MLC (Multileaf Collimator)
An MLC has many individual "leafs" (multileaf) or fingers of
metal that can be positioned by computer. Each leaf is set in position in
front of the radiation beam to precisely define the port, and thus, the
target to be treated, and to block radiation exposure to nearby tissue
(collimation). The double-focus design allows the leafs to accurately
track the radiation beam. The SIEMENS 3-D Multileaf Collimator is the only
fully integrated, double-focused 3-D MLC. It allows leaf travel a full 30
cm to provide maximum flexibility in designing treatment fields and has
low leakage values to minimize radiation to healthy tissue.
3-D MLC
Since divergent beam blocks
are the standard for radiation treatment of oncology patients, Siemens
incorporated a design for the only fully divergent and integrated 3-D
Multileaf Collimator available today.
The 3-D MLC has the following features:
- Compact design allowing generous patient clearance of 43 cm
- Physical geometry distances are the same as Siemens accelerators without an MLC
- The compact design yet large leaves provide the lowest MLC leakage values in the industry
- The fully divergent edge reduces errors in the delivery of IMRT
- Fully integrated into the accelerator control system. Real-time MLC icon displayed on controls console monitor shows you the location of each leaf.
- The only MLC system with bearing technology to keep leaf speed and intra-leaf leakage constant regardless of gantry position.
- MLC beam shaper product that automatically optimizes the position of the MLC leaves and collimator to reduce radiation to healthy tissue.
- Seamless transfer and editing of MLC prescription on Oncology Management System network
The Siemens 3-D MLC allows travel of individual leaves a full 30 cm, providing maximum flexibility in designing treatment fields. At the same time, the low leakage values minimize radiation to normal tissue, and make modern treatment techniques such as IMRT possible.
Along with the fact that mechanical and electronic components are kept at a minimum, ball bearing technology allows the leaves to move smoothly, simultaneously, and with minimum friction- especially when treating a lateral field. This results in increased reliability, long life, low interleaf leakage, and the ability to escalate doses to tumors when treating with IMRT.
