(72 days)
Use of the Axxent Radiation Shield - Rigid is indicated in cases in which protection of tissue and/or organs from x-radiation is desired. The Axxent Radiation Shield - Rigid can be used externally and internally, such as during intraoperative radiation therapy (IORT) when the treatment site is exposed surgically.
The Axxent Radiation Shield - Rigid is an optional radiation shielding accessory to the Axxent Electronic Brachytherapy System (cleared under K072683) intended to protect tissue and/or organs from unwanted radiation. It is a rigid stainless steel pad placed over the area requiring shielding. It can be used on external patient surfaces, such as skin, as well internally during Intraoperative Radiation Therapy (IORT).
The Axxent Radiation Shield - Rigid is fabricated entirely from 316L stainless steel (UNS S31603, ASTM A240/A240M). The shield is available in circular and ellipsoidal shapes in a range of various sizes.
The Axxent Radiation Shield - Rigid is provided non-sterile and can be reused. The user must sterilize the device using steam sterilization before each use.
Here's an analysis of the provided text regarding the Axxent® Radiation Shield - Rigid, focusing on acceptance criteria and the study that proves the device meets those criteria:
Acceptance Criteria and Device Performance Study for Axxent® Radiation Shield - Rigid
This 510(k) summary (K111299) describes the Axxent® Radiation Shield - Rigid, an accessory for the Axxent Electronic Brachytherapy System. The submission aims to demonstrate substantial equivalence to a predicate device.
1. Table of Acceptance Criteria and Reported Device Performance
The provided document doesn't explicitly list "acceptance criteria" for performance in a tabular format with corresponding "reported device performance." Instead, it highlights key performance characteristics tested against general safety and effectiveness principles and comparison to the predicate device. However, based on the Performance Testing section and the comparison table, we can infer the following:
| Acceptance Criterion (Inferred) | Reported Device Performance |
|---|---|
| Radiation Attenuation (at 50kVp) | Greater than 99% |
| Durability (Cleaning & Sterilization Cycles) | Withstands at least 50 cycles |
| Material Shedding | Did not shed material during worst-case clinical usage |
| Lead Equivalency (for comparison to predicate) | Not less than 0.20 mm at 50 kVp |
2. Sample Size Used for the Test Set and Data Provenance
- Sample Size: The document does not specify the exact sample sizes for each performance test (attenuation, durability, material shedding). It mentions "the Axxent Radiation Shield - Rigid" in singular, implying representative samples were used for testing.
- Data Provenance: The document does not explicitly state the country of origin of the data or whether the studies were retrospective or prospective. Given it's a 510(k) submission for device clearance, the testing would be prospective, conducted by the manufacturer, Xoft, an iCAD Company, located in Sunnyvale, CA, USA.
3. Number of Experts Used to Establish the Ground Truth for the Test Set and Qualifications
This type of information (number of experts, their qualifications, and ground truth establishment) is typically relevant for studies involving human interpretation (e.g., image analysis for diagnostics). For a physical medical device like a radiation shield, "ground truth" is established through objective physical measurements and engineering tests using calibrated equipment and standard methodologies, not through expert consensus in the traditional sense. Therefore, this section is not applicable in the context of this device's performance testing.
4. Adjudication Method for the Test Set
As explained above, since the performance tests are based on objective physical measurements and engineering tests, an adjudication method (like 2+1, 3+1) involving human experts for disagreement resolution is not applicable. The results are quantitative and determined by the test equipment and procedures.
5. Multi-Reader Multi-Case (MRMC) Comparative Effectiveness Study
No, a Multi-Reader Multi-Case (MRMC) comparative effectiveness study was not done. This type of study is primarily used for diagnostic devices involving physician interpretation of images, where the goal is to assess the impact of AI on clinical decision-making. The Axxent® Radiation Shield - Rigid is a passive device designed for physical shielding, not for data interpretation or diagnostic assistance.
6. Standalone (Algorithm Only Without Human-in-the-Loop Performance) Study
No, a standalone study (algorithm only) was not done. This is also not applicable as the device is a physical radiation shield and does not involve any algorithms or artificial intelligence.
7. Type of Ground Truth Used
The "ground truth" for the performance of the Axxent® Radiation Shield - Rigid was established through objective physical measurements and engineering tests:
- Radiation Attenuation: Measured using appropriate radiation detection equipment to determine the percentage of X-ray beam blocked. The method is referenced as "See Tab 12."
- Durability: Inferred to be through repeated cleaning and sterilization cycles, followed by inspection for degradation, as described by "See Tab 13 for device lifecycle testing."
- Material Shedding: Confirmed through "material shedding tests conducted on the device," referenced as "See Tab 14."
- Lead Equivalency: Calculated or measured based on the material's properties (316L Stainless Steel) and its attenuation characteristics.
8. Sample Size for the Training Set
Not applicable. This device is a physical medical device and does not involve any machine learning algorithms requiring a training set.
9. How the Ground Truth for the Training Set Was Established
Not applicable. As there is no training set for a machine learning algorithm, there is no ground truth to be established for it.
§ 892.5900 X-ray radiation therapy system.
(a)
Identification. An x-ray radiation therapy system is a device intended to produce and control x-rays used for radiation therapy. This generic type of device may include signal analysis and display equipment, patient and equipment supports, treatment planning computer programs, component parts, and accessories.(b)
Classification. Class II.