K151159 · Elekta Instrument AB · IWB · Oct 29, 2015 · Radiology
Device Facts
Record ID
K151159
Device Name
Leksell Gamma Knife Perfexion
Applicant
Elekta Instrument AB
Product Code
IWB · Radiology
Decision Date
Oct 29, 2015
Decision
SESE
Submission Type
Traditional
Regulation
21 CFR 892.5750
Device Class
Class 2
Attributes
Therapeutic, Pediatric
Indications for Use
Leksell Gamma Knife® Perfexion™ is a teletherapy device intended for stereotactic irradiation of head structures ranging from very small target sizes of a few millimeters to several centimeters e.g., metastatic tumors, recurrent glioblastomas, trigeminal neuralgia, medically refractory essential tremor, ocular tumors, optic nerve tumors, benign diseases (such as meningiomas, vestibular schwannomas, post-surgical pituitary adenomas, craniopharyngioma, hemangioblastomas, schwannomas, arteriovenous malformations, cavernous malformations, chordomas, glomus tumors, hemangiomas). skull base tumors, head and neck tumors (such as unknown of the head and neck, oral cavity, hypopharynx, oropharynx, nasopharynx, sinonasal, salivary gland), and pediatric tumors (such as glioma, ependymoma, pituitary tumors, hemangioblastoma, craniopharyngioma, metastasis, medulloblastoma, nasopharyngeal tumors, arteriovenous malformations, cavernous malformations, skull base tumors).
Device Story
Radiosurgery system for stereotactic irradiation of intracranial/head/neck structures; utilizes 192 Cobalt-60 sealed sources to deliver ionizing radiation shots to precise targets. System comprises medical unit (radiation source, patient positioning) and office unit (operator console, computer). Operated by clinicians in clinical settings. Preoperative radiological exams inform treatment planning. Device delivers highly accurate external irradiation; enables treatment of tumors, vascular malformations, and neurological conditions. Benefits include non-invasive precision targeting of small, complex lesions.
Clinical Evidence
No clinical data provided. Substantial equivalence supported by risk analysis and performance testing from previous submissions. Bench testing only.
Technological Characteristics
Teletherapy system; 192 Cobalt-60 sealed sources; stereotactic irradiation; patient positioning system; split architecture (medical unit in treatment room, office unit in control room). No changes from K133565.
Indications for Use
Indicated for stereotactic irradiation of intracranial, head, and neck structures in adults and children aged 2 years and older, including tumors (metastatic, glioblastoma, glioma, ependymoma, pituitary, skull base, head/neck, pediatric), vascular malformations (AVM, cavernous), trigeminal neuralgia, and essential tremor.
Regulatory Classification
Identification
A radionuclide radiation therapy system is a device intended to permit an operator to administer gamma radiation therapy, with the radiation source located at a distance from the patient's body. This generic type of device may include signal analysis and display equipment, patient and equipment supports, treatment planning computer programs, component parts (including beam-limiting devices), and accessories.
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Food and Drug Administration 10903 New Hampshire Avenue Document Control Center - WO66-G609 Silver Spring, MD 20993-0002
October 29, 2015
Elekta Instrument AB % Ms. Matilda Forsberg Regulatory Affairs Engineer Kungstensgatan 18 SE-103 93 STOCKHOLM SWEDEN
Re: K151159
Trade/Device Name: Leksell Gamma Knife Perfexion Regulation Number: 21 CFR 892.5750 Regulation Name: Radionuclide radiation therapy system Regulatory Class: II Product Code: IWB Dated: September 25, 2015 Received: September 28, 2015
Dear Ms. Forsberg:
We have reviewed your Section 510(k) premarket notification of intent to market the device referenced above and have determined the device is substantially equivalent (for the indications for use stated in the enclosure) to legally marketed predicate devices marketed in interstate commerce prior to May 28, 1976, the enactment date of the Medical Device Amendments, or to devices that have been reclassified in accordance with the provisions of the Federal Food, Drug, and Cosmetic Act (Act) that do not require approval of a premarket approval application (PMA). You may, therefore, market the device, subject to the general controls provisions of the Act. The general controls provisions of the Act include requirements for annual registration. listing of devices, good manufacturing practice, labeling, and prohibitions against misbranding and adulteration. Please note: CDRH does not evaluate information related to contract liability warranties. We remind you, however, that device labeling must be truthful and not misleading.
