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  Meet our Gamma Knife team

Samuel Critides, MD

Dr. Samuel Critides earned his medical degree from the University of Medicine and Dentistry of New Jersey and completed his residency training in neurosurgery at Penn State Milton S. Hershey Medical Center. Following his chief resident year, he completed a fellowship in complex spinal surgery at the Cleveland Clinic Spine Institute in Cleveland, Ohio.

Dr. Critides has special interests in the treatment of brain tumors, neurologic trauma surgery and spine surgery. He utilizes best practices and outcomes based treatments to provide the best possible treatments. He believes in judicious use of minimally invasive techniques for spinal surgery blended with maximal safety, predictable and durable outcomes. He also is a strong believer in motion preserving techniques of spinal surgery such as arthroplasty (disk replacement). With extensive training in surgical treatments of primary and metastatic tumors of the brain and spine as a resident, he completed training in stereotactic radiosurgery with Gamma Knife to augment his interest in providing high quality predictable surgical outcomes in brain surgery. In addition to the treatment of metastatic lesions to the brain, Dr. Critides uses Gamma Knife to treat many other conditions of the brain such as meningiomas, pituitary tumors, vestibular schwanommas (also known as acoustic neurommas) and trigeminal neuralgia. Although some conditions like tumors or infections may need immediate treatment, he believes wherever possible, all forms of conservative treatment should be considered before surgery is recommended, and prior to undergoing elective surgical treatment, patients should have the opportunity to seek advice from other providers to help make sound decisions about their health care.

Dr. Critides served in the United States Navy for 20 years. After serving as a battalion surgeon with the Marines, he was selected for training as a neurosurgeon and then served the remainder of his career as a neurosurgeon. One of his greatest accomplishments was treating U.S. servicemen and women from 2005 – 2008 during the war in the Middle East while assigned to National Naval Center Bethesda.

After the 2010 Haiti earthquake, he served as the spine surgeon on the USNS Comfort, a seagoing medical treatment facility, caring for victims. In his spare time, Dr. Critides stays active with cross fit and running. He enjoys spending time with his wife, Maricarmen, and their four children.

Robert Marcus, Jr., MD
Radiation Oncology

Dr. Robert Marcus, Jr pursued his medical school training, as well as his residency training, at the University of Florida, and subsequent to that, was on the faculty in the College of Medicine at the University of Florida, and later was appointed to the faculty in the College of Medicine at Emory University in Atlanta, Georgia. He directed the training of residents in Radiation Oncology in the University of Florida Department of Radiation Oncology, and has been an American College of Radiology Board Examiner to evaluate and certify candidates for their specialty boards in Radiation Oncology.

Dr. Marcus has always been interested in being at the leading edge of Radiation Oncology, and has expertise in the treatment of rare and unusual tumors. He has been on the faculty of institutions that have led the advancement of IMRT (Intensity Modulated Radiation Therapy) and is certified in Gamma Knife radiosurgery.

Veronica Carden, MD
Radiation Oncology

Dr. Veronica Carden graduated medical school from Florida State University. She completed her residency training in radiation oncology from State University of New York (SUNY) Upstate Medical University. Dr. Carden has special medical interests in treating all types of cancers with radiation therapy – especially breast and lung cancers. She is skilled in stereotactic body radiation therapy (SBRT) that delivers precise radiation to small, well-defined tumors at a very high dose.

Matthew Pearson, MD
Pediatric Neurosurgery

Dr. Matthew Pearson received his medical degree from Johns Hopkins University School of Medicine. He completed his internship and residency training at Vanderbilt University Medical Center. After his fellowship in pediatric neurosurgery at the University of Texas Southwestern Medical Center at Dallas, Dr. Pearson joined the faculty of neurological surgery at Vanderbilt and served on staff at the Monroe Carell Jr. Children’s Hospital, where he built the pediatric brain tumor and epilepsy surgery programs.

Juan Ronderos, MD

Dr. Juan Ronderos earned his medical degree from the University of South Alabama and completed his residency training in neurosurgery at Tulane University in New Orleans, Louisiana. He completed a complex spine fellowship at Barrow Neurological Institute in Phoenix, Arizona.

Dr. Ronderos has special interests in the treatment of spinal injuries and other neurological disorders. He specializes in complex spine surgery and the treatment of brain and spine tumors. Dr. Ronderos has expertise in minimally invasive spine surgery. He has served as a clinical instructor at the Mayo Clinic in the department of neurosurgery and most recently as an associate instructor at the University of South Alabama School of Medicine for over 15 years.

Charles Wolff, MD

Dr. Charles Wolff earned his medical degree from the University of Miami School of Medicine and attended his residency training in neurosurgery at the University of Virginia and University of Alabama at Birmingham. He completed a fellowship in spinal surgery at the University of Alabama at Birmingham School of Medicine.

Sherry Crosby, RN, came to Sacred Heart Hospital in 2003 and worked as a surgical technician while completing her nursing degree. She served in the Sacred Heart OR as circulating nurse, neurosurgical coordinator and charge nurse until taking on her new role as patient navigator for the Sacred Heart Gamma Knife Center in Pensacola.

Sherry contacts new Gamma Knife patients and walks them through the treatment process, including scheduling doctors visits, arranging transportation, and helping make their treatment as care-free as possible. She also coordinates Brain Tumor Conferences where a team of oncology, radiation oncology, neurosurgery, radiology, pathology and medical physiology specialists discuss each patient and decide on the best course of treatment for each individual.

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Sacred Heart Gamma Knife Center,
please call us at (850) 416-4980
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