The AlignRT Plus system is indicated for use to position and monitor patients relative to the prescribed treatment isocentre, and to withhold the beam automatically during radiation delivery. For cranial treatments, a manual head adjuster is included which can be used in concert with AlignRT Plus to provide fine corrections for pitch, roll and yaw rotations. AlignRT Plus is also used to track the patient's respiratory pattern for respiratory synchronized image acquisition therapy treatment. Patient contour data can be extracted and exported from the data acquired for the purpose of treatment planning. AlignRT Plus can be calibrated directly to the treatment beam isocentre and in turn assists in performing quality assurance on MV, kV imagers, room lasers and the treatment couch. AlignRT Plus is indicated for use during simulation, setup and stereotactic radiosurgery and precision radiotherapy for lesions, tumors and conditions anywhere in the body where radiation is indicated.

Device Description

AlignRT Plus system is a combination of the predicate devices AlignRT (K052682) and GateCT-RT (K072171). It is a video-based three-dimensional (3D) surface imaging system, which is used to image the skin surface of a patient in 3D before and during radiotherapy treatment. The system consists of advanced software, a computer workstation, and one, two or three 3D camera units (each camera unit comprising a stereo pair of sensors to allow 3D surface reconstruction). The system is non-invasive, does not require the use of body markers and produces no ionizing irradiation during the imaging process.

AI/ML Overview

Acceptance Criteria and Study for AlignRT Plus

The AlignRT Plus system is a video-based three-dimensional (3D) surface imaging system used to position and monitor patients during radiotherapy treatment. The following describes its acceptance criteria and the study demonstrating its performance.

1. Table of Acceptance Criteria and Reported Device Performance

Feature/Metric	Acceptance Criteria	Reported Device Performance
Positioning Accuracy	Target registration errors (as measured using calibration phantom) < 1mm for all couch angles.	Target registration errors (as measured using calibration phantom) < 1mm for all couch angles.
Respiratory Tracking	- Tracks respiratory signal from imaged surface data.- Sends to CT (4D CT) or to Linac or imaging device (gating).- Surface displacements can be tracked with RMS errors < 0.5mm over 10 or more breathing cycles.	- Tracks respiratory signal from imaged surface data and sends to CT (4D CT) or to Linac or imaging device (gating).- Surface displacements can be tracked with RMS errors < 0.5mm over 10 or more breathing cycles.
System Accuracy (Predicate AlignRT K052682)	Errors along each of 3 axes of treatment: max mean: 0.27mm; max std dev: 0.65mm.	(This is the reported performance for the predicate device, against which AlignRT Plus is compared for substantial equivalence. The new device is stated to be substantially equivalent with improved features.)

Note: The document focuses on demonstrating substantial equivalence to predicate devices (AlignRT K052682 and GateCT-RT K072171) rather than presenting a detailed, independent clinical study with specific acceptance criteria outside of the technical specifications listed above. The performance metrics listed effectively serve as the acceptance criteria for technical performance.

2. Sample Size and Data Provenance

The provided document (510(k) Premarket Notification) does not explicitly state specific sample sizes used for a test set for the AlignRT Plus device itself.

Instead, it relies on demonstrating substantial equivalence to its predicate devices. The performance figures presented are derived from:

Calibration phantom measurements: For positioning accuracy of the AlignRT Plus. The type and number of measurements are not specified.
Respiratory tracking performance: For AlignRT Plus, again using measurements from imaged surface data. The number of breathing cycles (10 or more) is mentioned, but not the number of patients or measurement instances.
Predicate device performance: The system accuracy for the predicate AlignRT (K052682) is cited, presumably from the studies conducted for its prior clearance.

Data Provenance: The document originates from Vision RT Ltd. in the United Kingdom. The data presented is likely derived from internal testing and validation activities characteristic of a premarket notification, rather than a large-scale, multi-center clinical trial. It is an internal retrospective analysis of technical performance.

3. Number of Experts and Qualifications for Ground Truth

The document does not detail the use of a panel of experts to establish a "ground truth" for a specific test set in the context of a reader study. The performance metrics (positioning accuracy, respiratory tracking RMS error) are objective technical measurements performed using phantoms or direct measurements from physical surfaces/breathing cycles. Therefore, expert consensus in the traditional sense for image interpretation is not directly applicable here.

4. Adjudication Method for the Test Set

Given that the "ground truth" is based on objective physical measurements (e.g., target registration errors from a phantom, RMS errors from surface displacement tracking), an adjudication method in the sense of reconciling divergent expert opinions is not applicable or described. The measurements are presumably taken directly and automatically by the system or calibrated instruments.