If your device is classified (see above) into either class II (Special Controls) or class III (PMA), it may be subject to additional controls. Existing major regulations affecting your device can be found in the Code of Federal Regulations, Title 21, Parts 800 to 898. In addition, FDA may publish further announcements concerning your device in the Federal Register.
Please be advised that FDA's issuance of a substantial equivalence determination does not mean that FDA has made a determination that your device complies with other requirements of the Act or any Federal statutes and regulations administered by other Federal agencies. You must comply with all the Act's requirements, including, but not limited to: registration and listing (21 CFR Part 807); labeling (21 CFR Part 801); medical device reporting (reporting of medical device-related adverse events) (21 CFR 803); good manufacturing practice requirements as set forth in the quality systems (QS) regulation (21 CFR Part 820); and if applicable, the electronic product radiation control provisions (Sections 531-542 of the Act); 21 CFR 1000-1050.
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If you desire specific advice for your device on our labeling regulation (21 CFR Part 801), please contact the Division of Industry and Consumer Education at its toll-free number (800) 638 2041 or (301) 796-7100 or at its Internet address
http://www.fda.gov/MedicalDevices/Resourcesfor You/Industry/default.htm. Also, please note the regulation entitled, "Misbranding by reference to premarket notification" (21 CFR Part 807.97). For questions regarding the reporting of adverse events under the MDR regulation (21 CFR Part 803), please go to
http://www.fda.gov/MedicalDevices/Safety/ReportaProblem/default.htm for the CDRH's Office of Surveillance and Biometrics/Division of Postmarket Surveillance.
You may obtain other general information on your responsibilities under the Act from the Division of Industry and Consumer Education at its toll-free number (800) 638-2041 or (301) 796-7100 or at its Internet address
http://www.fda.gov/MedicalDevices/ResourcesforYou/Industry/default.htm.
Sincerely yours.
For
Robert Ochs. Ph.D. Director Division of Radiological Health Office of In Vitro Diagnostics and Radiological Health Center for Devices and Radiological Health
Enclosure
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## Indications for Use
510(k) Number (if known)
### Device Name
Leksell Gamma Knife Perfexion
### Indications for Use (Describe)
Leksell Gamma Knife® Perfexion™ is a teletherapy device intended for stereotactic irradiation of head structures ranging from very small target sizes of a few millimeters to several centimeters e.g., metastatic tumors, recurrent glioblastomas, trigeminal neuralgia, medically refractory essential tremor, ocular tumors, optic nerve tumors, benign diseases (such as meningiomas, vestibular schwannomas, post-surgical pituitary adenomas, craniopharyngioma, hemangioblastomas, schwannomas, arteriovenous malformations, cavernous malformations, chordomas, glomus tumors, hemangiomas). skull base tumors, head and neck tumors (such as unknown of the head and neck, oral cavity, hypopharynx, oropharynx, nasopharynx, sinonasal, salivary gland), and pediatric tumors (such as glioma, ependymoma, pituitary tumors, hemangioblastoma, craniopharyngioma, metastasis, medulloblastoma, nasopharyngeal tumors, arteriovenous malformations, cavernous malformations, skull base tumors).
