South Sound Gamma Knife

The Gamma Team

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.

Medical Directors

Neurosurgeons

Radiation Oncologists

The team is lead by two medical directors, radiation oncologist, Michael McDonough, MD, and neurosurgeon Peter C. Shin, MD, MS.

Michael McDonough, MD
Medical Director, Radiation Oncology, South Sound Gamma Knife at St. Joseph

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 Systems, Good Samaritan Hospital, Auburn General Hospital and Multicare Health System.

Peter C. Shin, MD, MS
Medical Director, Neurosurgery, South Sound Gamma Knife at St. Joseph

Dr. Shin received his BS 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 VA hospital in Shreveport. He received training on the latest updates 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.

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 recently returned from Stockholm, Sweden where he received extensive training on the latest advances in Gamma Knife Radiosurgery at the institute where the leading-edge technology was developed. He holds medical staff privileges at Franciscan Health System and Good Samaritan Hospital.

Gamma Knife Trained Neurosurgeons

	Seth Joseffer, MD Neurosurgeon Dr. Joseffer graduated Phi Beta Kappa from The Johns Hopkins University in Baltimore, Maryland, and received his MD from New York University School of Medicine. His internship and residency (in neurosurgery) were also served at NYU School of Medicine. Dr. Joseffer's specialties are complex spinal surgeries and Gamma Knife Radiosurgery. He received his Gamma Knife credentials through the University of Pittsburgh Gamma Knife Center in Pennsylvania. Seth and his wife now live in the Tacoma area and greatly enjoy golf, hiking and other outdoor activities.
	Daniel G. Nehls, MD, FACS Neurosurgeon, South Sound Gamma Knife at St. Joseph 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 BS Degree in Biomedical Engineering, and his Doctor of Medicine 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 what is considered by many to be the finest training program in the country, 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, having 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 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 Neurosurgical 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.

Gamma Knife Trained Radiation Oncologists

	Kenneth Bergman, MD Radiation Oncologist 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.
	Dean G. Mastras, MD Radiation Oncologist Dr. Mastras joined Tacoma Radiation Oncology Center in 1993. He is board certified in Therapeutic Radiology. He holds medical staff privileges at Tacoma General, Good Samaritan, St. Joseph, and St. Francis Hospitals. His specialties include GYN brachytherapy, prostatic seed implantation, and the treatment of breast cancer. Dr. Mastras is especially interested in the treatment of prostate cancer and has participated in several regional symposiums on the subject. Dr. Mastras holds membership in multiple medical societies including the Washington State Medical Association, the American society for Therapeutic Radiation and Oncology, American College of Radiation Oncology, and the American Medical Association.
	Huong T. Pham, MD Radiation Oncologist St. Francis Outpatient Center/Radiation Oncology 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, radio surgery and lung cancer.
	John Rieke, MD, FACR Radiation Oncologist MultiCare Regional Cancer Center Dr. John 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 1980’s at Virginia Mason Clinic in Seattle was a founding member of the International Stereotactic Radiosurgery Society. He has presented radiosurgery research in the areas of acoustic neuroma, brain metastasis, glioma and vascular malformations.
	Michael Soronen, MD Radiation Oncologist Michael Soronen was born in Detroit, MI. He attended the University of Michigan and obtained his medical degree there in 1969. His postgraduate training includes a surgery internship and radiation oncology residency at William Beaumont Hospital in Royal Oak, MI. He relocated to Seattle, WA and was on the attending staffs of University of Washington Medical Center, Harborview Medical Center, and Veterans Administration Hospital. In 1974, he became board certified in Therapeutic Radiology. Dr. Soronen is a retired captain from the United States Air Force Reserve. He holds multiple medical memberships including the American College of Radiation Oncology, American Society of Therapeutic Radilogy and Oncology, the American Radium Society, WSMA, and the American College of Radiology. In July of 1975, Dr. Soronen began his practice of radiation oncology in Tacoma. In 1979, he and Dr. Howard Wong opened the first office of Tacoma Radiation Oncology in Jackson Hall. After two years, the need for a clinic in Puyallup arose and Valley Radiation Oncology Center came into existence. Dr. Wong retired in 1991. Dr. Soronen is the chief physician of the practice. His office is in St. Joseph Medical Pavilion. In addition to external beam radiation, he also performs GYN brachytherapy and external beam conformal stereotactic radiotherapy. His special interests include breast, head and neck, and lung cancer. He is on the active staff of St. Joseph Hospital and MultiCare Medical Center while holding courtesy positions at the rest of Franciscan Health Systems' sites and Good Samaritan and Puget Sound Hospitals. He also is Assistant Professor of the Department of Radiation Oncology at the University of Washington. Although Dr. Soronen enjoys traveling, he is content to spend most of his time in the Pacific Northwest where he enjoys family life and showing horses.
	Randy Sorum, MD Radiation Oncologist 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 has been accepted to the active staff of Good Samaritan Hospital and will hold courtesy privileges at MultiCare Medical Center, Franciscan Health Systems, 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 CNS 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.