Liver Cancer CyberKnife^® VSI™ Robotic Radiosurgery System

Robotic Radiosurgery for Liver Cancer

For liver cancer patients undergoing traditional radiation treatment, delivering radiation treatment directly to a liver tumor can pose as a challenge. This is because as the patient breathes in and out, his or her liver tumor moves. Standard radiation therapy delivery systems are not able to pinpoint moving targets such as lung and liver tumors. As a result, radiation may cause damage to healthy surrounding tissue.

However, with the CyberKnife^® VSI^™ Robotic Radiosurgery System, our radiation therapy team can deliver high doses of exceptionally precise radiation treatment to cancerous tumors that move with respiration. Using the CyberKnife System and its corresponding respiratory tracking system, we can follow and track tumor movement in real-time and treat moving targets like liver tumors. Thus, this highly innovative and sophisticated radiation therapy delivery system is providing new hope to patients who have primary and metastatic liver tumors.

How CyberKnife Is Used to Treat Liver Cancer

First, liver cancer patients who are candidates for CyberKnife treatment undergo a brief, outpatient procedure to place three to six fiducial markers (grain-sized seeds) into and around their liver tumors, using CT or ultrasound guidance. In some cases, a tiny camera that is passed through the digestive system may be used. The markers serve as reference points and help the tracking system determine the exact location of the tumor at all times during treatment.

Patients are also fitted with a special vest to be worn during CyberKnife treatment. The vest helps the system compare chest motion and breathing patterns with tumor position. Ultimately, the information the vest collects for each patient aids the system in tracking the tumor’s motion as each beam of radiation is delivered.

Prior to treatment, patients undergo several CT scans to determine the exact size, shape and location of the liver tumor. An MRI or other imaging test may also be taken to fully visualize the tumor and nearby anatomy.

Once the tests have been completed, the imaging data is digitally transferred to the CyberKnife System’s treatment planning software, so that our radiation oncologists and medical physicists can plan radiation treatment unique to each patient. The plan enables us to match the desired radiation dose to the exact tumor location, and identify critical structures to avoid.

Once radiation treatment planning is complete, patients return to the hospital for treatment. Patients wear their normal clothes for treatment. Prior to the start of each treatment session, they put on their special vests and are comfortably positioned on the system’s cushioned table.

As soon as a radiation therapist ensures the patient is positioned correctly and is ready, CyberKnife treatment begins. The system’s computer-controlled robot slowly moves around the patient, delivering radiation directly to the liver tumor. The system’s software and tracking system confirms the location of the tumor and continually tracks its movement. Digital images of the fiducial markers and the information obtained from the vest aid in the process, helping ensure the system follows the tumor as it moves and pinpoints radiation to the tumor as accurately and safely as possible.

Advantages of CyberKnife for Liver Cancer

Unlike standard radiation therapy, in which low doses of radiation are delivered over weeks and months, CyberKnife can treat a liver tumor with extreme accuracy and high doses of radiation in about five days. Each treatment session lasts between 30 to 90 minutes.

Potential advantages of CyberKnife include:

• Less harm to healthy surrounding tissue and organs
• Less damage to nearby critical structures
• Patients breathe normally during treatment
• Less discomfort during treatment
• Shorter treatment times
• Faster recovery time
• Quicker return to normal activities

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