(64 days)
The intended use of ACS:Centaur AFP Immunoassay is for the quantitative determination of alpha-fetoprotein (AFP) in the following:
- human serum and in amniotic fluid from specimens obtained at 15 to 20 weeks gestation, * as an aid in detecting open neural defects (NTD) when used in conjunction with ultrasonography and amniography testing,
- human serum, as an aid in managing non-seminomatous testicular cancer when used in * conjunction with physical examination, histology/pathology, and other clinical evaluation procedures, using the Chiron Diagnostics ACS:Centaur Automated Chemiluminescence System.
The Chiron Diagnostics ACS:Centaur AFP immunoassay is a two-site immunoassay using direct chemiluminometric technology, which uses constant amounts of two antibodies. The first antibody, in the Lite Reagent, is a purified polyclonal rabbit anti-AFP antibody labeled with acridinium ester. The second antibody, in the Solid Phase, is a monoclonal mouse anti-AFP antibody covalently coupled to paramagnetic particles. A direct relationship exists between the amount of AFP present in the patient sample and the amount of relative light units (RLU's) detected by the system.
Here's an analysis of the provided text regarding the acceptance criteria and the study proving the device meets them:
1. Table of Acceptance Criteria and Reported Device Performance
| Acceptance Criterion | Reported Device Performance |
|---|---|
| Sensitivity (Minimum Detectable Concentration) | 1.3 ng/mL |
| Accuracy (Correlation with Predicate Device ACS:180 AFP) | ACS:Centaur AFP = 1.05 (ACS:180 AFP) = - 0.3 ng/mL |
| Correlation Coefficient (r) | 0.99 |
2. Sample Size Used for the Test Set and Data Provenance
- Sample Size: 498 serum samples
- Data Provenance: Not specified (e.g., country of origin, retrospective or prospective).
3. Number of Experts Used to Establish the Ground Truth for the Test Set and Qualifications of Those Experts
The provided summary does not explicitly state the number of experts or their qualifications used to establish ground truth for the test set. The accuracy is reported as a correlation with a predicate device (ACS:180 AFP). This suggests that the "ground truth" for the test set was the results obtained from the predicate device, rather than a separate expert-driven ground truth establishment process.
4. Adjudication Method for the Test Set
No adjudication method is mentioned. The comparison is directly between the new device's readings and the predicate device's readings.
5. If a Multi-Reader Multi-Case (MRMC) Comparative Effectiveness Study Was Done, and the Effect Size of How Much Human Readers Improve with AI vs Without AI Assistance
This information is not applicable. The device described (ACS:Centaur AFP Immunoassay) is a standalone diagnostic assay, not an AI-assisted interpretation tool for human readers. Therefore, no MRMC study or AI assistance effect size is relevant here.
6. If a Standalone (i.e., algorithm only without human-in-the-loop performance) Was Done
Yes, a standalone performance assessment was done. The reported performance metrics (sensitivity, accuracy, correlation coefficient) are for the device (immunoassay system) operating independently to measure AFP concentration. There is no human-in-the-loop component described for these performance evaluations.
7. The Type of Ground Truth Used
The ground truth for the accuracy assessment was the results obtained from the predicate device, ACS:180 AFP Immunoassay. The study is essentially a comparison of the new device's measurements against an established, legally marketed device's measurements, assuming the predicate device provides a reliable measure of AFP.
8. The Sample Size for the Training Set
The document does not specify a training set or its sample size. This type of immunoassay development typically involves initial analytical validation and calibration, but the provided summary focuses on the performance comparison with the predicate device, which is more akin to a clinical validation set.
9. How the Ground Truth for the Training Set Was Established
Since no explicit training set is detailed, the method for establishing its ground truth is not provided. For an immunoassay, the "training" aspect would generally involve calibrating the system using known concentrations of AFP and optimizing reagents/protocols. The ground truth for this would be the known, prepared concentrations of AFP standards. However, the document doesn't detail this process.
§ 866.6010 Tumor-associated antigen immunological test system.
(a)
Identification. A tumor-associated antigen immunological test system is a device that consists of reagents used to qualitatively or quantitatively measure, by immunochemical techniques, tumor-associated antigens in serum, plasma, urine, or other body fluids. This device is intended as an aid in monitoring patients for disease progress or response to therapy or for the detection of recurrent or residual disease.(b)
Classification. Class II (special controls). Tumor markers must comply with the following special controls: (1) A guidance document entitled “Guidance Document for the Submission of Tumor Associated Antigen Premarket Notifications (510(k)s) to FDA,” and (2) voluntary assay performance standards issued by the National Committee on Clinical Laboratory Standards.