(42 days)
The system is intended for use in radiation therapy clinics together with diagnostic or treatment equipment and provides: · accurate and reproducible patient positioning. • a respiratory signal to be supplied to diagnostic imaging equipment (primarily CTs) for prospectively (aka 4DCT) gated imaging and reconstruction. The system cannot directly determine the intended treatment target, since only the patient external surface is detected. The actual target position must therefore, whenever deemed necessary by qualified personnel, be verified using other systems such as CBCT or EPID.
The Sentinel hardware consists of a single scanner unit containing the laser and camera, mounted in the ceiling in front of the CT. The scanner is connected to the PC running the c4D software. During patient surface acquisition, a laser line is swept along the patient while the camera records a number of images. From the data acquired, a complete 3D surface of the patient can be reconstructed using laser line triangulation. On this surface the user, a health care professional, virtually marks where on the patient the respiratory motion signal shall be measured and in the next step, when the 4DCT imaging starts, the signal is measured with a frequency of around 16Hz. In general, the system is capable of acquiring more than 50 contours per second. The acquired 3D surface can also be exported and used as a reference image in the treatment room. The Sentinel system for the CT room is used in radiation therapy clinics to perform prospective or retrospective gated imaging (4DCT) prior to treatment. The system provides information about a patient's respiratory motion during the localization of the tumour in CT imaging. The system shall only be used by hospital personnel, qualified to work in radiation therapy or diagnostics departments. The Sentinel platform is based on advanced laser technology with multipurpose software modules covering different tasks in the diagnostic procedure. The software is user friendly and requires a minimum of user interaction in the daily clinical workflow. The software is designed to integrate with existing CT systems at the clinic. The Sentinel system does not require any markers to be placed on the patient or the couch and doesn't subject the patient to any additional radiation. This also means that the personnel can stay in the CT room during the whole set up procedure. Sentinel for the CT room includes the cRespiration module for respiratory gating during diagnostic CT imaging, so called 4D CT studies.
Here's a breakdown of the acceptance criteria and study information, based on the provided document:
1. Table of Acceptance Criteria and Reported Device Performance
The provided document (a 510(k) summary) does not explicitly list quantitative acceptance criteria in a table format with specific performance metrics for the Sentinel system or its cRespiration module. It makes a general statement about safety and effectiveness.
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Acceptance Criteria (Implied): The device Sentinel, in particular its cRespiration module, should:
- Provide "accurate and reproducible patient positioning."
- Deliver "a respiratory signal to be supplied to diagnostic imaging equipment (primarily CTs) for prospectively and retrospectively (aka 4DCT) gated imaging and reconstruction."
- Be substantially equivalent to its predicate device (Sentinel K120668) in terms of technological characteristics, safety, and efficacy.
- Not introduce new issues of safety or efficacy due to software update (64-bit architecture) and rephrasing of intended use.
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Reported Device Performance:
- "The system is capable of acquiring more than 50 contours per second."
- Respiratory signal measured with a frequency of around 16Hz.
- Allows for two detection points for thoracic and abdominal breathing motions.
- Functionality of the software with respect to 64-bit support is unchanged.
- "Performance data has been submitted to show that Sentinel achieves its intended use and that the software update and rephrasing of intended use raise no new issues of safety or efficacy." (This is a general statement, not specific quantitative performance data in the document itself).
2. Sample Size Used for the Test Set and Data Provenance
The provided document does not specify the sample size used for the test set or the data provenance (e.g., country of origin, retrospective/prospective). It only mentions that "re-verification has been performed to verify that the design outputs meets the design inputs after the change from 32-bit to 64-bit support."
3. Number of Experts Used to Establish Ground Truth and Qualifications
The document does not provide details on the number of experts, their qualifications, or how they were used to establish ground truth for testing. It states that "the actual target position must therefore, whenever deemed necessary by qualified personnel, be verified using other systems such as CBCT or EPID," implying that qualified personnel are involved in clinical use and verification but not necessarily for structured testing with ground truth establishment.
4. Adjudication Method
The document does not mention any adjudication methods (e.g., 2+1, 3+1) for establishing ground truth in a test set.
5. Multi-Reader Multi-Case (MRMC) Comparative Effectiveness Study
The document does not mention a multi-reader multi-case (MRMC) comparative effectiveness study, nor does it provide any information on the effect size of human readers improving with AI vs. without AI assistance. The device in question is a positioning and respiratory gating system, not an AI-based diagnostic tool for interpretation.
6. Standalone (Algorithm Only Without Human-in-the-Loop Performance) Study
The document focuses on the system's capabilities (acquiring contours, measuring respiratory signals) and its integration into the clinical workflow, which inherently involves human interaction. It does not present data relevant to a standalone algorithm-only performance study. The system provides signals and positioning information to human professionals and other diagnostic equipment.
7. Type of Ground Truth Used
The document does not explicitly state the type of ground truth used for testing. For its intended use of patient positioning and respiratory signal provision, ground truth would likely involve highly accurate measurements from other, established systems (e.g., precise physical measurements, data from other high-accuracy imaging modalities or motion tracking systems) against which the Sentinel system's output is compared.
8. Sample Size for the Training Set
The document does not provide the sample size for the training set. Given that this is a premarket notification for a predicate device with a software update and rephrased intended use, it's possible that extensive de novo training data for a machine learning model, as would be required for a distinctly AI device, was not the primary focus of this submission. The "re-verification" mentioned suggests testing against design inputs rather than extensive new machine learning model training.
9. How the Ground Truth for the Training Set Was Established
The document does not provide information on how ground truth was established for any training set.
§ 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.