The XBeam Software can be used for validating the monitor units or radiation dose to a point that has been calculated by hand or another treatment planning system for external beam radiation therapy. In addition, the XBeam Software can also be used as a primary means of calculating the monitor units or radiation dose to a point for external beam radiation treatments.

XBeam is only intended to be used with Xstrahl's superficial and orthovoltage radiotherapy and surface electronic brachytherapy systems. XBeam is intended to be used by authorized personnel trained in medical physics.

Device Description

XBeam is a standalone dose calculation software for Xstrahl's medical devices include:

Xstrahl 100, Xstrahl 150, Xstrahl 200, Xstrahl 300 (K962613)
X80 RADiant Photoelectric Therapy System (K172080)
. RADiant Aura (X80 RADiant Photoelectric Therapy System) (K230611)

XBeam's dose calculation algorithm can be used to determine the beam-on time or monitor units based on the applicator and filter selected for the specific device. The beam-on time / monitor units are calculated based on the percent dose depth (PDD) curve and the absolute dose output for the specified applicatorfilter combination. The software allows for calculating treatment parameters for single or two (parallel opposed) beams.

XBeam is intended to be used within a clinical environment where the patient is treated with Xstrahl's medical systems. XBeam is intended to be used by authorized personnel trained in medical physics. It is not intended to be used by patients or general public.

AI/ML Overview

Here's an analysis of the provided text regarding the acceptance criteria and the study that proves the device meets those criteria:

The provided FDA 510(k) summary for the XBeam (v2) device focuses on demonstrating substantial equivalence to its predicate device, RADCalc (K193381), primarily through a comparison of intended use, technical characteristics, and a summary of non-clinical testing. While it mentions "acceptance criteria" through verification and validation activities, it does not explicitly define specific numerical acceptance criteria (e.g., "accuracy must be > 95%") for its performance when compared against ground truth.

Instead, the summary reports the results of the performance testing and concludes that they are acceptable, implying that these results meet implicit acceptance criteria for clinical equivalence and safety/effectiveness.

Given this, I will infer the implicit acceptance criterion based on the reported results.

1. Table of Acceptance Criteria and Reported Device Performance

Acceptance Criteria (Inferred)	Reported Device Performance
Dosimetric Accuracy (against hand calculation/RADCalc): Maximum difference in calculated dose/monitor units must be clinically acceptable.	Maximum difference found was 0.7%, attributed to interpolation/rounding errors. The output calculated by XBeam was "the same" as that calculated by hand calculation and by RADCalc.
Dosimetric Accuracy (against delivered dose for energies < 80kV): Measured and planned dose values must agree within clinically acceptable limits, considering measurement uncertainties.	Measured and planned dose values agree to within 3.6%. Overall measurement uncertainties estimated at 5.5% (with 5% attributed to the device used for measurement).
Dosimetric Accuracy (against delivered dose for energies > 80kV): Measured and planned dose values must agree within clinically acceptable limits, considering measurement uncertainties.	Measured and planned dose values agree to within 1.8%. Measurement uncertainties estimated at 1.7%.
Conformance to Standards: Device must meet requirements of specified medical device standards.	Conforms to IEC 62366-1, IEC 62304, and ISO 14971.
Usability, Risk Mitigation, and Functionality: Device functionality works as per intended use, risks are mitigated, and is substantially equivalent.	Verification activities included system tests, module tests, anomaly verification, code reviews, and run-through integration tests (323 tests executed, all passed). Validation activities included clinical workflow, treatment planning, and software usability.

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

The document states: "Three hundred twenty-three (323) independent verification tests were executed." This refers to verification activities (system tests, module tests, etc.) rather than a specific test set of patient cases or dosimetric scenarios for performance evaluation against ground truth.

For the dosimetric accuracy validation:

Sample size: Not explicitly stated as a number of distinct cases or patient datasets. It refers to comparing XBeam's output against two standard methods (hand calculations and RadCalc) and then comparing planned dose (presumably from XBeam) to delivered dose using physical measurements. The number of such comparisons or the range of parameters tested is not quantified.
Data provenance: Not specified in terms of country of origin. The study appears to be a prospective validation of the software's dose calculation against established methods and physical measurements, rather than clinical retrospective or prospective patient data analysis.

