(102 days)
The Varian Multileaf Collimator is intended to assist the clinician in the delivery of external beam radiation to defined target volumes during radiosurgery and radiotherapy while sparing surrounding normal tissue and critical organs from excess radiation.
The Varian Multileaf Collimator (MLC) is an accessory X-ray collimator designed to be mounted on a Varian radiotherapy linear accelerator. The Multileaf Collimator (MLC) head is mounted on a Varian Linear Accelerator, where it shapes the radiation beam before it is delivered to the patient. The MLC head is permanently bolted onto the casting that holds the X-Jaws and Y-Jaws of the Varian Linear Accelerator gantry. The MLC head assembly contains two leaf banks, plus associated electromechanical components. The MLC leaves reside in two carriages. Each leaf is driven by an independent motor. When shaping the radiation field perimeter to conform to the tumor outline, adjacent MLC leaves from opposing banks can move past one another. This feature, known as leaf inter-digitation, allows for the creation of complex shapes. The two carriage drives are independently controlled. Smooth motion of the leaves and carriages is achieved using a trapezoidal velocity profile that ramps up speed of the leaves or carriages to a fixed speed, and then ramps speed down until the leaf (or carriage) stops precisely at the final position. The various MLC models provide varying numbers and widths of leaves. The leaf banks extend over different widths within the Multileaf Collimator, for the 52-leaf. 80-leaf, and the 120-leaf Millennium MLC, and the HD120 Ml.C models. The Varian Multileaf Collimator (MLC) head contains many computer-controlled mechanical "leaves" or "slats" that continually shape the treatment beam as the radiation is delivered from different angles around the patient. The changes to the Varian Multileaf Collimator provide updates for electronics and information technology hardware, improvements in usability and serviceability, and additional discrepancy fixes. The operation and intended use of the device remain unchanged. Overall safety of the device is unchanged.
The provided text describes a 510(k) premarket notification for a Varian Multileaf Collimator (MLC). This document is primarily focused on demonstrating substantial equivalence to a predicate device rather than presenting a clinical study with detailed acceptance criteria and performance metrics typically seen for novel AI algorithms.
Therefore, many of the requested points, especially those related to AI-specific study details (such as sample sizes for test/training sets, ground truth establishment methods with expert consensus/pathology, MRMC studies, or standalone algorithm performance), are not applicable or not provided in this type of regulatory submission for a hardware device with software updates.
Here's an analysis based on the information provided:
1. Table of Acceptance Criteria and Reported Device Performance
The submission does not specify numerical acceptance criteria for a clinical study in terms of metrics like sensitivity, specificity, accuracy, or effect sizes for human reader improvement. Instead, the acceptance criteria are implicitly met by demonstrating that the device performs at least as well as the predicate device and met design input requirements.
| Acceptance Criteria (Implicit) | Reported Device Performance (Summary) |
|---|---|
| Performance and functionality of new and existing features meet design input requirements. | Verification testing confirmed performance and functionality met design input requirements. |
| Integrity of any changes is maintained (no adverse effects from modifications). | Regression testing verified the integrity of changes. |
| Device operates safely and effectively under clinically representative conditions. | Validation testing on a production-equivalent device under clinically representative conditions by qualified personnel. |
| Overall safety of the device is unchanged compared to the predicate device. | Operation and intended use remain unchanged; overall safety of the device is unchanged. |
| Device is substantially equivalent to the predicate device (K071992). | Conclusion: The Multileaf Collimator is safe and effective, and performs at least as well as the predicate device. |
| No adverse impact on the intended use (assist clinician in external beam radiation delivery, sparing normal tissue). | Intended Use Statement and Indications for Use remain consistent. |
2. Sample size used for the test set and the data provenance
- Sample Size: Not specified. The testing described is "Verification testing," "Regression testing," and "Validation testing" on a "production equivalent device." These typically involve engineering and functional tests rather than studies with "test sets" in the clinical AI sense.
- Data Provenance: Not applicable in the context of hardware/software functional testing. The testing would have been conducted internally by Varian Medical Systems.
3. Number of experts used to establish the ground truth for the test set and the qualifications of those experts
- This concept is not directly applicable here. The "ground truth" for this type of device (a medical linear accelerator accessory) would be its physical and functional specifications meeting engineering standards and its performance aligning with its intended use (accurate beam shaping). "Qualified personnel" are mentioned for validation testing, implying engineers and possibly clinical physicists who understand the device's operation. No mention of radiologists or other clinical experts establishing "ground truth" in terms of diagnoses or outcomes is made.
4. Adjudication method (e.g. 2+1, 3+1, none) for the test set
- Not applicable. Adjudication methods are typically used in clinical studies comparing human interpretations or AI outputs against a consensus. For a hardware device, performance is evaluated against engineering specifications.
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 is not an AI diagnostic or assistive device in the direct sense of providing interpretations to human readers. It is a radiation therapy accessory. Therefore, an MRMC study is not relevant here.
6. If a standalone (i.e. algorithm only without human-in-the loop performance) was done
- Not applicable. The device is a physical accessory controlled by software, working in conjunction with a linear accelerator and under clinician control for treatment planning and delivery. It's not a standalone algorithm in the sense of a medical diagnostic AI.
7. The type of ground truth used (expert consensus, pathology, outcomes data, etc)
- The "ground truth" for this device's performance would be the engineering specifications, functional requirements (e.g., leaf positioning accuracy, speed, inter-digitation capability), safety standards, and demonstrated equivalence to the predicate device's performance. It is based on engineering and functional test results demonstrating adherence to design inputs, rather than clinical ground truth like pathology or outcomes data.
8. The sample size for the training set
- Not applicable. This document describes a medical device accessory and its software updates, not an AI model that undergoes "training."
9. How the ground truth for the training set was established
- Not applicable, as there is no mention of a "training set" for an AI model.
§ 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.