The CyberKnife Robotic Radiosurgery System is a noninvasive, painless treatment option that with pin-point accuracy and no incision delivers high doses of radiation to both cancerous and non-cancerous tumors throughout the body, including the brain, kidneys, lungs, prostate, spine, liver and pancreas.
Designed by neurosurgeon, Dr. John Adler, and manufactured by Accuracy Inc. (Sunnyvale, Calif.), the CyberKnife robot was first introduced to oncology radiation during the mid-1990s, and new innovations for its use are an ongoing.
CyberKnife's robotic arm supports a linear accelerator that produces radiation and has the ability to move about a patient's body to various locations where it treats tumors from multiple directions typically by using between 100 and 200 radiation beams.
This mobility allows the CyberKnife System more than 1,200 possible angles and directions in order to deliver a precise dose and pattern of radiation uniquely prescribed for each patient, according to Andre Zajac, MD, radiation oncologist and CyberKnife Director, St. Catherine's Hospital, East Chicago, Ind.
Using image guidance software, the CyberKnife can track tumor movement (such as a lung tumor that moves with breathing) in real-time and adjust the delivery of the radiation accordingly throughout the procedure. The CyberKnife is particularly useful for treating hard to reach inoperable or surgically complex tumors that can't be accessed through conventional surgery.1
The treatment is so precise it is described by the manufacturer as "painting" a tumor with radiation.
In many cases, "CyberKnife treatments offer new hope for patients who can no longer endure traditional cancer treatment," offered Joey Spring, CyberKnife Manager, Nancy N. and J.C. Lewis Cancer & Research Pavilion at St. Joseph's Hospital, Savannah, Ga., part of the St. Joseph's /Candler Health System.
Painless & Precise
Because CyberKnife treatments don't require anesthesia or incision they tend to be painless and infection free with a short recovery time.
"As the CyberKnife is very precise it avoids damage to healthy surrounding tissues, and patients do well after treatments due to minimal side effects," explained Kelly Hamilton, RN, a CyberKnife nurse at Cancer Treatment Centers of America in Tulsa, Okla.
"Less time for treatment is less time for side effects," said Oralia Mendoza, MS, RN, OCN, practice administrator for the radiation oncologists at St. Catherine's Hospital. "There are fewer and less side effects compared to what we generally see with the traditional 30 days of radiation treatment."
CyberKnife patients initially attend a simulation planning session when a CT scan is performed in the region of the body to be treated.
Radiation oncologists use these images to localize and designate the target/tumor to be treated, and the normal organs and tissue to be avoided. A radiation physicist takes this information to develop a computerized treatment plan. A radiation oncologist prescribes radiation doses to be administered for each patient and finalizes individual plans.
Once approved this data is sent to the CyberKnife computer that's operated by a dosimetrist (a highly skilled radiation technician). Dosimetrists prepare patients for treatment and ensure the prescribed treatment plan is accurately delivered to each individual.
"At our Center an MRI is also ordered during a simulation planning session to get an even clearer picture of muscle and body structures, and the treating physician uses that data to identify the exact size, shape and location of the tumor," Hamilton explained.
On initial consultation patient and family teaching by nurses includes an informational packet and CD provided by the CyberKnife manufacturer.
"Cancer patients may be uncomfortable or experiencing pain, so our staff assess them and administer pain medications as comfort measures prior to treatments," said Mendoza.
"Active listening skills are an important part of the work we nurses do," said Lisa Winters, RN, a CyberKnife support team member at St. Joseph's Hospital.
Hamilton agreed. "My role as a CyberKnife nurse is to educate patients and families about the CyberKnife process," she said.
"Other nurses are assigned to work with radiation oncologists," Hamilton added. "Many preoperative procedures require specific tasks that must be completed, and as cancer patients may be overwhelmed with all the information I present, they tend to be forgetful, so I call them a day prior to when procedures are to be done."
When CyberKnife treatments are scheduled patients generally receive a prescription for medications to take one hour prior to a treatment to reduce anxiety and control nausea.
Those patients who have brain tumors are given a preventative steroid, Hamilton said, "because anything hit with radiation can result in a "cranky brain," or brain swelling, during each 30-60 minute treatment."
Patients with brain and spine tumors require a two-week plan for a CyberKnife treatment because it's so technical. Patients with lung, liver, pancreas and prostate cancer require a three-part treatment plan.
In addition to being a treatment options for many cancers, CyberkKnife is also a preferred treatment for some non-cancerous health conditions, such as: trigeminal neuralgia, a nerve condition that causes a sharp pain in the cheek; meningioma, a benign brain tumor; acoustic neuroma, a benign tumor of the hearing nerve that causes ringing in the ears and hearing loss; and vascular malformations (a cluster of blood vessels in the brain or spine).
Treatment & Recovery
CyberKnife treatments are like taking an X-ray as patients are required to lay still and tolerate the body position required for each treatment. When a treatment begins staff leave the room because radiation is present.
Marker surgery is first, Hamilton said. "Markers called Fiducials (tiny gold seeds) are implanted to allow the CyberKnife robot camera to track tumors during treatment. A week later, CT and MRI scans are done, and the next week a CyberKnife treatment is scheduled," she explained.
Patients are monitored throughout the treatment via a TV screen that ensures their visibility and staff's ability to support them.
"If a patient needs to use a restroom the therapist stops the treatment, the patient is assisted and the treatment is resumed exactly where it left off," Mendoza said.
When treatments are completed nurses check vital signs to assure nothing untoward has occurred, and patients are seen by their oncologists within 7-10 days for evaluation.
"We keep a close eye on our patients as CyberKnife treatments are high tech and we're giving large doses of radiation within a relatively short period of time," Mendoza said.
"Patients tend to think once the treatment is over that's it," Hamilton noted. "The prescribed dose of radiation will continue to work in patients' bodies for three months after a treatment. That's why we don't immediately scan patients" following the treatment "and wait a couple of months for a re-scan to see how they're doing."
Joan Fox Rose is a nurse and freelance writer.