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

Number of Experts: Not explicitly stated.
Qualifications of Experts: The ground truth for dose calculation was established by "hand calculations" and the output of the predicate device "RadCalc (version: 7.3)." This implies that the 'experts' or processes involved in performing these hand calculations or configuring/using RadCalc would be "authorized personnel trained in medical physics" as stipulated in the device's indications for use.

4. Adjudication Method

Not applicable/specified. The validation involves direct comparison of numerical outputs (dose, monitor units) against established calculational methods and physical measurements, rather than assessment by multiple human reviewers requiring adjudication for a "ground truth" establishment in a subjective medical imaging context.

5. Multi-Reader Multi-Case (MRMC) Comparative Effectiveness Study

No, a Multi-Reader Multi-Case (MRMC) comparative effectiveness study was not conducted or reported in this summary. The device is a dose calculation software, not an AI-powered diagnostic image analysis tool that would typically involve human readers interpreting results with and without AI assistance.

6. Standalone Performance Study

Yes, a standalone performance study was done. The summary describes the validation of the XBeam algorithm's output (dose calculations) by comparing it against two independent methods:

Hand calculations.
The output of the predicate device, RADCalc.
It also compared XBeam's planned dose to the physically delivered dose using measurement. This demonstrates the algorithm-only performance.

7. Type of Ground Truth Used

The ground truth used for the dosimetric accuracy validation was a combination of:

Expert Consensus/Established Methods: "Hand calculations" (representing established physics principles and manual computation).
A Legally Marketed Predicate Device's Output: "RadCalc (version: 7.3)".
Physical Measurements/Outcomes Data (Indirectly): Comparison of "planned dose" (from XBeam) to "delivered dose" (presumably measured with dosimetry equipment in a controlled setting).

8. Sample Size for the Training Set

The document does not explicitly mention a "training set" or "training data." The XBeam software appears to be a dose calculation algorithm based on physics models, rather than a machine learning model that requires a distinct training phase with labeled data. Therefore, the concept of a training set as typically understood in AI/ML is not directly applicable to this description.

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

As noted above, the concept of a training set is not explicitly referred to for XBeam. The data that would inform the development and calibration of such a physics-based dose calculation system would typically come from extensive commissioning data (e.g., PDD curves, absolute dose output, beam profiles) measured for each specific Xstrahl radiotherapy system it supports, established via standard medical physics protocols. These measurements would be considered the "ground truth" for calibrating the physics model within the software. However, the document does not detail this specific process for XBeam's development.

Summary

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December 4, 2024

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, with the letters "FDA" in a blue square, followed by the words "U.S. FOOD & DRUG" in blue, and then the word "ADMINISTRATION" in a smaller font in blue.

Xstrahl Ltd. Gupta Vineet Chief Technology Officer Unit 2 Maybrook Industrial Estate Maybrook Road Brownhills, West Midlands WS8 7DG United Kingdom

Re: K240671

Trade/Device Name: XBeam (v2) Regulation Number: 21 CFR 892.5050 Regulation Name: Medical Charged-Particle Radiation Therapy System Regulatory Class: Class II Product Code: MUJ Dated: March 10, 2024 Received: March 11, 2024

Dear Gupta Vineet:

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 (the 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 available at https://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfpmn/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.

Additional information about changes that may require a new premarket notification are provided in the FDA guidance documents entitled "Deciding When to Submit a 510(k) for a Change to an Existing Device"

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(https://www.fda.gov/media/99812/download) and "Deciding When to Submit a 510(k) for a Software Change to an Existing Device" (https://www.fda.gov/media/99785/download).

