The MRIdian Linac system supports advanced radiation therapy techniques such as image-guided radiation therapy (IGRT) and stereotactic radiation therapy and radiosurgery (SRT and SRS), as well as 3D conformal and intensity-modulated radiation therapy (IMRT). With its MRI capabilities, the system is intended to provide stereotactic radiosurgery and precision radiation therapy for lesions, tumors, and conditions anywhere in the body where radiation treatment is indicated.
MRI guidance and intelligent software deliver advantages throughout the treatment process:
- Pretreatment imaging — High-quality, volumetric soft-tissue imaging for accurate pretreatment positioning.
- On-table dose prediction and adaptive optimization — Accurate dose prediction for on-table quality assurance and plan adaptation.
- Treatment — Continuous, MRI-guided soft-tissue tracking and automatic beam control during treatments.
- Review and assessment — Software tools that help physicians better understand and manage the progress of treatment.
ALIGN - Pretreatment imaging
MRI Positioning Scan — Patient Setup
An integrated MRI unit captures volumetric soft-tissue images for accurate pre-treatment positioning in just a few seconds. The high quality soft-tissue contrast allows you to locate the tumor and align the patient to the treatment beams accurately without using X-ray, CT or surrogate registration markers.
MRIdian Linac allows for accurate automatic patient alignment.
ADAPT - On-table dose prediction and adaptive optimization
On-Table Dose Prediction
On-table dose computation rapidly produces dose distributions and DVHs to predict the anticipated dose delivery.
While the patient is on the treatment table the system compares the pre-treatment MRI image to the planning image and automatically calculates the required dose to be delivered to the target using the current treatment plan. If the dose prediction and prescribed treatment is not clinically acceptable, you can change this on demand.
MRIdian Linac provides real-time imaging that clearly defines the targeted tumor from the surrounding soft tissue and other critical organs.
Using an MR image captured at the beginning of each therapy session, the system automatically identifies and maps the patient’s soft tissue anatomy in 3D. It then transfers contours to the daily image using a rigid or deformable registration.
Utilizing our proprietary Monte Carlo algorithm and software, MRIdian Linac calculates the optimal treatment plan for the patient at the time of treatment. MRIdian Linac has the ability to automatically recalculate the dose and adapt the treatment plan to changes in the patient’s anatomy at the time of treatment. You can re-optimize and re-plan your treatment session in less than two minutes while the patient is on the table.
Track Soft Tissue and Manage Motion
MRIdian Linac captures multiple soft-tissue imaging planes concurrently during treatment, refreshing the image multiple times per second. This real-time imaging allows you to track the movement of the tumor and the surrounding healthy tissue directly as well as verify the target and tracking boundary. If a specified percentage of tumor or critical organ moves beyond a physician-defined boundary, the treatment beam automatically pauses. When the tumor moves back into the predefined boundary, treatment automatically resumes. Beam control is especially important in situations where tumors may be in close proximity to critical organs.
MRIdian Linac’s increased target accuracy allows you to treat patients with higher doses of radiation over fewer treatment fractions. This, combined with improved tumor visibility and accurate dose recordings, means you can treat patients who would not previously have been considered radiation therapy candidates. MRIdian Linac also captures and records a video of the delivered treatments, called MRIdian Linac Movie, for later evaluation.
Review and assessment
With the MRIdian Linac system, physicians have the tools to:
Review dose delivery. For each delivered fraction, users can recall and review the predicted dose distribution, observe motion trajectories, and determine how close an organ comes to meeting established constraints.
Track target and organ positions. Users may identify points in 3D space and track their motion during treatment using virtual markers to ensure that margins are appropriate and plans fully account for actual motion.
Verify soft-tissue targeting. Users can review the movie-like stream of images captured during treatment, observing when the beam is gated on or off and whether the target is being appropriately covered.