# K050442: Millennium Multi-Leaf Collimator

- Pathway: 510(k) (Special)
- Applicant: Varian Medical Systems
- Decided: Mar 23, 2005 after 29 days
- Product code: IYE (Accelerator, Linear, Medical)
- Device class: 2
- Regulation: 21 CFR 892.5050
- Recalls of this device: 2 (0 Class I)
- Data: FDA decisions to Oct 25, 2026; recalls to Oct 12, 2026

## Lineage
Longest line of descent: 3 generations back to K926449 (1995). 5 ancestors in all.
67 later devices descend from it; 3 cite it directly.
0 of 73 devices in its family (counting itself) have a Class I recall.

## Predicates on the family tree (from the FDA summary)
- K990085: Millennium MLC -120, Varian Assoc., Inc. (1999) Summary page 1.

## Most influential descendants
- K071992: High-Definition 120 Multileaf Collimator (HD120 MLC) (2007), 64 descendants of its own
- K092871: Trilogy MX (2009), 61 descendants of its own
- K111106: Truebeam (2011), 43 descendants of its own
- K123291: Truebeam (2012), 37 descendants of its own
- K123808: Agility (2013), 36 descendants of its own

## Recalls of this device
- Jan 16, 2012 · Not classified · Z-1091-2012: When using the Standard and Millennium 52-leaf MLC multi-leaf collimators for beam shaping, under specific treatment conditions, dose may be delivered outside of the intended treatment field that exce
- Jan 16, 2012 · Not classified · Z-1090-2012: When using the Standard and Millennium 52-leaf MLC multi-leaf collimators for beam shaping, under specific treatment conditions, dose may be delivered outside of the intended treatment field that exce

## Indications for use
The Varian Millennium 120 Multi-leaf Collimator (MLC) is provided to assist the radiation oncologist in the delivery of radiation to defined target volumes while sparing surrounding normal tissue and critical organs from excess radiation. In static mode, the MLC performs the same function as the customized shadow blocks. In a dynamic mode, a series of MLC leaf positions can be indexed to either Clinac dose fraction or gantry angle to create a changing beam shape while the radiation beam is on to create a three dimensional dose distribution.

Source page: https://510kreport.com/device/K050442
Methodology: https://510kreport.com/methodology