 Intensity modulation of radiation therapy portals using compensators has a long history beginning with the pioneering work of Ellis in 1956. More recently, the availability of computer numerical control (CNC) milling machine technology in bench top form has made compensator production much simpler and easier for clinics to manage. Thanks to the efforts of the linac manufacturers, there is interest in IMRT (intensity modulated radiation therapy). The number of clinics obtaining CT scans to be used in 3D treatment planning is such that most commercial treatment planning systems (TPS) support 3D compensator design for either forward or backward IMRT implementation. These compensators arise from straight-forward translation of the optimum intensity distribution maps for each field. These intensity maps can be output to a file for external production of a physical compensator.The CompMILL system consists of: a)
bench-top milling machine, b) software to convert TPS design of the compensator to milling machine instructions, c) linac-specific tray to mount Styrofoam molds in the wedge tray slot, d) simple utensils to hold and pour metal powder, e) QA tool to quickly check the Styrofoam mold. A QA text file that can be printed out and used as a check off guide when verifying the accuracy of the mold, is also generated. Each produced mold has alignment holes drilled so that it mounts in one unique way to the wedge slot mounting tray. This helps localize and center the finished product. The TPS generated filename, which is processed to create the mold, is carved into the Styrofoam to ensure that multiple fields and compensator molds are not confused. A 486 or higher PC* running Windows 95 or higher is needed to run the milling machine.
 The system allows a simple, easy to visualize, cost effective method of implementing either traditional or more sophisticated IMRT treatments on any and linear accelerator which has a slot to accept physical wedges.
Start-up kit
A start-up kit of convenient accessories is included with the system – 30# steel powder, mixing/pouring pan, utility knife, mylar tape/dispenser, glue, and scoop. Contact your MED-TEC account rep for details. |
