(116 days)
The kVCT Imaging Feature is an option within the indications for use of the Radixact Treatment Delivery System. The Radixact Treatment Delivery System is indicated for the delivery of radiation therapy, stereotactic radiotherapy or stereotactic radiosurgery to tumors or other targeted tissues anywhere in the body under the direction of a licensed medical practitioner.
The kVCT Imaging Feature is designed for use with the predicate Radixact Treatment Delivery System last cleared on K161146. The primary functions of the kVCT Imaging Feature are: 1) acquisition of kV x-ray images according to input protocols in concert with other subsystems, 2) correcting 2D images and 3) returning reconstructed 3D images.
The Radixact Treatment Delivery System is a radiation therapy delivery system that provides Image Guided Radiation Therapy (IGRT) using integral megavoltage CT imaging capabilities and delivers helical (rotational) and fixed-angle (non-rotational) radiation therapy to tumors and other targeted tissues.
The provided text describes the 510(k) summary for the Accuray kVCT Imaging Feature for the Radixact Treatment Delivery System. However, it does not contain the specific details of acceptance criteria for diagnostic imaging performance or the results of a study proving the device meets these criteria in the way typically found for AI/CADe devices.
Instead, this document focuses on establishing substantial equivalence to a predicate device (Radixact Treatment Delivery System, K161146) and a reference device (Motion Tracking And Compensation Feature For The Radixact Treatment Delivery System, K182687) by comparing technological characteristics and ensuring safety and performance are equivalent or better. It emphasizes that the kVCT imaging offers improved intrinsic tissue contrast and image quality characteristics compared to that of MVCT imaging (from the predicate).
Therefore, I cannot populate the table and answer all questions in the requested format for acceptance criteria and a study proving performance, as that information is not present. The document explicitly states: "No animal or clinical tests are being submitted to establish substantial equivalence with the predicate device."
However, I can extract the comparative performance specifications between the MVCT Imaging (predicate) and kVCT Imaging (subject device), which are presented as characteristics rather than formal acceptance criteria and study results.
Here's the information that can be extracted, acknowledging the limitations mentioned above:
1. A table of (comparative) performance characteristics:
| Characteristic | Predicate MVCT Imaging (K161146) | Subject kVCT Imaging Feature (K202412) | Analysis/Comment |
|---|---|---|---|
| Imaging Dose | 0.5 - 3.0 cGy (near center of Tomo-Phantom) | 0.6 - 4.3 cGy (CTDIvol, Head) 0.4 - 2.3 cGy (CTDIvol, Body) | For MVCT Imaging, "Identical. Differences shown are due to additional detail provided and dose characterized in CTDIvol." For kVCT, this feature was "Feature not present" in the predicate, so it's a new capability. Note: The text implies the kVCT energy range offers improved intrinsic tissue contrast and image quality characteristics compared to MVCT, suggesting this imaging dose provides better clinical information. |
| Acquisition Trajectory | Helical (for MVCT) | Helical (for kVCT) | For MVCT, "Identical". For kVCT, "Feature not present" in predicate. |
| Slice Spacing | MVCT: 1, 2, 3, 4 and 6 mm reconstruction Intervals | kVCT: 1.2, 1.8, 3.6 mm | For MVCT, "Identical". For kVCT, "Substantially equivalent. The kV Imaging subsystem provides three-dimensional CT images with equivalent or better performance than the predicate device (MVCT)." |
| Spatial Resolution | MVCT: 1.6 mm | kVCT: 1.0 mm (at 2.0 mm intervals) | For MVCT, "Substantially equivalent". For kVCT, "Substantially equivalent. The kV Imaging subsystem provides three-dimensional CT images with equivalent or better performance than the predicate device (MVCT)." (1.0 mm is better than 1.6 mm). |
| Image Size | MVCT: 512 x 512 pixels | kVCT: 512 x 512 pixels | For MVCT, "Identical". For kVCT, "Feature not present" in predicate. |
| Scan Length | MVCT: 135 cm | kVCT: Up to 135 cm | For MVCT, "Identical". For kVCT, "Feature not present" in predicate. |
| Field of View (FOV) | MVCT: 39 cm diameter | kVCT: 25 - 50 cm | For MVCT, "Identical". For kVCT, "Feature not present" in predicate. |
| Image Uniformity | MVCT: Within 25 HU | kVCT: Within 15 HU (Head) Within 25 HU (Body) | For MVCT, "Identical". For kVCT, "Feature not present" in predicate. The kVCT performance for Head (15 HU) is better than the MVCT (25 HU). |
| Image Noise | MVCT: Less than 43 HU | kVCT: Less than 10 HU (Head) Less than 20 HU (Body) | For MVCT, "Substantially equivalent". For kVCT, "Feature not present" in predicate. The kVCT performance is significantly better (lower HU indicates less noise) than MVCT. |
