(86 days)
The MRIdian Linac system, with magnetic resonance imaging capabilities, is intended to provide stereotactic radiosurgery and precision radiotherapy for lesions, tumors, and conditions anywhere in the body where radiation treatment is indicated.
This submission describes a modification to the currently marketed multi-leaf collimator (MLC) cleared as part of the MRIdian Linac system (K162393) intended to enhance beam resolution. The current MLC is comprised of 60 tungsten leaves in two opposing 30-leaf banks. The design modification discussed in this submission essentially divides the two existing leaf banks in half splitting them along the leaf motion direction and shifting the banks by one half of a leaf width. The "tonque and groove" is eliminated from the leaves and the shifted banks act effectively as better focused "tongue and groove" mechanism. As with the predicate, each MLC layer of the modified MLC is focused to a point beyond the source point of the Linac radiation to improve interleaf leakage performance. In this system, the focus point is 15 mm further away than the source point. The minimum projected leaf width then becomes one half the physical projected leaf width. The projected leaf width is 8.3 mm and the projected half leaf width is 4.15 mm. The modified MLC design has two layers of opposing tungsten leaves; the top and bottom layers have 34 and 35 leaves in each bank respectively for a total of 138 leaves. There have been no other changes to the cleared MRIdian Linac system (K162393).
My apologies. I cannot fulfill this request. The provided text is a US FDA 510(k) Premarket Notification document, which primarily focuses on demonstrating substantial equivalence of a modified medical device (MRIdian Linac System with 138-leaf Collimator) to a legally marketed predicate device (MRIdian Linac System with 60-leaf Collimator).
The document does not describe an AI/ML-driven device or study parameters typical for such devices, such as:
- Acceptance criteria related to AI performance metrics (e.g., sensitivity, specificity, AUC)
- Sample sizes for test sets in the context of AI model evaluation (e.g., number of images, patients)
- Data provenance for AI model training or testing (e.g., retrospective vs. prospective data cohorts, country of origin)
- Expert involvement in establishing ground truth for AI model testing
- Adjudication methods for AI performance evaluation
- MRMC comparative effectiveness studies with AI assistance
- Standalone AI algorithm performance studies
- Ground truth types specific to AI applications (e.g., pathology reports, long-term outcomes)
- Training set details for AI models
Instead, the document focuses on:
- Changes to a hardware component: The modification is to the Multi-Leaf Collimator (MLC), specifically increasing the number of leaves from 60 to 138 to improve beam resolution.
- Engineering and Safety Testing: The "Summary of Performance Testing" section details various IEC and ISO standards for electrical safety, EMC, usability, software lifecycle, and general medical device performance, verifying that the modified hardware system still meets these standards.
- Substantial Equivalence Argument: The core of the 510(k) is to show that despite the MLC change, the device's fundamental functionality and safety remain equivalent to the predicate.
Therefore, I cannot extract the requested information about AI model acceptance criteria and study design from this document because it is about a hardware modification to a radiation therapy system, not an AI/ML medical device.
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Food and Drug Administration 10903 New Hampshire Avenue Document Control Center - WO66-G609 Silver Spring, MD 20993-0002
June 7, 2017
ViewRay Incorporated % Sean Delaney Director, Regulatory Affairs and Development Quality Assurance 2 Thermo Fisher Wav OAKWOOD VILLAGE OH 44146
Re: K170751
Trade/Device Name: MRIdian Linac System with 138-leaf Collimator Regulation Number: 21 CFR 892.5050 Regulation Name: Medical Charged-Particle Radiation Therapy System Regulatory Class: Class II Product Code: IYE, LNH Dated: May 22, 2017 Received: May 23, 2017
Dear Sean Delaney:
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 of medical device
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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.
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/ResourcesforYou/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,
Michael D.'Hara
For
Robert A. 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) K170751 Device Name MRIdian Linac System with 138-leaf Multi-Leaf Collimator
Indications for Use (Describe)
The MRIdian Linac system, with magnetic resonance imaging capabilities, is intended to provide stereotactic radiosurgery and precision radiotherapy for lesions, tumors, and conditions anywhere in the body where radiation treatment is indicated.
