# K973889: Varian Multileaf Collimator with Dynamic Arc Therapy Feature

- Pathway: 510(k) (Traditional)
- Applicant: Varian Medical Systems, Inc.
- Decided: Nov 21, 1997 after 38 days
- Product code: IYE (Accelerator, Linear, Medical)
- Device class: 2
- Regulation: 21 CFR 892.5050
- Recalls of this device: none
- Data: FDA decisions to Oct 25, 2026; recalls to Oct 12, 2026

## Lineage
Longest line of descent: 1 generation back to K926449 (1995). 3 ancestors in all.
70 later devices descend from it; 1 cites it directly.
0 of 74 devices in its family (counting itself) have a Class I recall.

## Predicates on the family tree (from the FDA summary)
- K926449: Varian Multileaf Collimator, Release 4.0, Varian Assoc., Inc. (1995) Summary page 1.
- K943224: Varian Multileaf Collimator, Varian Assoc., Inc. (1996) Summary page 1.
- K970586: Brainlab Micro Multi-Leaf Collimator, Brainlab Med. Computersysteme GmbH (1997) Summary page 1.

## Most influential descendants
- K990085: Millennium MLC -120 (1999), 69 descendants of its own
- K050442: Millennium Multi-Leaf Collimator (2005), 67 descendants of its own
- 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

## Indications for use
The Varian MultiLeaf 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 this the MLC performs the same function as customized shadow blocks. Employing the MLC Arc Therapy feature enables movement of individual leaves of the MLC according to a pre-existing schedule while the host Clinac® finear accelerator is performing arc therapy. In this modality the beam shape created by the MLC can correspond to a beam’s eye view of the treatment volume at all times while the gantry is rotating in arc therapy.

Source page: https://510kreport.com/device/K973889
Methodology: https://510kreport.com/methodology