(163 days)
The MRI Marker is a component device indicated as an accessory for use in conjunction with brachytherapy seed carrier sleeves and radionuclide brachytherapy sources containing one of the following isotopes: Iodine 125 (1851). Palladium 103 (103Pd) or Cesium 131 (131Cs). It is indicated for permanent interstitial implantation in the prostate of patients with confirmed prostatic malignancy.
C4 Imaging's MRI Marker™ consists of a sealed polyether ether ketone (PEEK) polymer capsule containing a cobalt chloride:N-Acetylcysteine (CoCl2:NAC) solution. It is used as an accessory to radionuclide sources (seeds) during prostate brachytherapy procedures. The length of the capsule is 5.5 mm and the diameter is 0.8 mm.
Here's an analysis of the provided text regarding the MRI Marker, addressing your requested information:
1. Table of Acceptance Criteria and Reported Device Performance
The provided text focuses on the safety and effectiveness of the MRI Marker, rather than specific performance metrics against pre-defined acceptance criteria in the traditional sense of diagnostic accuracy or sensitivity/specificity. The criteria are largely related to established medical device standards and the device's intended function.
| Acceptance Criterion (Implicit) | Reported Device Performance |
|---|---|
| Sterilization Efficacy (Sterility Assurance Level - SAL) | Validated to provide a Sterility Assurance Level (SAL) of 10-6 (per ISO 11137). |
| Biocompatibility | Nonirritant, nontoxic, with no concerns for long-term safety (per ISO 10993-1, addressed through in vivo and in vitro tests for irritation, sensitization, cytotoxicity, sub-acute and sub-chronic toxicity, and implantation). Animal testing also indicated a very low potential for toxicity. |
| MRI Safety (Induced Displacement Force, Torque, Heating) | Labeled as MR Conditional. No induced displacement force or torque observed. Not expected to pose a hazard (per ASTM F2052, F2213, F2119, F2182). |
| Radiographic Visualization (MR Imaging) | Phantom prostate imaging testing produced a positive-signal MRI image demonstrating the ability of the MRI Marker to perform the intended use of facilitating localization of adjacent radioactive seeds. |
| Radiographic Visualization (X-ray Imaging) | X-ray imaging of the seeds and MRI Markers loaded in strands and brachytherapy needles demonstrated the MRI Marker performed as intended in effectively spacing the seeds. |
| Effective Spacing of Brachytherapy Seeds | X-ray imaging (as above) demonstrated effective spacing. The device description also states its use as an accessory to maintain spacing between radioactive seeds. |
| Substantial Equivalence to Predicate Devices | The technological characteristics are similar to or equivalent to the predicate devices. Differences in design do not raise new issues of safety and effectiveness. (This is the overarching acceptance criterion for 510(k) clearance). |
2. Sample Size Used for the Test Set and Data Provenance
The document does not specify a distinct "test set" in the context of diagnostic performance (e.g., a specific number of images or patients for evaluation). The performance demonstrations are through:
- Sterilization Validation: No explicit sample size mentioned for this, as it's a validation of a process.
- Biocompatibility Testing: "In vivo and in vitro tests were performed." No specific numbers of samples or animals are provided.
- MRI Safety Testing: No specific sample size mentioned for the devices tested.
- Radiographic Visualization: "Phantom prostate imaging testing" (implies one or more phantoms) and "X-ray imaging of the seeds and MRI Markers loaded in strands and brachytherapy needles." No specific number of phantoms, strands, or needles are given.
- Animal Testing: "Animal testing indicates..." No specific number of animals or data provenance (e.g., country of origin, retrospective/prospective) is provided.
3. Number of Experts Used to Establish the Ground Truth for the Test Set and Qualifications of Those Experts
This information is not provided in the document. The studies described are technical performance tests (e.g., sterilization, biocompatibility, MRI compatibility) and visualization tests using phantoms or animal models, rather than clinical studies requiring expert ground truth for interpretation.
4. Adjudication Method for the Test Set
This information is not applicable/provided as there is no mention of a human-read test set requiring adjudication in the context of the described performance testing.
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
No, an MRMC comparative effectiveness study was not done. The device (MRI Marker) is a physical marker for brachytherapy seeds, not an AI or software algorithm itself that would assist human readers in interpretation.
6. If a Standalone (i.e. algorithm only without human-in-the loop performance) was done
No, a standalone performance study in the context of an algorithm or AI was not done, as the MRI Marker is a physical medical device, not a software algorithm.
7. The Type of Ground Truth Used
The "ground truth" for the various tests was primarily based on:
- Sterilization: Industry standards (ISO 11137) and laboratory verification (e.g., absence of microbial growth).
- Biocompatibility: Established biological endpoints (e.g., absence of irritation, toxicity) as defined by ISO 10993-1 and observed in in-vitro, in-vivo, and animal models.
- MRI Safety: Measurement of physical forces (displacement, torque) and temperature changes according to ASTM standards.
- Radiographic Visualization & Spacing: Direct observation of images (MRI and X-ray) to confirm the presence of a positive signal and appropriate spacing in phantoms and simulated setups.
8. The Sample Size for the Training Set
This information is not applicable/provided. The MRI Marker is a physical device and does not involve AI or machine learning algorithms that would require a training set.
9. How the Ground Truth for the Training Set was Established
This information is not applicable/provided. As above, there is no training set for this device.
§ 892.5730 Radionuclide brachytherapy source.
(a)
Identification. A radionuclide brachytherapy source is a device that consists of a radionuclide which may be enclosed in a sealed container made of gold, titanium, stainless steel, or platinum and intended for medical purposes to be placed onto a body surface or into a body cavity or tissue as a source of nuclear radiation for therapy.(b)
Classification. Class II (special controls). A prostate seeding kit intended for use with a radionuclide brachytherapy source only is exempt from the premarket notification procedures in subpart E of part 807 of this chapter subject to the limitations in § 892.9.