The CyberKnife Process - A Patient's Guide

Step 1 - Initial Consultation

The initial consultation involves the radiation oncologist, a surgeon and other physicians, if required. They will determine if CyberKnife® is right for you. Please bring a list of all of your medications to these appointments.

Step 2 - Treatment Preparation

Soft Tissue Fiducial Placement

Fiducials are tiny gold marker seeds that are implanted into soft tissues in or near the tumor to accurately guide the CyberKnife radiation beams. These markers are typically required for tumors in the abdomen, pelvis, prostate and some lung cancers. They are not required for tumors in the brain or spine.

If your treatment requires the placement of fiducial markers, the Connecticut CyberKnife Center staff will arrange for the procedure. For more details about placement of fiducial markers, please click on the link for your type of cancer on the left side of this page.

Step 3 - Imaging and Simulation

Making a Mask or Body Immobilizer

One to two weeks after the fiducials are placed, the patient will be scheduled to return for imaging and simulation. At this appointment, the CyberKnife nurse will explain the entire process.

The patient will then lie on the table in the exact position in which he/she will be treated. For patients with brain or head and neck tumors, a plastic mesh mask is custom molded to the face. This mask is used during treatment to help prevent movement. For all other patients, a comfortable foam immobilizing system is made which is molded to the body. These devices are used to help minimize patient movement during treatment. The process is simple and painless.

For lung, liver and pancreatic cancers, or any lesion that moves with respiration, the patient is also outfitted with the synchrony tracking vest. This comfortable vest is worn during treatments, and contains light-emitting diodes used for tracking the breathing motion.

Imaging and Simulation

Imaging and Simulation 3 Imaging and Simulation 2 Imaging and Simulation 1 

CT scanFine-cut CT scans are performed which will be transferred to the CyberKnife planning computers. When scheduling this appointment, you will receive instructions regarding the scan. You may be given an IV contrast (dye) injection. Please inform the staff immediately if you are allergic to x-ray or CT scan dye. 

Depending on the type of tumor to be treated, MRI and/or PET scans may also be required to accurately identify the lesion.

Step 4 - Tumor Mapping/Computer Programming

Cyberknife planningOnce your CT studies are complete, they are transferred to the CyberKnife computer, where they are fused onto any MRI or PET scans which may have been performed. The radiation oncologist and surgeon carefully map the tumor and all nearby organs on the computer.

Planning considerations include exact tumor or lesion configuration and its relationship to nearby normal body structures, which in turn influence the number, intensity and direction of the radiation beams that the robotic arm will send to the tumor. This will help ensure that we can deliver a sufficient dose to the tumor in order to destroy it, while minimizing to the greatest degree possible, the radiation dose to neighboring normal tissues.

When the physicians have completed their work, the medical physicists begin the treatment planning process. Please be aware that this may take several days, depending upon the complexity. When the planning is complete, the CyberKnife Coordinator will contact you to schedule a date and time for your treatment(s).

Step 5 - Treatment

Getting Ready

  • Take your normal daily medications as usual with the exception of diuretics (“water pills”). Diuretics should not be taken until after treatment is finished that day.
  • Wear comfortable clothing and no jewelry. A blanket is provided for warmth if needed.
  • Most patients can drive to and from treatment, however, you may need transportation if you require sedation or relaxation for treatment. Our staff will review this with you before treatment begins.

Patient and TechsWhen you Arrive

  • CyberKnife radiation therapists will have you lie on the treatment table and position you into your mask or body mold system.
  • X-ray images will be taken. The table then adjusts to provide the necessary millimeter alignment, and the robotic arm then moves the linear accelerator to its first position and delivers the first treatment beam.
  • This process is repeated many times as the X-ray system zeroes in on the target and the robotic arm realigns the linear accelerator from multiple different positions – often more than than 100 times. At each angle, the CyberKnife delivers a precise radiation beam. The image-guidance system utilizes bony landmarks or implanted fiducial markers to track the exact location of the tumor during the entire treatment process, creating an extremely accurate and precise radiation treatment procedure.
  • If a lung or upper abdominal tumor is treated, the breathing cycle is also continuously tracked and correlated with the tumor’s position, causing the robotic arm to assume a real time “breathing” pattern that tracks the tumor. This robotic breathing pattern follows the tumor exactly as it moves throughout the breathing cycle, keeping the radiation beam squarely on the tumor throughout the entire treatment.
  • During treatment, you will need to lie still and breathe normally.
  • Generally, no sedation is required because the treatment is painless, although medication will be available if necessary.
  • You can watch a movie on the flat screen TV on the ceiling, or listen to music during the treatment.
  • CyberKnife treatments are delivered in one to five sessions, within seven to 10 days, depending upon your situation. Treatment sessions last from from 30-120 minutes.
  • You will receive written discharge instructions from the nurse at the end of the course of treatment.
  • Typically, you may return home and resume normal activities immediately following treatment.
  • Please ask questions if you do not understand a process or instructions!

Step 6 - Follow Up

Patients are seen for evaluation 1-2 months after treatment, at which time CT or MRI scans may be taken to evaluate response to the treatment. Because some tumors may continue to respond for up to 4-6 months, further follow-up evaluations may be required. Patients are also advised to continue with follow-up appointments with their referring physicians.