(58 days)
The TomoTherapy Treatment System is intended to be used as an integrated system for the planning and precise delivery of radiation therapy, stereotactic radiotherapy, or stereotactic radiosurgery to tumors or other targeted tissues while minimizing the delivery of radiation to vital healthy tissue. The megavoltage x-ray radiation is delivered in a rotational, non-rotational, modulated (IMRT), or non-modulated (non-IMRT/three dimensional conformal) format in accordance with the physician approved plan.
The TomoTherapy Treatment System is a radiation therapy system that integrates planning, dose calculation, megavoltage CT imaging for IGRT functionality, and helical (rotational) and fixed beam (non-rotational) radiation therapy treatment capabilities into a single comprehensive system. The TomoTherapy Treatment System is a prescription device. It delivers radiation in accordance with a physician approved plan. The device does not diagnose disease, recommend treatment regimens, or quantify treatment effectiveness. The megavoltage CT imaging functionality is not intended for diagnostic use.
The provided text describes the Accuray TomoTherapy Treatment System (K121934), a radiation therapy system. It is a 510(k) submission, indicating that the device is seeking clearance based on its substantial equivalence to a predicate device.
Here's an analysis of the acceptance criteria and study information provided (or lacking thereof, as is common in 510(k)s for certain types of devices):
1. Table of Acceptance Criteria and Reported Device Performance
| Acceptance Criteria | Reported Device Performance |
|---|---|
| Safety Standards Compliance | The TomoTherapy Treatment System was tested and shown to be in compliance with the requirements of applicable recognized consensus safety standards for medical devices. |
| Design Specifications | Results of verification and validation testing confirm the TomoTherapy Treatment System conforms to design specifications. |
| User Needs | Results of verification and validation testing confirm the TomoTherapy Treatment System meets the needs of the intended users. |
| Substantial Equivalence | The TomoTherapy Treatment System is substantially equivalent to the predicate device (TomoTherapy Treatment System (K112776)). Its performance data demonstrate it is as safe, as effective, and performs as well as the predicate device. Minor technological differences (enhancements to software for asymmetric positions and dynamic motion of the primary beam limiting device) do not raise new types of safety or effectiveness questions. |
2. Sample Size Used for the Test Set and Data Provenance
The submission states, "No clinical tests were required to establish substantial equivalence." This implies that the performance data primarily relied on non-clinical testing (bench testing, verification, and validation) rather than testing on patient data sets. Therefore, there is no specific sample size for a test set (e.g., patient images or clinical cases) detailed in this submission. The data provenance would be related to the internal testing environment rather than patient data.
3. Number of Experts Used to Establish Ground Truth for the Test Set and Qualifications of those Experts
Given that "No clinical tests were required," there is no mention of experts establishing ground truth for a clinical test set. The substantial equivalence is based on engineering and performance validation against internal specifications and consensus standards, rather than expert-adjudicated clinical outcomes or interpretations.
4. Adjudication Method for the Test Set
As there was no clinical test set requiring expert interpretation, no adjudication method is described.
5. Multi-Reader Multi-Case (MRMC) Comparative Effectiveness Study
No MRMC comparative effectiveness study was mentioned. The device is a radiation therapy system, not a diagnostic imaging device that typically undergoes MRMC studies to evaluate human reader performance with or without AI assistance. The focus here is on the system's ability to plan and deliver radiation accurately and safely, comparable to its predicate.
6. Standalone (Algorithm Only Without Human-in-the-Loop Performance) Study
The document describes the "TomoTherapy Treatment System" as an integrated system, highlighting its planning, dose calculation, and delivery capabilities. Its functions include IGRT (image-guided radiation therapy), which inherently involves a human (e.g., physician, dosimetrist, radiation therapist) in planning and overseeing the treatment. While the software has algorithmic components, the system itself is not purely "standalone" in the AI sense, as it requires human input and clinical judgment for its intended use. The performance data presented refers to the system's compliance with safety standards and design specifications, which would include the performance of its software algorithms within the integrated system, but it's not a "standalone algorithm-only" study in the context of diagnostic AI.
7. Type of Ground Truth Used
For a radiation therapy delivery system, the "ground truth" for non-clinical performance studies would likely be:
- Engineering specifications and design requirements: The system's output (e.g., radiation dose, beam shape, image acquisition parameters) must match predetermined, validated specifications.
- Physical measurements: Using phantoms and dosimeters to verify the accuracy of dose delivery and image quality.
- Compliance with recognized consensus safety standards: Demonstrating adherence to established industry-wide safety and performance metrics (e.g., IEC standards for medical electrical equipment, specific standards for radiation therapy devices).
8. Sample Size for the Training Set
The document does not provide information on a training set sample size. This type of device relies on physics-based models and validated algorithms rather than machine learning models trained on large datasets in the way typical AI/ML devices might. The software enhancements mentioned (asymmetric positions and dynamic motion of the primary beam limiting device) are likely based on deterministic algorithms and physical principles, thoroughly verified, rather than deep learning models requiring extensive training data.
9. How the Ground Truth for the Training Set Was Established
As there's no mention of a training set for machine learning, this information is not applicable or provided. The "ground truth" for the development and verification of the system's physics-based algorithms and control software would be derived from fundamental principles of radiation physics, medical imaging, and robust engineering validation processes.
§ 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.