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

No MRMC comparative effectiveness study is presented or mentioned in this 510(k) premarket notification. The document focuses on the technical capabilities and safety of the device to demonstrate substantial equivalence to previously cleared predicate devices. It does not assess the improvement of human readers with AI assistance because the device is a patient positioning and monitoring system, not an AI-assisted diagnostic or treatment planning tool that directly involves human readers' interpretation of output in the same way an imaging AI might.

6. Standalone (Algorithm Only) Performance Study

Yes, the performance data provided largely represents standalone (algorithm only) performance. The metrics of positioning accuracy and respiratory tracking capability describe the intrinsic technical accuracy of the AlignRT Plus system in performing its designated functions (e.g., identifying target registration errors, tracking surface displacements) without direct human intervention in the measurement process itself. The "user" interaction described pertains to setup (e.g., selecting tracking points) and monitoring, but the reported accuracy figures are inherent to the system's measurements.

7. Type of Ground Truth Used

The ground truth for the reported performance metrics is based on objective physical measurements rather than expert consensus, pathology, or outcomes data:

Target registration errors: Established using a physical calibration phantom with known, precise reference points.
Surface displacements/respiratory tracking: Established by measuring the movement of the imaged surface against known or expected movements (e.g., during breathing cycles).

8. Sample Size for the Training Set

The document does not specify a sample size for a training set. As a medical device for patient positioning and monitoring, the AlignRT Plus utilizes algorithms for 3D surface reconstruction and tracking. While such algorithms undergo internal development and validation, the 510(k) summary does not typically disclose details of internal algorithm training data, particularly for devices that are not primarily AI/ML-driven in the diagnostic sense. The underlying principles are based on established optical and image processing techniques.

9. How Ground Truth for the Training Set Was Established

Given that a specific training set size is not provided, the method for establishing ground truth for any internal training or validation of the algorithms is not detailed in this public document. It is implicitly assumed to be based on engineering validation and testing using phantoms or controlled environments to ensure the accuracy of the 3D surface reconstruction and tracking algorithms.

Summary

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K12337

AlignRT Premarket Notification -

JAN 06 2013

The information below is provided for the modifications to AlignRT following the format of 21 CFR 907.92.

Vision RT Ltd.: Submitter: Dove House Arcadia Avenue London, N3 2JU United Kingdom Contact Name: Dr. Norman Smith +44(0)20 8346 4300 Phone: +44(0)20 8346 4634 Fax: nsmith@visionrt.com . . . . . . Email:

Date Summary was prepared 25th October 2012

Name of the Device:	AlignRT Plus
Trade/Proprietary Name:	AlignRT Plus
Common or Usual Name:	Patient Positioning System
Classification Name:	Accessory to Medical charged-particle radiation therapyaccessories, 90IYE, (per 21 CFR section 892.5050)

Predicate Device to claim substantial equivalence

Vision RT AlignRT (K052682)

Vision RT GateCT-RT (K072171)

Description of Device:

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510(k) Premarket Notification

AlignRT Plus is also able to perform both respiratory synchronised CT imaging and treatment delivery. In both . instances, the system acquires a gated 3D surface model of the patient. User selected points are then tracked in real time in order to provide gating and position monitoring signals.

Real-time imaging and surface matching of the patient is possible during both setup and the treatment delivery to determine any patient movement. During treatment delivery, AlignRT Plus is also able to withhold the beam automatically, should the patient move outside user-defined tolerances.

Patient contour data may be extracted from surface data acquired by the system and exported for the purpose of treatment planning by radiotherapy professionals.

AlignRT Plus may be calibrated directly to the treatment beam isocentre using an optional custom designed calibration phantom and image processing software. It can analyse MV and kV digital imaging data acquired by other cleared devices. This in turn assists the user in performing quality assurance on MV, kV imagers, room lasers and the treatment couch.

The AlignRT Plus system includes the optional Head Adjuster for cranial treatments to allow for the manual, fine correction of pitch, roll and yaw in the patient's head position.

Precise isocenter calibration and the optional Head Adjuster provide improved frameless Stereotactic Radiosurgery (SRS).

Intended Use Statement:

The AlignRT Plus system is indicated for use to position and monitor patients relative to the prescribed treatment isocentre, and to withhold the beam automatically during radiation delivery. For cranial treatments, a manual head adjuster is included which can be used in concert with AlignRT Plus to provide fine corrections for pitch, roll and yaw rotations. AlignRT Plus is also used to track the patient's respiratory pattern for respiratory synchronized image acquisition, and radiation therapy treatment. Patient contour data can be extracted and exported from the data acquired for the purpose of treatment planning. AlignRT Plus can be calibrated directly to the treatment beam isocentre and in turn assists in performing quality assurance on MV, kV imagers, room lasers and the treatment couch. AlignRT Plus is indicated for use during simulation, setup and stereotactic radiosurgery and precision radiotherapy for lesions, tumors and conditions anywhere in the body where radiation is indicated.

