Cutting-Edge Radiation Technology

Respiratory Gating

RPMHigh-resolution conformal radiation therapy demands that you accurately localize the tumor and define the tumor contour. You can then maximize the dose to the tumor while minimizing the dose to the surrounding healthy tissue. Unfortunately, physiological functions, such as normal respiration, can change the tumor position during treatment, requiring you to use a larger treatment volume to compensate for tumor movement.

Key Features

  • Accurate tumor tracking allows maximum dose to tumor and minimum dose to normal tissue
  • Quick and easy respiratory monitoring minimizes treatment time
  • Lightweight marker ensures patient comfort
  • Predictive Filter automatically holds treatment delivery when respiration deviates from normal pattern
  • Superior Clinac® design eliminates dark current during gating
  • Treatment beam gating integrated with dynamic MLC leaf motion
  • Now available for CT simulation

Precise Tumor Tracking
Varian's innovative RPM Respiratory Gating system allows you to accurately and cost-effectively monitor and compensate for tumor motion during the course of treatment. The system is designed to be used anywhere you encounter the effects of respiratory motion. These areas include, but are not limited to, the lung, breast, liver, pancreas, kidney and organs in the pelvis region, such as the prostate.

Cough
The Predictive Filter automatically turns the beam off when respiration deviates from the normal pattern, as shown here during coughing.

Quick, Easy and Accurate Respiratory Monitoring
Varian's Respiratory Gating system lets you monitor respiration quickly and easily–without sacrificing accuracy and patient comfort. First, the system uses a sophisticated video monitor to characterize the patient's breathing pattern. The pattern is obtained by tracking the motion of the lightweight, retro-reflective marker placed on the patient.

Then through video image analysis and signal processing, the system identifies both the full range of chest wall motion during respiration and the normal pattern of that motion. By correlating this data with the motion of the tumor in simulation, you can create a treatment plan that gates the treatment beam on only when the tumor falls within the planned beam aperture.Meanwhile, the Respiratory Gating system allows the patient to breathe naturally and remain comfortable.

Advanced Predictive Filter
During the course of treatment, unanticipated patient movement (e.g., sneezing, coughing) could interfere with the normal operation of the Respiratory Gating system. For these reasons, Varian's RPM Respiratory Gating system features the Predictive Filter (patent pending), which analyzes the patient'srespiration, establishes a baseline respiratory pattern, and detects any deviations from the expected pattern.Deviations from the "predicted" respiratory pattern result in an automatic hold of treatment delivery until the baseline respiratory pattern is re-established.Optional Audio Respiration Coaching provides assistance with inspiration and expiration based on the baseline respiratory pattern.

Superior Gating With Clinac Accelerator
The key to the success of respiratory gated radiation therapy treatment lies with the superior design of the Varian Clinac accelerator. Accurate treatment gating is supported by Varian's high-speed digital control system and gridded electron gun.These features provide <100 millisecond beam-on times with accurate gated dose rates and uncompromised beam flatness and symmetry. While at the same time, the Clinac's gridded gun eliminates unwanted dose due to dark current during the "beam-off " time.

Seamless Integration with Dynamic MLC
The Respiratory Gating interface to the Clinac system is integral to dynamic MLC control. Treatment beam gating holds the MLC motion during "beam-off " times, even during dynamic conformal therapy treatments and IMRT. Leaf motion continues during the "beam-on" time with precise registration to the MLC shape defined for treatment delivery.With the advent of IMRT and dose escalation, the ability to improve patient positioning accuracy becomes a necessity. Let Varian's sophisticated Respiratory Gating system help you meet this objective.