About Us
Gamma Knife® patients receive coordinated care from a multi-disciplinary team of neurosurgeons, radiation oncologists, radiation physicists, technicians and nurses. The team’s goal is to provide the most advanced, effective treatment in a compassionate and comfortable setting.
The Gamma Knife Team
The team is lead by two medical directors; radiation oncologist Randy Sorum, MD, and neurosurgeon Peter C. Shin, MD, MS.
Neurosurgery
Medical Director
Peter C. Shin, MD, MS
Medical Director, Neurosurgery
South Sound Gamma Knife at St. Joseph
Neurosurgeon
South Sound Neurosurgery
Dr. Shin received his undergraduate degree in Biomedical Engineering from Boston University, and a Master’s Degree in Electrical Engineering from Ohio State University before graduating from medical school at Northeast Ohio University. He was awarded a National Institute of Health sponsored scientist training grant and research fellowship in artificial intelligence programming to stimulate brain development. He completed his residency in neurological surgery at Rush Presbyterian St. Luke’s Medical Center.
Dr. Shin then became Assistant Professor of Neurosurgery at Louisiana State University Health Science Center specializing in functional neurosurgery, epilepsy, brain tumor aneurysms, spine surgery and Gamma Knife radiosurgery. He also served as Chief of Neurosurgery at Overton Brooks Veterans Administration hospital in Shreveport. He received training on the latest updates in Gamma Knife at the Queen Sophia Hospital and Karolinska University Hospital Gamma Knife centers in Stockholm, Sweden, where the leading-edge technology was originally developed.
Dr. Shin’s rare dual credentials in both neurosurgery and biomedical engineering have made him a leader in the fields of computer-guided imaging, micro-surgical navigation, and biomechanics. He holds medical staff privileges at Franciscan Health System and Good Samaritan Hospital.
Neurosurgeons
Alex Mohit, MD, PhD
Neurosurgeon
Neurosurgery Northwest – Tacoma
Franciscan Medical Group
Dr. Mohit provides comprehensive neurosurgery, specializing in spine and skull base surgery. He received his medical degree from University of Southern California School of Medicine in Los Angeles, California and completed his residency at University of Washington Hospitals. Dr. Mohit recently completed a Complex Spine Surgery Fellowship at Cleveland Clinic Spine Institute in Ohio. Following a Skull Base Surgery Fellowship at Harborview Medical Center in Seattle, he completed an elective International Neurosurgery Fellowship at Atkinson Morley’s Hospital in London, England. Dr. Mohit is a member of the American Association of Neurological Surgeons, North American Spine Society and Congress of Neurological Surgeons. He has held teaching and research posts at USC School of Medicine, Fred Hutchinson Cancer Center and California Institute of Technology. He is fluent in English, Farsi and Spanish. Dr. Mohit enjoys spending time with his family and is an avid cyclist and runner. Dr. Mohit holds privileges at Franciscan Health System hospitals.
Daniel G. Nehls, MD, FACS
Neurosurgeon
Neurosurgery Northwest – Tacoma
Franciscan Medical Group
Dr. Nehls established his practice in Tacoma in 1993, bringing his exceptional surgical expertise and patient care to the area. He is highly skilled in both spine and brain surgery, and was the first neurosurgeon in the South Sound to implant Glaidel chemotherapy wafers into brain tumors. He has a special interest in Trigeminal Neuralgia, with expertise in glycerol injection, balloon gangliolysis, radiofrequency treatment, microvascular decompression and Gamma Knife treatment. He is known and appreciated for his down-to-earth style and genuine interest in his patients and their families, and personally works to ensure they receive the highest quality care, education and support.
Dr. Nehls received his undergraduate degree in Biomedical Engineering, and his medical degree from Northwestern University, followed by a General Surgery internship at Walter Reed Army Medical Center in Washington, D.C. Dr. Nehls completed his residency training in Neurosurgery at Barrow Neurological Institute in Phoenix, Arizona. With his interest in research, he applied for and won the Charles Elsberg Fellowship, an endowment that provides a year of study at any location worldwide. Dr. Nehls chose the Wellcome Surgical Institute in Glasgow, Scotland, where he studied brain blood flow and metabolism, and explored treatments for stroke. Dr. Nehls received his training for the Gamma Knife at the University of Pittsburgh, the center which acquired the first unit in the United States, and has the most experience and has treated over 7000 patients.
