(30 days)
The PSA method for the Dimension® RxL with the heterogeneous immunoassay module is a device used to measure PSA in serum as an aid in the management of prostate cancer patients.
The PSA method is a one-step enzyme immunoassay. Sample is incubated with chromium dioxide particles (CrO2) coated with monoclonal antibodies specific for a binding site on the PSA molecule and conjugate reagent [β-galactosidase (β-gal) labeled monoclonal antibodies specific for a second binding site on the PSA molecule] to form a particle/PSA/conjugate sandwich. Unbound conjugate and analyte are removed by magnetic separation and washing. The sandwich bound ß-gal catalyzes the hydrolysis of chlorophenol red-β-d galactopyranoside (CPRG) to chlorophenol red (CPR). The color change measured at 577nm due to the formation of CPR is directly proportional to the concentration of PSA present in the patient sample.
Here's a breakdown of the acceptance criteria and study details for the Dade International Prostate Specific Antigen (PSA) Method, based on the provided document:
Acceptance Criteria and Reported Device Performance
The core of the acceptance criteria for this 510(k) submission is substantial equivalence to the predicate device, the aca® plus PSA Test Kit. This is primarily demonstrated by a strong correlation in performance.
| Acceptance Criteria (Implicit for Substantial Equivalence) | Reported Device Performance (Dimension® RxL PSA vs. aca® plus PSA) |
|---|---|
| High correlation coefficient | 0.994 |
| Slope close to 1 | 1.06 ± 0.01 |
| Intercept close to 0 | -0.07 ± 0.14 ng/mL |
| Consistent results across healthy and disease states | Compared well in all healthy and disease state categories. Data consistent with clinical status. |
Study Details
2. Sample size used for the test set and the data provenance:
- Sample Size: 596 clinical patient samples.
- Data Provenance: The document does not explicitly state the country of origin. It refers to "clinical patient samples," implying real-world patient data. Given the submitter's location (Newark, DE, USA) and the FDA submission, it's highly probable the data is from the USA. The study design is retrospective as it involves "split sample comparison," meaning existing samples were tested on both devices.
3. Number of experts used to establish the ground truth for the test set and the qualifications of those experts:
- The document does not mention a number of experts or their qualifications for establishing ground truth. The "ground truth" in this context is implicitly the measurement from the predicate device (
aca® plus PSA Test Kit). The comparative study focuses on the agreement between the new device and the predicate device.
4. Adjudication method for the test set:
- None explicitly stated in the context of expert adjudication. The study is a direct comparison of results between two devices on the same samples.
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. This is an in vitro diagnostic (IVD) device for quantitative measurement, not an imaging device or one that involves human (reader) interpretation in the same way an AI-assisted diagnostic tool might. The "readers" here are laboratory instruments, and the comparison is between the instrument's output.
6. If a standalone (i.e. algorithm only without human-in-the-loop performance) was done:
- Yes, the performance described is a standalone performance study. The device (Dimension® RxL PSA method) directly measures PSA levels. The comparison is between the output of this automated method and the output of the predicate automated method, without any human 'in-the-loop' interpretation influencing the quantitative result.
7. The type of ground truth used:
- The ground truth used for performance comparison is the results obtained from the legally marketed predicate device, the aca® plus PSA Test Kit. This is a common method for demonstrating substantial equivalence for IVDs. The "clinical status of the patient" is mentioned as being consistent with the data, but the primary ground truth for the statistical comparison is the predicate's measurement.
8. The sample size for the training set:
- The document does not mention a separate training set. As this is an immunoassay (chemical detection) method, rather than a machine learning/AI algorithm, the concept of a "training set" for the device itself is not directly applicable in the same way it would be for an AI-based diagnostic. The device's operational parameters and calibration would be established through internal development and validation, but this document focuses on its performance using a clinical test set against a predicate.
9. How the ground truth for the training set was established:
- Not applicable in the context of a "training set" for an AI algorithm. For the development and internal validation of the immunoassay method, the ground truth would typically be established through highly characterized reference materials, spiked samples, and potentially clinical samples with established PSA levels using recognized reference methods or established assays. However, this level of detail is not provided in a 510(k) summary for an immunoassay.
§ 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.