| Contrast Resolution | MVCT: 3% contrast for 30 mm object | kVCT: 1% contrast for 10 mm object (Head) 2% contrast for 15 mm object (Body) | For MVCT, "Substantially equivalent". For kVCT, "Feature not present" in predicate. The kVCT contrast resolution is significantly better (lower contrast percentage for smaller objects indicates better resolution) than MVCT. |
| kV Detector Pixel Pitch | Reference (K182687): 0.4 mm pitch | Subject: 0.15 mm pitch | "Substantially equivalent. The subject device provides the same or better active area with the same or better pixel resolution as compared to the reference device." (0.15 mm is better resolution than 0.4 mm). |
2. Sample size used for the test set and the data provenance:
- The document explicitly states: "No animal or clinical tests are being submitted to establish substantial equivalence with the predicate device."
- Therefore, there is no test set of clinical images described in this document for evaluating diagnostic imaging performance against acceptance criteria. The data provenance is not applicable in this context.
3. Number of experts used to establish the ground truth for the test set and the qualifications of those experts:
- Not applicable as no clinical test set with ground truth established by experts is mentioned.
4. Adjudication method (e.g., 2+1, 3+1, none) for the test set:
- Not applicable as no clinical test set is mentioned.
5. If a multi reader multi case (MRMC) comparative effectiveness study was done, if so, what was the effect size of how much human readers improve with AI vs without AI assistance:
- No MRMC study is mentioned. This device is an imaging feature, not an AI/CADe device designed to assist human readers in interpretation.
6. If a standalone (i.e., algorithm only without human-in-the-loop performance) was done:
- The performance data cited ("Results of verification and validation testing confirm that the use of the kVCT Imaging Feature on the Radixact Treatment Delivery System conforms to design specifications and meets the needs of the intended users") refers to the engineering and technical performance of the imaging system itself, such as spatial resolution, image noise, contrast resolution, uniformity, and radiation dose, as shown in the table. These are intrinsic performance characteristics of the imaging modality, not a "standalone algorithm" performance in the context of an AI/CADe device.
7. The type of ground truth used (expert consensus, pathology, outcomes data, etc.):
- For the technical performance characteristics listed (e.g., spatial resolution, image noise), the ground truth is typically established through phantom studies and metrology, comparing measured values against engineering specifications rather than clinical ground truth like pathology or expert consensus.
8. The sample size for the training set:
- Not applicable as this document does not describe an AI/CADe device that uses a training set of images.
9. How the ground truth for the training set was established:
- Not applicable.
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December 18, 2020
Image /page/0/Picture/1 description: The image contains the logo of the U.S. Food and Drug Administration (FDA). On the left is the Department of Health & Human Services logo. To the right of that is the FDA logo, which is a blue square with the letters "FDA" in white. To the right of the blue square is the text "U.S. FOOD & DRUG ADMINISTRATION" in blue.
Accuray Incorporated % Keith Picker Senior Regulatory Affairs Specialist 1240 Deming Way MADISON WI 53717
Re: K202412
Trade/Device Name: kVCT Imaging Feature for the Radixact Treatment Delivery System Regulation Number: 21 CFR 892.5050 Regulation Name: Medical charged-particle radiation therapy system Regulatory Class: Class II Product Code: IYE Dated: November 24, 2020 Received: November 25, 2020
Dear Keith Picker:
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. Although this letter refers to your product as a device, please be aware that some cleared products may instead be combination products. The 510(k) Premarket Notification Database located at https://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfpmp/pmn.cfm identifies combination product submissions. 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-related adverse events) (21 CFR 803) for devices or postmarketing safety reporting (21 CFR 4, Subpart B) for combination products (see
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https://www.fda.gov/combination-products/guidance-regulatory-information/postmarketing-safety-reportingcombination-products); good manufacturing practice requirements as set forth in the quality systems (QS) regulation (21 CFR Part 820) for devices or current good manufacturing practices (21 CFR 4, Subpart A) for combination products; and, if applicable, the electronic product radiation control provisions (Sections 531-542 of the Act); 21 CFR 1000-1050.
