Once your medical history and imaging studies have been reviewed by the multidisciplinary team at a weekly case conference, and you are determined an appropriate candidate for CyberKnife treatment, then you are notified and you are scheduled for the next steps in the treatment process as outlined below.
Step 1: Initial Consultation
During the initial consultation, the patient will meet with several members of our highly trained staff, including the radiation oncologist, the CyberKnife coordinator, the radiation therapist, and/or a surgical specialist if needed. At this time, the procedure, treatment objectives and risks and benefits will be explained in depth; questions are welcomed and encouraged.
Step 2: Patient Treatment Preparation
- Soft Tissue Fiducial Placement (not required for all cases): The CyberKnife is a completely frameless treatment system, which often utilizes bony structures in the body as landmarks to track tumor location. For some tumors or lesions, however, tiny gold seeds, called fiducials, may be implanted to accurately guide the radiation beams. These are typically used to mark tumors in the chest, the abdomen, pelvis or other soft tissue areas. If fiducial placement is needed, the CyberKnife Center will typically coordinate this procedure with an interventional radiologist or a surgeon (see Fiducial insert for more information).
- Making a Mask or Body Immobilizer: In addition, either a plastic “mesh” mask (used with brain, head or neck tumors) or a comfortable foam body mold will be made to help minimize movement during treatment. This simple and painless process is done in the CyberKnife Center. The patient will then undergo imaging (CT, MRI, PET, etc.) with the mask or the body mold.
- Imaging: CT Scan, MRI, PET scan, CT cisternogram / myelogram One or more of the imaging tests outlined below may be prescribed in order to provide the most detailed map possible of your treatment area. When you are consulting with your radiation oncologist, you will be informed of which imaging out of those listed below is needed to plan for your treatment.
- Computed Tomography (CT) uses x-rays to capture extremely detailed cross-sectional images of your body, called slices. The image slices allow physicians to view internal organs, tissue, bones, and blood vessels at various angles.
What to expect:
- You will be asked to remove all jewelry, hairpins, eyeglasses, hearing aids and dentures. For abdominal exams, you should refrain from eating and /or drinking after midnight prior to your exam date.
- Let the technologist know if you have had allergic reactions to a contrast medium, iodine, or shellfish, or if you have asthma. Also inform the radiologic team if you have diabetes or take medication.
- If contrast medium is used, it will be given either intravenously or by mouth to coat the gastrointestinal tract. Most people tolerate the contrast medium without any problems and merely feel flushed for a moment.
- Though the images are acquired in a few seconds, the entire exam takes about 15-30 minutes – longer if contrast medium is used.
- Magnetic Resonance Imaging (MRI) uses a huge magnet and radio waves to create a high resolution image of body tissues. The open design facilitates ease and comfort for each patient.
What to expect:
- Let the technologist know if you have a pacemaker; other imaging will be substituted.
- No special preparation is usually needed prior to your MRI. Eat normally and take medications as usual, unless your doctor or the CyberKnife nurse instructs you otherwise.
- You will be asked to remove your eyeglasses, watch, jewelry, credit cards, dentures, hearing aids and any other metallic objects that you are carrying.
- Generally, you lie on your back. A lightweight surface coil may be placed over the part of the body to be scanned. The exam itself usually takes 15-30 minutes.
- Positive Emission Tomography (PET)/CT detects changes in cells in internal organs and living tissue, diagnosing the presence of disease at the molecular level. The CT pinpoints exact location with fine structural detail of the anatomy. For the PET you will be injected with a drug that contains a dose of radiation to localize the disease.
What to expect:
- For six (6) hours before your test, do not eat or drink (except water), do not even chew gum. Your last meal should be high in protein and low in carbohydrates. No caffeine or exercise 24 hours before the test.
- Take medication as prescribed, but if taken with food try to eat a few soda crackers only four to eight hours prior to your exam. If you have diabetes, call the CyberKnife nurse at least 48 hours prior to your appointment.
