510(k) · Cleared
ClearedXknife-4
Data to Oct 25, 2026 (FDA decisions) Oct 12, 2026 (recalls) Sep 30, 2026 (MAUDE) refreshed weekly
Radionics, Inc. · IYE Accelerator, Linear, Medical
Cleared on Sep 29, 1998 after a 190-day review. The FDA summary names its predicate without a number. 5 later devices descend from it.
- Decided
- Sep 29, 1998
- Review
- 190 days
- Class
- Class II
- Product code
- IYE
- Recalls
- None
- Predicates
- 0
5 later devices descend from it, 2 citing it directly.
- This deviceK981055 Xknife-4Radionics, Inc. · 1998
- Descendant · cites it directly · 2 of its ownK991237 Xplan-2 with Head and Neck Localizer, Model HNLRadionics, Inc. · 1999 · Recalled
- Descendant · 2 generations on · 1 of its ownK081935 Stereotactic Head and Neck Localizer, Model 50-100Aktina Medical Physics Corp. · 2008
- Descendant · cites it directly · 1 of its ownK041997 Radionics Xknife RT 3 with Non Stereotactic ModuleRadionics, A Division of Tyco Healthcare Group LP · 2004
- Descendant · 3 generations on · 0 of its ownK103616 Pinpoint Stereotactic Head and Neck LocalizerAktina Medical Physics Corp. · 2011
- Descendant · 2 generations on · 0 of its ownK061893 Integra Radionics Xknife RT 4Integra Radionics, Inc. · 2006
Most influential descendants
Showing 5 of 5 · See all- K991237Xplan-2 with Head and Neck Localizer, Model HNLRadionics, Inc. · 1999 · cites it directly2descendants
- K081935Stereotactic Head and Neck Localizer, Model 50-100Aktina Medical Physics Corp. · 2008 · 2 generations on1descendant
- K041997Radionics Xknife RT 3 with Non Stereotactic ModuleRadionics, A Division of Tyco Healthcare Group LP · 2004 · cites it directly1descendant
- K103616Pinpoint Stereotactic Head and Neck LocalizerAktina Medical Physics Corp. · 2011 · 3 generations on0descendants
- K061893Integra Radionics Xknife RT 4Integra Radionics, Inc. · 2006 · 2 generations on0descendants
View FIG. 1 as a table
Line of descent and top descendants
| Generation | Number | Device | Applicant | Decided | Recalls |
|---|---|---|---|---|---|
| 0 (this device) | K981055 | Xknife-4 | Radionics, Inc. | 1998 | — |
| +1 | K991237 | Xplan-2 with Head and Neck Localizer, Model HNL | Radionics, Inc. | 1999 | 1 |
| +2 | K081935 | Stereotactic Head and Neck Localizer, Model 50-100 | Aktina Medical Physics Corp. | 2008 | — |
| +1 | K041997 | Radionics Xknife RT 3 with Non Stereotactic Module | Radionics, A Division of Tyco Healthcare Group LP | 2004 | — |
| +3 | K103616 | Pinpoint Stereotactic Head and Neck Localizer | Aktina Medical Physics Corp. | 2011 | — |
| +2 | K061893 | Integra Radionics Xknife RT 4 | Integra Radionics, Inc. | 2006 | — |
Descendants by year cleared
| Year cleared | Devices | With a Class I recall |
|---|---|---|
| 1999 | 1 | 0 |
| 2004 | 1 | 0 |
| 2006 | 1 | 0 |
| 2008 | 1 | 0 |
| 2011 | 1 | 0 |
Sources: FDA 510(k) database (decision fields), the FDA summary (predicates and indications), FDA recall and enforcement reports, and MAUDE; processed by 510(k) Report. Verify on FDA.gov · Methodology and accuracy.
Planning a device in IYE? A 510(k) Report weighs predicate choices, recall history and review times for a new device like this one.
Top candidate predicates for a new IYE device
- #1 K252977 Halcyon, Ethos Radiotherapy System (5.0)score 18.8 · 18 generations · no Class I recall
- #2 Held for the reportin the report
- #3 Held for the reportin the report
What was it cleared against? (2)
Devices the submitter claimed this one is substantially equivalent to (*), and reference devices cited for a specific test or feature (†), as written in the FDA summary.
| Type | Number | Device | Decided |
|---|---|---|---|
| * | — | XKnife-3 System Named without a submission number | |
| * | — | XPlan-1 System Named without a submission number |
What descends from it? (5)
2 later devices cite it directly; ranked here by how many devices descend from each in turn.
Has anything in its family been recalled? (0 Class I)
No FDA recall names this device.
No ancestor or descendant has a Class I recall.
What does this lineage say?
- Of its descendants, K991237 (Radionics, Inc., 1999) has gone furthest, with 2 descendants of its own.
How does its category compare?
All IYE devicesIYE Accelerator, Linear, Medical: FDA decisions, review times, recalls and adverse event reports over 20 years.
FDA decisions per year · IYE
12in 2025
2026 to Oct 25, outlined.
Median 510(k) review, days · IYE
170in 2025
Receipt to decision; years with fewer than 3 clearances left blank.
Recalls per year · IYE
1in 2025
Class I (0 since 2007) Class II/III not classified
Adverse event reports per year · IYE
101in 2025
MAUDE reports naming product code IYE, not matched to any one device; reports are not rates.
View these four charts as a table
| Year | Decisions | Median 510(k) review, days | Recalls (Class I) | MAUDE reports |
|---|---|---|---|---|
| 2007 | 23 | 44 | 78 | 155 |
| 2008 | 14 | 69 | 49 | 114 |
| 2009 | 20 | 63 | 22 | 174 |
| 2010 | 23 | 74 | 27 | 246 |
| 2011 | 11 | 94 | 73 | 280 |
| 2012 | 28 | 106 | 20 | 128 |
| 2013 | 18 | 88 | 11 | 96 |
| 2014 | 20 | 100 | 14 | 124 |
| 2015 | 20 | 108 | 8 | 100 |
| 2016 | 21 | 97 | 7 | 97 |
| 2017 | 23 | 94 | 7 | 125 |
| 2018 | 21 | 58 | 7 | 85 |
| 2019 | 19 | 83 | 2 | 91 |
| 2020 | 20 | 67 | 4 | 74 |
| 2021 | 19 | 86 | 5 | 68 |
| 2022 | 12 | 172 | 3 | 66 |
| 2023 | 18 | 129 | 7 | 128 |
| 2024 | 9 | 239 | 1 | 81 |
| 2025 | 12 | 170 | 1 | 101 |
| 2026 | 14 | 120 | 4 | — |
What is it indicated for?
XKnife-4 is intended for use in stereotactic, collimated beam, computer planned, LINAC (linear accelerator) based radiosurgery and radiotherapy treatment.
Indications for use read by OCR from a scanned FDA summary, so letters may be misread. Check the PDF before quoting it.
https://510kreport.com/device/K981055 · printed Nov 4, 2026
Cite this page
510(k) Report. “K981055: Xknife-4.” Lineage record from FDA 510(k) data and the FDA summary. Updated Nov 3, 2026. Accessed Nov 4, 2026. https://510kreport.com/device/K981055
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Record history
- FDA decision record loaded May 2, 2026
- Summary read Oct 13, 2026 (extraction version 9eaa42aa01ed)
- Lineage and recalls computed Nov 3, 2026
- Page last updated Nov 3, 2026