Millennium 120 MLC
Varian's standard-tier multi-leaf collimator. 120 leaves total, 5 mm leaf width at isocenter across the central 20 cm field, 10 mm at the outer edges. Ships on TrueBeam standard configuration and legacy Clinac iX installs.
Why it matters to buyers: Adequate for IMRT, VMAT, and routine SBRT. Not the tool for sub-centimeter SRS — that's the job of the finer-pitch HD120.
Why it matters to engineers: Leaf-motor failures are a common service event. Leaf-position accuracy is a required TG-142 monthly check; worst-leaf reporting is a QA line item. Carriage wear and leaf-bank alignment drift matter more on high-duty-cycle VMAT programs.
Related
- HD120 MLC — fine-leaf sibling
- Elekta Agility MLC — competitor
- TrueBeam
- Clinac iX
- Linear Accelerator
- AAPM TG-142