(91 days)
Model 1177 MapCHECK 2 is a two-dimensional (2D) radiotherapy beam dosimetry QA system intended for the measurement of radiation dose distributions for the purpose of comparison with a simulated dose distribution in the same phantom geometry as calculated by the treatment planning system (TPS).
ArcCHECK, Model 1220 is a three-dimensional (3D) radiotherapy beam dosimetry QA system intended for the measurement of radiation dose distributions for the purpose of comparison with a simulated dose distribution in the same phantom geometry as calculated by the treatment planning system (TPS).
The Model 1177 MapCHECK 2 and Model 1220 ArcCHECK devices are diode detector arrays that allow the user to perform radiation therapy delivery quality assurance (QA) and dosimetry.
The MapCHECK 2 is a two-dimensional detector array intended to measure radiation dose distribution. The 1527 diode detectors are embedded in polymethyl methacrylate (PMMA) phantom in an array size of 32 cm, with a detector spacing of 7.07 mm and a weight of 7.1 kg. With the provided software installed on the user's computer and connected to the MapCHECK 2 with an 8 pin DIN power/data conduit cable, the software provides the ability for the user to perform QA analysis of a patient's radiation therapy plan prior to treatment.
The ArcCHECK is a three-dimensional cylindrical detector array designed for coherent measurement geometry during rotational treatment delivery. The 1386 diode detectors are embedded in a PMMA phantom on a cylindrical geometric surface with an array size of 21 cm diameter x 21 cm length, with a detector spacing of 10 mm and a weight of 16 kg. This cylindrical array allows for dosimetry measurements to be made from all gantry angles as the therapy beam rotates about the diode array. With the provided software installed on the user's computer and connected to the ArcCHECK with an 8 pin DIN power/data conduit cable, the software provides the ability for the user to perform QA analysis of a patient's radiation therapy plan prior to treatment.
Both MapCHECK 2 and ArcCHECK use the same software application that includes functions for array and dose calibration; measurement and display of the spatial distribution of the dose resulting from delivery of a radiation treatment plan; saving the measurement; importing the treatment planning system (TPS) calculated dose distribution; comparing the measured and planned dose distributions using the analysis methods of gamma or dose difference and distance to agreement (DTA) with user specified analysis criteria; and a report of this analysis that includes percent pass rates.
The provided document describes the Sun Nuclear MapCHECK 2 and ArcCHECK devices, which are radiation therapy dosimetry quality assurance (QA) systems. However, it does not explicitly state quantitative acceptance criteria or a detailed study proving the device meets those criteria.
Instead, the document focuses on demonstrating substantial equivalence to a predicate device (RIT113 Film Analysis System, K935928) based on intended use, performance testing, safety, and effectiveness.
Here's a breakdown of the information that can be extracted or inferred:
1. Table of Acceptance Criteria and Reported Device Performance:
No specific quantitative acceptance criteria (e.g., pass rates for gamma analysis, dose difference thresholds) are provided in the document. The performance is described qualitatively as having "correlation with the actual treatment plan" and "good correlation" when compared to film dosimetry devices.
| Acceptance Criteria (Implied) | Reported Device Performance |
|---|---|
| Correlation with actual treatment plan | "results were found to have correlation with the actual treatment plan" |
| Correlation with film dosimetry | "results had good correlation" |
| Compliance with design specifications | "perform within their design specifications" |
| Electrical safety and EMC standards | "compliance with relevant electrical safety and EMC standards" |
2. Sample Size Used for the Test Set and Data Provenance:
- Sample Size: Not explicitly stated. The document mentions "known patient treatment plan outputs" and "tests were also performed to compare the results... with film dosimetry devices." This suggests a test set was used, but its size is not quantified.
- Data Provenance: The tests were conducted in "non-clinical and clinical settings," but no specific country of origin is mentioned. It discusses "patient treatment plan outputs," implying patient-specific data, but it's unclear if this refers to retrospective clinical data or simulated patient plans. The design suggests these are phantom-based measurements against planned data, not direct measurements on patients.
3. Number of Experts Used to Establish the Ground Truth for the Test Set and Qualifications of Those Experts:
- This information is not provided in the document. The "ground truth" for the device's comparison is the "simulated dose distribution... as calculated by the treatment planning system (TPS)" and "film dosimetry devices." This implies the "ground truth" is derived from computational models and established dosimetry methods rather than expert human interpretation of image data.
4. Adjudication Method for the Test Set:
- Not applicable/Not provided. The testing described involves comparing a measured dose distribution from the device to a calculated dose distribution from a TPS or a measured distribution from a film dosimetry device. This is an objective, quantitative comparison (e.g., gamma analysis, dose difference, DTA) rather than a subjective human adjudication process.
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. This document describes a device for objective dose measurement and QA in radiation therapy, not an AI-assisted diagnostic tool that would involve human readers or interpretation of complex medical images. Therefore, an MRMC comparative effectiveness study involving human readers and AI assistance is not relevant to this device and was not performed.
6. If a standalone (i.e. algorithm only without human-in-the-loop performance) was done:
- This device essentially operates in a "standalone" manner in terms of its measurement capabilities. It measures the radiation dose distribution, and its software then provides quantitative comparisons (e.g., gamma analysis, dose difference). The output (pass rates, dose maps) is then presented to a human user for review and decision-making. The core measurement and comparison functionality within the software can be considered an "algorithm only" performance, as it objectively compares two dose distributions based on predefined criteria. The human's role is to define the comparison criteria (e.g., gamma parameters) and interpret the results, but the device's primary function is the automated measurement and comparison.
7. The type of ground truth used (expert consensus, pathology, outcomes data, etc):
- The ground truth used for performance evaluation is primarily:
- Treatment Planning System (TPS) calculated dose distributions: The device's measurements are compared against the expected dose distributions generated by the TPS.
- Film dosimetry results: Comparisons were also made against measurements from established film dosimetry devices, which themselves serve as a reference for dose distribution measurement.
8. The sample size for the training set:
- Not applicable/Not provided. The MapCHECK 2 and ArcCHECK are hardware devices with associated software for measurement and analysis, not machine learning or AI algorithms that require a "training set" for model development.
9. How the ground truth for the training set was established:
- Not applicable/Not provided. As stated above, these devices do not involve machine learning and therefore do not have a "training set" in the conventional sense.
§ 892.5050 Medical charged-particle radiation therapy system.
(a)
Identification. A medical charged-particle radiation therapy system is a device that produces by acceleration high energy charged particles (e.g., electrons and protons) intended for use in 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. When intended for use as a quality control system, the film dosimetry system (film scanning system) included as an accessory to the device described in paragraph (a) of this section, is exempt from the premarket notification procedures in subpart E of part 807 of this chapter subject to the limitations in § 892.9.