(120 days)
Yes
The intended use statement explicitly states that the device is "an artificial intelligence (Al)/machine learning (ML)-based computer-aided diagnosis (CADx) software device".
No
The device is a computer-aided diagnosis (CADx) software intended to assist physicians in analyzing medical images for cancer risk assessment. It explicitly states that "Patient management decisions should not be made solely on the results of the Koios DS analysis," indicating it provides information for diagnosis rather than directly treating or preventing disease.
Yes
The 'Intended Use / Indications for Use' section explicitly states that "Koios DS is an artificial intelligence (Al)/machine learning (ML)-based computer-aided diagnosis (CADx) software device intended for use as an adjunct to diagnostic ultrasound examinations...". The phrase "computer-aided diagnosis (CADx)" directly indicates its role as a diagnostic device.
Yes
The device description explicitly states that Koios DS is a "software application" and a "web application" accessed through a compatible client. It processes images transmitted electronically to a server. There is no mention of any hardware component being part of the device itself.
Based on the provided information, Koios DS is not an In Vitro Diagnostic (IVD) device.
Here's why:
- IVD Definition: In Vitro Diagnostic devices are used to examine specimens derived from the human body (like blood, urine, tissue samples) to provide information about a patient's health.
- Koios DS Function: Koios DS analyzes medical images (ultrasound and mammography) of lesions and nodules within the body. It does not analyze samples taken from the body.
- Intended Use: The intended use clearly states it's an adjunct to diagnostic ultrasound examinations and analyzes image data.
- Device Description: The device description confirms it processes DICOM images.
Therefore, Koios DS falls under the category of medical imaging software or a computer-aided diagnosis (CADx) device, not an IVD.
No
The letter does not explicitly state that the FDA has reviewed, approved, or cleared a Predetermined Change Control Plan (PCCP) for this specific device. It only references "Design verification and validation and product labelling include all requirements proscribed in the 21 CFR 892.2060 Special Controls," which does not confirm PCCP authorization.
Intended Use / Indications for Use
Koios DS is an artificial intelligence (Al)/machine learning (ML)-based computer-aided diagnosis (CADx) software device intended for use as an adjunct to diagnostic ultrasound examinations of lesions or nodules suspicious for breast or thyroid cancer.
Kolos DS allows the user to select or confirm regions of interest (ROIs) within an image representing a single lesion or nodule to be analyzed. The software then automatically characterizes the selected image data to generate an AI/MLderived cancer risk assessment and selects applicable lexicon-based descriptors designed to improve overall diagnostic accuracy as well as reduce interpreting physician variability.
Koios DS may also be used as an image viewer of multi-modality digital images, including ultrasound and mammography. The software includes tools that allow users to adjust, measure and document images, and output into a structured report.
Koios DS software is designed to assist trained interpreting physicians in analyzing the breast ultrasound images of adult (>= 22 years) female patients with soft tissue breast lesions and/or thyroid ultrasounds of all adult (>= 22 years) patients with thyroid nodules suspicious for cancer. When utilized by an interpreting physician who has completed the prescribed training, this device provides information that may be useful in recommending appropriate clinical management.
Limitations:
· Patient management decisions should not be made solely on the results of the Koios DS analysis.
· Koios DS software is not to be used for the evaluation of normal tissue, on sites of post-surgical excision, or images with doppler, elastography, or other overlays present in them.
· Koios DS software is not intended for use on portable handheld devices (e.g. smartphones or tablets) or as a primary diagnostic viewer of mammography images.
• The software does not predict the thyroid nodule margin descriptor, extra-thyroidal extension. In the event that this condition is present, the user may select this category manually from the margin descriptor list.
Product codes
POK, QIH
Device Description
Koios DS is a software application designed to assist trained interpreting physicians in analyzing breast and thyroid ultrasound images. The software device is a web application that is deployed to a Microsoft IIS web server and accessed by a user through a compatible client. Once logged in and granted access to the Koios DS application, the user examines selected breast or thyroid ultrasound DICOM images. The user selects Regions of Interest (ROls) of orthogonal views of a breast lesion or thyroid nodule for processing by Koios DS. The ROI(s) are transmitted electronically to the Koios DS server for image processing and the results are returned to the user for review.