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 https://www.fda.gov/medical-device-safety/medical-device-reportingmdr-how-report-medical-device-problems.
For comprehensive regulatory information about medical devices and radiation-emitting products, including information about labeling regulations, please see Device Advice (https://www.fda.gov/medicaldevices/device-advice-comprehensive-regulatory-assistance) and CDRH Learn (https://www.fda.gov/training-and-continuing-education/cdrh-learn). Additionally, you may contact the Division of Industry and Consumer Education (DICE) to ask a question about a specific regulatory topic. See the DICE website (https://www.fda.gov/medical-device-advice-comprehensive-regulatoryassistance/contact-us-division-industry-and-consumer-education-dice) for more information or contact DICE by email (DICE@fda.hhs.gov) or phone (1-800-638-2041 or 301-796-7100).
Sincerely,
For
Thalia T. Mills, Ph.D. Director Division of Radiological Health OHT7: Office of In Vitro Diagnostics and Radiological Health Office of Product Evaluation and Quality Center for Devices and Radiological Health
Enclosure
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Indications for Use
510(k) Number (if known) K202412
Device Name
kVCT Imaging Feature for the Radixact Treatment Delivery System
Indications for Use (Describe)
The kVCT Imaging Feature is an option within the indications for use of the Radixact Treatment Delivery System. The Radixact Treatment Delivery System is indicated for the delivery of radiation therapy, stereotactic radiotherapy or stereotactic radiosurgery to tumors or other targeted tissues anywhere in the direction of a licensed medical practitioner.
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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Image /page/3/Picture/0 description: The image shows the Accuray logo. The logo consists of a stylized atom symbol in teal, green, and purple, followed by the word "ACCURAY" in teal, with a registered trademark symbol next to it. The logo is clean and modern.
Section 8 510(k) Summary
Submitter
Accuray Incorporated 1240 Deming Way Madison, WI 53717 Phone: 608-824-3069 Fax: 608-824-2996
| Contact: | Keith Picker |
|---|---|
| Date Prepared: | November 24, 2020 |
Device Identification
Device Name: kVCT Imaging Feature for the Radixact Treatment Deliverv System Trade & Brand Names: ClearRT Helical kVCT for the Radixact Treatment Delivery System Common Name: Radiation Therapy System Regulation Number: 21 CFR 892.5050 Regulation Name: Medical charged-particle radiation therapy system Regulatory Class: Class II Product Code: IYE
Predicate Device
Radixact Treatment Delivery System (K161146)
Reference Device:
Motion Tracking And Compensation Feature For The Radixact Treatment Delivery System (K182687)
Device Description
The kVCT Imaging Feature is designed for use with the predicate Radixact Treatment Delivery System last cleared on K161146. The primary functions of the kVCT Imaging Feature are: 1) acquisition of kV x-ray images according to input protocols in concert with other subsystems, 2) correcting 2D images and 3) returning reconstructed 3D images.
The Radixact Treatment Delivery System is a radiation therapy delivery system that provides Image Guided Radiation Therapy (IGRT) using integral megavoltage CT
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imaging capabilities and delivers helical (rotational) and fixed-angle (non-rotational) radiation therapy to tumors and other targeted tissues.
Neither the Radixact Treatment Delivery System nor the kVCT Imaging Feature diagnose disease, recommend treatment regimens or quantify treatment effectiveness. Accordingly, they are not intended for diagnostic use.
Intended Use
The kVCT Imaging Feature is an option within the intended use of the Radixact Treatment Delivery System. The Radixact Treatment Delivery System is intended to be used for the delivery of radiation therapy, stereotactic radiotherapy or stereotactic radiosurgery to tumors or other targeted tissues. The megavoltage x-ray radiation is delivered using rotational, non-rotational, intensity modulated (IMRT), or non-modulated (non-IMRT/three dimensional conformal) treatment techniques and using image-guided (IGRT) or non-image-guided workflows in accordance with the physician approved plan.