Type of Use (Select one or both, as applicable)
- Prescription Use (Part 21 CFR 801 Subpart D)
_ Over-The-Counter Use (21 CFR 801 Subpart C)
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Section 6: 510(k) Summary
The information below is provided for the modified MRIdian Linac system, following the format of 21 CFR 807.92.
-
- Address and Contact Information:
ViewRay Incorporated
- Address and Contact Information:
2 Thermo Fisher Way
Oakwood Village, OH 44146
Contact Name: Sean A. Delaney
Phone: (650) 252-0969
Fax: (650) 625-9187
E-mail: sdelaney@viewray.com
- Date Summary was prepared: March 9, 2017
-
- Name of Device: MRIdian Linac System
Trade/Proprietary Name: MRIdian Linac System
Common or Usual Name: Accelerator, Linear, Medical
Regulation description/number:
Medical charged-particle radiation therapy system
21 CFR §892.5050, Class II
Product Code: IYE, LNH
Device classification name: Accelerator, Linear, Medical
3. Predicate Device to claim substantial equivalence
MRIdian Linac System - K162393
4. Description of the Device
This submission describes a modification to the currently marketed multi-leaf collimator (MLC) cleared as part of the MRIdian Linac system (K162393) intended to enhance beam resolution. The current MLC is comprised of 60 tungsten leaves in two opposing 30-leaf banks. The design modification discussed in this submission essentially divides the two existing leaf banks in half splitting them along the leaf motion direction and shifting the banks by one half of a leaf width. The "tonque and groove" is eliminated from the leaves and the shifted banks act effectively as better focused "tongue and groove" mechanism. As with the predicate, each MLC layer of the modified MLC is focused to a point beyond the source point of the Linac radiation to improve interleaf leakage performance (see Fig. 6 and Fig. 7 in TECH-697). In this system, the focus point is 15 mm further away than the source point. The minimum projected leaf width then becomes one
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half the physical projected leaf width. The projected leaf width is 8.3 mm and the projected half leaf width is 4.15 mm. The modified MLC design has two layers of opposing tungsten leaves; the top and bottom layers have 34 and 35 leaves in each bank respectively for a total of 138 leaves. There have been no other changes to the cleared MRIdian Linac system (K162393).
5. Intended Use Statement
The MRIdian Linac system, with magnetic resonance imaging capabilities, is intended to provide stereotactic radiosurgery and precision radiotherapy for lesions, tumors, and conditions anywhere in the body where radiation treatment is indicated.
6. Indication for Use Statement
The MRIdian Linac system, with magnetic resonance imaging capabilities, is intended to provide stereotactic radiosurgery and precision radiotherapy for lesions, tumors, and conditions anywhere in the body where radiation treatment is indicated.
7. Substantial Equivalence
ViewRay has demonstrated that the MRIdian Linac system (K162393) performs in a substantially equivalent manner when using either the 60 or 138-leaf MLC for beam collimation.
8. Technological Characteristics
The cleared MRIdian Linac system (K162393) is an Image-Guided Radiation Therapy System (IGRT) that uses a 6 MV linear accelerator radiotherapy system to deliver ionizing radiation while using a magnetic resonance imaging system (MRIS) unit for image quidance in real-time. The MRIdian Linac system has equivalent functionality when employing the proposed 138-leaf MLC described in this submission.
The current MLC is comprised of 60 tungsten leaves in two opposing 30-leaf banks. The design modification discussed in this submission essentially divides the two existing leaf banks in half splitting them along the leaf motion direction and shifting the banks by one half of a leaf width. The "tongue and groove" is eliminated from the leaves and the shifted banks act effectively as better focused "tongue and groove" mechanism. As with the predicate, each MLC layer of the modified MLC is focused to a point beyond the source point of the Linac radiation to improve interleaf leakage performance (see Fig. 6 and Fig. 7 in TECH-697). In this system, the focus point is 15 mm further away than the source point. The minimum projected leaf width then becomes one half the physical projected leaf width. The projected leaf width is 8.3 mm and the projected half leaf width is 4.15 mm. The modified MLC design has two layers of opposing tungsten leaves; the top and bottom layers have 34 and 35 leaves in each bank respectively for a total of 138 leaves.