Summary of the Technological Characteristics:

The Substantial Equivalence Comparison Table shown below provides a comparison of the technological characteristics of AlignRT Plus to those of the predicate device:

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		NEW DEVIC	AlignRT. Plus	Vision RT Ltd	The AlignRT Plus system is indicated for use toposition and monitor patients relative to theorescribed treatment isocenter, and	radiation delivery. For cranial treatments, a manual head adjuster is included which cawithhold the beam automatically durin			be used in concert with AlignRT Plus to provide fine corrections for pitch, roll and yaw rotations. AlignRT Plus also also rolled to the patient forrespiratory synchronized image acquisition	ontour data can be extracted and exporteand radiation therapy treatment. Patient	from the data acquired for the purpose treatment planning. AlignRT Plus can be	calibrated directly to the treatment beam	uality assurance on MV, kV imagers, roomsocenter and in turn assists in performing	lasers and the treatment couch. AlignRT Plumay be used during simulation, setup and	stereotactic radiosurgery and precisiradiotherapy for lesions, tumors ar	conditions anywhere in the body whenradiation is indicated.
isi�nrt	510(k) Premarket Notification – AlignRT Plus	PREDICATE DEVICE 2	.Vision RT's GateCT-RT (K072171	Vision RT Ltd	::	. ::	The GateCT-RT system is used to1999 1991	:	obtain the block of the subscriptions. Statures internet in assemblement of the comment and the comment of the manufacturer in the management of the comments of the comments				automatically.		·		October 201
		PREDICATE DEVICE	Vision RT's AlignRT (K052682	/ision RT Ltd					The AlignRT system is used to positiopatients at the isocentre of the linear	accelerator for radiation therapy procedures. Patient contour data car	be extracted and exported from thequired data for the purpose of	treatment planning.
			DEVICE NAMI	1ANUFACTURER					. .	ndications for Use							06 Issue 3.0

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									Page 4 of 6
	NEW DEVICE	Video based imaging of 3D skin surface datausing surface matching software. Imageprocessing of radiographic image data.	Any individual (adult or child) undergoingradiotherapy	PC workstation, cables, video cameras. BlockPolystyrene (calibration phantom), carbonfibre laminate material (head adjuster) whichis substantially equivalent to the clearedBionix (K100691) device.	Positioning accuracy: Target registrationerrors (as measured using calibrationphantom) < 1mm for all couch angles.Respiratory tracking: Tracks respiratory signalfrom imaged surface data and sends to CT (4DCT) or to Linac or imaging device (gating).	Surface displacements can be tracked withRMS errors < 0.5mm over 10 or morebreathing cycles.	No direct contact with patient:Indirect contact with Head adjuster. This ismade out of carbon fibre laminate materialwhich is substantially equivalent to thecleared Bionix (K100691) device.
visionrt510(k) Premarket Notification – AlignRT Plus	PREDICATE DEVICE 2	Video based imaging of 3D skin surfacedata using surface matching software.	Any individual (adult or child)undergoing radiotherapy.	PC workstation, cables, video cameras.	Tracks respiratory signal from imagedsurface data and sends to CT (4D CT)or to Linac or imaging device (gating).Surface displacements can be trackedwith RMS errors < 0.5mm over 10 ormore breathing cycles.	No contact with patient		25 October 2012
	PREDICATE DEVICE 1	Video based imaging of 3D skinsurface data using surface matchingsoftware.	Any individual (adult or child)undergoing radiotherapy.	PC workstation, cables, videocameras.	Sends computed coordinates totreatment couch.	System accuracy: Errors along each of3 axes of treatment: max mean:0.27mm; max std dev: 0.65mm.	No contact with patient
		Principles of operation	Target Population	Materials	System Performance andAccuracy	Biocompatibility			06 Issue 3.0

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	510(k) Premarket Notification – AlignRT Plus
	PREDICATE DEVICE 1	PREDICATE DEVICE 2	NEW DEVICE
Mechanical Safety	Cameras are ceiling mounted and do not contact patient or user	Cameras are ceiling mounted and do not contact patient or user	Cameras are ceiling, mounted and do not contact patient or user.Head adjuster is clamped to the treatment couch through universal base plate.
Anatomical treatment sites	Entire body surface	Anywhere one encounters the effects of respiratory motion. These areas include, but are not limited to, the lung, breast, liver, pancreas, kidney and organs in the pelvis region, such as the prostate.	Entire body surface.
Human factors	Imaging process is fully automatic as is estimation of new couch position; 3D visual display provided to show any discrepancy in patient position	User selects tracking point(s) during first session. This is detected automatically during subsequent sessions. Tracking of the respiratory signal is fully automated. Thresholds for gating are selected manually via software. Motion and irregular breathing are detected automatically.	Imaging process is fully automatic as is estimation of new couch position; 3D visual display provided to show any discrepancy in patient position.For respiratory tracking, user selects region of interest or tracking point(s) during first session. These are detected automatically during subsequent sessions.For cranial treatments, a manual head adjuster may be used by turning designated dials to provide fine corrections for pitch, yaw and roll rotations in concert with real time visual feedback provided to the user by AlignRT Plus.
Optical pattern	Optical (near infra-red) pattern is projected to patient.	Optical (near infra-red) pattern is projected to patient.	Optical (near infra-red) pattern is projected to patient.
			Page 5 of 6
			25 October 2012
			06 Issue 3.0

