# K203669: Mobius3D

- Pathway: 510(k) (Special)
- Applicant: Varian Medical Systems, Inc.
- Decided: Jan 14, 2021 after 29 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: 13 generations back to K954874 (1996). 78 ancestors in all.
3 later devices descend from it; 2 cite it directly.
0 of 82 devices in its family (counting itself) have a Class I recall.

## Predicates on the family tree (from the FDA summary)
- K192424: Mobius3D, Varian Medical Systems, Inc. (2019) Summary page 4.

## Most influential descendants
- K223834: AccuCheck (2023), 1 descendant of its own
- K250696: AccuCheck (2025), 0 descendants of its own
- K250099: Mobius3D (4.1) (2025), 0 descendants of its own

## Indications for use
Mobius3D software is used for quality assurance, treatment plan verification, and patient alignment and anatomy analysis in radiation therapy. It calculates radiation dose three-dimensionally in a representation of a patient or a phantom. The calculation is based on read-in treatment plans that are initially calculated by a treatment planning system and may additionally be based on external measurements of radiation fields from other sources such as linac delivery log data. Patient alignment and anatomy analysis is based on read-in treatment planning images (such as computed tomography) and read-in daily treatment images (such as registered cone beam computed tomography). Mobius3D is not a treatment planning system. It is only to be used by trained radiation oncology personnel as a quality assurance tool.

Source page: https://510kreport.com/device/K203669
Methodology: https://510kreport.com/methodology