Indications for Use
The kVCT Imaging Feature is an option within the indications for use of the Radixact Treatment Delivery System. The Radixact Treatment Delivery System is indicated for the delivery of radiation therapy, stereotactic radiotherapy or stereotactic radiosurgery to tumors or other targeted tissues anywhere in the body under the direction of a licensed medical practitioner.
The intended use and indications for use statements for the kVCT Imaging Feature (shown above) are the same as for the Radixact Treatment Delivery System (last cleared on K161146), except for the addition of the introductory sentence as kVCT Imaging is a type of Image Guided Radiotherapy (IGRT).
Technological Characteristics
The Radixact Treatment Delivery System with the use of the kVCT Imaging Feature has imaging and treatment capabilities equivalent to those of the predicate Radixact Treatment Delivery System. It also has a similar functionally-equivalent CT style gantry and patient couch.
The intended use and indications for use of the kVCT Imaging Feature fit within those of the predicate Radixact Treatment Delivery System. Additionally, the predicate and subject devices have substantially equivalent performance specifications and technological characteristics. Further, the Radixact Treatment Delivery System with the use of the kVCT Imaging Feature and the predicate device employ the same fundamental scientific principles and have substantially equivalent principles of operation. The main difference between the predicate and the subject device is the use of the kVCT Imaging Feature. Where there are technological differences between the subject and predicate devices, those differences do not raise different questions of safety or effectiveness.
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A substantial equivalence table comparing the similarities and differences between the Radixact Treatment Delivery System with the use of the kVCT Imaging Feature and the predicate device is presented below in Table 5.5.1. The minor differences between the subject and predicate devices do not raise different questions of safety or effectiveness.
A table comparing the similarities and differences between the Radixact Treatment Delivery System with the use of the kVCT Imaging Feature and the reference device (K182687) is provided in Table 5.5.2 below. The minor differences between the subject and predicate devices do not raise different questions of safety or effectiveness. The kV Imaging subsystem provides three-dimensional CT images with equivalent or better performance than the predicate device (MVCT). The kVCT energy range offer improved intrinsic tissue contrast and image quality characteristics compared to that of MVCT imaging.
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Table 5.5.1 Device Comparison Table: Radixact Treatment Delivery System with kVCT Imaging Feature
| DeviceCharacteristic | Predicate DeviceRadixact TreatmentDelivery System(K161146) | Subject DeviceRadixact TreatmentDelivery System withkVCT ImagingFeature | Analysis |
|---|---|---|---|
| System Description | |||
| Intended Use | The Radixact TreatmentDelivery System isintended to be used forthe delivery of radiationtherapy, stereotacticradiotherapy orstereotactic radiosurgeryto tumors or othertargeted tissues. Themegavoltage x-rayradiation is deliveredusing rotational, non-rotational, intensitymodulated (IMRT), ornon-modulated (non-IMRT/three dimensionalconformal) treatmenttechniques and usingimage-guided (IGRT) ornon-image-guidedworkflows in accordancewith the physicianapproved plan. | The kVCT ImagingFeature is an optionwithin the intended useof the RadixactTreatment DeliverySystem. The RadixactTreatment DeliverySystem is intended tobe used for the deliveryof radiation therapy,stereotacticradiotherapy orstereotacticradiosurgery to tumorsor other targetedtissues. Themegavoltage x-rayradiation is deliveredusing rotational, non-rotational, intensitymodulated (IMRT), ornon-modulated (non-IMRT/threedimensional conformal)treatment techniquesand using image-guided(IGRT) or non-image-guided workflows inaccordance with thephysician approvedplan. | Identical |