- Most people receive the radiopharmaceutical (called FDG) intravenously, a procedure that is usually painless. You will then rest quietly for about 60-90 minutes to allow the FDG to distribute throughout your body. The scan itself will take approximately 2 hours.
- Myelography is a type of radiographic exam of the spinal cord by the use of contrast medium injected into the space around the spinal cord and the nerves, visualization using fluoroscopy and a series of x-rays. A cisternogram is a similar exam of the cerebral (brain) spinal fluid. Both tests will show soft tissues that regular x-ray and other imaging may not show in order to develop your individualized CyberKnife treatment plan.
What to expect:
- Some medications such as aspirin, ibuprofen or Plavix will need to be held for one week prior. Others should be held for only 48 hours prior to the exam. Be sure to review all prescribed and over-the-counter medications with the CyberKnife nurse prior to your exam date.
- You will need to abstain from eating after midnight on the night before the imaging appointment. You may drink clear liquids (clear broth, tea, clear juice, coffee w/out dairy products) up to the time of your examination. You are encouraged to drink 2- 3 glasses of fluid prior to the test.
- On the morning of your imaging, you should take a bath/shower and dress in comfortable clothing and leave all jewelry (metal) at home.
- Before going to the Radiology department you will be asked to empty your bladder and you may be given a prescribed medication that may make you drowsy or your mouth dry.
- You will be taken to the x-ray area via stretcher. Your family should wait in the waiting room. You will be placed on your abdomen on an x-ray table and the Radiologist explains the treatment to you. The Radiologist will then anesthetize (numb) the part of your spine where the needle will be inserted. With the needle, he/she will inject the dye into the spinal canal. The x-ray table may be tilted at one point so that the dye moves to the part of your spine to be x-rayed and a series of x-rays will be taken. The procedure may take about one hour. After the procedure you will be watched for several hours with your head elevated before going home. Further instructions will be given to you upon discharge.
Step 3: Treatment Planning
The CyberKnife physician(s) and the medical physicist will use the high resolution imaging conducted above to identify the exact size, shape and location of the tumor, along with the surrounding health tissues to be avoided. The imaging data is downloaded to the CyberKnife treatment planning computer where physicians use advanced software to customize the number, intensity, and direction of radiation beams the robot will send to the target. This may take a few days depending upon the complexity. The patient is not present during this step. When the planning is complete, a date and time for treatment(s) will be scheduled.
Step 4: CyberKnife Treatment
When you are preparing for your first treatment, you may want to enlist the help of a close friend, family member or driver in case you should require sedation for treatment. Wear comfortable clothes and avoid wearing jewelry. A blanket will be provided for warmth if needed. Take all medication as usual unless specifically told otherwise – avoid diuretics.
CyberKnife treatment will be given once or up to 5 times depending on your unique situation. When the treatment begins, the patient lies flat on the treatment couch while the imaging system acquires the first set of x-rays. The treatment table then moves to the correct position for accurate alignment with the robotic arm. The robotic arm then moves around the patient to deliver the radiation beams—often greater than 100 times. This process takes anywhere from 20 to 130 minutes; so patients need to prepare to lie still for this time frame. Plan on spending two hours at the center on the first day of treatment to allow for variability, though if more than one treatment is given, this time will be more firm after the first treatment.
There are cameras in the treatment room so the CyberKnife team can monitor the entire process. A microphone allows the patient, who is alone in the treatment room, to communicate directly with the radiation therapist at all times. The entire process is painless, but if the patient becomes uncomfortable during treatment, the patient should tell the radiation therapist.
If the treatment plan calls for more than one treatment session, the radiation therapists will schedule all appointment times with you.
Follow Up
The proximity of these tumors to vital nerve and vascular structures makes them surgically problematic. Risk of injury, infection and residual tumor growth make CyberKnife a leading treatment.
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