soft-tissue targeting and automatic beam control for precision treatments

The ViewRay™ radiotherapy system is designed to watch a tumor and adjust for its movement in real time. With sophisticated methods for tracking organ motion and controlling the beam, the ViewRay system can help assure accurate treatment delivery while decreasing the dose to critical structures and surrounding normal tissues.

During treatment, the ViewRay system monitors the patient’s anatomy and adjusts for motion in real time, delivering the dose only when the tumor is located exactly where it should be. MRI soft-tissue tracking and beam control are:

• Continuous. Subsecond imaging continues throughout the treatment, producing a stream of high-quality images that are continuously checked by the gating system.
• Automatic. Every time a subsecond image is captured, the gating system automatically compares the new image to the treatment planning image, checks the acceptable deviations set by the physician, and determines whether to continue or pause the treatment beam.
• Free of fiducials. Because the ViewRay system captures volumetric images, no implanted fiducials or external markers are required to locate points in space.
• Free of ionizing radiation. MR imaging captures high-quality images without unnecessarily exposing the patient to additional ionizing radiation.

If the tumor or a critical structure moves beyond a physician-defined volumetric boundary, the beam automatically pauses; when the target moves back into the predefined boundary, treatment automatically resumes. The system makes treat-or-pause assessments, based on the physician’s instructions, every 300 milliseconds. A typical ViewRay treatment takes no more time than a traditional treatment.

Resources

MR Imaging and Soft-Tissue Targeting Brief [PDF]