(104 days)
ZDi Z-Tilt is intended for use by trained medical professionals for patient support and immobilization during external beam radiation therapy in clinics and hospitals. The Z-Tilt and accessories provide patient comfort and stability in various positions for radiation treatment. The Z-Tilt and is used in the treatment of cancer under the supervision and administration of licensed doctors and clinical staff.
The Z-Tilt is a patient-positioning device designed specifically for applications within Proton Therapy. The Z-Tilt features a thin, low-stopping power backboard able to hold the heaviest of patients treated with proton therapy. The Z-Tilt offers a scoop feature that acts as a seat for patients to rest against. This seat allows an easily reproducible, fixed hip position. The scoop prevents the patient from sliding down the tilt, and also ensures thoracic alignment in the treatment area. The Z-Tilt is sixteen inches wide at its widest point, tapering into a ten-inch square to receive another ZDi device, the Z-Square. The Z-Square easily indexes to the Z-Tilt backboard to securely lock and index the custom foam patient molds to the device. The Z-Tilt is designed to be strong and sturdy, but with minimal amounts of material in critical areas of potential beam passage. The Z-Tilt backboard is attached to a slim, strong base. The base is narrow in the middle to allow beam passage, but wide enough to prevent wobble. The cranial end of the base is also a ten-inch square, holding hinged support legs to brace the backboard at various positions equaling four, eight, and twelve degrees; the most commonly needed patient tilt positions. The Z-Tilt base is designed with indexing holes to index to any standard index bar used on treatment tables. It is designed to remain within sixteen inches wide to prevent interference with table edges, table tracks, and CT bores. The Z-Tilt will have marks on each hole for accurate reproducibility of the Z-Square indexing system and for the leg supports for the incline. The patient will be in contact with their custom mold used on top of the Z-System.
The associated accessories include:
- Z-Square Indexing System for patient mold reproducibility
- Z-Bar Index Bar for Z-Square mounting
- Z-Box for custom formation of patient molds
- Z-Pulls for arms-down reproducible arm positioning
- Z-Foam for various foam patient supports under the custom patient molds
- Z-Scoop for thoracic positioning on the Z-Tilt and table
- Z-Roll for lateral positioning of the Z-Tilt
The provided document describes the Z-Box/Z-Tilt Breast and Thoracic Positioning Device and its accessories, intended for patient support and immobilization during external beam radiation therapy. Here's a breakdown of the acceptance criteria and the study that proves the device meets them:
1. Table of Acceptance Criteria and Reported Device Performance:
| Acceptance Criteria | Reported Device Performance |
|---|---|
| Mechanical Performance (Weight Test) | |
| Backboard support (manufacturer recommended) | Held 250 pounds for 60 minutes at each of the three incline degrees (four, eight, and twelve degrees). |
| Accessory support (manufacturer recommended) | Each accessory held its respective suggested weight of 50 lbs for 60 minutes. |
| Material Performance (Radiation Attenuation) | |
| Beam influence | Same as predicate device due to both consisting of carbon fiber components with similar dimensions and characteristics. (Implicitly, minimal radiation beam attenuation is an acceptance criterion for such devices). A table of absorption factors for carbon fiber at various beam energies is provided, showing low percentages (e.g., 2.6% for 20mm Carbon Fiber at Co-60). |
| Biocompatibility | Carbon fiber, the main component of the device, has no cytotoxic effects in vivo and in vitro, as per an unspecified article. The device will be used with custom patient molds (expandable foam and vacuum locking molds) which are already approved devices (K951808 and K935300). |
| Effectiveness | The device is similarly designed to the predicate device, which has a track record of successful outcomes in treatments. The device functions as an aid for aligning and supporting the patient, not for the actual treatment. The subject device, considering all features, is stated to be no less effective than the predicate device. This is a comparative effectiveness statement. |
| Safety | No adverse events reported or concerns raised from the performance data presented. |
2. Sample Size Used for the Test Set and Data Provenance:
The document describes performance testing rather than a clinical study with a "test set" of patients.
- Mechanical Testing: The sample size for the mechanical weight test is not explicitly stated as a number of devices tested, but rather refers to "the subject device" (singular) and "each accessory." This implies at least one instance of the device and each accessory was tested.
- Data Provenance: The mechanical and material testing appears to be prospective testing conducted by the manufacturer, ZDi, Solutions, LLC, for the purpose of this 510(k) submission. There is no mention of country of origin for this specific testing, but the submission is to the U.S. FDA.
3. Number of Experts Used to Establish the Ground Truth for the Test Set and Qualifications of Those Experts:
This section is not applicable as the document describes physical performance testing (mechanical and material) and a comparative effectiveness argument based on predicate device history, not a study evaluating diagnostic accuracy or clinical outcomes that would require expert-established ground truth. The "effectiveness" claim is based on the device's function as an aid and comparison to a predicate, not on a ground truth established by experts.
4. Adjudication Method for the Test Set:
This is not applicable as there is no "test set" requiring adjudication in the context of expert review for diagnostic accuracy or clinical outcomes. The testing described is objective mechanical and material performance.
5. If a Multi-Reader Multi-Case (MRMC) Comparative Effectiveness Study was Done:
No, a MRMC comparative effectiveness study was not done. The document makes a comparative effectiveness statement regarding the device's function as an aid for patient positioning being "no less effective" than the predicate device. This is based on design similarities and the predicate's known successful outcomes, not on a formal MRMC study. There is no mention of human readers or AI assistance in this context.
6. If a Standalone (i.e., algorithm only without human-in-the-loop performance) was Done:
This is not applicable. The device is a physical patient positioning and immobilization system, not an algorithm or software. Therefore, the concept of "standalone algorithm performance" does not apply.
7. The Type of Ground Truth Used:
- Mechanical Testing: The "ground truth" for mechanical testing is based on engineered specifications and the ability of the device and its accessories to withstand specific weights for a defined duration. This could be considered objective physical measurement/engineering standards.
- Material Testing (Radiation Attenuation): The "ground truth" is based on known physical properties of carbon fiber and its interaction with various radiation beams, presented as absorption factors.
- Biocompatibility: The "ground truth" is based on published scientific literature (an unspecified article) stating carbon fiber's lack of cytotoxic effects, and the prior approval status of related components (custom molds).
- Effectiveness: The "ground truth" for effectiveness is inferred from the longitudinal successful outcomes associated with the predicate device (which the subject device is similar to) and the subject device's role as an "aid" rather than a treatment delivery system.
8. The Sample Size for the Training Set:
This is not applicable. The device is a physical product, not an AI or machine learning algorithm that requires a training set.
9. How the Ground Truth for the Training Set was Established:
This is not applicable for the reasons stated in point 8.
§ 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.