Your device is also subject to, among other requirements, the Quality System (QS) regulation (21 CFR Part 820), which includes, but is not limited to, 21 CFR 820.30, Design controls; 21 CFR 820.90, Nonconforming product; and 21 CFR 820.100, Corrective and preventive action. Please note that regardless of whether a change requires premarket review, the QS regulation requires device manufacturers to review and approve changes to device design and production (21 CFR 820.30 and 21 CFR 820.70) and document changes and approvals in the device master record (21 CFR 820.181).

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 Part 803) for devices or postmarketing safety reporting (21 CFR Part 4, Subpart B) for combination products (see https://www.fda.gov/combination-products/guidance-regulatory-information/postmarketing-safety-reportingcombination-products); good manufacturing practice requirements as set forth in the quality systems (OS) regulation (21 CFR Part 820) for devices or current good manufacturing practices (21 CFR Part 4, Subpart A) for combination products; and, if applicable, the electronic product radiation control provisions (Sections 531-542 of the Act); 21 CFR Parts 1000-1050.

All medical devices, including Class I and unclassified devices and combination product device constituent parts are required to be in compliance with the final Unique Device Identification System rule ("UDI Rule"). The UDI Rule requires, among other things, that a device bear a unique device identifier (UDI) on its label and package (21 CFR 801.20(a)) unless an exception or alternative applies (21 CFR 801.20(b)) and that the dates on the device label be formatted in accordance with 21 CFR 801.18. The UDI Rule (21 CFR 830.300(a) and 830.320(b)) also requires that certain information be submitted to the Global Unique Device Identification Database (GUDID) (21 CFR Part 830 Subpart E). For additional information on these requirements, please see the UDI System webpage at https://www.fda.gov/medical-device-advicecomprehensive-regulatory-assistance/unique-device-identification-system-udi-system.

Also, please note the regulation entitled, "Misbranding by reference to premarket notification" (21 CFR 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-regulatory

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assistance/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,

Locon Weidner

Lora D. Weidner, Ph.D. Assistant Director Radiation Therapy Team DHT8C: Division of Radiological Imaging and Radiation Therapy Devices OHT8: Office of 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) K240671

Device Name XBeam (v2)

Indications for Use (Describe)

The XBeam Software can be used for validating the monitor units or radiation dose to a point that has been calculated by hand or another treatment planning system for external beam radiation the XBeam Software can also be used as a primary means of calculating the monitor units or radiation dose to a point for external beam radiation treatments.

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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K240671

Xstrahl Ltd Unit 2 Maybrook Industrial Estate Maybrook Road, Brownhills, West Midlands, WS8 7DG United Kingdom T +44 (0)1543 688920 E support@xstrahl.com

Xstrahl.com

510(K) SUMMARY

A. SUBMITTERS NAME

Xstrahl Ltd.

FDA Establishment Registration No. 3004561814

B. ADDRESS

Unit 2, Maybrook Industrial Estate Maybrook Road Brownhills, West Midlands WS8 7DG United Kingdom

C. CONTACT

Name: Designation: Vineet Gupta, Ph.D. Phone: Chief Technology Officer Email: (412) 320 5048 vineetgupta@xstrahl.com

D. DATE PREPARED:

03-December-2024

E. DEVICE NAME:

F. DEVICE CLASS:

Device Trade Name: Classification Name: Common Name:

XBeam Medical Charged-Particle Radiation Therapy System System, Planning, Radiation Therapy Treatment

Device Class: Panel: Product Code: Regulation Number:

II Radiology MUI 21CFR 892.5050

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G. PREDICATE DEVICES:

RADCalc (K193381)

H. STATEMENT ON INDICATIONS FOR USE:

I. DEVICE DESCRIPTION:

XBeam is a standalone dose calculation software for Xstrahl's medical devices include:

Xstrahl 100, Xstrahl 150, Xstrahl 200, Xstrahl 300 (K962613)
X80 RADiant Photoelectric Therapy System (K172080)
. RADiant Aura (X80 RADiant Photoelectric Therapy System) (K230611)

J. PREDICATE DEVICE INFORMATION:

The XBeam software is substantially equivalent to its primary predicate device RADCalc (K193381; Decision Date: 31-Dec-2019).

