# K123015: .Decimal Photon Block

- Pathway: 510(k) (Traditional)
- Applicant: .Decimal, Inc.
- Decided: Nov 21, 2012 after 54 days
- Product code: IXI (Block, Beam-Shaping, Radiation Therapy)
- Device class: 2
- Regulation: 21 CFR 892.5710
- 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 K111759 (2011). 1 ancestor in all.
No later device cites it as a predicate yet.
0 of 2 devices in its family (counting itself) have a Class I recall.

## Predicates on the family tree (from the FDA summary)
- K111759: .Decimal Electron Aperture, .Decimal, Inc. (2011) Summary page 2.

## Indications for use
In IMRT therapy for cancer, a photon beam is aimed at the cancerous tissue using a linear accelerator. The linear accelerator is rotated around the patient while the patient lies on a treatment table; the linear accelerator consists of the gantry, which rotates around the patient. The gantry contains a collimator, which points at pre-determined positions to maximize efficiency and dose delivery to the tumor volume. Each gantry angle, or "port", requires custom-made, beam modifying, patient specific devices called: Photon Block. The Photon Block is inserted into the gantry's collimator to shape and focus the beanm as it exits the gantry en route to the targeted area. The photon block is also called a cerrobend block, which defines the area that is to be treated with the photon beam. Photon Blocks are generated out of the treatment planning system or physician's specifications and are unique to each patient and each gantry angle.

Source page: https://510kreport.com/device/K123015
Methodology: https://510kreport.com/methodology