Stereotactic Localization System
Mechanical accuracy relies on the stereotactic localization system. First, a stereotactic localization head frame, suitable for the chosen diagnostic procedure (CT or MRI), is fixed on the skull of the patient with sterile screws. With the head frame in place, tomographic scans are made covering the treatment site. The images are transferred to treatment planning system to determine the treatment spot size and location (in terms of the coordinates of the frame support).
The patient is positioned on the treatment couch with the head frame attached to the frame support and the X, Y, Z axes are set according to the treatment plan. The system control automatically carries out the planned treatment including moving the patient in and out of the treatment space, and delivering the required amount of radiation dose for each focal spot location.
Additional specifications include:
- The mechanical center (isocenter) indicated by the stereotactic frame system (including the frame and the frame support) is within 0.3 mm from the rotational isocenter when fully engaged in the treatment position.
- The mechanical center as indicated by the stereotactic localization system is accurate with relation to the radiation isocenter to within 0.5 mm in all directions. Adjustments can be made to the frame or the support so that the service engineers can fine-tune the localization system at installation or during later service to meet these requirements.
- The frame is made of aluminum and the screws are titanium. The design is comparable to existing stereotactic frames on the market.
- The screws and the frame are to be sterilized after every use.
- Deformation in any dimension is less than 0.1 mm when 50 kg force is applied. The weight of the entire frame including the screws is less than 1 kg. The frames will withstand 400 kg of clamping force.
- An accuracy verification device is available for daily verification of the integrity of the frame.
- Coordinate markers are available for both CT and MRI scans. The positions of the markers are clearly visible on the corresponding images and are suitable for automatic computer recognition and manual identification.
Robotic Head Positioning System (RHPS)
This Robotic System is based on high precision optical dish drives in the x-y-z direction. These drives are accurate to microns and are completely located under the patient's shoulders. No headroom is lost with this upgrade.The base of the system is a standard optical instrument x-y drive system under the patient's shoulder. This drive system is completed with a z-drive and the head ring mounting structure.