| DeviceCharacteristic | Predicate DeviceRadixact TreatmentDelivery System(K161146) | Subject DeviceRadixact TreatmentDelivery System withkVCT ImagingFeature | Analysis |
| Indications forUse | The Radixact TreatmentDelivery System isindicated for the deliveryof radiation therapy,stereotactic radiotherapyor stereotacticradiosurgery to tumors orother targeted tissuesanywhere in the bodyunder the direction of alicensed medicalpractitioner. | The kVCT ImagingFeature is an optionwithin the indicationsfor use of the RadixactTreatment DeliverySystem. The RadixactTreatment DeliverySystem is indicated forthe delivery ofradiation therapy,stereotacticradiotherapy orstereotacticradiosurgery to tumorsor other targeted tissuesanywhere in the bodyunder the direction of alicensed medicalpractitioner. | Identical |
| Classification | §892.5050 Medicalcharged-particle radiationtherapy system, class II | Same as predicate | Identical |
| SystemConfiguration | Stand-alone radiationdelivery system (does notinclude data managementsystem or planningsystem) | Stand-alone radiationdelivery system withkV imaging added(does not include datamanagement system orplanning system) | Substantiallyequivalent. Theintroduction ofthe kVCTimaging featuredoes not raisedifferent issuesof safety oreffectiveness.The riskacceptabilitydeterminationwas notimpacted by themodified design. |
| DeviceCharacteristic | Predicate DeviceRadixact TreatmentDelivery System(K161146) | Subject DeviceRadixact TreatmentDelivery System withkVCT ImagingFeature | Analysis |
| Vault (Treatment Room) | |||
| Minimum RoomDimensions(HWL) | 274 x 462 x 602 cm | 274.3 x 463 x 602 cm | Substantiallyequivalent. Minordifferences arenegligible. |
| DeviceDimensions(gantry + couch)(HWL) | 255 x 280 x 473 cm | 255 x 280 x 470.5 cm | Substantiallyequivalent. Minordifferences arenegligible. |
| Device Mass(kg) | 6580 kg | 7000 kg (approximate) | Substantiallyequivalent. Theadded mass due tothe kVCT imagingsubsystem does notresult in differentquestions of safetyor effectiveness. |
| Line Voltage | 380 - 480 Vac 3-Phase | 380 - 480 Vac 3-Phase | Identical |
| Ambient RoomTemperature | 20 - 24 °C | 20 - 24 °C | Identical |
| RelativeHumidity(non-condensing) | 30 - 60 % | 30 - 60 % | Identical |
| DeviceCharacteristic | Predicate DeviceRadixact TreatmentDelivery System(K161146) | Subject DeviceRadixact TreatmentDelivery System withkVCT ImagingFeature | Analysis |
| Gantry Mechanical Features | |||
| Bore Diameter | 85 cm | 85 cm | Identical |
| Degrees ofRotation | Continuous rotationaround Y- axis(axes per IEC 61217) | Continuous rotationaround Y- axis(axes per IEC 61217) | Identical |
| Direction ofRotation | Clockwise | Clockwise | Identical |
| RotationalSpeed(Treatment) | 1 - 5 RPM | 1 - 5.08 RPM | Substantiallyequivalent. Minordifferences arenegligible and donot result indifferent questionsof safety oreffectiveness. |
| RotationalSpeed (Imaging) | 10 RPM | Up to 10 RPM | Substantiallyequivalent.Rotational speed isunchanged forMVCT imaging.Slower speeds areused for somekVCT imagingapplications. |
| Couch Supportin Bore | Provided | Provided | Identical |
| Radiation Delivery Modes | |||
| Description | Helical, Direct | Helical, Direct | Identical |
| DeviceCharacteristic | Predicate DeviceRadixact TreatmentDelivery System(K161146) | Subject DeviceRadixact TreatmentDelivery System withkVCT ImagingFeature | Analysis |
| Photon Beam | |||
| AcceleratorType | Standing wave | Standing wave | Identical |
| RF Source | Magnetron | Magnetron | Identical |
| Nominal Energy | 6 MV | 6 MV | Identical |
| Fixed Field Size | 1.0 cm x 40 cm2.5 cm x 40 cm5.0 cm x 40 cm | 1.0 cm x 40 cm2.5 cm x 40 cm5.0 cm x 40 cm | Identical |
| Dynamic FieldSize | 1.0 – 2.5 cm x 40 cm1.0 – 5.0 cm x 40 cm | 1.0 – 2.5 cm x 40 cm1.0 – 5.0 cm x 40 cm | Identical |
| Dose Rate | 850 cGy/min standard1000 cGy/minoptional | 850 cGy/min standard1000 cGy/min optional | Identical |
| MV Beam Collimation | |||
| Description | Primary collimation,jaws and multi-leafcollimator (MLC) | Primary collimation,jaws and multi-leafcollimator (MLC) | Substantially equivalent. kVCTdoes not changethe behavior of thejaws. |