The fundamental scientific technology of XBeam with respect to its predicate device (RADCalc) for dose calculation for Xstrahl's medical devices is the same. The intended use and indications for use of the XBeam software is similar to that of the RADCalc software.

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K. COMPARISON TO THE PREDICATE DEVICE:

This section provides the summary of comparison of XBeam to its predicate device.

Table 1 Indications for Use Comparison

	Proposed Device	Predicate Device
	XBeam v2 (K240671)	RADCalc (K193381)
Device Trade Name	XBeam	RADCalc
Intended Use /Indications for Use	The XBeam Software can be usedfor validating the monitor units orradiation dose to a point that hasbeen calculated by hand or anothertreatment planning system forexternal beam radiationtherapy. In addition, the XBeamSoftware can also be used as aprimary means of calculating themonitor units or radiation dose to apoint for external beam radiationtreatments.XBeam is only intended to be usedwith Xstrahl's superficial andorthovoltage radiotherapy andsurface electronic brachytherapysystems. XBeam is intended to beused by authorized personneltrained in medical physics.	1. RadCalc performs a secondarydose calculation verification on thetreatment plan done by thetreatment planning software. Thisis RadCalc's primary function.Radiation therapy systemstypically calculate the monitorunits needed to deliver the desiredamount of radiation to a point ofreference within the patient. In thissituation, RadCalc will serve tovalidate those monitor unitscomputed by the primary radiationtherapy planning system.Additional verification activitiesrevolve around point dosecomparisons, 3D dose evaluationvia Gamma analysis, and DVHcomparisons. It is not the intentionof RadCalc to replace thecalculation performed by theprimary radiation therapy planningcomputer but to validate itscalculation as a means of qualityassurance. The practice ofperforming a secondary check isrecommended by the AmericanAssociation of Physicists inMedicine (AAPM) Task Group 40as part of a good quality assuranceprogram. This practice is animportant aspect in providingquality patient care.2. Import data from the treatmentplanning software and export thedata from the treatment planningsystem to the verify and recordsystem, which is the device thatactually controls the radiationbeam. This will reduce the number
	of errors that occur as a result ofmanually inputting this data.
	3. In addition to performing thesecondary dose verificationcalculation, RadCalc can also beused as the primary means ofcalculating monitor units insituations where the physiciandoes not order the use of aradiation therapy treatment plan.RadCalc can independentlycalculate the amount of radiationthe beam should produce (calledthe MU or monitor unit) to deliverto the patient the radiation dose thedoctor recommends. This functionis usually only used in urgent,emergency situations.
	4. In addition, RadCalc performsbrachytherapy-type calculations.Fo brachytherapy calculations,High Dose Rate(HDR), Low Dose Rate (LDR),and Permanent type treatments canbe verified. Verification activitiesrevolve around point dosecomparisons, 3D dose evaluationvia Gamma analysis, and DVHcomparisons. RadCalc is not usedas a primary means of calculatingpatient dose for brachytherapytreatments.
	5. Analysis affluence and dosemaps can be performed viapercentage difference, distance toagreement, or gamma analysismethodologies.
	6.Interoperability with externaldose calculation engines (EDCE)by sending them treatment plansand associated information in theirnecessary format so that the EDCEcan perform a 3D dose calculationusing its dose calculationalgorithm. The computed dosevolume is received back and the3D analysis tools described aboveare used to compare against thetreatment planning system.
	Proposed DeviceXBeam v2 (K240671)	Predicate DeviceRADCalc (K193381)
Product Code	MUJ	MUJ
Class	II	II
Regulation Number	21CFR 892.5050	21CFR 892.5050
Classification Name	Medical Charged-ParticleRadiation Therapy System	Medical Charged-ParticleRadiation Therapy System
Common Name	System, Planning, RadiationTherapy Treatment	System, Planning, RadiationTherapy Treatment
Devices Supported	X80 (RADiant / RADiant Aura),Xstrahl 100, Xstrahl 150, Xstrahl200, Xstrahl 300	X80 (RADiant / RADiant Aura),Xstrahl 100, Xstrahl 150, Xstrahl200, Xstrahl 300
Treatment Types Supported
Brachytherapy	No	Yes
Superficial /Orthovoltage (kV)	Yes	Yes
Tomotherapy	No	Yes
Photons (MV)	No	Yes
Electrons	No	Yes
Workflow Comparison
Beam Data Input	Yes	Yes
Patient Information	Yes	Yes
Prescription	Yes	Yes
Treatment Time /Monitor UnitsCalculation	Yes	Yes
Print Reports	Yes	Yes
Beam Data Inputs / Setup
Machine Type	Yes	Yes
Filter (mm)	Yes	Yes
HVL (mm)	Yes	Yes
Applicator Type	Yes	Yes
Focal Spot Distance(FSD)	Yes	Yes
kVp	Yes	Yes
mA	Yes	Yes
Prescription
Prescribed Dose (cGy)	Yes	Yes
Dose Per Fraction (cGy)	Yes	Yes
Number of Fractions	Yes	Yes
Number of Beams	1 and 2	1 and 2
Stand Off (cm)(Optional)	Yes	Yes
Backscatter (Optional)	No	Yes
Cone / Custom Cutout(Optional)	Yes	Yes

