(29 days)
Mobius3D software is used for quality assurance, treatment plan verification, and patient alignment and anatomy analysis in radiation therapy. It calculates radiation dose three-dimensionally in a representation of a patient or a phantom. The calculation is based on read-in treatment plans that are initially calculated by a treatment planning system and may additionally be based on external measurements of radiation from other sources such as linac delivery log data. Patient alignment and anatomy analysis is based on read-in treatment planning images (such as computed tomography) and read-in daily treatment images (such as registered cone beam computed tomography).
Mobius3D is not a treatment planning system. It is only to be used by trained radiation oncology personnel as a quality assurance tool.
Mobius3D (v4.0) is a software product used within a radiation therapy clinic for quality assurance and treatment plan verification. It is important to note that while Mobius3D operates in the field of radiation therapy, it is neither a radiation delivery device (e.g. a linear accelerator), nor is it a Treatment Planning System (TPS). Mobius3D cannot design or transmit instructions to a delivery device, nor does it control any other medical device. Mobius3D is an analysis tool meant solely for quality assurance (QA) purposes when used by trained medical professionals. Being a softwareonly QA tool, Mobius3D never comes into contact with patients.
Mobius3D performs dose calculation verifications for radiation treatment plans by doing an independent calculation of radiation dose is initially calculated by a Treatment Planning System (TPS), which is a software tool that develops a detailed set of instructions (i.e. a plan) for another system (e.g. a linear accelerator) to deliver radiation to a patient. The dose calculation performed by Mobius3D uses a proprietary collapsed cone convolution superposition (CCCS) algorithm.
Mobius3D also performs dose delivery quality assurance for radiation treatment plans by using the measured data recorded in a linear accelerator's delivery log files to calculate a delivered dose. This is presented to the end user in a software component of Mobius3D called MobiusFX. The MobiusFX component is available to users through licensing as an add-on to the core Mobius3D software features.
Mobius3D performs quality assurance of a patient's alignment and anatomy analysis is based on comparison of Cone Beam Computed Tomography (CBCT) images taken immediately before treatment to the images used for treatment planning, which are typically acquired using standard Computed Tomography (CT). This analysis is presented to the end user in an add-on software module within Mobius3D called CBCT Checks.
The provided text describes the regulatory clearance of Mobius3D v4.0 and its equivalence to the predicate device Mobius3D v3.0 (K192424) for quality assurance in radiation therapy. However, it does not contain the specific acceptance criteria or the details of a study that proves the device meets those criteria, as requested.
The document states:
- "No animal studies or clinical tests have been included in this pre-market submission."
- "The predicate device was cleared based only on non-clinical testing, and no animal or clinical studies were performed for the subject device."
- "The non-clinical verification and validation data demonstrates that the subject device should perform as intended in the specified use conditions."
This indicates that the clearance was based on software verification and validation testing, and compliance with certain standards, rather than a clinical study with acceptance criteria in the manner typically associated with diagnostic or prognostic AI devices.
Therefore, many of the requested details, such as sample size for test sets, data provenance, number of experts for ground truth, adjudication methods, MRMC studies, standalone performance, and training set details, are not present in this document.
Based on the provided text, here is what can be inferred/stated:
1. A table of acceptance criteria and the reported device performance:
| Acceptance Criteria (Inferred from regulatory filing context for software) | Reported Device Performance (Inferred from submission) |
|---|---|
| Conformance to applicable software requirements and specifications | Test results demonstrate conformance to applicable requirements and specifications. |
| Compliance with relevant medical device software standards | Conforms to IEC 62304, IEC 62366-1, IEC 61217 |
| Functionality of new features (Dose Calculation on CBCT) | Dose calculation on CBCT is performed and presented to the user. |
| Equivalence to predicate device (Mobius3D v3.0) | Substantially equivalent, with non-clinical verification and validation data. |
2. Sample size used for the test set and the data provenance (e.g. country of origin of the data, retrospective or prospective):
- Not specified. The document refers to "Software Verification and Validation Testing" and "non-clinical testing," but no details on the size or nature of data used for these tests are provided.
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):
- Not applicable/Not specified. The ground truth in software verification and validation would typically be established based on functional requirements, design specifications, and expected outputs, rather than expert interpretation of medical images or outcomes data.
4. Adjudication method (e.g. 2+1, 3+1, none) for the test set:
- Not applicable/Not specified. This is typically relevant for studies involving human interpretation or clinical outcomes, which are not described here.
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. The document explicitly states: "No animal studies or clinical tests have been included in this pre-market submission." An MRMC study would be considered a clinical test.
6. If a standalone (i.e. algorithm only without human-in-the-loop performance) was done:
- Yes, to the extent of "non-clinical verification and validation data." The device is a "software-only QA tool" and "an analysis tool," suggesting its performance was evaluated in a standalone capacity against its specified functional requirements. However, specific metrics of its standalone performance (e.g., accuracy against a gold standard for dose calculation) are not provided.
7. The type of ground truth used (expert consensus, pathology, outcomes data, etc):
- Software functional requirements and specifications. For "Dose Calculation on CBCT," the "ground truth" for verification would likely involve comparing the software's calculated dose outputs against established physics models, phantom measurements, or validated reference calculation engines for a given input. This is inferred from the "non-clinical testing" description.
8. The sample size for the training set:
- Not specified/Not applicable for this type of submission. Mobius3D uses a "proprietary collapsed cone convolution superposition (CCCS) algorithm" for dose calculation. This is a deterministic physics-based algorithm, not typically a machine learning model that would require a "training set" in the conventional sense of AI/ML.
9. How the ground truth for the training set was established:
- Not applicable. As a deterministic physics-based algorithm, there isn't a "training set" with ground truth in the machine learning context. The algorithm's parameters and underlying physics models would be based on theoretical principles and empirical validation.
§ 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.