| DeviceCharacteristic | Predicate DeviceRadixact TreatmentDelivery System(K161146) | Subject DeviceRadixact TreatmentDelivery System withkVCT ImagingFeature | Analysis |
| MVCT Imaging | |||
| Source | MegavoltageComputedTomography | MegavoltageComputedTomography | Identical |
| Field of View(FOV) | 39 cm diameter | 39 cm diameter | Identical |
| Scan Length[Specificationnot detailed inK161146] | 135 cm | 135 cm | Identical |
| Imaging Dose | 0.5 - 3.0 cGy(imaging dose nearcenter of Tomo-Phantom) | 1.1 - 3.4 cGy(CTDIvol, Head)0.8 - 2.5 cGy(CTDIvol, Body) | Identical.Differences shownare due toadditional detailprovided and dosecharacterized inCTDIvol |
| Slice Spacing | 1, 2, 3, 4 and 6 mmreconstructionIntervals | 1, 2, 3, 4 and 6 mmreconstructionIntervals | Identical |
| SpatialResolution | 1.6 mm | 1.6 mm (at 3.2 mmintervals) | Substantiallyequivalent |
| Image Size[Specificationnot detailed inK161146] | 512 x 512 pixels | 512 x 512 pixels | Identical |
| ImageUniformity[Specificationnot detailed inK161146] | Within 25 HU | Within 25 HU | Identical |
| DeviceCharacteristic | Predicate DeviceRadixact TreatmentDelivery System(K161146) | Subject DeviceRadixact TreatmentDelivery System withkVCT ImagingFeature | Analysis |
| Image Noise[Specificationnot detailed inK161146] | Less than 43 HU | Less than 43 HU | Substantiallyequivalent |
| ContrastResolution[Specificationnot detailed inK161146] | 3% contrast for 30 mmobject | 3% contrast for 30 mmobject or better | Substantiallyequivalent |
| AcquisitionTrajectory[Specificationnot detailed inK161146] | Helical | Helical | Identical |
| DeviceCharacteristic | Predicate DeviceRadixactTreatmentDelivery System(K161146) | Subject DeviceRadixact TreatmentDelivery System withkVCT Imaging Feature | Analysis |
| kVCT Imaging | |||
| Imaging Dose | Feature not present | 0.6 - 4.3 (CTDIvol, Head)0.4 - 2.3 (CTDIvol, Body) | |
| AcquisitionTrajectory | Feature not present | Helical | |
| Slice Spacing | Feature not present | 1.2, 1.8, 3.6 mm | Substantiallyequivalent. The kV |
| SpatialResolution | Feature not present | 1.0 mm (at 2.0 mmintervals) | Imaging subsystemprovides three- |
| Image Size | Feature not present | 512 x 512 pixels | dimensional CTimages withequivalent or betterperformance thanthe predicatedevice (MVCT).The kVCT energyrange offerimproved intrinsictissue contrast andimage quality |
| Scan Length | Feature not present | Up to 135 cm | |
| Field of View(FOV) | Feature not present | 25 - 50 cm | |
| ImageUniformity | Feature not present | Within 15 HU (Head)Within 25 HU (Body) | |
| Image Noise | Feature not present | Less than 10 HU (Head)Less than 20 HU (Body) | |
| ContrastResolution | Feature not present | 1% contrast for 10 mmobject (Head)2% contrast for 15 mmobject (Body) | characteristicscompared to thatof MVCT imaging. |
| Image Display | Feature not present | Simultaneous acquisitionand reconstruction; realtime display | |
| DeviceCharacteristic | Predicate DeviceRadixact TreatmentDelivery System(K161146) | Subject DeviceRadixact TreatmentDelivery System withkVCT ImagingFeature | Analysis |
| Laser System | |||
| Stationary | Green lasers, identifyvirtual and actualisocenter | Green lasers, identifyvirtual and actualisocenter | Substantiallyequivalent. Minordifferences arenegligible and do |
| Moveable(for patientpositioningand registration) | Red lasers, offset fromvirtual isocenter | Red lasers, offset fromvirtual isocenter | negligible and donot result indifferent questionsof safety oreffectiveness. |
| Patient Couch | |||
| Motion | Independent of each ofthe other axes | Independent of each ofthe other axes | Identical |
| Biocompatibility | |||
| Couch Top | Carbon-fiber top | Carbon-fiber top | Identical |
| Power Distribution | |||
| Isolation | Transformer | Transformer | Substantiallyequivalent. Thisfeature is stillpresent. |
| UPS for DataBack-up | Provided | Provided | Substantiallyequivalent. Thisfeature is stillpresent. |
| Operator Station (Treatment Delivery Console) | |||
| Description | User interface tosystem functions (i.e.,patient and procedureselection, andprocedure delivery) | User interface tosystem functions (i.e.,patient and procedureselection, andprocedure delivery) | Substantiallyequivalent. Themodified devicedoes not changethis architecture. |
