(204 days)
Advanced Nuclide Technologies LLC (ANT) Model 1 Brachytherapy Sources, with individual activities up to 5 mCi (185 MBq), are indicated for temporary or permanent interstitial, intracavitary, intraluminal or intraoperative implantation or surface application to treat selected localized tumors. They can be used either as primary treatment for unresectable tumors, or as treatment for residual disease after excision of primary or recurrent tumors such as for lung cancer. ANT Model 1 Brachytherapy Source may be used concurrently with or following treatment with other interventions, such as external beam therapy, or chemotherapy. Tumors of the head, neck, lung, pancreas, prostate, breast and other accessible tumors are commonly treated.
ANT Model 1 is a singly-encapsulated Brachytherapy Source. It consists of a titanium capsule containing a solid radioactive material. There are two versions of the ANT Model 1. The ANT Model 1 Type-Y contains a solid 169Ytterbium pellet. The ANT Model 1 Type-I contains a solid nonradioactive Ytterbium pellet onto which is plated radioactive 125Iodine. In both cases, the capsule which contains the pellet consists of a deep-drawn titanium can which is closed on the end with a titanium plug which is laser-welded to the can. The ANT Model 1 Brachytherapy Source emits gamma rays and characteristic x-rays from the decay of the respective radionuclides.
This document is a 510(k) premarket notification for the ANT Model 1 Brachytherapy Source. The device appears to be a medical device, and the information provided is primarily focused on demonstrating substantial equivalence to predicate devices, rather than establishing acceptance criteria and performance against those criteria in a typical clinical study format for a diagnostic or AI-driven device.
Based on the provided text, here's an analysis of the "acceptance criteria" and "study" as they pertain to this type of medical device submission:
It's important to note that for a brachytherapy source, "acceptance criteria" often relate to safety, effective radiation delivery, and technical specifications, rather than diagnostic performance metrics like sensitivity or specificity. Moreover, the "study" is primarily non-clinical testing and dosimetric analysis rather than a human-reader clinical trial.
1. A table of acceptance criteria and the reported device performance
For this type of device, the "acceptance criteria" are generally derived from recognized standards and the performance of predicate devices. The "reported device performance" demonstrates that the new device meets or is equivalent to these standards and predicate performance.
| Acceptance Criterion | ANT Model 1 Reported Performance | Predicate Device Performance (SPEC M-31, I-Plant 3500) |
|---|---|---|
| Design | Singly-encapsulated Titanium capsule (0.85 mm dia x 4.5 mm long) containing a solid Ytterbium rod (0.5 mm dia x 3.0 mm long) for Type-Y, or a solid nonradioactive Ytterbium pellet plated with 125Iodine for Type-I. Capsule is seal welded. | SPEC M-31: Singly-encapsulated Titanium capsule (0.42 mm dia x 5.1 mm long) containing a solid 169Ytterbium rod (0.25 mm dia x 1.25 mm long). Capsule is seal welded. |
| I-Plant 3500: Laser-welded titanium capsule containing a silica tube (substrate for 125Iodine) around a silver radiopaque x-ray marker. | ||
| Material (Encapsulation) | Titanium (Medical Grade) | Titanium (Medical Grade) for both predicates. |
| Radionuclide | 169Ytterbium OR 125Iodine | 169Ytterbium (SPEC M-31), 125Iodine (I-Plant 3500) |
| Dosimetry (TG43) | Dose Rate Const (λ): | |
| (169Yb): 1.20 cGy h-1 U-1 | ||
| (125I): 1.00 cGy h-1 U-1 | ||
| Anisotropy (φav): | ||
| (169Yb): 0.95 | ||
| (125I): 0.93 | ||
| Radial Dose Fn: Shown in Figure 1 (not provided in text) | SPEC M-31: | |
| Dose Rate Const (λ): 1.24 cGy h-1 U-1 | ||
| Anisotropy (φav): 0.99 | ||
| Radial Dose Fn: Shown in Figure 11 (not provided in text) | ||
| I-Plant 3500: | ||
| Dose Rate Const (λ): 1.01 cGy h-1 U-1 | ||
| Anisotropy (φav): 0.95 | ||
| Radial Dose Fn: Shown in Figure 12 (not provided in text) | ||
| Sterility | Non-sterile when shipped; sterilized by the user. | Non-sterile when shipped; sterilized by the user for both predicates. |
| Biocompatibility | Outer encapsulation of medical grade titanium, determined to be biocompatible. | Outer encapsulation of medical grade titanium, determined to be biocompatible for both predicates. |
| Mechanical Safety | ANSI N43.6 Class C54212 (Prototype sources equaled or exceeded requirements for C53211) | ANSI N43.6 Class C54212 (SPEC M-31), ANSI N43.6 Class C54213 (I-Plant 3500) |
| Energy Delivered | 169Ytterbium: Principal photon emissions 50, 51, 63, 94, 110, 118, 131, 177, 198, 261 and 308 keV gammas. | |
| 125Iodine: Principal photon emissions 27.4 and 31.4 keV x-rays and a 35.5 keV gamma. Also 22.1 and 25.2 keV fluorescent x-rays. | 169Ytterbium (SPEC M-31): Principal photon emissions 50, 51, 57 and 59 keV x-rays and 198, 261 and 308 keV gammas. | |
| 125Iodine (I-Plant 3500): Principal photon emissions 27.4 and 31.4 keV x-rays and a 35.5 keV gamma. Also fluorescent x-rays from silver marker. | ||
| Standards Met | ANSI N43.6, AAPM TG-43 | ANSI N43.6, AAPM TG-43 for both predicates. |
2. Sample size used for the test set and the data provenance (e.g. country of origin of the data, retrospective or prospective)
- Sample Size: This device is a brachytherapy source, not a diagnostic imaging or AI device that uses patient data for a "test set" in the conventional sense. The "test set" here refers to the number of prototype sources subjected to physical and dosimetric testing. The text states "Prototype sources were subjected to the tests..." but does not specify an exact number. It implies a limited number necessary to demonstrate conformity with standards.
