Imran Mohiuddin, MD, PhD, directs the Gamma Knife and GammaTile programs at AdventHealth. He is also the clinical leader of CNS radiotherapy at AdventHealth.
Precision Without Incision
On any given morning at AdventHealth Orlando, a patient walks into a treatment room carrying something heavy; fear, uncertainty, and often a diagnosis that has already changed everything. What they do not walk into is an operating room.
There are no bright surgical lights. No trays of instruments. No countdown to anesthesia. Instead, the room feels unexpectedly calm. Music plays softly. The machine itself is open, almost inviting, nothing like the claustrophobic tunnel many associate with medical imaging. A team of specialists moves with quiet confidence, checking settings, confirming plans, and speaking in reassuring tones.
“It’s like having 192 flashlights all pointed at one exact spot. Each one by itself is too weak to do anything. But when they all come together, that’s where the treatment happens.” —Dr. Mohiuddin, radiation oncologist at AdventHealth
For many patients, the realization comes slowly: this is brain surgery—but it does not look, sound, or feel like anything they expected. “It doesn’t feel like anything,” says Dr. Imran Mohiuddin, a radiation oncologist who directs the Gamma Knife and GammaTile programs at AdventHealth. He also serves as the clinical leader of CNS Radiotherapy at AdventHealth.“There’s no pain, no burning, no sensation at all. I often ask patients, ‘What does an X-ray feel like?’ And the answer is always the same—nothing. That’s what this feels like.”
What is happening in that room, however, is anything but ordinary. The patient is undergoing Gamma Knife treatment, one of the most advanced and precise forms of brain therapy available today. It is a technology capable of targeting tumors, vascular abnormalities, and even certain neurological disorders with sub-millimeter accuracy—all without a single incision. For Central Floridians, it is a powerful resource hiding in plain sight, one of only two such machines in the state.
Melvin Field, MD serves as the Medical Director for the AdventHealth Minimally Invasive Brain Surgery program.
Despite its dramatic name, Gamma Knife is not a knife, nor is it surgery in the traditional sense. Dr. Mohiuddin explains, “there’s no cutting, no opening of the skull, no general anesthesia. It’s completely non-invasive.”
Instead, Gamma Knife uses highly focused beams of radiation to treat conditions deep within the brain. 192 individual beams converge on a single target, delivering a powerful dose precisely where it is needed while leaving surrounding tissue largely untouched. Senior Medical Physicist Ken Cashon explains the concept in terms we can easily understand. “There are 192 radiation pellets inside of it. That’s where the value is; it surrounds the patient. And that’s only about 27 grams of material to give 5,000 curies of radiation”.
Cashon points out this technology “allows us to get to spots we would never get to.”
“It’s like having 192 flashlights all pointed at one exact spot,” noted Dr. Mohiuddin. “Each one by itself is too weak to do anything. But when they all come together, that’s where the treatment happens.”
That convergence is what makes the technology so effective—and so different from traditional approaches. “The accuracy is incredible,” Dr. Mohiuddin adds. “We’re talking about fractions of a millimeter. If we can see it, we can treat it.”
Gamma Knife technology is not new, though it continues to evolve in remarkable ways. It was first developed in 1968 by Swedish neurosurgeon Lars Leksell, who envisioned a way to treat deep brain structures without the risks of open surgery.
AdventHealth has been using Gamma Knife for nearly three decades, steadily refining its program and expanding its capabilities. “We’ve had this technology here for about 30 years,” Dr. Mohiuddin says. “But the key is not just having it—it’s continuing to advance it.”
That commitment has positioned AdventHealth as a leader in the field. The program is not only delivering care but also helping train other physicians and institutions. “It’s one thing to offer a technology,” he says. “It’s another thing to be an expert in it and teach others how to use it.”
Senior Medical Physicist at AdventHealth Orlando Kenneth Cashon, M.S. is an integral part of the Gamma Knife process.