| DeviceCharacteristic | Predicate DeviceRadixact TreatmentDelivery System(K161146) | Subject DeviceRadixact TreatmentDelivery System withkVCT ImagingFeature | Analysis |
| Machine Control Software | |||
| Description | Controls radiationdelivery andpositioning systems(referred to as the ECS – Embedded ControlsSubsystem) | Controls radiationdelivery andpositioning systems(referred to as the ECS – Embedded ControlsSubsystem) | Substantiallyequivalent, exceptfor the following:Controls wereadded for thedynamic kVCollimator and kVPanel Actuator,and kV triggering |
| Database | |||
| Data InterfacesOperator Station | Providesmeasurements andstatus during operation | Providesmeasurements andstatus during operation | Substantiallyequivalent. ThekVCT imagingfunctionality wasadded to theexisting design. Nodifferent issues ofsafety oreffectiveness. |
| DatabaseDescription | External database usedfor gatheringoperational data andstorage of proceduredata | External database usedfor gatheringoperational data andstorage of proceduredata | Substantiallyequivalent. Theintroduction of thekVCT imagingfeature does notmodify this designoutside ofaccommodating formore data. |
| DeviceCharacteristic | Predicate DeviceRadixact TreatmentDelivery System(K161146) | Subject DeviceRadixact TreatmentDelivery System withkVCT ImagingFeature | Analysis |
| Safety Features | |||
| InterlockSubsystems | Interlock Subsystems | Present | Substantiallyequivalent. The kVsubsystem isintegrated into theSafety Interlocks.No different issuesof safety oreffectiveness. |
| Data IntegrityChecking | Data IntegrityChecking | Present | Substantiallyequivalent. Thisfeature is stillpresent in themodified device. |
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| DeviceCharacteristic | Reference DeviceMotion Tracking andCompensation forRadixact(K182687) | Subject DeviceRadixact TreatmentDelivery System withkVCT ImagingFeature | Analysis |
|---|---|---|---|
| MV BeamCollimation | Primary collimation,jaws and multi-leafcollimator (MLC) | Primary collimation,jaws and multi-leafcollimator (MLC) | kVCT does notchange thebehavior of thejaws. Identical tothe dynamicbehaviorintroduced inK182687. |
| MachineControlSoftware | Controls radiationdelivery andpositioning systems(referred to as the ECS– Embedded ControlsSubsystem) | Controls radiationdelivery andpositioning systems(referred to as the ECS– Embedded ControlsSubsystem) | Substantiallyequivalent, exceptfor the following:Controls wereadded for thedynamic kVCollimator and kVPanel Actuator,and kV triggeringwas modified.These controls aresimilar in nature tothose introduced inK182687. |
| DeviceCharacteristic | Reference DeviceMotion Tracking andCompensation forRadixact(K182687) | Subject DeviceRadixact TreatmentDelivery System withkVCT ImagingFeature | Analysis |
| kV Imaging Beam | |||
| Source | 50 – 150 kVRadiography Class I(60601-2-28) X-raytube assembly | 40 – 150 kVRadiography Class I(60601-2-28) X-raytube assembly | |
| Focal Spot Size | 0.6 mm x 0.6 mm(small spot)1.0 mm x 1.0 mm(large spot) | 0.6 mm x 0.6 mm(small spot)1.2 mm x 1.2 mm(large spot) | Substantiallyequivalent. The X-ray generationassembly(including thetube) has beenupdated to handle |
| Anode HeatCapacity | 600 KHU | 1500 KHU | the increaseddemands of kVCTimaging over thesolely 2-Dradiographimaging available |
| Tube HeatManagement[Specificationnot detailed inK182687] | Passive | Active oil cooled, 2.4 kW | in the predicate. |
| Generatorspecifications[Specificationnot detailed inK182687] | 400/480 V, 45 kW | 400/480 V, 80 kW | |
| Source to axisdistance[Specificationnot detailed inK182687] | 575 mm | 1040 mm | Substantiallyequivalent. Thecombination ofsource to axis |
| Source todetector distance[Specificationnot detailed inK182687] | 1130 mm | 1560 mm | detector distanceand pixel pitchhave beenmodified in thesubject device withno material impact. |
| DeviceCharacteristic | Reference DeviceMotion Tracking andCompensation forRadixact(K182687) | Subject DeviceRadixact TreatmentDelivery System withkVCT ImagingFeature | Analysis |