- Data Provenance: The testing was non-clinical. The standards referenced (ANSI, ISO, AAPM, ESTRO) are international/US standards. The Monte Carlo simulation data would be generated computationally. Therefore, no country of origin or retrospective/prospective data type applies in the context of human patient data.
3. Number of experts used to establish the ground truth for the test set and the qualifications of those experts (e.g. radiologist with 10 years of experience)
- This question is not applicable to the type of device and submission. "Ground truth" for this device refers to established physical and dosimetry principles and compliance with recognized standards. This is assessed by specialists in medical physics, radiation safety, and material science, whose expertise is inherent in the development and validation of such standards and the performance of these non-clinical tests. The text cites several peer-reviewed articles by medical physicists (Currier et al., Duggan et al., Perez-Calatayud et al.) which form the basis for the dosimetric analysis.
4. Adjudication method (e.g. 2+1, 3+1, none) for the test set
- This question is not applicable. Adjudication methods like 2+1 (two readers agree, a third acts as tie-breaker) are used in clinical trials involving human interpretation of medical images. For physical and dosimetric testing of a medical device, compliance with standards is typically definitively measured or calculated, not adjudicated by multiple human readers.
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
- This question is not applicable. An MRMC study is designed for evaluating diagnostic devices, especially those that involve human interpretation and AI assistance. This submission describes a brachytherapy source, which delivers radiation for treatment, not a diagnostic device.
6. If a standalone (i.e. algorithm only without human-in-the-loop performance) was done
- This question is not applicable. "Standalone performance" in the context of an algorithm refers to its diagnostic accuracy without human intervention. The ANT Model 1 is a physical brachytherapy source; its "performance" is its ability to safely and effectively deliver radiation as determined by physical and dosimetric properties, not an algorithmic output.
7. The type of ground truth used (expert consensus, pathology, outcomes data, etc)
- The "ground truth" for this device's performance is based on established physical laws, validated dosimetric models (Monte Carlo simulation), and internationally recognized engineering and safety standards (ANSI N43.6, ISO 2919, AAPM TG-43). It is not derived from clinical expert consensus, pathology, or outcomes data in the traditional sense, as this device's primary function is physical radiation delivery, not diagnosis.
8. The sample size for the training set
- This question is not applicable. "Training set" refers to data used to train machine learning models. The development and validation of a brachytherapy source do not involve machine learning in this context. The underlying physical and dosimetric models are based on fundamental physics and vast amounts of accumulated scientific data and research, not a specific "training set" of patient data for an algorithm.
9. How the ground truth for the training set was established
- This question is not applicable, as there is no "training set" for a machine learning model. The underlying scientific principles and validated models used in the design and dosimetric analysis are established through decades of physics research, experimental validation, and peer review in the field of medical physics.
§ 892.5730 Radionuclide brachytherapy source.
(a)
Identification. A radionuclide brachytherapy source is a device that consists of a radionuclide which may be enclosed in a sealed container made of gold, titanium, stainless steel, or platinum and intended for medical purposes to be placed onto a body surface or into a body cavity or tissue as a source of nuclear radiation for therapy.(b)
Classification. Class II (special controls). A prostate seeding kit intended for use with a radionuclide brachytherapy source only is exempt from the premarket notification procedures in subpart E of part 807 of this chapter subject to the limitations in § 892.9.