Jennifer Crawley, Radiation Therapist, and Scott Wyler, Chief Physicist and Radiation Safety Officer set up the CyberKnife for a simulation treatment for the brain.
Baptist acquires CyberKnife® Robotic Radiosurgery System
The future is here: tumor treatment that is painless, requires no anesthesia, no incision, allows for treatment in the patient’s own clothes, limits actual treatment time to less than an hour and allows her to run carpool, keep her dinner plans and anything else on her agenda following the procedure.
Assuming eligibility criteria for treatment is met, this is the new paradigm for patients with radiosurgery in their treatment plan to address their tumors, whether cancerous or benign. The CyberKnife is an alternative to surgery that delivers image-guided, targeted, high dose radiation with extreme accuracy. And the news gets better.
“The emerging data shows excellent long-term control – upwards of 95 percent tumor growth control at five years, which is not seen with conventional radiation,” explained Jason Weaver, MD, neurosurgeon at Semmes-Murphey Neurological and Spine Institute, assistant professor of neurosurgery at the University of Tennessee Health Science Center (UTHSC) and advocate for the CyberKnife’s appropriate use.
“In select patients this is a very robust form – to maintain local control tumor growth, often without the need for any aggressive surgical intervention. Overall, that is less morbidity for the patient and a better outcome.”
September 28 was the go-live date when the first patient received treatment with the new $5-million CyberKnife® Robotic Radiosurgery System at Baptist Center for Cancer Care-Memphis. According to Weaver, Baptist purchased the most state-of-the-art equipment available, designed to treat a tumor in any location of the body using stereotactic radiation therapy.
Though CyberKnife technology has been available for approximately 10 years, the hospital recently acquired the technology as part of its goal to provide comprehensive cancer treatment for patients.
The CyberKnife is housed in the Radiation Oncology department at the Baptist Center for Cancer Care at 55 Humphreys and will eventually be moved to the new $65 million facility to be built at Germantown Parkway and Wolf River Boulevard.
As chairman of BMHCC Memphis Cancer Committee, Weaver helped spearhead the efforts for procurement of the CyberKnife system that includes the CyberKnife VSI™ System with the most advanced features.
“From my perspective, (the CyberKnife) was on my radar and that of Semmes-Murphey Clinic for almost a decade… because we recognized the need to deliver (stereotactic) radiosurgery to areas outside the brain, which is the only capability of the (Leksell) Gamma Knife,” Weaver said.
The Gamma Knife is specifically approved for treating brain tumors, whereas, the CyberKnife can treat tumors essentially in any location in the body.
Having the CyberKnife will reduce many patients’ waiting time for tumor treatment.
“We have been doing stereotactic surgery to the brain and spine with the Varian Trilogy system since 2007,” Weaver said. “With our volumes rapidly expanding, we recognized the need for the CyberKnife System. Our patients were waiting longer and longer for treatments.”
During the first year of operation, 100 patients are expected to receive treatment.
The CyberKnife and its forerunners, such as the Varian Trilogy system and the Gamma Knife, have revolutionized treatment for both malignant and non-malignant tumors, especially those occurring in locations deemed inoperable.
Technology Brings About Major Change
“I would say that we have seen this type of technology drastically change the way that we go about managing patients with brain and spine tumors,” Weaver said. “It has allowed us to be less invasive and less aggressive surgically, but not sacrifice our ability to control tumor growth and give the best possible outcome with today’s technology.”
“The equipment is operated by radiation therapists under the direction of the radiation oncologist,” said Beverly Cusano, director of radiation oncology. “The patient’s specific treatment planning is done by the radiation oncologist, the staff physicist and the medical dosimetrist.”
“My role as a neurosurgeon is to help with planning of the cases,” said Weaver. It’s a team approach just like we have in the operating room.” Weaver indicated that each team member has an integral role in the complex planning process which is the most challenging work of the case. Actual treatment takes an hour or less.
Unique Aspects of the CyberKnife
The new CyberKnife system software allows the patient to move and not be rigidly strapped in a device, Weaver stated.
“Baptist…got the latest and greatest CyberKnife technology that exists today. The planning software is quite remarkable in its ability to plan complex cases and come up with a uniquely tailored plan. It has a six dimensional rotational couch which… allows us to set up the patient in a very accurate manner, reduce treatment time and achieve a high degree of accuracy.”
Weaver further explained, “The Iris™ Variable Aperture Collimator works like an eye; it allows the beam to focus to smaller or larger beams during treatment which can further enhance accuracy and conformality of the tumor.” Additionally, the linear accelerator can be positioned in any direction by the robotic manipulator with sub-millimeter accuracy. And the imaging system generates high-resolution images that it continually compares to previous images to adjust the target location precisely with the patient’s position.
“It has the ability to reach some tumors that other technology cannot. Its pinpoint accuracy is one of its most important features,” added Cusano.
Typically treatment is completed in one session because of the high dose, image-guided delivery of radiation to the specific area targeted, said Weaver. Often the dose is tumoricidal and requires no further treatment. If there is a history of radiation or the tumor is too large, treatments can be fractionated, he added.
Indications for use?
The CyberKnife is indicated for both malignant and non-malignant tumors anywhere in the body, said Weaver. It will be used to treat tumors of the brain, spine, liver, pancreas, kidney, prostate, lung and intra-abdominal pathologies.
“In my area of focus specific to neurosurgery, it can be used for benign and malignant primary tumors of the brain and spine, and metastatic tumors of the spinal column and brain. These include acoustic neuromas, meningiomas, schwannomas, and metastatic lesions that may spread from other organs in the body. CyberKnife has also been used for pain disorders like trigeminal neuralgia and other functional disorders.
“Each site that purchases the CyberKnife establishes its own protocol and patient eligibility criteria,” said Cusano. The number of treatments is determined individually for each patient by the team, which develops the patient’s treatment plan.
Can the treatment be repeated?
The limitations for repeat treatments are dependent on individual circumstances.
“There are factors which affect the possibility of repeat treatments including the patient’s tumor, how much radiation the patient has had in the past, what structures the tumor is next to, and whether or not those structures can tolerate more radiation,” said Weaver.
“It’s a very high focused form of radiation but as long as (treatment) is delivered appropriately, there are no significant adverse effects,” Weaver indicated. “The benefits are that the normal tissue – and the surrounding organs like the esophagus and the spinal cord – does get a very low dose of radiation, so the things we might see with traditional radiation, like acute toxicities to those organs, are largely avoided.
“I would like to see us develop a comprehensive approach to the care of cancer patients. This is a modality not used alone and is not suitable for every single cancer patient. It requires a very thoughtful approach…and oftentimes it’s used in conjunction with open surgery and adjuvant treatments like chemotherapy. It’s not just stand-alone technology.”