Breast Functionality:
Koios DS software automatically classifies breast lesions suspicious for cancer based on image data into one of four ACR BI-RADS® Atlas32 or European U1-U53 Classification System-aligned categories (Benign, Probably Benign, Suspicious or Indeterminate, or Probably Malignant) and also displays a continuous graphical Confidence Level Indicator depicting where the lesion falls within its respective category and its relation to neighboring categories. The software automatically classifies the shape (Round, Oval, Irregular) and orientation (Parallel, Not Parallel) of the selected lesion.
Thyroid Functionality:
Koios DS is a software medical device used to analyze ultrasound data to classify user-selected regions containing thyroid nodules suspicious for cancer. The software generates a set of user-editable sonographic nodule descriptor recommendations (Composition, Echogenicity, Shape, Margin, Echogenic Foci) along with an optional, deep-learning derived cancer risk assessment of the suspected nodule from two orthogonal views. Nodule descriptor recommendations are subsequently mapped to a categorical assessment and risk level rating via the ACR TI-RADS ATLAS™45 or American Thyroid Association (ATA) risk stratification systems (RSSs) based on user preference. The software's direct, non-descriptor-based cancer risk assessment is presented as the Koios "AI Adapter" that, when used in conjunction with the ACR TI-RADS or ATA guidelines for nodule risk stratification, is shown to improve overall diagnostic performance of both systems. The Al Adapter operates as an optional lexicon-specific input used to modify the final categorization in the ACR TI-RADS and ATA systems, respectively. This process creates an Al-augmented categorization that is meant to be used with no other modifications to the decision-making pathway of either RSS. A trained interpreting physician may choose to incorporate or exclude the Koios Al Adapter from the overall assessment when finalizing their diagnostic interpretation.
Koios DS enables the following functionality:
- Breast and Thyroid diagnostic core AI engines enabled by state-of-the-art computer vision and machine learning techniques capable of reading, interpreting, analyzing, classifying and generating findings from ultrasound image data resulting in an automated risk assessment for breast lesions and thyroid nodules suspicious for cancer
- Automatic classification of thyroid nodules aligned to both TI-RADS and ATA descriptors of: Composition, Echogenicity, Shape, Margin, and Echogenic Foci based on user-selected regions of interest (ROIs)
- Automatic classification of breast lesion BI-RADS and U1-U5 Descriptors Shape and Orientation based on user-selected or confirmed regions of interest (ROIs)
- Annotation and description of ultrasound images based on ACR BI-RADS Breast Imaging Atlas and U1-U5 for Koios DS Breast
- Annotation and description of ultrasound images based on and ACR TI-RADS Atlas and ATA classification guidelines for Koios DS Thyroid
- Reporting forms for breast lesion or thyroid nodule identification and tracking in the Electronic Health Record
- Smart Calipers - extraction of user-supplied ROI data (alternately referred to as Calipers) embedded in DICOM SR files from the ultrasound modality
- Smart Click (Breast only) - generation of automated ROI based on user-supplied position (click on a lesion) within the image
- Ability to save findings to PACS
- Ability to export findings to reporting software
- Remote analysis interface to generate and view results within compatible software (e.g. ultrasound equipment or PACS workstation software)
- Installer and Configuration Wizard
- Single Sign-on (SSO) Windows and LDAP Authentication
- Operating system and platform-agnostic usage
- Zero-footprint web-based HTML5 DICOM image viewer with image manipulation and annotation tools
User Profile:
Koios DS is for use by trained professionals only. Koios DS is not for use by patients. Users must have appropriate medical professional competence, such as trained sonographers and interpreting physicians.
Use Environment:
Koios DS is a software application for use within a healthcare setting for the examination and assessment of breast lesions or thyroid nodules using ultrasound. It is a platform-agnostic web application that queries and accepts DICOM compliant digital medical files from any compliant device subject to the specified DICOM Conformance Statement for Koios DS. Processing of the image(s) occurs in conjunction with a trained interpreting physician's typical diagnostic case read. The output of the system is a digital display to be used as a concurrent read and report input that may be added as an addendum to the DICOM series selected for processing or exported directly into a patient's draft report.
Operating Principle:
Koios DS is an ASP.NET web application deployed to a Microsoft IIS web server inside a Windows operating system environment accessed by a user through a compatible client. The application provides image-derived data via web triggering and remote analysis.
