaldson, MD
Professor of Radiation Oncology (Radiation Therapy)

Dr. Sarah S. Donaldson is the Catharine and Howard Avery Professor at Stanford University School of Medicine and Associate Program Director in the Department of Radiation Oncology at Stanford. She also serves as the Chief of the Radiation Oncology service at the Lucile Packard Children’s Hospital at Stanford. She is an established clinical investigator and educator with special interests in malignancies of the central nervous system, eye/orbit, sarcoma, breast, lymphoma, and pediatric radiation therapy. She has a long time interest in the late effects of cancer and its treatment. Dr. Donaldson received her undergraduate and nursing degrees from the University of Oregon and her MD from Harvard Medical School. She joined the Department of Radiation Oncology for residency training at Stanford in 1969, was appointed to the faculty in 1973, and has served Stanford continuously since her initial appointment.

A member of many professional organizations, Dr. Donaldson has held numerous national leadership roles. She has served as president of both the American Board of Radiology the American Society of Therapeutic Radiology and Oncology and the Radiological Society of North America. She also has served the Board of Directors of the American Society of Clinical Oncology and their Foundation, as well as The Board of Trustees of the Radiological Society of North America Foundation.

Dr. Donaldson has received numerous honors and awards including the Marie Curie Award of the American Association for Women Radiologists, the Janeway Medal of the American Radium Society, and the Henry S Kaplan Memorial Prize for teaching at Stanford. She has received gold medals from the del Regato Foundation, the American College of Radiology (ACR), and ASTRO. She is a fellow of ASTRO, ACR, and AAAS, and a member of The National Academies Institute of Medicine.

Iris C. Gibbs, MD, FACR
Professor of Radiation Oncology

Dr. Gibbs is a board-certified radiation oncologist who specializes in the treatment of CNS tumors. Her research focuses on developing new radiation techniques to manage brain and spinal tumors in adults and children. Dr. Gibbs has gained worldwide acclaim for her expertise in Cyberknife robotic radiosurgery.

Steven Hancock, MD
Professor of Radiation Oncology

Dr. Steven Hancock is a Professor of Radiation Oncology at Stanford University Medical Center who has practiced at Stanford for over 30 years. He specializes in genitourinary cancers, such as prostate cancer, bladder cancer, kidney cancer, penile and urethral cancers. He also specializes in radiation and radiosurgery treatment of malignant and benign conditions that affect the central nervous system, including glioblastoma, astrocytoma, oligodendroglioma, meningioma, acoustic neuroma, arteriovenous malformations, and hemangioblastomas associated wtih Von Hippel Lindau syndrome. Dr. Hancock serves on the National Cancer Center Network (NCCN) guidelines panels for Kidney and Testicular cancers. Research activities have involved initial clinical trials of radiation sensitizer and hypoxic cell cytotoxic agents, initial clinical evaluation of the Cyberknife radiosurgical instrument and longitudinal studies of treatment outcomes and late effects of radiation therapy, such as secondary malignancies and radiation associated cardiovascular disease. Current interests are in the application of new imaging and treatment technologies for improving tumor control and minimizing short and long term side effects of radiation and combined modality therapy.

Kathleen Horst, MD
Associate Professor of Radiation Oncology (Radiation Therapy)

Albert Koong, MD, PhD
Professor of Radiation Oncology (Radiation Therapy)

Quynh-Thu Le, MD, FACR, FASTRO
Professor, Radiation Oncology

Quynh-Thu Le, MD received both her medical school and radiation oncology training at the University of California, San Francisco (UCSF). She then joined the Stanford faculty in 1997. She became the Chair of the Stanford Radiation Oncology Department in September 2011. She also holds the Katharine Dexter McCormick & Stanley Memorial Professorship at Stanford University.

Billy W. Loo, Jr, MD, PhD, DABR
Associate Professor of Radiation Oncology (Radiation Therapy)

Hilary Bagshaw, MD,
Clinical Assistant Professor, Radiation Oncology (Radiation Therapy)

Susan Hiniker, MD,
Assistant Professor, Radiation Oncology (Radiation Therapy)

Erqi Liu Pollom, MD,
Assistant Professor, Radiation Oncology (Radiation Therapy)

Head and Neck Surgery

Nikolas Blevins, MD
Larry and Sharon Malcolmson Professor in Otolaryngology

Dr. Blevins received his bachelor's degree from Stanford University in Biology before completing his medical training at Harvard. He finished his residency in Otolaryngology at the University of California at San Francisco, where he remained for additional fellowship training in otology/ neurotology and skull base disorders.

Dr. Blevins then became the director of the Division of Otology and Neurotology at Tufts University in Boston. In 2003, he returned to Stanford, where he is now the Larry and Sharon Malcolmson Professor of Otolaryngology, and is the Chief of the Division of Otology/Neurotology.

He specializes in disorders of the ear, facial nerve, and skull base, including the comprehensive multimodality treatment of skull base tumors. He is the Director of the Stanford Cochlear Implant Center, which is dedicated to the application of the most advanced technology to hearing preservation and restoration.

Dr. Blevins has an active research interest in innovative minimally invasive surgical methods and the application of computer technology to surgical education and preoperative planning.

Robert Jackler, MD
Edward C. and Amy H. Sewall Professor in Otorhinolaryngology and Professor, by courtesy, of Neurosurgery and Surgery

Dr. Jackler was raised in Waterville, Maine, attended college and medical school in Boston, and moved west to the University of California, San Francisco for residency in Otolaryngology-Head & Neck Surgery. After taking a Neurotology fellowship at the House Ear Clinic (1985), Dr Jackler joined the faculty at UCSF where he remained until 2003 when he become the Sewall Professor and Chair of the Department at OHNS and professor in the departments of Neurosurgery and Surgery at the Stanford University School of Medicine.


Jennifer Semodo,
Director, Cyberknife

Monika VanHuyStee
Cyberknife Coordinator Supervisor

Luz Tovar
CyberKnife Coordinator

Tevaite Valenzuela
CyberKnife Coordinator

Maria Ronquillo
CyberKnife Coordinator

Laurie Tupper, NP
Radiation Oncology Nurse Practitioner

Jackei Lo, RTT
Radiation Therapist

Stacey Sturken, RTT
Radiation Therapist

Sandra Kuerth, RTT
Radiation Therapist

Lucia Musumanasi, RTT
Radiation Therapist

Armine Tayag, NP
Neurosurgery Nurse Practitioner

Louisa Pangilinana, NP
Neurosurgery Nurse Practitioner

Patricia Thompson, NP
Neurosurgery Nurse Practitioner

Selma Mansour, NP
Radiation Oncology Nurse Practitioner

Lei Wang, PhD, DABR
Chief, CyberKnife Physics

Tony Ho, PhD, DABR
Radiation Oncology Clinical Physicist

Tony Lo, PhD, DABR
Radiation Oncology Clinical Physicist