Type of Use (Select one or both, as applicable)
X Prescription Use (Part 21 CFR 801 Subpart D)
Over-The-Counter Use (21 CFR 801 Subpart C)
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## ELEKTA INSTRUMENT AB
Dokumentnamn/Name of document
Traditional 510(k)
| Utfärdare/Issuer | Matilda Forsberg |
|-----------------------------|-------------------------------|
| Avser/Regarding | Leksell Gamma Knife Perfexion |
| Ref nr/Dok nr/Ref no/Doc no | -- |
| Utgåva /Edition | -- |
| Directory | -- |
# Section 4- 510(k) Summary
As Required by 21 CFR 807.92(c) 510 (k) Summary
#### 1. Subscribers Name & Address
Elekta Instrument AB Kungstensgatan 18, P.O. Box 7593 SE-103 93 Stockholm, Sweden Tel: (011) 46 8 587 254 00 Fax: (011) 46 8 587 255 00 Official Correspondent: Ms Louise Wachtmeister
Date summary prepared: 2015-04-22
#### 2. Trade Name
Leksell Gamma Knife® Perfexion™
#### Device Classification 3.
| Common Name | Product Code | Class | Regulation<br>Number |
|---------------------------------|--------------|-------|----------------------|
| Leksell Gamma Knife® Perfexion™ | IWB | II | 21 CFR 892.5750 |
#### 4. Predicate Device Identification
| Legally marketed devices to which equivalence is being claimed | 510(k) # |
|----------------------------------------------------------------|----------|
| TrueBeam, TrueBeam STx, Edge | K140528 |
| Leksell Gamma Knife® Perfexion™ | K133565 |
#### 5. Other relevant submissions
| Devices | 510(k) # |
|-----------------------------|----------|
| Leksell Stereotactic System | K080355 |
| Leksell GammaPlan® PFX | K103093 |
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## ELEKTA INSTRUMENT AB
Dokumentnamn/Name of document
| Utfärdare/Issuer | Ref nr/Dok nr/Ref no/Doc no | Utgåva /Edition | Traditional 510(k) |
|-------------------------------|-----------------------------|-----------------|--------------------|
| Matilda Forsberg | -- | -- | |
| Avser/Regarding | | Directory | |
| Leksell Gamma Knife Perfexion | -- | -- | |
#### Device Description 6.
Leksell Gamma Knife Perfexion is a radiosurgery system for use in the stereotactic irradiation of intra-cranial structures. Surgery is achieved by delivering a prescribed dose as one or more shots of ionizing radiation to the exact site of the target.
Based on preoperative radiological examinations, the Leksell Gamma Knife Perfexion unit provides highly accurate external irradiation of intra-cranial structures using collimated beams of ionizing radiation.
Each unit contains 192 sealed sources of Cobalt 60.
Leksell Gamma Knife Perfexion systems consists of several units, physically separated in an Office side in the control room and a Medical side in the treatment room.
- The medical side consists basically of the radiation unit with a patient positioning o system. The system control and power units are placed inside the cover of the radiation unit.
- The office side consists of the operator console with control panel and office computer. 0
#### Summary of Clinical and Non Clinical testing 7.
Clinical testing was not required to support substantial equivalence with the predicate devices. A risk analysis review was performed to investigate the impact from the new intended use. The conclusion was that the Leksell Gamma Knife® Perfexion is as safe and as effective as its predicate for the new indications.
#### 8. Performance testing
The technical characteristics of the device has not changed compared to the previously cleared Leksell Gamma Knife® Perfexion K133565 and no new performance testing has been made.
#### 9. Intended Use
Leksell Gamma Knife® Perfexion™ is a teletherapy device intended for stereotactic irradiation of head structures ranging from very small target sizes of a few millimeters to several centimeters e.g., metastatic tumors, recurrent glioblastomas, trigeminal neuralgia, medically refractory essential tremor, orbital tumors, ocular tumors, optic nerve tumors, benign diseases (such as meningiomas, vestibular schwannomas, post-surgical
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## ELEKTA INSTRUMENT AB
Dokumentnamn/Name of document
| | | Traditional 510(k) |
|--------------------------------------------------|-----------------------------|--------------------|
| Utfärdare/Issuer | Ref nr/Dok nr/Ref no/Doc no | Utgåva /Edition |
| Matilda Forsberg | -- | -- |
| Avser/Regarding<br>Leksell Gamma Knife Perfexion | | Directory<br>-- |
pituitary adenomas, craniopharyngioma, hemanqioblastomas, schwannomas, arteriovenous malformations, cavernous malformations, chordomas, glomus tumors, hemangiomas), skull base tumors, head and neck tumors (such as unknown primary of the head and neck, oral cavity, hypopharynx, oropharynx, nasopharynx, sinonasal, salivary gland), and pediatric tumors (such as glioma, ependymoma, pituitary tumors, hemanqioblastoma, craniopharynqioma, meninqioma, metastasis, medulloblastoma, nasopharyngeal tumors, arteriovenous malformations, cavernous malformations, skull base tumors).