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DEPARTMENT OF HEALTH & HUMAN SERVICES

Image /page/6/Picture/1 description: The image shows the logo for the U.S. Department of Health & Human Services. The logo consists of a circular seal with the text "DEPARTMENT OF HEALTH & HUMAN SERVICES - USA" arranged around the perimeter. Inside the circle is a stylized symbol that resembles a caduceus or a staff with a serpent entwined around it, though it is a more abstract representation.

Public Health Service

Food and Drug Administration 10903 New Hampshire Avenue Document Control Center - WO66-G609 Silver Spring, MD 20993-002

January 8, 2013

Dr. Norman Smith Chief Executive Officer Vision RT Ltd., Dove House Arcadia Avenue LONDON. N3 2JU, UK

Re: K123371

Trade/Device Name: AlignRT Plus Regulation Number: 21 CFR 892.5050 Regulation Name: Medical Charged-particle radiation therapy system Regulatory Class: II Product Code: IYE Dated: October 26, 2012 Received: November 1, 2012

. Dear Dr. Smith:

We have reviewed your Section 510(k) premarket notification of intent to market the device referenced above and have determined the device is substantially equivalent (for the indications for use stated in the enclosure) to legally marketed predicate devices marketed in interstate commerce prior to May 28, 1976, the enactment date of the Medical Device Amendments, or to devices that have been reclassified in accordance with the provisions of the Federal Food, Drug, and Cosmetic Act (Act) that do not require approval of a premarket approval application (PMA). You may, therefore, market the device, subject to the general controls provisions of the Act. The general controls provisions of the Act include requirements for annual registration, listing of devices, good manufacturing practice, labeling, and prohibitions against misbranding and adulteration. Please note: CDRH does not evaluate information related to contract liability warranties. We remind you, however, that device labeling must be truthful and not misleading.

If your device is classified (see above) into either class II (Special Controls) or class III (PMA), it may be subject to additional controls. Existing major regulations affecting your device can be found in the Code of Federal Regulations, Title 21, Parts 800 to 898. In addition, FDA may publish further announcements concerning your device in the Federal Register.

Please be advised that FDA's issuance of a substantial equivalence determination does not mean that FDA has made a determination that your device complies with other requirements of the Act or any Federal statutes and regulations administered by other Federal agencies. You must comply with all the Act's requirements, including, but not limited to: registration and listing (21 CFR Part 807); labeling (21 CFR Part 801); medical device reporting (reporting of medical device-related adverse events) (21 CFR 803); good manufacturing practice requirements as set forth in the quality systems (QS) regulation (21 CFR Part 820); and if applicable, the electronic product radiation control provisions (Sections 531-542 of the Act); 21 CFR 1000-1050.

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If you desire specific advice for your device on our labeling regulation (21 CFR Part 801), please go to http://www.fda.gov/AboutFDA/CentersOffices/CDRH/CDRHOffices/ucm115809.htm for the Center for Devices and Radiological Health's (CDRH's) Office of Compliance. Also, please note the regulation entitled, "Misbranding by reference to premarket notification" (21CFR 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 Small Manufacturers, International and Consumer Assistance at its toll-free number (800) 638 2041 or (301) 796-7100 or at its Internet address http://www.fda.gov/MedicalDevices/Resourcesfor You/Industry/default.htm.

Sincerely yours,

Michael J. O'Hara

Janine M. Morris 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): K123371

Device Name: AlignRT Plus

Indications For Use:

Prescription Use x (Part 21 CFR 801 Subpart D) AND/OR

Over-The-Counter Use (21 CFR 807 Subpart C)

(PLEASE DO NOT WRITE BELOW THIS LINE-CONTINUE ON ANOTHER PAGE IF NEEDED)

Concurrence of CDRH, Office of In Vitro Diagnostics and Radiological Health (OIR)

Michael J. D. O'Hara

Division Sign-Off Office of In Vitro Diagnostic Device Evaluation and Safety

510(k)

Page 1 of

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.