The RefleXion Medical Radiotherapy System is indicated for treatment planning and precise delivery of image-guided radiation therapy, stereotactic radiotherapy, or stereotactic radiosurgery for tumors or other targeted tissues anywhere in the body when radiation treatment is indicated, while minimizing the delivery of radiation to vital healthy tissue. The megavoltage X-ray radiation is delivered in a rotational, modulated, image-guided format in accordance with the physician approved plan.

Device Description

The RefleXion Medical Radiotherapy System (RMRS), a hybrid imaging-therapy system, is capable of delivering intensity-modulated radiation therapy (IMRT), stereotactic body radiation therapy (SBRT), stereotactic radiotherapy (SRT) and stereotactic radiosurgery (SRS) utilizing an on-board kilovoltage CT (kVCT) system for patient localization and field sizes based on jaws which are 40 cm wide, with slice width choices of 1.0 cm and 2.0 cm to optimize patient treatment. It is also equipped with a binary multileaf collimator (MLC) used to create intensity modulated radiation fields at a source-axis distance of 85 cm. It can achieve a nominal dose rate of 850 cGy/min.

The RMRS consists of the following clinical subsystems: 6 MV photon radiotherapy delivery, Kilovoltage (KV) X-ray CT imaging, MV X-ray detection, and treatment planning. The LINAC along with the fixed primary collimator, adjustable collimators, and multileaf collimator (MLC) mount in the therapy plane. The kVCT imaging plane is separate from the therapy plane and provides images used to localize the patient prior to treatment. Additionally, the system is designed architecturally to include PET imaging components for future product enhancements. Although the PET subsystem hardware is present in the system, its functionality is currently disabled.

AI/ML Overview

Here's an analysis of the acceptance criteria and study information provided in the document:

1. Acceptance Criteria and Reported Device Performance

Performance Test	Acceptance Criteria	Reported Device Performance
Coincidence of mechanical and radiation isocenter	≤ 1mm	Conformance to applicable requirements and specifications
kVCT imaging to MV treatment plane localization accuracy	≤ 1mm	Conformance to applicable requirements and specifications
kVCT geometric accuracy	≤ 1mm	Conformance to applicable requirements and specifications
Dosimetric accuracy	>90% of points passing 3%/3mm (for points greater than 10% maximum dose)	Conformance to applicable requirements and specifications
Dose rate output constancy	≤ 2%	Conformance to applicable requirements and specifications
Dose output linearity	± 2% ≥5MU; ± 5% (2-4 MU)	Conformance to applicable requirements and specifications
High contrast spatial resolution (kVCT)	Not explicitly stated as a pass/fail criterion, but a target is implied.	4 lp/cm (Predicate: 3 lp/cm)
Low contrast resolution (kVCT)	Not explicitly stated as a pass/fail criterion, but a target is implied.	Visibility of 5 mm object for 1% contrast (Predicate: 2% density for 2 cm object)

Notes: The document states that "Results of bench testing showed conformance to applicable requirements and specifications" for all listed performance tests. While specific numerical results are provided for high and low contrast resolution, they are presented as comparisons to the predicate device rather than explicit acceptance criteria and direct performance measurements against those criteria. However, the implicit indication is that these improved or comparable values meet expectations.

2. Sample Size Used for the Test Set and Data Provenance

The document states, "No animal studies or clinical tests have been included with this pre-market submission." This indicates that the testing was primarily bench testing and in-vitro verification and validation. Therefore, the concept of a "test set" with "data provenance" in the clinical sense (e.g., patient data from a specific country, retrospective/prospective) is not applicable here.

3. Number of Experts Used to Establish the Ground Truth for the Test Set and Qualifications of Those Experts

Not applicable. As per point 2, no clinical test set was used that would require expert-established ground truth. The "ground truth" for the performance tests would be established through a combination of:

Physical phantoms and measurement devices: For tests like dosimetric accuracy, isocenter coincidence, and geometric accuracy.
Standards and specifications: The acceptance criteria themselves are drawn from industry standards and internal design specifications.

