(192 days)
The Photon Radiosurgery System is intended to be used for the irradiation of intracranial tumors.
The Photon Radiosurgery System (PRS) is a complete system for highly focused treatment of intracranial tumors. The PRS includes an X-ray Source and Control Box, along with accessories for clinical treatment, quality assurance, laboratory calibration and dose verification. The miniature X-ray source incorporates a 3.175 mm diameter. 10 cm long interstitial probe and is designed to be mounted on a stereotactic frame so that the probe tip, covered with a sterile sheath, can be positioned precisely into the tumor. High dose rate, low energy X-rays are emitted from the probe tip in a spherical pattern and a prescribed therapeutic radiation dose delivered in a single fraction destroys the tumor from the inside out. Voltage, beam current, and treatment time or photon count are set on the Control Box which is powered by a rechargeable battery. Accessories are provided to assist in placement of the interstitial probe and to perform quality control of the X-ray source in the clinical setting. Additional laboratory-based components of the PRS include an automated dosimetry water tank for calibration and a CCD-camera based radiochromic film reader for dose verification.
Here's a breakdown of the acceptance criteria and study information for the Photoelectron Corporation PHOTON RADIOSURGERY SYSTEM (K964947), based on the provided text:
Acceptance Criteria and Reported Device Performance
The provided 510(k) summary does not explicitly list quantitative acceptance criteria in a table format with corresponding reported performance metrics. Instead, it focuses on demonstrating substantial equivalence to predicate devices in terms of intended use, technological/functional features, construction, materials, safety, and effectiveness.
The "acceptance criteria" can be inferred from the claims made regarding the device's performance and similarity to predicate devices, particularly that it is "as safe and effective as legally marketed predicate devices for the irradiation of intracranial tumors."
Here's an attempt to structure the information based on the available text:
| Acceptance Criteria (Inferred) | Reported Device Performance |
|---|---|
| Safety: | |
| Emit high-dose rate, low-energy X-ray radiation. | Emits high dose rate, low energy X-ray radiation in a spherical pattern from the tip of an X-ray Source probe. |
| Be able to be placed inside the body. | Probe can be placed inside the body. |
| Create highly demarcated areas of tissue destruction in targeted animal tissue without evidence of deleterious effects. | Demonstrated in preclinical animal studies to create highly demarcated areas of tissue destruction in targeted animal tissue without evidence of deleterious effects. |
| Compliance with electromagnetic compatibility. | Preclinical tests included testing for compliance with electromagnetic compatibility. |
| Materials biocompatibility. | Preclinical tests included testing for materials biocompatibility. |
| Demonstrate safety in human subjects. | Two phases of clinical studies conducted over four years at multiple sites, assessing safety through clinical, radiological, functional, and quality of life measures, and autopsy data. Concluded to be safe. |
| Minimal collateral radiation protection concerns compared to predicate devices. | Discussion of collateral radiation protection against predicate devices. |
| Effectiveness: | |
| Irradiate and destroy intracranial tumors in a precise and controllable manner. | Targeted tumors can be irradiated and destroyed in a precise and controllable manner. |
| Achieve therapeutic radiation dose in a single fraction. | Prescribed therapeutic radiation dose delivered in a single fraction. |
| Be comparable to predicate devices in radiation sources, methods of application, relative dose rates, and dose adjustment methods. | Technological and functional characteristics are similar to interstitial brachytherapy and external beam stereotactic radiosurgery systems (LINAC and/or Gamma Knife) in these aspects. |
| Demonstrate effectiveness in human subjects for irradiation of intracranial tumors. | Two phases of clinical studies conducted over four years at multiple sites, assessing effectiveness through clinical, radiological, functional, and quality of life measures, and autopsy data. Concluded to be effective. |
Detailed Study Information:
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Sample size used for the test set and the data provenance:
- Sample Size (Clinical Test Set): "eligible subjects diagnosed with primary or metastatic intracranial tumors which were either solitary or multiple in number." No specific number is provided in the summary, but it implies a cohort of human patients.
- Data Provenance: "at multiple clinical sites" (implies prospective human clinical data). "Autopsy data was also obtained" (retrospective on deceased subjects).
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Number of experts used to establish the ground truth for the test set and the qualifications of those experts:
- The document does not specify the number of experts or their qualifications for establishing ground truth in the clinical studies. It mentions "clinical, radiological, functional and quality of life measures," which would typically involve expert interpretation (e.g., radiologists for imaging, neurologists for functional assessments, etc.), but this is not detailed.
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Adjudication method for the test set:
- The document does not specify an adjudication method (e.g., 2+1, 3+1, none) for the clinical test set data.
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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 study was not done. This device is an X-ray radiation therapy system, not an AI-powered diagnostic imaging tool. Therefore, the concept of "human readers improve with AI vs without AI assistance" does not apply.
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If a standalone (i.e., algorithm only without human-in-the-loop performance) was done:
- Yes, a standalone performance was done in the sense of the device performing its intended function without direct human "in-the-loop" assistance for radiation delivery. The device delivers radiation based on pre-programmed parameters. Preclinical in vitro laboratory studies and animal studies would represent standalone performance of the system against biological tissues.
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The type of ground truth used:
- Preclinical: "Highly demarcated areas of tissue destruction" observed in animal studies.
- Clinical: "Autopsy data" (direct objective evidence of tissue effects), "clinical, radiological, functional and quality of life measures." This implies a combination of direct pathological evidence and various clinical/imaging outcomes.
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The sample size for the training set:
- The document does not specify a separate "training set" sample size. The description of clinical studies refers to the overall evaluation of safety and effectiveness, implying a single study phase for reporting to the FDA rather than a distinct training/test split in the modern machine learning sense. The device itself is not described as an AI/ML algorithm that requires a "training set" in that context.
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How the ground truth for the training set was established:
- As there's no mention of a "training set" in the context of an AI/ML device, this question is not directly applicable. For the overall studies, ground truth was established through a combination of animal tissue analysis, human autopsy data, and various clinical and radiological assessments as outlined above.
§ 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.