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Table 2 General Comparison

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For the treatment type supported, XBeam supports the required features and workflow steps that are present in the predicate device (K193381).

XBeam's fundamental technical characteristics are the same as those of the predicate device (K193381). In addition, the target population and the indications for use are similar to that of the predicate device (K193381). Any minor differences in the features do not raise any concerns for safety, performance, or effectiveness of the device. The characteristics / features of XBeam with respect to the predicate device is described in the comparison chart above.

L. SUMMARY OF TESTING:

Design verification and validation testing was performed to ensure that the device functionality works as per its intended use, all risks are mitigated, is substantially equivalent, and the product conforms to the required standards.

Non-clinical testing, including verification of risk control measures, was completed. The details of the design verification and validation activities were performed as recommended by FDA's Guidance for Industry and FDA Staff, "Guidance for the Content of Premarket Submissions for Software in Medical Devices."

The verification activities included system tests, module tests, anomaly verification, code reviews, and run-though integration tests. Three hundred twenty-three (323) independent verification tests were executed. Tests that failed were re-executed. All the verification tests passed. The validation activities included clinical workflow, treatment planning, software usability, and dosimetric accuracy. The output of the dose calculation algorithm was validated by comparing it against two standard methods: hand calculations and RadCalc (version: 7.3). The results indicated that the output calculated by XBeam was the same as that calculated by hand calculation and by RADCalc. The maximum difference found was 0.7% which can be attributed to interpolation / rounding errors in calculation. The planned dose was also compared to the delivered dose to show that the treatment plan can be accurately delivered. The results indicate that the measured and planned dose values agree to within 3.6% for energies below 80kV. The overall measurement uncertainties were estimated at 5.5%, mainly due to the device used which has a 5% uncertainty on the measured dose. For energies above 80kV, the measured and planned dose values agree to within 1.8%, with measurement uncertainties estimated at 1.7%. This demonstrates that the errors in the measurements made fall largely within the expected uncertainties in the measurements. It also demonstrates that the XBeam-generated treatment times deliver the prescribed dose within the expected uncertainties, to accuracy levels acceptable within the radiotherapy community.

Based upon the performance testing results for XBeam, the system is substantially equivalent to its predicate device (RADCalc) and raises no new issues related to safety or effectiveness.

Conclusion:

The verification and validation results demonstrate that the XBeam software met its design requirements and specifications, is substantially equivalent to its predicate device, and conforms to the applicable sections of standards that includes:

IEC 62366: Medical devices Part 1: Application of usability engineering to medical devices ●
IEC 62304: Medical device software - Software life cycle processes
ISO 14971: Medical devices Application of risk management to medical devices ●

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.