4. Adjudication Method for the Test Set

Not applicable, as no clinical test set requiring expert adjudication was used.

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

Not applicable. The RefleXion Medical Radiotherapy System is a radiation treatment and imaging system, not an AI-assisted diagnostic or interpretation tool for human readers. There is no mention of such a human reader study.

6. If a Standalone (i.e. algorithm only without human-in-the loop performance) was Done

The performance data presented in the table are for the standalone device performance (e.g., mechanical accuracy, dosimetric accuracy, imaging performance). The device's treatment planning software is part of the system, and its accuracy is tested (e.g., "Treatment Planning System Dose accuracy tests"), indicating a standalone assessment of the algorithm's output. These results are implied to be "conforming to applicable requirements and specifications."

7. The Type of Ground Truth Used

The ground truth for the verification and validation tests was established through:

Physical measurements and industry standards: For mechanical, dosimetric, and imaging performance tests (e.g., phantoms, dosimeters, rulers, calibrated test equipment against known values).
Design specifications and requirements: The device's performance was measured against its predefined technical specifications and relevant international standards (e.g., IEC standards).

8. The Sample Size for the Training Set

Not applicable. The document describes a medical device (a linear accelerator and its associated systems) and its performance, not a machine learning or AI model that requires a "training set" in the context of data-driven algorithm development. While the system undoubtedly has complex software, the document focuses on its overall and component performance validation rather than the training of a predictive model.

9. How the Ground Truth for the Training Set was Established

Not applicable, as there is no "training set" discussed in this submission.

Summary

{0}------------------------------------------------

March 12, 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 square is the text "U.S. FOOD & DRUG ADMINISTRATION" in blue.

RefleXion Medical, Inc % Kathy O'Shaughnessy, PhD V.P. Regulatory, Quality Assurance, Clinical 25841 Industrial Blvd, Suite 275 HAYWARD CA 94545

Re: K190978

Trade/Device Name: RefleXion Medical Radiotherapy System Regulation Number: 21 CFR 892.5050 Regulation Name: Medical charged-particle radiation therapy system Regulatory Class: Class II Product Code: IYE, MUJ Dated: February 13, 2020 Received: February 14, 2020

Dear Dr. O'Shaughnessy:

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

{1}------------------------------------------------

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

{2}------------------------------------------------

Indications for Use

510(k) Number (if known) K190978

Device Name RefleXion Medical Radiotherapy System

Indications for Use (Describe)

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)

CONTINUE ON A SEPARATE PAGE IF NEEDED.

This section applies only to requirements of the Paperwork Reduction Act of 1995.

DO NOT SEND YOUR COMPLETED FORM TO THE PRA STAFF EMAIL ADDRESS BELOW.

The burden time for this collection of information is estimated to average 79 hours per response, including the time to review instructions, search existing data sources, gather and maintain the data needed and complete and review the collection of information. Send comments regarding this burden estimate or any other aspect of this information collection, including suggestions for reducing this burden, to:

Department of Health and Human Services Food and Drug Administration Office of Chief Information Officer Paperwork Reduction Act (PRA) Staff PRAStaff(@fda.hhs.gov

"An agency may not conduct or sponsor, and a person is not required to respond to, a collection of information unless it displays a currently valid OMB number."

{3}------------------------------------------------

Premarket Notification [510(k)] Summary

Premarket Notification [510(k)] Summary
	Reflexion Medical Radiotherapy System RXM1000
SUBMITTER	Reflexion Medical, Inc.25841 Industrial Blvd, Suite 275Hayward, CA 94545
	Contact Name: Kathy O'Shaughnessy, PhDPhone: (650) 239-9070 x1035Fax: (650) 521-5916Date of preparation: March 11, 2020
DEVICE	Name of Device: Reflexion Medical Radiotherapy SystemTrade or Brand Name: Reflexion System One, Reflexion System RXM1000Common/usual Name: Medical Linear AcceleratorRegulation Number: 21 CFR 892.5050Classification Name: Medical charged-particle radiation therapy systemRegulatory Class: Class IIProduct Code IYE (radiation therapy), MUJ (planning)
PREDICATE DEVICE	TomoTherapy Treatment System (K121934)

DEVICE DESCRIPTION

{4}------------------------------------------------

Image /page/4/Picture/0 description: The image shows the word "reflexion" in a sans-serif font. The letters are dark gray, except for the "x", which is orange. The word is written in lowercase letters.

