Catalyst HD optical surface scanning and re-projection

The Precise Answer to Stereotactic Radiation Therapy

Continued technical evolution has expanded stereotactic treatment to both intracranial and extra-cranial sites. It is developing rapidly, particularly in developed radiation therapy markets such as North America and Europe. Stereotactic Radiation Therapy (SRT) has the potential to reduce fractions and improve survivorship. Stereotactic Body Radiation Therapy (SBRT) for lung cancer is an example of an alternative to surgery.

The capability of linear accelerators to deliver higher doses for SRT is increasing and it is expected that this technique will be applied more widely in clinical settings. To deliver even higher doses, new technology must be provided that is compatible with stereotactic delivery, namely high-precision patient positioning and intra-fraction motion management.

During treatment, patient breathing, as well as movement of the tumor or normal tissue can impact the clinical result by missing targets or causing extra dose distribution to normal tissue.

Catalyst HD offers a complete Surface Image Guided Radiation Therapy (SIGRT) solution on SRT for online patient tracking before and during treatment delivery, thus ensuring the best possible treatment outcome without non-prescribed doses. The Catalyst HD can also be used for VMAT, IMRT and 3D CRT delivery.

In the treatment room, the system provides the following benefits compared to other SIGRT solutions:

Submillimeter accuracy Surface Image Guided SRT Solution

• Catalyst HD is integrated into the stereotactic treatment workflow, from Setup and Positioning to Intra-Fraction Motion Monitoring to Respiratory Gating Treatment with submillimeter accuracy for non-coplanar treatment
• Large patient surface coverage (1300x800x700mm) with optimal 360-degree coverage
• During treatment, the patient is constantly under surveillances by Catalyst HD
• Interactive visual guidance via colour map projected on patient body during setup
• Correct any posture or positioning errors immediately
• Auto couch correction in set-up
• Any patient movements over tolerance immediately trigger beam hold
• Respiratory gating
• Absolute value calculation with baseline monitoring capability
• Tracking of both thoracic and abdominal respiratory motion in parallel
• Breath-hold, deep inspiration and coached/free breathing modes are all supported
• Optional audio-visual coaching helps the patient follow optimal breathing patterns. Patient baseline is calculated as an absolute parameter that can be used during the delivery

High level of patient safety and user confidence

• No markers on or around the patient
• Dose-free motion management
• Auto patient data retrieve
• Tracking of both thoracic and abdominal respiratory motion in parallel with virtual monitoring
• Optional audio-visual coaching through in-room speakers and video solution, assisting the patient to follow the optimal breathing pattern
• Compliable to the immobilisation devices for SRT

Sophisticated software to streamline the workflow

• Catalyst HD can retrieve all data acquired by Sentinel from a central database and the same surface points and breathing curve will be automatically tracked in the treatment room at every fraction without manual intervention
• Multi-vendor interfaces have been developed to ensure the seamless clinical workflow, i.e. Varian TrueBeam, C-series; Elekta VersaHD, Infinity, Synergy

Increasing productivity without compromising the treatment quality

• Non-rigid algorithm improves accuracy and speed of clinical application
• Reduces the dose on heart and lung during DIBH treatment for left breast cancer and lymphoma
• Potential to improve quality and speed of the positioning process, for example, extremity sarcoma
• Highly integrated QA/QC procedure – Daily QC within 5 minutes
• The QA workflow with PentaGuide matches the coordinates of the Catalyst HD with those of the Linac to improve accuracy

Selected specifications

Light projection

• Measuring light: 405 nm (near-invisible violet)
• Projection light: 528 nm (green), 624 nm (red)

Performance

• Scan volume (X * Y * Z): 800 mm x 1300 mm x 700 mm
• Measurement reproducibility: 0.2 mm
• Long term stability: 0.3 mm
• Warm-up time: 30 minutes
• Frame rate: 200 frames/s
• Registration method: Real-time, non-rigid with deformable models for computing 6 DOF isocentric shifts
• Positioning accuracy: Within 0.5 mm for rigid body
• Motion detection accuracy: Within 0.5 mm