The intended patients are adults and children from the age of 2 years and up.
#### 10. Technological Characteristics
This submission does not introduce any modifications to the device. The technical characteristics of the device are the same as the previously cleared Leksell Gamma Knife Perfexion K133565.
#### 11. Substantial Equivalence
The intended use statement for the Leksell Gamma Knife Perfexion is similar to its predicate devices K140258 and K133565. The change to the intended use includes added indications typical to conditions in the head and the neck region that may be treated with stereotactic irradiation of these indications does not affect the safety and effectiveness of the device and fall within the previously cleared indications for use. The functionality and technical characteristics of the device have not changed from the previous submission and are substantially equivalent to the previously cleared device K133565.
The conclusion is that the Leksell Gamma Knife® Perfexion is as safe and as effective as its predicate for the new indications.
Two short videos show you everything — or skip straight to the written tutorial if you'd rather read. You can reopen this any time from the Tutorial button in the top bar.
Part 1 — Search, results, and everyday workflows 16 min
Part 2 — Embeddings: the galaxy map 3 min
1. Search: exact and fuzzy
Type a phrase like "coronary artery calcification" into the search box. You get two kinds of results. Exact results match the literal phrase — prefix searches work ("coronary artery calcificati") but suffix searches do not. Fuzzy results match on the meaning and intent of your phrase rather than the exact words, and are sorted by relevance score. Hover over the Exact or Fuzzy badge on any row to see exactly why it matched.
Use the checkboxes above the results to narrow: SaMD keeps only software-only devices, AI / ML keeps only devices with AI.
Exact vs. fuzzy search: what's the difference?
Exact matches on the literal phrase (prefix search works, suffix does not). Fuzzy matches on the meaning and intent of the phrase rather than the exact words. Hover over the badge on any row to see why it matched.
You search "coronary artery calcification" and want only software devices with AI. What two filters do you apply?
Narrow by SaMD (software-only devices), then narrow by AI/ML (devices with AI).
2. The results table
Scroll right in the results table. The intended use is extracted for you — no need to open the PDF. The device story gives a high-level snapshot of what the device does and how it's used. The AI Performance sub-table shows each output name, acceptance criteria, observed values, and development/test dataset descriptions — the same format Innolitics uses for regulatory strategy outputs, and the fastest high-level fingerprint of an AI device. It is AI-generated but has been very reliable in practice.
Where do you find a device's intended use without opening the PDF?
Scroll right in the search results table. The intended use column is extracted for you; no need to dig into the 510(k) summary PDF.
What does the AI Performance sub-table show, and why is it useful?
Output name, acceptance criteria, observed values, development dataset description, and test dataset description. It's the same format we use for regulatory strategy output and Fast 510(k) input, and the fastest high-level fingerprint of an AI device. AI-generated but reliable in practice.
3. Judging fuzzy relevance
Fuzzy results trail off in relevance as you scroll. Use three signals to decide how far down to go: the fuzzy badge explanations, the intended use column, and whether your target output (e.g., Cobb angle) still appears in the AI Performance sub-table. Once it stops appearing, you're past the relevant zone. A top hit with a low score (~0.4) and a stretched explanation is a hint the closest predicates are far away — the project may be headed for De Novo. Note the fuzzy search is a pattern match: it doesn't handle negation ("not") well, and hardware devices can appear — filter by SaMD/AI ML to cut them.
How do you judge how far down fuzzy search results to go?