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Image /page/5/Picture/0 description: The image is a logo for ViewRay. The logo consists of a green sphere with white lines running through it on the left side. To the right of the sphere is the word "VIEWRAY" in bold, black letters, with a thin gray line underneath. Below the line is the phrase "Visibly Different" in a smaller, lighter font.
The leaf sequencing algorithm of the predicate MRIdian Linac with 60-leaf MLC supports leaf sequencing with or without elimination of "tonque and groove" effect, as well as leaf sequencing with or without interdigitation. The 138-leaf MLC uses the same fundamental leaf-sequencing algorithm as the predicate, in its most efficient realization, with a method to prevent the production of undeliverable segments. The leaf sequencer starts with an internal representation of the MLC with 0.415mm leaf spacing, and follows the same process as that used for the 60leaf MLC to produce leaf positions along each row. The sequencer then combines the leaf settings into segments. Because of the double-layered design of the 138leaf MLC, this process can lead to rare occurrences of non-deliverable segments when two disjoint openings that are neighboring by a ½ leaf width are produced. Such cases are handled by preventing the creation of such segments when combining row leaf settings into segments. This approach has no effect on the quality of the delivered dose distributions and the removal of the algorithm for the elimination of "tongue and groove" effect makes it beam-on-time efficient. Please see TECH Report 700 for further detail in Attachment 12.1.
The MRIdian Linac system functions in a substantially equivalent manner when employing either the cleared 60-leaf (K162393) or the proposed 138-leaf MLC. Both configurations collimate the radiation beam such that ionizing dose distributions are delivered to the patient while using MRI imaging during treatment. However, the 138-leaf MLC has improved beam resolution at isocenter from 1.43cm in the cleared MRIdian Linac system to 0.415cm.
| Construction | 60-leaf MLC(Cleared K162393) | Proposed 138-leaf MLC |
|---|---|---|
| Number ofleaves | 60 | 138 |
| Leafarrangement | Single layer,30 leaves per bank, | Two layers (top and bottom),34 leaves per bank - top layer35 leaves per bank – Bottom layer |
| Leaf curvature | Focused at 50cm from distal face ofthe MLC | Focused at 41cm from distal face ofthe MLC |
| Calibrationscheme | Precision spaced calibration blocks | Precision spaced optical calibrationsensors |
| Homing scheme | Homing bar | Homing bar |
| Leaf height | 9cm | 11cm (2 x 5.5cm) |
| Tongue andgroove features | Required and present to minimizeleakage between leaves | Not required since leakage betweenone layer of leaves is blocked by aleaf in the other layer |
Significant changes to the predicate MLC are listed below:
Page 6-3 CONFIDENTIAL
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Image /page/6/Picture/0 description: The image contains the ViewRay logo. On the left is a green sphere with white lines running through it. To the right of the sphere is the word "VIEWRAY" in bold, black letters. Underneath the word "VIEWRAY" is the phrase "Visibly Different" in a smaller, lighter font.
| MLC Controls | One motor and controller per leafHoming Bar | One motor and controller per leafHoming BarLaser Light Beam Sensors |
|---|---|---|
| Motor rotationto leaf drivemechanisms | Spindle and threaded rod | Spindle and threaded rod |
| Motor to leaflinkage | Motor to spindle couplings,threaded rod to leaf pin joints | Motor to spindle couplings,threaded rod to leaf pin joints |
| Leaf Guide | Rollers and PEEK guides | PEEK guides |
| Motorarrangement | A single 2-D array of motors perbank | Two sub-layers of 2-D array ofmotors per bank |
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Image /page/7/Picture/0 description: The image is a logo for ViewRay. The logo consists of a green sphere with white lines running across it, and a blue dot on the top left. To the right of the sphere is the word "VIEWRAY" in black, bold letters. Below the word "VIEWRAY" is the phrase "Visibly Different" in a smaller, lighter font.