Dr. Nehls’ experience also includes six years of neurosurgery at Walter Reed Army Medical Center in Washington D.C., and at William Beaumont Army Medical Center in El Paso, Texas. He served as both Chief and Assistant Chief of Neurosurgery Service at these Centers. At Walter Reed, Dr. Nehls spent three years as a senior faculty member training Neurosurgery residents. He has lectured throughout the United States and Europe and has authored over 50 scientific articles and book chapters. He currently retains an appointment as Assistant Professor of Surgery at the Uniformed Services University of Health Sciences in Bethesda, Maryland. Board certified in Neurological Surgery since 1990, Dr. Nehls holds medical staff privileges with Franciscan Health System, MultiCare Health System and Good Samaritan Hospital.
Richard N.W. Wohns, MD, MBA
Neurosurgeon
South Sound Neurosurgery
Dr. Wohns received extensive training in the latest advances in Gamma Knife Radiosurgery at the Queen Sophia Hospital and Karolinska University Hospital Gamma Knife Centers in Stockholm, Sweden, where the leading-edge technology was originally developed. He is a Magna Cum Laude graduate of Harvard College in Biochemistry, and a graduate of the Yale University School of Medicine. He completed his neurosurgical residency at the University of Washington. Dr. Wohns also received his Executive MBA from the University of Washington where he serves as an Associate Clinical Professor of Neurological Surgery.
His other areas of expertise in the field of neurosurgery include brain tumor and skull base surgery, numerous complex minimally invasive spinal surgical techniques, teleradiology, computer-based neuronavigation and stereotaxis. He is one of the first US neurosurgeons qualified to perform the revolutionary XLIF technique for minimally invasive lumbar fusions.
Dr. Wohns is President of the Washington State Association of Neurological Surgeons, and Chairman of the Northwest Quadrant of the Council of State Neurosurgical Societies. He is also Chairman of the Board of NeoSpine, LLC.
In his “off-duty” time, Dr. Wohns is a leader in the field of mountain medicine and served as Medical Director to the Ultima Thule Expedition to Mount Everest, and is widely known in the climbing community for having performed an emergency appendectomy on the Baltoro Glacier, while on a K2 expedition.
A highly disciplined martial arts devotee, he currently holds a 3rd degree black belt in Tae Kwon Do. He is also an avid bicyclist, skier and tennis player.
Anthony Harris, MD, PhD
Neurosurgeon
MultiCare Neurosurgery
Dr. Harris is a board-certified physician specializing in neurological surgery. He is a graduate of the University of Pittsburgh School of Medicine, where he also completed his surgical internship and neurosurgical residency. Dr. Harris accepts referrals for all adult and pediatric neurosurgical consultations and offers expertise in a wide range of options, including spine surgery, neurovascular disease and image-guided cranial procedures.
Radiation Oncology
Medical Director
Randy Sorum, MD
Medical Director, Radiation Oncology
South Sound Gamma Knife at St. Joseph
Radiation Oncologist
Tacoma/Valley Radiation Oncology Centers
Dr. Sorum joined Tacoma Radiation Oncology Center in 1999. He is a board certified radiation oncologist. He holds memberships with the Washington State Medical Association, American Society for Therapeutic Radiology and Oncology, and the American College of Radiology among others. He on the active staff of Good Samaritan Hospital and holds courtesy privileges at MultiCare Medical Center, Franciscan Health System and Puget Sound Hospital.
Dr. Sorum is a native of Sioux Falls, SD. He is an undergraduate of Creighton University in Omaha, NE, and obtained his medical degree at the University of South Dakota School of Medicine, where he also completed his internship. He completed his residency of Radiation Oncology at St. Mary’s Medical Center in San Francisco, CA.
Dr. Sorum’s specialties include IMRT (intensity modulated radiation therapy), 3-dimensional conformal radiotherapy, stereotactic radiosurgery and radiotherapy, high dose rate and low dose rate brachytherapy, and prostatic seed implantation. He also has an interest in brain cancers and diseases of the central nervous system that may benefit from stereotactic radiosurgery. He has had specialty training in Marseilles, France for Gamma Knife treatment of functional disorders.