Use the relevancy signals: the fuzzy badge explanations, the intended use column, and whether the target output (e.g., Cobb angle) still appears in the AI Performance sub-table. Once it stops appearing, results are trailing off in relevancy.
4. Device detail page: chat and citations
Click a device name to open its detail page: device facts on the left, a chat window on the right. Ask something like "Describe the training data". The answer carries little citation bubbles — click one to jump to the highlighted passage in the source PDF, so you can verify every AI answer against the document. There's also a Download PDF button for sharing.
How do you verify an AI chat answer on the device detail page?
Click the citation bubbles to jump to the relevant highlight in the source document.
Reading rule for every project: how many summaries do you read in full?
At least the three most relevant 510(k) or De Novo summaries, in full. After that, use targeted chat questions to confirm your memory quickly. The tool supports this professional habit — it doesn't replace it.
5. Side-by-side comparison
Select multiple rows in the results table (aim for under ~10), then open the PDF Viewer tab. Ask one question — it goes to all selected devices in parallel, each with citations. This is the fastest way to compare and contrast devices: training data, PCCP scope, how they handled adding new scanners, and so on.
What does the side-by-side PDF viewer mode do?
Select multiple devices, open the PDF viewer tab, and ask one question (e.g., "Describe the training data"). It queries all selected devices simultaneously with citations, so you can compare and contrast quickly.
6. Collections
With rows selected, go to the Collections tab and create a labeled collection (e.g., "Cobb Angle Project"). Reload that selection any time — before a client call, pull up the collection and ask questions across all of its devices at once.
How do you save a set of selected devices for later use?
Select the rows, go to the Collections tab, and create a labeled collection (e.g., "Cobb Angle Project"). You can reload the selection anytime and carry it into the PDF viewer and other tabs that support selections.
7. Product codes and the regulations tree
Click a product code in the results to jump to it in the regulations tree — identification text, sibling product codes, and devices you can open in a PDF viewer on the right. Click a regulation number to see its identification, special controls, and related product codes. You can also search by product code or regulation number at the top of the tree. Always read the special controls if any exist for your device — it broadens your search and sharpens pre-kickoff research.
What can you do from the regulations tree view?
Browse product codes and regulation numbers, read the identification text and special controls, browse sibling product codes, open device PDFs on the right, and search by product code or regulation number at the top of the tree.
8. Chart view
Click Show Chart and segment by regulation number (or product code) to see which regulations dominate your result set. Clicking a regulation takes you into the regulations tree. Great for spotting that most matches are, say, hardware laparoscopic devices — a cue to go back and filter.
How do you see which regulations dominate a search result set?
Click "Show Chart" and segment by Regulation Number. Clicking a regulation takes you to the regulations tree.
9. The predicate graph
Open the Predicates tab for a family-tree view of predicate relationships. Click a node to trace its parents and children; selections from search carry over pre-selected. Commonly predicated devices are worth reading — a lot of people predicated them for a reason. The visual lineage is also handy on client calls, e.g. to show how a predicate family evolved and justify why your predicate still holds.
In the predicate graph, why are commonly predicated devices worth reading?
A lot of people predicated them for a reason. Clicking a node traces parents and children, and selections from search carry over pre-selected.
10. Embeddings: the galaxy map
The Embeddings tab plots every matching document in a 2-D "galaxy map" where semantically similar devices cluster together. Hover or click clusters to explore, and let AI label the clusters for you. Embeddings beat product codes for grouping: two devices can carry different product codes (LLZ vs. QIH) yet do the same thing — the embedding captures the meaning of the intended use and device story. This is also exactly how retrieval-augmented generation (RAG) works under the hood, and it makes a great visual on client calls.
Try it yourself
Head to the search page and work through a few of these AI/ML fuzzy searches to build intuition: perivascular fat on CT · aortic valve calcification opportunistic screening on noncontrast CT · breast cancer prediction on digital pathology slides · autism detection · gestational age prediction · a hearing aid that can also detect a pulse · foundation model based analysis of ECG · large language models · penetration test. Watch how the relevance scores, intended use, and AI Performance tables tell you when results stop being meaningful.