| kV Beam Filtering & Collimation | |||
| kV Collimation(description)[Specificationnot detailed inK182687] | Static collimation | Dynamic IEC-Xbcollimating blades,Dynamic IEC-Ybcollimating blades | Substantiallyequivalent. Thisimpacts kVradiographs, sincethe modifieddevice now limitsthe imaging beamto the active areaof the kV detectorusing thecollimator blades,as opposed to thestatic collimationused in thepredicate. |
| kV SpectralFiltering(description)[Specificationnot detailed inK182687] | 0.5 mm copper | Dynamicallyselectable filter of0.2 mm, 0.3, or0.5 mm copper, oropen air | Substantiallyequivalent. Thereis no impactrelative to thereference device,since the modifieddevice continues touse the 0.5 mmcopper filteravailable |
Table 5.5.2: Device Comparison Table: Radixact Treatment Delivery System with kVCT Imaging Feature and the Reference Device
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| DeviceCharacteristic | Reference DeviceMotion Tracking andCompensation forRadixact(K182687) | Subject DeviceRadixact TreatmentDelivery System withkVCT ImagingFeature | Analysis |
|---|---|---|---|
| kV Detector | |||
| Active Area[Specificationnot detailed inK182687] | 410 mm x 410 mm1024x1024 pixels, 0.4mm pitch | 432 mm x 432 mm2880x2880 pixels,0.15 mm pitch | Substantiallyequivalent. Thesubject deviceprovides the sameor better activearea with the sameor better pixelresolution ascompared to thereference device. |
| DetectorConfiguration | Flat panel CsI: TlThallium activatedCesium Iodide | Flat panel CsI: TlThallium activatedCesium Iodide | Substantiallyequivalent. Thematerials have notchanged. |
| Actuation | Feature not present | -225 to +25 mm alongthe IEC-Xr axis (axesper IEC 61217) | Substantiallyequivalent. Themodified devicecan dynamicallycollimate the beamto the detectorposition |
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Performance Data
The Radixact Treatment Delivery System with the use of the kVCT Imaging Feature was tested and shown to comply with the requirements of applicable FDA recognized consensus safety standards for radiation therapy equipment. Results of verification and validation testing confirm that the use of the kVCT Imaging Feature on the Radixact Treatment Delivery System conforms to design specifications and meets the needs of the intended users.
No animal or clinical tests are being submitted to establish substantial equivalence with the predicate device. The performance data demonstrate that the kVCT Imaging Feature is compatible with the Radixact Treatment Delivery System, and the Radixact Treatment Delivery System with the use of the kVCT Imaging Feature is as safe and effective and performs as well as the predicate device. Further, these test results demonstrate that the Radixact Treatment Delivery System with the use of the kVCT Imaging Feature has substantially equivalent safety and performance characteristics in comparison to the predicate device.
Conclusion
The Radixact Treatment Delivery System with the use of the kVCT Imaging Feature is substantially equivalent to the predicate device. The intended use and indications for use of the kVCT Imaging Feature fit within those of the predicate Radixact Treatment Delivery System. Additionally, the major technological characteristics and the principles of operation of the Radixact Treatment Delivery System with the use of the kVCT Imaging Feature are substantially equivalent to those of the predicate device. Minor differences do not raise different questions of safety and effectiveness of the Radixact Treatment Delivery System with the use of the kVCT Imaging Feature in comparison to the predicate device. Further, the performance data demonstrate that the kVCT Imaging Feature is compatible with the Radixact Treatment Delivery System, and the Radixact Treatment Delivery System with the use of the kVCT Imaging Feature is as safe and effective and performs as well as the predicate device. Therefore, the Radixact Treatment Delivery System with the use of the kVCT Imaging Feature is substantially equivalent to the predicate device.
§ 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.