Our Team

At South Nassau Communities Hospital, we’re focused on the health and well being of you and your family. Committed to healthcare excellence, we’re at the forefront of medical advances that are changing the very foundation of the health care environment. Staffed with dedicated, skilled professionals and the finest technology available, we concentrate on our core value – providing the finest healthcare available to our patients, their families and our communities.

See below to learn more about our compassionate team of expert cancer care professionals:

Dr. Mullen

Edward E. Mullen, MD
Director, Radiation Oncology
Co-Medical Director, Long Island Gamma Knife
Dr. Mullen is well known for his delivery of advanced techniques of therapeutic radiation medicine. In collaboration with South Nassau breast surgeons, he introduced partial breast irradiation (breast brachytherapy) using the MammoSite® technique to the South Shore, enabling women to complete radiation treatment in one week, rather than the traditional seven. Dr. Mullen received his medical degree from the University of Virginia and his post-graduate training at Columbia-Presbyterian Medical Center. He is also board certified in radiation oncology. Dr. Mullen spent three years at the University of Pittsburgh, where he was engaged in extensive clinical research through numerous clinical cooperative groups, including Gamma Knife studies. He is conversant in German. Contact information: 516-632-3370.

Dr. Brisman

Michael H. Brisman, MD
Chief, Surgical Neuro-Oncology and
Co-Medical Director, Long Island Gamma Knife
Dr. Brisman specializes in the management of malignant and benign brain tumors and is a recognized national expert in the treatment of face pain/trigeminal neuralgia, as well as metastatic brain cancer. Experienced in Gamma Knife radiosurgery, he also performs linear accelerator-based stereotactic radiotherapy. Dr. Brisman is a graduate of Harvard University, completed his medical degree at Columbia University, and a neurosurgical residency at Mt. Sinai Medical Center in New York. He is board certified in neurosurgery. Contact information: 516-255-9031.

Dr. Wu

Leester Wu, MD
Associate Director, Radiation Oncology
Dr. Wu brings a diverse background in community practice, research, and academic training to South Nassau’s Radiation Oncology Department. He was the recipient of numerous honors throughout his undergraduate work at Harvard University and while he was in medical school at the University of Pennsylvania. He completed his residency at Columbia University Medical Center in New York, training in state-of-the-art external beam radiation therapy and Gamma Knife stereotactic radiosurgery. Dr. Wu is board certified in radiation oncology. He is fluent in Taiwanese and conversant in Spanish. Contact information: 516-632-3370.

Mr. Presser

Joseph Presser, MS, DABR
Director, Radiation Physics and Radiation Safety Officer
Mr. Presser has headed the Physics Team at South Nassau since 2004. He is responsible for the overall function of the Physics Department as well as the quality assurance programs for two linear accelerators, the Novalis Tx™, CT scanners, and associated treatment planning software. Under his leadership, the Department of Radiation Oncology achieved American College of Radiology Accreditation in 2007. As Radiation Safety Officer, Mr. Presser administers, as well as designed, South Nassau’s radiation safety program and ensures regulatory compliance with New York State Department of Health for maintenance of the Radioactive Materials License. Mr. Presser has served in similar capacities at Virginia Mason Medical Center, NY Hospital-Cornell Medical Center, and Memorial Sloan-Kettering Cancer Center. He is a New York State-licensed Medical Physicist and received his Therapeutic Radiologic Physics Certification in 1998 from The American Board of Radiology.

Mr. O'Donnell

Lee R. O'Donnell, BS, LRT (R)(T)
Manager, Radiation Oncology Service
Mr. O'Donnell is the manager of South Nassau’s radiation oncology department and Long Island Gamma Knife®. He is responsible for the overall operation of the department as well as spearheading the accreditation process with organizations such as the American College of Radiology and The Joint Commission. He is also responsible for deployment of new radiation therapy technologies. Mr. O'Donnell previously served as the Radiation Oncology Manager for North Fork Radiology/Radiation Oncology in Riverhead, NY. Mr. O'Donnell has more than twenty years’ experience in the field of radiology and radiation oncology. He holds a B.S. in Community and Human Services, an A.A.S. in Radiologic Technology Radiation Therapy and an A.A.S. in Radiologic Technology Diagnostic Radiology. He is also a registered technologist by the American Registry of Radiologic Technologists.

Ms. Lehmann

Kathleen Lehmann, RN, MSN, OCN, CBCN, ANP-C
ANP-C, OCN Adult Nurse Practitioner, Radiation Oncology
Ms. Lehmann has worked at South Nassau Communities Hospital her entire nursing career, which spans over 20 years. She is certified in oncology as well as breast health, and is responsible for the overall management of patient services in the Oncology Department. Ms. Lehmann earned her nursing MS from Molloy College as well as her BS degree. She also earned her certified Post Masters certificate in the Adult Nurse Practitioner Program from Molloy College in 2009. Ms. Lehmann is a member of the South Nassau Pain Management Team and was nominated in 2010 for the South Nassau Nurse Excellence award. Contact information: 516-632-3336.

Kathleen Smith Walker, RN
Radiosurgery Nurse, Coordinator, Long Island Gamma Knife
South Nassau Communities Hospital
Department of Radiation Oncology
One Healthy Way
Oceanside, New York 11572
Contact information: 516-632-3366

Kathy Garizio, RN
Radiosurgery Nurse, Coordinator, Radiation Oncology
South Nassau Communities Hospital
Department of Radiation Oncology
One Healthy Way
Oceanside, New York 11572
Contact information: 516-632-3369 or 516-632-3360

service image

What to Expect

The Long Island Gamma Knife Center at South Nassau Communities Hospital offers Long Islanders...

Read More

service image

Amazing Stories

Every day, the expert cancer care professionals at South Nassau Communities Hospital...

Read More

service image

Physician Resources

At South Nassau, we want to make it easy for you to refer your patients...

Read More

service image

Patient Resources

Please use the available resources below to stay connected and informed about your condition...

Read More

service image

Our Team

At South Nassau Communities Hospital, we’re focused on the health and well being of you and your family...

Read More

service image

FAQ

The Gamma Knife is used to treat small–to medium–sized brain abnormalities such as...

Read More