INDICATIONS FOR USE/INTENDED USE STATEMENT

COMPARISON OF TECHNOLOGICAL CHARACTERISTICS WITH THE PREDICATE DEVICE

The RefleXion Medical Radiotherapy System and the predicate device employ the same fundamental scientific principles and have substantially equivalent principles of operation and technological characteristics.

The treatment delivery components of the RefleXion and TomoTherapy devices are the same or equivalent with regards to energy, beam properties, materials and other physical properties.

Key differences between the subject device and the predicate device include the following:

. Faster rotation of the system at 60 RPM.
Use of a new faster-speed binary MLC design.
Addition of a kVCT subsystem for patient positioning.
. Addition of a method to correct for pitch and yaw set-up errors.

DeviceCharacteristic	Predicate Device:TomoTherapy TreatmentSystem	Subject Device:Reflexion MedicalRadiotherapy System	Analysis
510(k) number	K121934	K190978
Ring Gantry
Bore Diameter	85 cm	85 cm	Same
Speed of Rotation			Substantially equivalent.
Treatment	1 to 5 RPM	60 RPM
Imaging	6 RPM	60 RPM
Photon Beam
Beam energy	6 MV (single energy)	6 MV (single energy)	Same
Fixed Field Size	1.0 cm x 40 cm2.5 cm x 40 cm5.0 cm x 40 cm	1.0 cm x 40 cm2.0 cm x 40 cm3.0 cm x 40 cm (QA mode)	The field sizes for clinical useare substantially equivalent.Differences do not inhibit it'sintended use.
Isocenter distance	85 cm	85 cm	Same
Nominal Dose Rate	850 cGy/min	850 cGy/min	Same
Collimation
PrimaryCollimation	Tungsten block withrectangular, fixed aperture	Tungsten block withrectangular, fixed aperture	Same
Jaw placement	Jaws are placed after the MLC	Split jaw design – the lowerjaws are placed after the MLC	Substantially equivalent.Subject device uses a split jawdesign.
DeviceCharacteristic	Predicate Device:TomoTherapy TreatmentSystem	Subject Device:Reflexion MedicalRadiotherapy System	Analysis
Jaw - movement	Static ModeDynamic Mode	Static mode	Substantially equivalent.Subject device is static only.
MultileafCollimator	0 to 400 mm wide by 5 to 20mm longBinary (fully in or fully out);pneumatic64 tungsten leaves (tongue andgroove), 10cm thick	0 to 400 mm wide by 10 to 30mm longBinary (fully in or fully out);spring-loaded pneumatic64 tungsten leaves (tongue andgroove), 11cm thick	Substantially equivalent. Minordifferences are negligible.
Leaf Resolution atisocenter	0.625 cm in IEC-x direction atisocenter	0.625 cm in IEC-x direction atisocenter (leaf width is 0.614cm)	Same
MLC Leaf transitiontime	<20 msec	<7 msec	Substantially equivalent. Thesubject device's MLC leavesmove faster to accommodatefaster gantry rotation.
Imaging - for patient positioning
Energy	MVCT – 3.5 MV (nominal forpositioning)Provided by the therapy beam(at lower energy)	kVCT - 120 kVSeparate system located in aplane approx. 40 cm fromtherapy plane	Substantially equivalent.
Dose per image(typical)	0.5 – 3.0 cGy depending onresolution and body thickness	2.45 cGy (body), 5.13 cGy(head) (CTDIvol, nominalsettings)	Similar; physician chooses attime of treatment planning
High contrastspatial resolution	3 lp/cm (typical)	4 lp/cm	Similar
Low contrastresolution	2% density for 2 cm object(typical)	Visibility of 5 mm object for 1%contrast	Subject device increasesvisibility of lowercontrast/smaller objects
Treatment Planning
AssociatedTreatment DeliverySystem	Determines treatment planningand dose distribution for theTomotherapy System.	Determines treatment planningand dose distribution for theReflexion System.	Same function for each system
Planning	6 MV External beam x-ray andinverse planning	6 MV External beam x-ray andinverse planning	Same
Image Series Used	Image series (CT)	Image series (CT)	Same
Treatment Delivery Software
Delivery ModesSupported	IMRT, SRS, SRT, SBRT	IMRT, SRS, SRT, SBRT	Same
Patient Setup andLocalization	Yes	Yes	Same
Patient Couch
Biocompatible	Yes	Yes - Couch top isbiocompatible	Same
Degrees ofFreedom	Y, Z (software control)X (manual)Roll (adjust initial gantry angle)Pitch, yaw (rotate patient)	X, Y, Z, pitch, yaw (softwarecontrol)Roll (adjust initial gantry angle)	The subject device addssoftware correction in the x,pitch and yaw axes.