Summary of Performance Testing 9.
Design Verification testing was performed according to the FDA Quality System Regulation (21 CFR §820), ISO 13485 Quality Management System standard, ISO 14971 Risk Management Standard and the other FDA recognized consensus standards presented below.
The imaging and radiation therapy capabilities of the MRIdian Linac system when using the proposed 138-leaf MLC showed substantial equivalence to the predicate 60-leaf MLC (K162393). Testing executed on the system verified conformance to design requirements and ensured all identified risks and hazards were mitigated, and demonstrated conformance to relevant safety standards. The MRIdian Linac system with 138-leaf MLC described in this premarket notification passed all verification testing, and the system conformed to all applicable sections of the standards presented below.
Software verification testing was conducted as recommended by FDA's Guidance for Industry and FDA Staff, "Guidance for the Content of Premarket Submissions for Software Contained in Medical Devices." The MRIdian Linac software is considered as a "major" level of concern, since a failure or latent flaw in the software could directly result in serious injury or death to the patient or operator.
Electrical safety and electromagnetic compatibility (EMC) testing were conducted on the MRIdian Linac system which verified the system complies with the IEC 60601-1-2 EMC standard and continues to meet IEC 60601-1 safety standards.
| Name | Description |
|---|---|
| IEC 60601-1: 2005 + CORR. 1 (2006) +CORR. 2 (2007) ed 3.1 | General requirements for basic safety and essentialperformance |
| IEC 60601-1-2:2010 ed. 3.0 | Electromagnetic compatibility (EMC) |
| IEC 60601-2-33:2015 ed. 3.2 | MR for Medical Diagnosis |
| IEC/EN 60601-2-1:2009 ed. 3.0 | Medical electrical equipment - Part 2-1: Particularrequirements for the basic safety and essentialperformance of electron accelerators in the range 1MeV to 50 MeV |
| IEC/EN 60976:2007 ed. 2.0 | Medical electrical equipment - Medical electronaccelerators - Functional performance characteristics |
| IEC 60601-1-6:2013 ed. 3.1 | Usability |
| IEC 61217:2011 ed. 2.0 | Radiotherapy Equipment - Coordinates, Movements &Scales |
| IEC 62083:2009 ed. 2.0 | Radiotherapy Treatment Planning Systems |
| ΕΝ 62304:2006 ed. 1.0 | Software Lifecycle Processes |
| ΕΝ 62366:2014 ed. 1.1 | Usability |
| ISO 10993-1:2009 | Biocompatibility |
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Image /page/8/Picture/0 description: The image shows the ViewRay logo. The logo consists of a green sphere with white lines on the left side and the word "VIEWRAY" in black on the right side. Below the word "VIEWRAY" is a horizontal line, and below the line is the phrase "Visibly Different" in a smaller font.
10. Conclusion
Verification testing of the MRIdian Linac system with the 138-leaf MLC demonstrated that the device met established standards and design requirements. System performance was found to be equivalent in function to the predicate 60leaf MLC currently used in the cleared MRIdian Linac system (K162393). Therefore, the MRIdian Linac system performs in a substantially equivalent manner when using with either the cleared 60-leaf MLC (K162393) or the proposed 138-leaf MLC described in this submission.
§ 892.5050 Medical charged-particle radiation therapy system.
(a)
Identification. A medical charged-particle radiation therapy system is a device that produces by acceleration high energy charged particles (e.g., electrons and protons) intended for use in radiation therapy. This generic type of device may include signal analysis and display equipment, patient and equipment supports, treatment planning computer programs, component parts, and accessories.(b)
Classification. Class II. When intended for use as a quality control system, the film dosimetry system (film scanning system) included as an accessory to the device described in paragraph (a) of this section, is exempt from the premarket notification procedures in subpart E of part 807 of this chapter subject to the limitations in § 892.9.