(54 days)
.decimal's Photon Block manufacturing service manufactures Photon Blocks for external beam photon radiation therapy. The Photon Block is designed by the customer's treatment planning system or physician specifications to block radiation from hitting critical structures and healthy tissue while guiding the radiation to the targeted area.
Photon Blocks are intended for use by healthcare professionals.
In IMRT therapy for cancer, a photon beam is aimed at the cancerous tissue using a linear accelerator. The linear accelerator is rotated around the patient while the patient lies on a treatment table; the linear accelerator consists of the gantry, which rotates around the patient. The gantry contains a collimator, which points at pre-determined positions to maximize efficiency and dose delivery to the tumor volume. Each gantry angle, or "port", requires custom-made, beam modifying, patient specific devices called: Photon Block.
The Photon Block is inserted into the gantry's collimator to shape and focus the beam as it exits the gantry en route to the targeted area. The photon block is also called a cerrobend block, which defines the area that is to be treated with the photon beam. Photon Blocks are generated out of the treatment planning system or physician's specifications and are unique to each patient and each gantry angle.
The .decimal Photon Block is a Cerrobend block (or material with similar attenuating properties) with a 2D pattern/hole made from it, which defines the area that is to be treated with a photon beam. The design for a .decimal Photon Block is generated out of a customer's treatment planning system (TPS) or physician's specifications and is unique to each patient. The device functions as a beam shaping block. The block fits into a customer's linear accelerator. As radiation is passed through the collimator, the beam passes through cerrobend and it will be blocked the opening of the photon block where there is no ccrrobend, the radiation will pass through targeted area defined by the radiation therapy professional.
The provided document describes the .decimal Photon Block, a device used in radiation therapy to shape and focus photon beams. It details the device's description, intended use, and indications for use, and also includes a 510(k) summary for regulatory approval.
However, the document explicitly states: "Clinical testing was not performed as part of the development of this product. Clinical testing is not advantageous in demonstrating substantial equivalence or safety and effectiveness of the device since testing can be performed such that no human subjects are exposed to risk."
Instead, the document mentions: "Clinically oriented validation test cases were written and excelled in house by .decimal personnel including a Board Certified Medical Physicist where Photon Blocks were deemed safe and effective for clinical medical. The tests show that .decimal Photon Blocks performed as well as the predicate device."
This indicates that the manufacturer performed non-clinical testing to demonstrate substantial equivalence to a predicate device (.decimal Electron Aperture K111759) rather than a study with acceptance criteria and a detailed performance report in the manner expected for a device proving its efficacy via clinical trials.
Therefore, most of the requested information regarding acceptance criteria, study details involving human subjects, ground truth, expert involvement, and sample sizes for test and training sets cannot be extracted from this document because such a study was explicitly not performed.
Here's what can be inferred or extracted based on the provided text, acknowledging the absence of a typical clinical study:
1. A table of acceptance criteria and the reported device performance
Since no specified acceptance criteria or detailed performance metrics from a formal clinical study are provided, this section cannot be completed as requested. The document only broadly states that the device "performed as well as the predicate device."
No specific acceptance criteria or performance metrics were detailed in the provided document, as no clinical study was performed.
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 for test set: Not applicable, as no clinical test set was used. "Clinically oriented validation test cases" were performed in-house, but the sample size of these test cases is not specified, nor is their provenance.
- Data provenance: Not applicable. The validation was described as "in house."
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)
- Number of experts: The document mentions "in house by .decimal personnel including a Board Certified Medical Physicist." It doesn't specify if multiple experts were involved or just one for establishing ground truth for the validation test cases.
- Qualifications of experts: "Board Certified Medical Physicist." No years of experience are specified.
4. Adjudication method (e.g. 2+1, 3+1, none) for the test set
- Not applicable. The in-house validation did not describe a formal adjudication method.
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 MRMC comparative effectiveness study was done. The device described (Photon Block) is a physical beam-shaping device, not an AI-assisted diagnostic or therapeutic tool for human readers.
6. If a standalone (i.e. algorithm only without human-in-the-loop performance) was done
- Not applicable in the context of an algorithm. The device is a physical component. Its "performance" was likely assessed against physical specifications and its ability to shape the beam accurately, which would be a standalone evaluation of the physical device. The document mentions "validation test cases," suggesting a standalone performance evaluation of the device's manufacturing and function.
7. The type of ground truth used (expert consensus, pathology, outcomes data, etc.)
- For the "clinically oriented validation test cases," the ground truth was established by ".decimal personnel including a Board Certified Medical Physicist." This suggests an expert-driven assessment of whether the Photon Blocks met their design specifications and functioned correctly to achieve the intended beam shaping, likely comparing actual block dimensions and beam profiles against design specifications.
8. The sample size for the training set
- Not applicable, as this is a physical device and no machine learning model requiring a training set is described.
9. How the ground truth for the training set was established
- Not applicable, as no machine learning model requiring a training set is described.
§ 892.5710 Radiation therapy beam-shaping block.
(a)
Identification. A radiation therapy beam-shaping block is a device made of a highly attenuating material (such as lead) intended for medical purposes to modify the shape of a beam from a radiation therapy source.(b)
Classification. Class II.