{5}------------------------------------------------

refle»«on

{6}------------------------------------------------

Image /page/6/Picture/0 description: The image shows the word "reflexion" in a sans-serif font. The letters are mostly dark gray, except for the "X" in the middle, which is orange. The word is presented in a clean and modern style.

PERFORMANCE DATA

Verification and validation testing have been conducted to demonstrate that the device performs as intended.

Bench testing included system and subsystem tests including:

. Performance tests to applicable standards (including electrical safety and electromagnetic compatibility).
Safety/Interlock tests to ensure risk mitigations performed as specified.
Dosimetric performance evaluation of the RefleXion system.
Treatment Planning System Dose accuracy tests to evaluate the accuracy of the RefleXion treatment planning system.
. Geometric localization accuracy tests for the RefleXion system.
Imaging performance testing.
. Validation testing including end-to-end tests, usability testing, and tests to ensure the system performance checks function as intended.

Results of bench testing showed conformance to applicable requirements and specifications. Specifications of key performance tests are provided below:

Performance Test	Specification
Coincidence of mechanical and radiation isocenter	≤ 1mm
kVCT imaging to MV treatment plane localization accuracy	≤ 1mm
kVCT geometric accuracy	≤ 1mm
Dosimetric accuracy	>90% of points passing 3%/3mm (for pointsgreater than 10% maximum dose)
Dose rate output constancy	≤ 2%
Dose output linearity	± 2% ≥5MU± 5% (2-4 MU)

Software verification and validation documentation was provided 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 software for this device was considered as a "major" level of concern.

The subject device conforms in whole or in part with the following standards: IEC60601-1, IEC60601-1-2, IE60601-1-3, IEC60601-1-6, IEC60601-2-1, IEC60601-2-44, IEC60601-2-68, IEC62366-1, IEC60976, IEC61217, IEC62083, IEC6274. For those recognized standards in which there are clauses that are not applicable, summary reports with justifications have been included in the submission.

No animal studies or clinical tests have been included with this pre-market submission.

{7}------------------------------------------------

Image /page/7/Picture/0 description: The image shows the word "reflexion" in a sans-serif font. The letters are dark gray, except for the "x", which is orange. The word is horizontally oriented and centered in the image.

CONCLUSION

The non-clinical data support the safety of the device and the verification and validation testing performed demonstrates that the RefleXion Medical Radiotherapy System performs as intended in the specified use conditions. RefleXion therefore considers the RefleXion Medical Radiotherapy System to be substantially equivalent to the predicate device.

Regulation Number and Section

§ 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.