Once logged in and granted access to the Koios DS application, the user examines selected breast and thyroid ultrasound DICOM images. The user selects or confirms up to two orthogonal views that represent a single breast lesion for processing by the system. For thyroid functionality, two ROIs are required for analysis by the system. The first ROI must be drawn on the transverse view, with the second on the longitudinal view of the nodule. For breast functionality, bench testing has verified a single ROI does not significantly decrease system AUC performance. The ROI(s) are transmitted electronically to the Koios DS server by the Koios DS Breast or Koios DS Thyroid software for image processing and the results are returned to the user for review in the respective interface. Images and data can be stored, communicated, processed, and displayed within the system and/or across computer networks at distributed locations.
The software does not require any specialized hardware to return a diagnostic output, but the time to process ROIs will vary depending on the hardware specifications.
Koios DS contains two distinct AI/ML engines to characterize breast lesions and thyroid nodules. Based on the structured data that exists within the DICOM header for a patient study, the Koios DS system calls the corresponding engine for analysis of the identified lesion or nodule. Each system uses computer vision and machine learning techniques embedded within an engine capable of reading, interpreting, and generating findings from ultrasound data. The underlying breast and thyroid engines draw upon knowledge learned from a large database of known cases, tying image features to their eventual diagnosis, to form a predictive model.
Koios DS results can be saved or transferred in three separate ways: in-transmission, saving to Picture Archiving and Communication System (PACS), and exporting results to third-party reporting software. In-transit transmission may be utilized when users wish to share analyses across viewing workstations. Results can be stored in in-transit memory for a preset period of time defined by a system administrator. After that preset period of time, all results are wiped from the local memory. Another method of saving a report in the patient study on the PACS. After single or multiple lesion or nodule analyses have been performed and ultimately accepted by a trained interpreting physician, Koios DS can export a summary report to PACS as an addendum to the DICOM study that was selected for processing. This report serves as future reference and aid in the comparison of cases requiring follow up. This functionality is strictly reserved for approved users and must be configured by a site administrator.
Koios DS also supports exporting results to third-party reporting software to facilitate the reporting process. Saving or exporting preferences can be configured by the system administrator and user.
Mentions image processing
Yes
Mentions AI, DNN, or ML
Yes
Input Imaging Modality
Ultrasound, Mammography
Anatomical Site
Breast, Thyroid
Indicated Patient Age Range
Adult (>= 22 years)
Intended User / Care Setting
Trained interpreting physicians, healthcare setting
Description of the training set, sample size, data source, and annotation protocol
Not Found
Description of the test set, sample size, data source, and annotation protocol
The breast and thyroid engine validation sets are composed of 900 lesions from 900 different patients and 650 lesions from 650 different patients, respectively. Each was set aside from the systems' training data for the purpose of validating performance.
For breast validation, ground truth was determined by pathology or 1-year follow-up for cases that were not biopsied. Each lesion was represented by two orthogonal images (e.g. radial and anti-radial), providing a total of 1800 images.
For thyroid validation, ground truth for malignancy risk classification was determined by pathology results only. The system was analyzed on 500 lesions from 500 different patients set aside from the system's training data for the purpose of validating performance. Each lesion was represented by two orthogonal images (e.g. radial and anti-radial), providing a total of 1000 images. The final validation set data is divided into 2 subsets; 500 cases from United States locations and 150 cases from European locations.
Summary of Performance Studies (study type, sample size, AUC, MRMC, standalone performance, key results)
Breast Engine (Bench Testing):
- Study type: Bench testing
- Sample size: 900 lesions from 900 different patients (1800 images), with an additional 50 new cases added to test for robustness to dataset drift.
- AUC: 92.9% (0.913, 0.945 95% CI) for the updated breast engine. For the additional 50 new cases, AUC was 0.930 [0.914, 0.946 95% Cl].
- Standalone performance: System performance on the 900 cases: Sensitivity of 0.97 [0.96, 0.99] and a Specificity of 0.61 [0.57, 0.66].
- Key results: Demonstrated a significant increase in AUC (5%) and specificity (24%) compared to the predicate device (Koios DS Breast v2.0) with no significant change in sensitivity. Performance does not degrade with Smart Click generated ROIs.
Thyroid Engine (Bench Testing):
- Study type: Bench testing
- Sample size: 500 lesions from 500 different patients (1000 images).
