(64 days)
The Symtium Corporation precision milled brass compensators are used for modulation of beam intensity during radiation therapy.
The Symtium Corporation Mod1 Compensators for Radiation Beam Therapy are used for modulation of beam intensity during radiation therapy (IMRT). Initially, a plan for the compensator design is generated by the staff of the Cancer Center using treatment planning software such as Pinnacle, Eclipse, or CMS (and others). This compensator design file is then transferred to Symtum Corporation via secure online data transfer, and imported into their custom designed manufacturing software. Typically, a brass round is used as a basis for the compensator. It is placed into the milling machine and worked into precise X, Y and Z dimensions to match the treatment planning output. It is then removed from the milling machine and subjected to an extensive QA process to verify the accuracy of the process non the match between the physical dimensions of the compensator and the treatment planing outputs. The device is then mounted onto a carrier specific to the linear accelerator (LINAC) used for patient treatment. The finished device is then packaged and mailed to the Cancer Center via commercial package transport companies.
Once received by the Cancer Center, the compensator is unpackaged and once again undergoes a QA process to confirm the accuracy of the manufacturing process in onec ugain andiation fluency map as well as radiation dose. At this point, the device is moved into the LINAC vault for patient freatient The compensator is then locked into place on the LINAC in the accessory collect
During patient treatment, a photon beam is generated by the LINAC and directed toward the patient. The compensator attenuates the photon beam based upon the thickness and shape of the brass. In general, the device shields sensitive portions of the treatment, and may. Of the was. In of the radiation on the tumor. Brass is a heavy, dense material with the ability to "attenuate" or block the amount of radiation that passes through it. When the milled brass compensator is mounted in the accessory collar of the LINAC, the photon beam aimed at the patient is "attenuated" is the area according to the thickness of the brass. Thicker areas "attenuate" or block more photon bean than the thinner areas. Generally, the thinner areas of the compensator would correspond to the tumor, while the thicker areas would overly surrounding "normal" tissue. In this way the tumor receives a maximum, effective dose of radiation while surrounding areas receive little or no radiation, sparing them from damage and the patient from side effects of the treatment.
The Symtium Corporation Mod1 Compensators for Radiation Beam Therapy's acceptance criteria and the study proving it meets these criteria are outlined in the "Determination of Substantial Equivalence" section of the provided document.
1. Table of Acceptance Criteria and Reported Device Performance
| Acceptance Criteria | Reported Device Performance |
|---|---|
| Measured composite dose within 2% of the expected value | Measured composite dose was within 2% of the expected value. |
| Isodose lines and distance to agreement within industry standard Van Dyke criteria | Isodose lines and distance to agreement were within industry standard Van Dyke criteria. |
2. Sample Size Used for the Test Set and Data Provenance
- Sample Size: The document mentions that "brass compensators were milled to specification" based on "a treatment plan adopted from a prostate case." This implies that at least one prostate case was used to generate compensators for testing, but a specific number of compensators or total patient treatment plans tested is not provided.
- Data Provenance: The testing was conducted at a "participating Cancer Center site." No specific country of origin is mentioned, but the company address is in San Antonio, TX, USA. The data appears to be prospective as the compensators were manufactured and then tested.
3. Number of Experts Used to Establish Ground Truth for the Test Set and Their Qualifications
The document does not explicitly state the number of experts or their qualifications for establishing ground truth. The description implies that the "staff of the Cancer Center" generated the initial compensator design and would likely be involved in verifying the results. Given the context, these would likely be radiation oncologists, medical physicists, or dosimetrists, but no specific professional credentials or years of experience are listed.
4. Adjudication Method for the Test Set
The document does not describe a formal adjudication method (e.g., 2+1, 3+1). It states that the "compensator production was verified through a QA process" and that "Each compensator was tested using equivalent dose rates with two separate industry standard QA devices." This suggests instrumental verification rather than human adjudication for establishing the direct performance metrics.
5. If a Multi-Reader Multi-Case (MRMC) Comparative Effectiveness Study Was Done
No, a Multi-Reader Multi-Case (MRMC) comparative effectiveness study was not conducted or described. The study focuses on the physical accuracy and performance of the device (compensator) itself, not on how human readers' interpretation or effectiveness might improve with or without AI assistance.
6. If a Standalone (i.e., algorithm only without human-in-the-loop performance) Was Done
Yes, a standalone performance assessment was conducted. The device (compensator) is designed to modulate beam intensity based on a treatment plan, and its performance was evaluated instrumentally against established physical standards (composite dose and Van Dyke criteria). This is a standalone evaluation of the device's output. While a human designs the compensator initially, the test itself assesses the manufactured compensator's adherence to that design, independent of real-time human intervention during the test.
7. The Type of Ground Truth Used
The ground truth used was instrumental measurements and industry standards.
- The "expected value" for composite dose and "industry standard Van Dyke criteria" serve as the ground truth against which the device's performance was compared.
- The comparison was enabled by specialized QA devices for IMRT measurements.
8. The Sample Size for the Training Set
The document does not mention a training set. This is not an AI/machine learning device that requires a training set. The device is a physical compensator milled to specifications.
9. How the Ground Truth for the Training Set Was Established
Not applicable, as no training set was used or 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.