For much of modern medicine, treating brain conditions has meant surgery. In many cases, it still does. But surgery carries inherent risks—particularly in an organ as delicate and complex as the brain. “When you think about traditional brain surgery, you’re talking about opening the skull, navigating through critical structures, removing a tumor, and then closing everything back up,” Dr. Mohiuddin explains. “There are risks at every step.”
Those risks include bleeding, infection, stroke, and long recovery times. Even in successful cases, patients often face weeks of healing before additional therapies can begin. Gamma Knife offers a fundamentally different approach. “There’s no incision, no wound to heal, and no delay in continuing treatment,” he says. “Patients can often resume chemotherapy or other therapies almost immediately.” That difference can be critical—not just for convenience, but for outcomes.
Traditional radiation therapy has long been a cornerstone of cancer treatment. But it comes with limitations. “With conventional radiation, it’s like using a spotlight,” Dr. Mohiuddin says. “You can aim it, but the light spreads. Some of that energy inevitably affects healthy tissue.” That spread can lead to side effects such as fatigue, cognitive changes, and hair loss.
Gamma Knife, by contrast, behaves more like a laser. “We’re able to focus the radiation so precisely that just millimeters away, there’s essentially no effect,” he says. “That’s what allows us to preserve memory, vision, and overall brain function.”
The distinction is not merely technical—it is deeply personal for patients navigating already difficult circumstances.
What Gamma Knife Can Treat
While many people associate Gamma Knife with cancer, its applications extend far beyond oncology.
Brain Metastases
One of the most common uses is treating metastatic tumors—cancer that has spread to the brain from other parts of the body.
“These are often small lesions that traditional therapies can’t reach effectively,” Dr. Mohiuddin says. “Gamma Knife allows us to target them directly, often in a single session.”
Benign Tumors
Not all brain tumors are cancerous, but even so-called benign tumors can pose serious risks.
“In the brain, benign doesn’t mean harmless,” says Dr. Melvin Field, a neurosurgeon and co-director of the program. “If a tumor grows in the wrong place, it can affect speech, movement, or vital functions.”
Gamma Knife can stop these tumors from growing—without invasive surgery.
Vascular Conditions
Conditions like arteriovenous malformations (AVMs), where abnormal blood vessels can rupture, are another key application.
“These can be life-threatening if they bleed,” Dr. Mohiuddin says. “With Gamma Knife, we can treat them in a way that reduces that risk over time.”
Neurological Disorders
Perhaps most surprising are the non-cancer uses. Gamma Knife is increasingly being used to treat:
- Trigeminal neuralgia, a severe facial pain condition
- Movement disorders such as tremors
- Certain cases of epilepsy
“These are conditions that can be incredibly debilitating,” Dr. Field says. “For some patients, this offers a new path forward.”
Gamma Knife is one of the most sophisticated procedures we do in medicine. And we have perfected it at AdventHealth.” — Ken Cashon, Senior Medical Physicist at AdventHealth.
For many patients, the idea of brain treatment is overwhelming. But Gamma Knife is designed to be as approachable as possible. “A lot of people come in expecting something intimidating,” Cashon says. “But it’s actually a very calm environment.” The process begins with detailed imaging—typically a high-resolution MRI tailored specifically for treatment planning. From there, the team creates a precise map of the target area.
On the day of treatment, patients are fitted with either a custom mask or, in more complex cases, a specialized frame to keep the head perfectly still. “It’s about precision,” explained Dr. Melvin Field, who serves as the Medical Director for the AdventHealth Minimally Invasive Brain Surgery program. He is also the co-director of AdventHealth’s Gamma Knife and Neuro-Oncology programs and an associate professor of Neurosurgery at UCF’s College of Medicine. He is the Past President of the Caribbean Association of Neurological Surgeons. “We’re working at a scale where even tiny movements matter.” Once treatment begins, patients simply lie still while the machine delivers radiation. Many listen to music. Some fall asleep. “We even ask patients what kind of music they want,” Cashon explains. “It’s part of making the experience as comfortable as possible.” When the session is complete, patients go home the same day. “There’s essentially no recovery time,” Dr. Mohiuddin says. “That’s one of the biggest advantages.”