- AUC: For ACR TI-RADS guidelines, AUC of 79.8%. For ATA classifications with AI Adapter, physician AUC demonstrates a significant increase of 9.135% [5.975, 12.294].
- Standalone performance (ACR TI-RADS): When recommending biopsy, sensitivity is 0.644 [0.545, 0.744] and specificity is 0.612 [0.566, 0.658]. When recommending follow-up, sensitivity is 0.879 [0.812, 0.946] and specificity is 0.495 [0.446, 0.544].
- Standalone performance (ATA): Sensitivity shows a non-significant increase of 0.511% [-5.182, 6.204], while specificity shows a significant increase of 18.741% [9.885, 27.596].
- Key results: Demonstrated significant increase over average physician AUC for ACR TI-RADS, and improved performance for ATA classifications. Met performance requirements across different reporting systems and with independent site data.
Breast (Clinical Study - K190442 reference):
- Study type: Clinical study (previously executed and referenced from K190442)
- Sample size: 900 patient cases, 15 readers.
- AUC: AUC improvement of 0.0370 (0.030, 0.044) at α = .05 for "USE + DS" compared to "USE Alone".
- MRMC: Yes, Multi-Reader, Multi-Case (MRMC) study.
- Key results: Statistically significant improvement in overall reader performance (AUC). Demonstrated a significant increase in the average Kendall Tau-B (from 0.5404 to 0.6797), indicating reduced inter-operator variability. Statistically significant reduction in intra-reader variability (class switching rate reduced from 13.6% to 10.8%, p = 0.042).
Thyroid (Clinical Study - CRRS-3):
- Study type: Observational case-controlled, Multi-Reader, Multi-Case (MRMC) retrospective clinical trial.
- Sample size: 650 retrospectively collected cases (1300 total cases per reader for review), 15 readers.
- AUC: Primary Endpoint 1 (all readers, all data): +0.083 [0.066, 0.099] (parametric), +0.079 [0.062, 0.096] (non-parametric). Primary Endpoint 2 (US readers, US data): +0.074 [0.051, 0.098] (parametric), +0.073 [0.049, 0.096] (non-parametric).
- MRMC: Yes, Dorfman-Berbaum-Metz (DBM) ANOVA after jackknife method used for AUC analysis.
- Key results: Statistically significant improvement in overall reader performance of US-based readers when utilizing Koios DS for the interpretation of US-based thyroid ultrasound studies (0.074 [0.051, 0.098] in parametric AUC). Impact on interpretation time: -23.6% (all readers, all data).
Key Metrics (Sensitivity, Specificity, PPV, NPV, etc.)
Breast Engine (Bench Testing):
- Sensitivity: 0.97 [0.96, 0.99]
- Specificity: 0.61 [0.57, 0.66]
- Previous (Koios DS Breast v2.0 predicate): 5% increase in AUC, no significant change in sensitivity, 24% increase in specificity.
- Also tested: Positive Predictive Value (PPV), Negative Predictive Value (NPV), Positive Likelihood Ratio (PLR), Negative Likelihood Ratio (NLR).
Thyroid Engine (Bench Testing):
- ACR TI-RADS (biopsy recommendation): Sensitivity 0.644 [0.545, 0.744], Specificity 0.612 [0.566, 0.658].
- ACR TI-RADS (follow-up recommendation): Sensitivity 0.879 [0.812, 0.946], Specificity 0.495 [0.446, 0.544].
- ATA (with AI Adapter): Sensitivity increase of 0.511% [-5.182, 6.204], Specificity increase of 18.741% [9.885, 27.596].
