Varian Linear Accelerator Base Frame Removal

In the 90’s and early 2000’s, most Varian linear accelerators installed globally included a base frame that consisted of a 36” diameter turntable–the industry referred to them as the “standard base frame”. As Varian introduced more advanced linear accelerator models into the market, the company developed a newer base frame that was slightly broader called the “VEO base frame”. The VEO base frame’s design consists of a larger, 52” diameter turntable and weighs an estimated 2260 pounds (1025kg).

Base frames can be removed and re-purposed for future use, however, preserving a base frame requires a careful process that demands attentiveness. The following steps can be taken to properly remove and save a base frame from a Varian linear accelerator:

1. Ensure that there is good ventilation in the room, blocking off any vents to prevent dust damage
2. Take thorough measurements of the pit
3. Use a diamond edge saw to cut around the perimeter of the base gram
4. Punch holes around the perimeter, filling the newly punctured holes with expansion concrete
5. Use jackhammers to remove concrete in the appropriate areas
6. Clear the rubble
7. Utilize an A-Frame to remove the base frame, tub, and turntable
8. Fill the bit with concrete or modify the pit for its new base frame

Varian linear accelerator models using the VEO base frame include: Clinac 21EX, Clinac 2100CD, Clinac 23EX, Clinac 2300CD, iX, Trilogy, and TrueBeam. It is often recommended that VEO base frames be replaced with new ones when purchasing a linac, although most cases, the existing one can be used.

If you require further insight in base frame removals or linear accelerator removals, contact ROS and we can assist you with any questions and concerns you may have.