(28 days)
The Varian Head Frame System is for use with a computed tomography scanner to perform imaging for treatment planning and a charged particle accelerator to perform immobilization of the treatment target for stereotactic radiosurgery or radiotherapy treatments on cranial lesions, tumors and conditions where radiation treatment is indicated.
The Head Frame provides rigid immobilization of a patient's skull by attaching a rigid halo (head frame) to the patient through four invasive contact points (called screws or pins) which penetrate the patient's skin and contact the bone of the skull. The head frame is secured to either the CT table or the treatment table via a bracket which is included in the system. This ensures the patient cannot easily move during imaging or treatment. This level of immobilization is generally used for stereotactic radiosurgery.
The provided text does not contain information about acceptance criteria or a study that proves the device meets those criteria, as typically seen for AI/ML-enabled devices. This document is a 510(k) premarket notification for a Varian Head Frame, which is a physical medical device used for patient immobilization during radiation therapy.
Therefore, many of the requested categories in the prompt, such as "effect size of how much human readers improve with AI vs without AI assistance," "standalone (algorithm only without human-in-the-loop performance)," and information about training/test set sample sizes for algorithms, are not applicable to this submission.
The document discusses performance testing in terms of conformance to requirements specifications, hazard safeguards, and cleaning/sterilization validation. It also explicitly states: "Clinical Tests No clinical tests have been included in this pre-market submission".
Here's an attempt to fill in the requested information based on the provided text, indicating where information is not applicable or not found:
Acceptance Criteria and Study Details for Varian Head Frame (K180586)
1. Table of Acceptance Criteria and Reported Device Performance
| Acceptance Criteria (What the device aims to achieve) | Reported Device Performance (How the device met the criteria) |
|---|---|
| Rigid immobilization of a patient's skull. | Device provides rigid immobilization by attaching a rigid halo to the patient through four invasive contact points. |
| Securement to CT or treatment table. | Head frame secured to either the CT table or the treatment table via a bracket. |
| Prevention of patient movement during imaging or treatment. | Ensures the patient cannot easily move during imaging or treatment. |
| Compatibility with CT scanners. | "CT compatible." |
| Effective cleaning processes for reuse. | Validated outlined cleaning procedures for Head Frame and Posts. |
| Effective sterilization processes for reuse. | Validated outlined sterilization procedures for Cranial pins, Head Frame, and Posts. |
| Durability for reprocessing. | Head Frame ring can be reprocessed up to 60 cycles; posts up to 286 cycles. |
| Conformance to applicable requirements specifications. | "Results of verification and validation testing showed conformance to applicable requirements specifications." |
| Assured hazard safeguards function properly. | "Assured hazard safeguards functioned properly." |
2. Sample size used for the test set and the data provenance
- Not Applicable. This is a physical device, not an AI/ML algorithm that uses a "test set" of data in the common sense. Performance was assessed through engineering verification and validation testing, including cleaning, sterilization, and reprocessing studies, not on patient data test sets.
3. Number of experts used to establish the ground truth for the test set and the qualifications of those experts
- Not Applicable. Ground truth in the context of expert review for medical image analysis is not relevant here. The ground truth for performance was established through engineering tests measuring physical properties, durability, and effectiveness of cleaning/sterilization protocols.
4. Adjudication method (e.g. 2+1, 3+1, none) for the test set
- Not Applicable. Not relevant for the type of testing performed for this physical device.
5. If a multi reader multi case (MRMC) comparative effectiveness study was done, If so, what was the effect size of how much human readers improve with AI vs without AI assistance
- Not Applicable. This device is a physical head frame, not an AI assistance tool for human readers. No MRMC study was performed.
6. If a standalone (i.e. algorithm only without human-in-the-loop performance) was done
- Not Applicable. This is a physical device, not an algorithm.
7. The type of ground truth used (expert consensus, pathology, outcomes data, etc.)
- The ground truth for this device's performance was established through:
- Engineering specifications and standards: The device's physical properties, materials, and mechanical functions were verified against established performance requirements.
- Laboratory testing: Specifically for cleaning, sterilization, and reprocessing, where established protocols and efficacy metrics (e.g., microbial reduction, material degradation) would serve as the ground truth.
8. The sample size for the training set
- Not Applicable. This is a physical device; there is no "training set" in the context of machine learning.
9. How the ground truth for the training set was established
- Not Applicable.
Summary of Non-Clinical Testing Performed:
The submission highlights "verification and validation testing" demonstrating conformance to requirements and proper function of hazard safeguards. It also specifically mentions:
- Cleaning, sterilization, and reprocessing testing which validated procedures.
- Demonstrating that the Head Frame ring can be reprocessed up to 60 cycles and posts up to 286 cycles.
The document explicitly states "No clinical tests have been included in this pre-market submission." Therefore, the "study" proving the device meets criteria is a collection of non-clinical, engineering, and laboratory-based verification and validation tests against established performance specifications and recognized standards (listed in the document such as IEC 62366, ISO 10993, AAMI standards).
§ 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.