(164 days)
The Qualisys PSA Immunoassay is a paramagnetic particle immunoassay for the in vitro quantitative determination of prostate-specific antigen (PSA) in human serum. The Qualisys PSA Immunoassay is further indicated for the serial measurement of PSA as an aid in the prognosis and management of patients with prostate cancer.
The Qualisys PSA Immunoassay is a two-site chemiluminescense assay. 1st incubation: 15 minutes at room temperature. Specimen, control or calibrator [100 µL] and PSA Antibody Solution [100 µL] react to form a sandwich complex. 2nd incubation: 2 minutes at room temperature. Streptavidin-coated paramagnetic particle solution [25 µL] is added to the reaction mixture. After the 2-minute incubation, the sandwich complex is bound to the solid-phase via the interaction of biotin and streptavidin. Removal of unbound materials: The paramagnetic particles are washed four times with wash buffer [1.0 mL/wash] to remove unbound materials. Re-suspension of paramagnetic particles: Deionized (DI) water [25 uL] is added to re-suspend the washed paramagnetic particles. Substrate addition and detection: Chemiluminogenic substrate [50 uL] is added to the solid-phase bound complex and results in "glow" chemiluminescence, which is measured using a luminometer (photomultiplier). Emission of light is quantified for 1 second, and is expressed in relative light units (RLU). The amount of bound labeled antibody in RLU's is directly proportional to the concentration of PSA in the sample. Results are determined using cubic spline immunoassay curve fitting.
The Qualisys PSA Immunoassay is a device designed for the in vitro quantitative determination of prostate-specific antigen (PSA) in human serum, specifically for the serial measurement of PSA to aid in the prognosis and management of patients with prostate cancer.
Here's an analysis of its acceptance criteria and the supporting study:
1. Table of Acceptance Criteria and Reported Device Performance
The document does not explicitly state "acceptance criteria" in a go/no-go fashion. Instead, it presents performance characteristics for the Qualisys PSA Immunoassay and compares them to the predicate device, Abbott IMx® PSA. For the purpose of this response, the performance characteristics of the Qualisys PSA are considered the reported device performance, and the comparison to the predicate implies that similar or improved performance is an acceptance benchmark for substantial equivalence.
| Feature | Predicate Device (Abbott IMx® PSA) Performance | Qualisys PSA Immunoassay Reported Performance |
|---|---|---|
| Precision | ||
| Intra-assay: Low | 3.5% (at 4.6 ng/mL) | 3.4% (at 0.52 ng/mL) |
| Intra-assay: Med | 3.3% (at 15.6 ng/mL) | 1.7% (at 3.05 ng/mL) |
| Intra-assay: High | 3.1% (at 60.2 ng/mL) | 3.0% (at 23.06 ng/mL) |
| Inter-assay: Low | 4.7% (at 4.6 ng/mL) | 5.7% (at 0.52 ng/mL) |
| Inter-assay: Med | 4.5% (at 15.6 ng/mL) | 2.6% (at 3.05 ng/mL) |
| Inter-assay: High | 5.3% (at 60.2 ng/mL) | 3.7% (at 23.06 ng/mL) |
| Analytical Sensitivity | 0.1 ng PSA/mL | 0.003 ng PSA/mL |
| Functional Sensitivity | Not reported | 0.1 ng PSA/mL |
| Spike Recovery | 91 to 103% | 90 to 110% |
| Dilution Recovery | Not reported | 92 to 108% |
| Method Comparison | (Reference device for comparison) | y = 0.9955x + 0.5185 (r² = 0.9747) vs Abbott IMx® PSA |
| Interfering Substances | No interference up to specific concentrations | Similar or improved interference thresholds |
| High Dose Hook Effect | Not reported | No high dose hook effect up to 1250 ng/mL |
Note: The specific PSA concentrations for the Qualisys precision targets differ from the predicate, making direct percentage comparison difficult without further context on the clinical relevance of those specific concentrations. However, the percentages themselves are in a similar range, indicating comparable precision.
2. Sample Size Used for the Test Set and Data Provenance
- Method Comparison Study: The test set for the method comparison study consisted of n = 108 samples.
- Data Provenance: The document does not specify the country of origin of the data or whether it was retrospective or prospective. Given the nature of a 510(k) submission, it's highly likely to be prospective study data collected to demonstrate device performance.
3. Number of Experts Used to Establish the Ground Truth for the Test Set and Qualifications of Those Experts
This device is an immunoassay for quantitative determination of PSA levels, not an imaging or interpretive device that requires expert review for ground truth. The "ground truth" for the test set in this context refers to the actual PSA concentrations in the samples, which were implicitly determined by the predicate device (Abbott IMx® PSA) that the Qualisys device is being compared against, or by a reference method. The document does not mention experts establishing ground truth in the way described for interpretive medical devices.
4. Adjudication Method for the Test Set
Not applicable. As this is a quantitative immunoassay, there would be no subjective interpretation requiring an adjudication method. The method comparison involves comparing numerical results obtained by the test device against the predicate device.
5. If a Multi-Reader Multi-Case (MRMC) Comparative Effectiveness Study Was Done
No. An MRMC study is relevant for interpretive tasks where multiple readers evaluate cases. This device is a quantitative immunoassay and does not involve human "readers" in the performance assessment in the context of an MRMC study.
6. If a Standalone (i.e., algorithm only without human-in-the-loop performance) Was Done
Yes, the performance characteristics listed (precision, sensitivity, recovery, method comparison, interference, hook effect) are all standalone performance metrics of the Qualisys PSA Immunoassay device itself, independent of human interpretation or intervention beyond performing the assay procedure.
7. The Type of Ground Truth Used
The ground truth for the method comparison study was established by the Abbott IMx® PSA device. The predicate device's measurements served as the reference against which the Qualisys PSA Immunoassay's measurements were compared (y = 0.9955x + 0.5185, r² = 0.9747). For other performance characteristics like precision, sensitivity, and recovery, the "ground truth" refers to the known concentrations of analytes in control samples or spiked samples.
8. The Sample Size for the Training Set
The document does not provide information on a "training set" or sample sizes used for training. Immunoassays are typically developed and validated rather than "trained" in the machine learning sense. The performance characteristics described are related to the analytical validation of the device.
9. How the Ground Truth for the Training Set Was Established
Not applicable. As noted above, immunoassays typically undergo analytical validation rather than machine learning training. Therefore, a "training set" and its associated ground truth establishment method are not relevant in this context.
§ 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.