Thyroid (Clinical Study - CRRS-3):
- Change in average Sensitivity and Specificity of FNA with Koios DS (all readers, all data): +0.084 [0.054, 0.113] (sensitivity), +0.140 [0.125, 0.155] (specificity)
- Change in average Sensitivity and Specificity of FNA with Koios DS (US readers, US data): +0.058 [0.017, 0.098] (sensitivity), +0.130 [0.110, 0.151] (specificity)
- Change in average Sensitivity and Specificity of FNA with Koios DS (EU readers, EU data): +0.125 [0.014, 0.237] (sensitivity), +0.171 [0.109, 0.233] (specificity)
- Change in average Sensitivity and Specificity of Follow-up with Koios DS - excluding cases recommended for FNA (all readers, all data): +0.092 [0.043, 0.141] (sensitivity), +0.242 [0.220, 0.264] (specificity)
- Change in average Sensitivity and Specificity of Follow-up with Koios DS - excluding cases recommended for FNA (US readers, US data): +0.087 [0.023, 0.151] (sensitivity), +0.206 [0.176, 0.235] (specificity)
- Change in average Sensitivity and Specificity of Follow-up with Koios DS - excluding cases recommended for FNA (EU readers, EU data): +0.084 [-0.133, 0.300] (sensitivity), +0.350 [0.267, 0.434] (specificity)
- Change in average Sensitivity and Specificity of Follow-up with Koios DS - including cases recommended for FNA (all readers, all data): +0.060 [0.040, 0.080] (sensitivity), +0.206 [0.192, 0.219] (specificity)
- Change in average Sensitivity and Specificity of Follow-up with Koios DS - including cases recommended for FNA (US readers, US data): +0.053 [0.026, 0.080] (sensitivity), +0.180 [0.161, 0.198] (specificity)
- Change in average Sensitivity and Specificity of Follow-up with Koios DS - including cases recommended for FNA (EU readers, EU data): +0.060 [-0.009, 0.129] (sensitivity), +0.296 [0.238, 0.354] (specificity)
Predicate Device(s):
Reference Device(s):
Not Found
Predetermined Change Control Plan (PCCP) - All Relevant Information
Not Found
§ 892.2060 Radiological computer-assisted diagnostic software for lesions suspicious of cancer.
(a)
Identification. A radiological computer-assisted diagnostic software for lesions suspicious of cancer is an image processing prescription device intended to aid in the characterization of lesions as suspicious for cancer identified on acquired medical images such as magnetic resonance, mammography, radiography, or computed tomography. The device characterizes lesions based on features or information extracted from the images and provides information about the lesion(s) to the user. Diagnostic and patient management decisions are made by the clinical user.(b)
Classification. Class II (special controls). The special controls for this device are:(1) Design verification and validation must include:
(i) A detailed description of the image analysis algorithms including, but not limited to, a detailed description of the algorithm inputs and outputs, each major component or block, and algorithm limitations.
(ii) A detailed description of pre-specified performance testing protocols and dataset(s) used to assess whether the device will improve reader performance as intended.
(iii) Results from performance testing protocols that demonstrate that the device improves reader performance in the intended use population when used in accordance with the instructions for use. The performance assessment must be based on appropriate diagnostic accuracy measures (
e.g., receiver operator characteristic plot, sensitivity, specificity, predictive value, and diagnostic likelihood ratio). The test dataset must contain sufficient numbers of cases from important cohorts (e.g., subsets defined by clinically relevant confounders, effect modifiers, concomitant diseases, and subsets defined by image acquisition characteristics) such that the performance estimates and confidence intervals of the device for these individual subsets can be characterized for the intended use population and imaging equipment.(iv) Standalone performance testing protocols and results of the device.
(v) Appropriate software documentation (
e.g., device hazard analysis; software requirements specification document; software design specification document; traceability analysis; and description of verification and validation activities including system level test protocol, pass/fail criteria, results, and cybersecurity).(2) Labeling must include:
(i) A detailed description of the patient population for which the device is indicated for use.
(ii) A detailed description of the intended reading protocol.
(iii) A detailed description of the intended user and recommended user training.
(iv) A detailed description of the device inputs and outputs.
(v) A detailed description of compatible imaging hardware and imaging protocols.
(vi) Warnings, precautions, and limitations, including situations in which the device may fail or may not operate at its expected performance level (
e.g., poor image quality or for certain subpopulations), as applicable.(vii) Detailed instructions for use.
(viii) A detailed summary of the performance testing, including: Test methods, dataset characteristics, results, and a summary of sub-analyses on case distributions stratified by relevant confounders (
e.g., lesion and organ characteristics, disease stages, and imaging equipment).
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Image /page/0/Picture/0 description: The image contains the logo of the U.S. Food and Drug Administration (FDA). On the left is the Department of Health & Human Services logo. To the right of that is the FDA logo, which is a blue square with the letters "FDA" in white. To the right of the square is the text "U.S. FOOD & DRUG ADMINISTRATION" in blue.
Koios Medical, