(340 days)
The MammoSite Radiation Therapy System is intended to provide brachytherapy when the physician chooses to deliver intracavitary radiation to the surgical margins following lumpectomy for breast cancer.
The MammoSite™ RTS is a radiation therapy system that includes the MammoSite RTS Catheter Tray and the MammoSite HDR Afterloader Accessories Tray. The MammoSite RTS Catheter Tray includes the MammoSite catheter and accessories to assist with the implantation of the catheter. The MammoSite catheter is a shaft with an inflatable balloon that positions the radiation source within the resected cavity for radiation delivery. The MammoSite is a variable 4 cm - 5 cm spherically inflated balloon. The MammoSite Afterloader Accessories Tray contains the items needed to connect the afterloader to the MammoSite RTS.
Here's an analysis of the provided text regarding the MammoSite™ Radiation Therapy System (RTS) and its clinical study, organized according to your requested criteria:
Device: MammoSite™ Radiation Therapy System (RTS)
Intended Use: The MammoSite Radiation Therapy System is intended to provide brachytherapy when the physician chooses to deliver intracavitary radiation to the surgical margins following lumpectomy for breast cancer.
1. Table of Acceptance Criteria and Reported Device Performance
The provided document (510(k) Summary) is for a substantial equivalence determination, not a post-market performance report. Therefore, it does not explicitly define quantitative "acceptance criteria" in terms of specific performance metrics (like sensitivity, specificity, accuracy, or reduction in recurrence rates with specific thresholds) that the device must meet, nor does it provide a direct table of these criteria alongside reported device performance against those specific numbers.
Instead, the implied acceptance criterion for this 510(k) submission is to demonstrate safety and effectiveness equivalent to predicate devices for its intended use.
The device performance is reported qualitatively:
| Criterion Type | Acceptance Criteria (Implied) | Reported Device Performance |
|---|---|---|
| Safety | No new safety concerns compared to predicate devices. | - Biocompatibility testing demonstrated materials meet requirements. |
- Animal studies illustrated successful delivery of a clinical dose of brachytherapy.
- Clinical study evaluated safety; "Brachytherapy was successfully delivered to all patients."
- No new questions about safety identified.
- FDA added a warning regarding unestablished safety/effectiveness for replacement of whole breast irradiation in the treatment of breast cancer. |
| Effectiveness (Clinical) | Equivalent clinical performance for delivering brachytherapy to surgical margins following lumpectomy for breast cancer, compared to predicate devices. | - "Brachytherapy was successfully delivered to all patients." - "The clinical study demonstrated that the MammoSite RTS is intended to provide brachytherapy when the physician chooses to deliver intracavitary radiation to the surgical margins following lumpectomy for breast cancer."
- "Could deliver an equivalent radiation dose to current brachytherapy applicators" (based on dosimetry characterization). |
| Technological Equivalence | Similar technological characteristics, materials, dimensions, and method of application to predicate devices. | - "MammoSite has the same intended use, similar technological characteristics, and similar materials/dimensions of the predicates." - Compared implant duration, target sites, component materials and dimensions, radionuclide source, and clinical usage.
- "Utilize 1921 seed or ribbon as the radiation source with similar dosimetric properties."
- "Differences do not affect safety or effectiveness." |
| Pre-clinical Performance | Catheter, accessories, and packaging perform as intended under simulated use and challenge conditions. | - "In vitro laboratory studies to demonstrate that the MammoSite catheter, its accessories and packaging performed as intended under simulated use and challenge conditions." |
2. Sample Size Used for the Test Set and Data Provenance
- Sample Size: The document states that a "multi-center phase II clinical study was conducted." It indicates that "all patients" (implied, the patients in this study) successfully received brachytherapy, and a "complete clinical summary including data analysis and individual patient data was provided to FDA." However, the exact number of patients (sample size) in this multi-center phase II clinical study is not explicitly stated in the provided 510(k) summary.
- Data Provenance: The study was a "multi-center phase II clinical study." Given the applicant's address (Alpharetta, GA, USA) and the FDA approval, it is highly probable the centers were primarily in the United States. The study was prospective as it "included breast cancer patients who were undergoing tumor resection" and evaluated safety and effectiveness based on radiological and clinical measures post-treatment.
3. Number of Experts Used to Establish the Ground Truth for the Test Set and Qualifications
The document does not specify the number or qualifications of experts used to establish a "ground truth" for the test set in the way one might for an imaging algorithm studying diagnostic accuracy.
For this device, the "ground truth" or primary outcome measures were related to the delivery of radiation therapy and patient outcomes (safety and effectiveness). These would typically be assessed by:
- Treating physicians (e.g., radiation oncologists, surgeons) at the clinical sites for successful delivery and clinical measures.
- Radiologists for radiological assessments.
- Pathologists for initial tumor resection confirmation (though not directly for device performance evaluation in the clinical study).
The document states, "Assessment methods used to evaluate safety and effectiveness included radiological and clinical measures." This implies a standard clinical evaluation by the attending medical staff, rather than a separate "ground truth panel" for retrospective assessment as might be seen for AI diagnostic devices.
4. Adjudication Method for the Test Set
The document does not describe an explicit adjudication method for the test set outcomes (e.g., 2+1, 3+1 consensus). Clinical studies of this nature typically rely on individual site investigators' assessments and then aggregate data. If discrepancies arose in clinical data reporting, they would usually be handled by a clinical review committee (e.g., Data Safety Monitoring Board or study principal investigators), but this is not detailed in the summary.
5. If a Multi-Reader Multi-Case (MRMC) Comparative Effectiveness Study Was Done, and Effect Size
No, an MRMC comparative effectiveness study was not done.
MRMC studies typically compare human reader performance (with or without AI assistance) in tasks like diagnosis or detection using a specific set of cases. The MammoSite RTS is an interventional device for delivering brachytherapy, not a diagnostic or screening tool. The clinical study evaluated the device's ability to safely and effectively deliver radiation, not how human readers interpret images.
6. If a Standalone (i.e., algorithm only without human-in-the-loop performance) Was Done
No, a standalone algorithm performance study was not done.
The MammoSite RTS is a physical medical device (catheter and accessories) used to deliver radiation, not an algorithm or AI software intended to perform a task independently. Its "performance" inherently involves human-in-the-loop (physician-guided implantation and radiation delivery).
7. The Type of Ground Truth Used
The "ground truth" in this context refers to the ultimate determination of safety and effectiveness as evaluated in the clinical trial. This would implicitly be based on:
- Clinical Outcomes/Measures: Direct observation of successful brachytherapy delivery, patient safety profiles (adverse events), and response to treatment as determined by treating physicians and follow-up.
- Radiological Measures: Imaging studies (e.g., mammograms, ultrasound, MRI) to assess the treated area, cavity size, and recurrence (or lack thereof) during follow-up.
- Dosimetry Characterization: For the pre-clinical phase, physical measurements and calculations confirmed the delivered radiation dose, which forms a basis for effectiveness.
It is not based on:
- Expert consensus (in the sense of a panel reviewing diagnostic images).
- Pathology (as in determining a diagnosis from tissue, though pathology of the initial lumpectomy would define the patient population).
- Outcomes data specific to a pre-defined "gold standard" for AI, but rather broad patient outcome data.
8. The Sample Size for the Training Set
Not applicable.
The MammoSite RTS is a physical medical device. It does not involve a "training set" in the context of machine learning algorithms. The preclinical and clinical studies were designed to validate the device's performance and safety, not to train an algorithm.
9. How the Ground Truth for the Training Set Was Established
Not applicable.
As there is no "training set" for an algorithm associated with this physical device, there is no ground truth established for it in that sense.
§ 892.5700 Remote controlled radionuclide applicator system.
(a)
Identification. A remote controlled radionuclide applicator system is an electromechanical or pneumatic device intended to enable an operator to apply, by remote control, a radionuclide source into the body or to the surface of the body for radiation therapy. This generic type of device may include patient and equipment supports, component parts, treatment planning computer programs, and accessories.(b)
Classification. Class II.