Dr. Sorum’s hobbies include raising, breeding and showing Arabian and Hackney horses. He also enjoys traveling.
Gamma Knife-Trained Radiation Oncologists
Kenneth Bergman, MD
Radiation Oncologist
Tacoma/Valley Radiation Oncology Centers
Dr. Bergman received his bachelor’s degree from the University of California-Santa Barbara and his medical degree from UCLA; he graduated with academic honors from both colleges. While at UCLA, he was involved in basic science and clinical research and published several papers about his work using Positron Emission Tomography (PET), an imaging technique that enables physicians to monitor the chemical function of organs and tissues.
Dr. Bergman completed his internship at Tucson Medical Center and did his residency training at the University of Washington, where he was awarded an American Cancer Society Clinical Oncology Fellowship.
His areas of specialization include 3D conformal radiation therapy, as well as breast and prostate cancer. He’s on staff at MultiCare Medical Center, Good Samaritan, St. Joseph, St. Francis and St. Clare hospitals.
A board certified radiation oncologist, Dr. Bergman joined the staff of Tacoma/Valley Radiation Oncology Centers in 2002. He holds memberships with the Washington State Medical Association, American Society for Therapeutic Radiation and Oncology, American College of Radiation Oncology and the American Medical Association.
Michael McDonough, MD
Radiation Oncologist
Tacoma/Valley Radiation Oncology Centers
A native of Tacoma, Dr. McDonough received his bachelor’s degree from the University of Washington and his medical degree from St. Louis University. He completed an internship in internal medicine at St. Mary’s Medical Center in San Francisco. He completed residency training in Radiation Oncology at Wayne State University in Detroit. He is board certified in Therapeutic Radiology.
Dr. McDonough practiced radiation oncology at St. Anthony’s Hospital in St. Louis. He also served on the faculty of the Medical College of Ohio in Toledo. He returned to Tacoma to join the Tacoma/Valley Radiation Oncology Centers in June 2001. He holds memberships with the Pierce County Medical Society, Washington State Medical Association, American College of Radiology, American College of Radiation Oncology, American Society for Therapeutic Radiology and Oncology, and American Brachytherapy Society.
He holds medical staff privileges at Franciscan Health System, Good Samaritan Hospital, Auburn General Hospital and Multicare Health System.
Huong T. Pham, MD
Radiation Oncologist
St. Francis Radiation Oncology Clinic
Dr. Pham received her medical degree from the University of Maryland in Baltimore. She completed her internship at St. Mary’s Hospital in San Francisco and did her residency training at Cooper Hospital, University Medical Center Robert Wood Johnson Medical School in Camden, New Jersey. Dr. Pham’s fellowship in Radiation Oncology was completed at the University of California San Francisco. Her areas of special medical interest are treatment of brain tumors, radiosurgery and lung cancer.
Herbert Wang, MD
Radiation Oncologist
Tacoma/Valley Radiation Oncology
Dr. Wang earned his medical degree from the University of California at Davis, School of Medicine. He completed a one-year internship at the University of California, San Francisco / California Pacific Medical Center prior to his residency and fellowship in radiation oncology at the University of Chicago Medical Center. He remained as an instructor for one year at the University of Chicago before venturing into private practice. Dr. Wang is board certified.
Dr. Wang joined Tacoma/Valley Radiation Oncology Centers in August of 2004. He holds staff privileges at Auburn General Hospital, Good Samaritan, MultiCare Health System, and Franciscan Medical Group.
He holds memberships in multiple medical societies including: American Society for Therapeutic Radiation and Oncology, American Society of Clinical Oncology, American College of Radiology, American College of Radiation Oncology, American Medical Association, Pierce County Medical Association, and Washington State Medical Association.
John Rieke, MD, FACR
Radiation Oncologist
MultiCare Regional Cancer Center
Dr. Rieke attended medical school in Oregon, and then completed training in Internal Medicine in Minnesota and Radiation Oncology at Stanford University in California, becoming board certified in both specialties. Dr. Rieke has practiced radiation oncology and stereotactic radiosurgery in this region beginning in the late 1980s at Virginia Mason Clinic in Seattle. He was a founding member of the International Stereotactic Radiosurgery Society. He has presented radiosurgery research in the areas of acoustic neuroma, brain metastases, glioma and vascular malformations.