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The TomoTherapy HI-ART System is intended to be used as an integrated system for the planning and delivery of intensity modulated radiation therapy (IMRT) for the treatment of cancer. The HI-ART System provides precise delivery of radiation to tumors while minimizing the delivery of radiation to vital healthy tissue.

The HI-ART System's planning station is intended to be used by the physician/oncologist to prescribe a radiation therapy plan for a particular patient. The HI-ART System then calculates the treatment plan which the physician reviews and approves.

The HI-ART system's operator station and status console is then intended to be used by the therapist to select and implement the patient's treatment plan. The treatment process will begin by performing an MVCT scan (a CT using the onboard linear accelerator as the radiation source). This MVCT image will confirm that the patient's position is correct for the radiation therapy as well as assist in patient re-positioning when necessary. The MVCT image is not for diagnostic use.

When patient positioning is complete, the HI-ART System is then intended to be used by the therapist to confirm the selected treatment plan. The HI-ART System delivers the radiation therapy treatment in accordance with the physician approved plan using IMRT techniques delivered in a helical tomographic pattern.

The TomoTherapy HI-ART System is a radiation therapy system that integrates planning, dose calculation, megavoltage CT scanning, and helical radiation therapy treatment capabilities into a single comprehensive IMRT system.

The HI-ART System's planning station is used by the physician to prescribe and enter the radiation therapy plan. The patient's diagnostic CT image is imported via a DICOM protocol from another diagnostic CT device. The regions of interest, regions to avoid, and other prescribing information are entered in a manner that is similar to other commercially available planning systems.

The HI-ART System utilizes a 6 MV linear accelerator as the radiation source. The linear accelerator along with the primary collimator, multi-leaf collimator (MLC), xenon detector, various control devices and power supplies are mounted on a rotating gantry, much like a CT gantry. During treatment or imaging, the patient is positioned on the couch support, and the couch moves axially through the bore of the gantry, and the radiation is delivered in a helical pattern.

The primary collimator and the MLC control the beam dimensions during radiation delivery so that the range of collimated beam size can vary from 0 to 400 mm wide by 5 to 45 mm at the isocenter. The MLC is constructed of 64 tungsten leaves that open and close as determined by the radiation therapy plan. The intensity of the radiation beam is proportional to the length of time that a particular leaf is open. The opening and closing of various leaves as the radiation is delivered in this helical pattern allows for an IMRT plan to be delivered with precise control. The result is a highly conformal dose to the region of interest with low doses to surrounding healthy tissue.

Because the HI-ART System is operating in a helical mode similar to CT systems, it inherently has the ability to obtain a CT image. The system utilizes the linear accelerator to obtain a megavoltage (MVCT) scan of the region of interest prior to the delivery of radiation therapy. This MVCT image is then used in a non-diagnostic mode to ascertain that the patient is correctly positioned prior to treatment. The radiation dose to the patient from an MVCT scan is comparable to diagnostic CT or portal imaging.

This document describes the TomoTherapy HI-ART System, a radiation therapy system designed for Intensity Modulated Radiation Therapy (IMRT) for cancer treatment. It integrates planning, dose calculation, megavoltage CT scanning (MVCT), and helical radiation therapy.

While the document thoroughly describes the device's intended use, its components, and safety considerations, it does not present specific acceptance criteria or a dedicated study explicitly designed to prove the device meets pre-defined acceptance criteria in the format requested.

Instead, the document focuses on:

• Substantial Equivalence: The 510(k) submission successfully argues that the HI-ART System is substantially equivalent to legally marketed predicate devices, a common regulatory pathway for medical devices.
• Validation and Verification Testing: It generally states that "The HI-ART System was extensively validated for system functionality, including planning, imaging, delivery, database management, DICOM communications, etc. Test tools utilized in this testing included IMRT phantoms, ion chambers and other test phantoms."

Therefore, many of the specific details requested regarding acceptance criteria and study design cannot be extracted from this document. The information provided is at a high level, confirming that validation activities occurred rather than detailing the specific criteria and results of those activities in a structured manner to demonstrate meeting acceptance criteria.

Below is an attempt to structure the available information, with many sections noted as "Not Provided" due to the nature of the submitted document.

1. Table of Acceptance Criteria and Reported Device Performance

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

• Sample Size: Not provided. The document mentions "IMRT phantoms, ion chambers and other test phantoms" were used as test tools, implying inanimate objects rather than patient data for acceptance testing.
• Data Provenance: Not provided. Given the use of phantoms, the concept of "country of origin of the data" or "retrospective/prospective" does not directly apply to the primary validation described in the 510(k). If patient data was used for any part of the "extensive validation," its provenance is not stated.

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

• Not Provided. The validation described appears to rely on physical measurements with phantoms and ion chambers, rather than expert-established ground truth on clinical images or patient data for the acceptance criteria demonstration. Therefore, the number and qualifications of experts for this purpose are not mentioned.

4. Adjudication Method for the Test Set

• Not Applicable / Not Provided. Since the described validation primarily involves physical measurements using phantoms and instruments, and not, for example, image interpretation requiring expert consensus, an adjudication method for a test set is not relevant or described.

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

• Not done (or not described). The document does not mention any MRMC study comparing human readers with and without AI assistance. The HI-ART system is a radiation delivery system, and its MVCT imaging component is explicitly stated as "not for diagnostic use," suggesting it's not primarily an AI-driven diagnostic imaging interpretation device that would typically undergo MRMC studies for reader improvement.

6. Standalone Performance Study

• Implied, but details not provided. The general statement "The HI-ART System was extensively validated for system functionality" suggests that the system's various modules (planning, imaging, delivery, etc.) were tested for their inherent performance. However, specific standalone performance metrics or studies are not detailed in the document. The validation description focuses on the integrated system's functionality rather than a specific "algorithm only" component.

7. Type of Ground Truth Used

• Physical Measurements / Reference Standards. For the validation noted, the ground truth would be based on the known properties and responses of "IMRT phantoms, ion chambers and other test phantoms," which serve as reference standards for dose delivery accuracy, beam characteristics, and imaging fidelity (though the MVCT is non-diagnostic). It is not expert consensus, pathology, or outcomes data.

8. Sample Size for the Training Set

• Not Applicable / Not Provided. The TomoTherapy HI-ART System, as described, is a complex integrated hardware and software system for radiation therapy delivery. It's not presented as a machine learning or AI algorithm that undergoes "training" in the typical sense with a "training set" of data to learn patterns. Its functionality is based on physics models, control systems, and deterministic algorithms.

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

• Not Applicable / Not Provided. As the system is not described as involving a machine learning "training set," the concept of establishing ground truth for such a set is not relevant to the information provided.

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