One of the strengths of AdventHealth’s program is its ability to deliver treatment quickly when needed.
Behind every Gamma Knife treatment is a team of specialists working together. “This is not something one person does,” Dr. Field says. “And it shouldn’t be.”
Each case is reviewed by a multidisciplinary team that may include:
- Radiation oncologists
- Neurosurgeons
- Medical physicists
- Neuroradiologists
- Neuro-Oncologist
“We tailor the approach to each patient,” Dr. Mohiuddin says. “That collaboration is what leads to the best outcomes.”
Gamma Knife is not the right solution for every patient, but it is an option for more people than many realize. “It’s particularly effective for small to medium-sized lesions, especially in areas that are difficult to reach surgically, Dr. Field notes. Patients who may not be ideal candidates include those with very large tumors or diffuse brain cancers, where other treatments may be more appropriate. “The key is choosing the right tool,” he says. “And sometimes that means combining approaches.”
“In cancer care, timing is critical,” Dr. Mohiuddin says.
“We work very hard to ensure patients receive treatment within the optimal window.” In some cases, Gamma Knife is even used before surgery to streamline care. “That level of coordination is something we’re very proud of,” he says.
Despite its capabilities, Gamma Knife remains relatively unknown outside of medical circles.
“It’s almost like a hidden gem,” Dr. Mohiuddin says. “We’ve had this technology for decades, but many people don’t know about it.” That lack of awareness is something the AdventHealth team hopes to change.
“Everyone will either face cancer, know someone who has it, or be affected in some way,” he says. “This should be part of the conversation.” For Orlando magazine readers—many of whom are navigating health decisions for themselves or loved ones—the message is clear:
Stay informed. Ask questions. Explore your options. “If someone is told they need brain surgery or radiation, they should absolutely ask about Gamma Knife,” Dr. Mohiuddin says.
Because in a field where precision can mean the difference between preserving function and losing it, this technology offers something remarkable:
A way to treat the brain without disrupting the life around it.
As Central Florida continues to grow, so too will the demand for advanced medical care.
“The need for oncology services is expected to rise significantly in the coming years,” Dr. Mohiuddin says. With programs like AdventHealth’s Gamma Knife leading the way, the region is well positioned to meet that demand—not just with access, but with innovation and expertise.
“Gamma Knife is one of the most sophisticated procedures we do in medicine. And we have perfected it at AdventHealth,” Cashon says. “And it’s right here.” For patients and families facing some of life’s most difficult diagnoses, that reality offers something invaluable: Hope, delivered with precision.
Gamma Knife® treatment is available at AdventHealth Orlando.
Gamma Knife Resources
Gamma Knife® is the gold standard in minimally invasive, precision radiosurgery for specific brain disorders. There’s only one place in Central Florida where you can find this groundbreaking treatment: AdventHealth Neuroscience Institute.
AdventHealth has over 30 years of experience in offering world-class Gamma Knife radiosurgery, devoting decades of expertise to helping patients heal in body, mind and spirit.
Using precise beams of radiation, the Gamma Knife® system targets multiple brain lesions during a single session and leaves the surrounding healthy tissue untouched. With a Gamma Knife® procedure, there are no incisions or anesthesia, so patients can go home the same day and often resume normal activities the day after surgery. Tumors and brain lesions once considered inoperable are now highly treatable, often in less than one hour.
AdventHealth treats patients using the most advanced Gamma Knife®: Elekta EspritTM. This state-of-the-art technology provides guaranteed precision and the utmost safety. It also enhances your physician’s ability to seamlessly plan and perform your procedure.
Gamma Knife® treatment is available at AdventHealth Orlando
2604 N. Orange Avenue. Suite 181. Orlando, FL
Phone: 407-303-7944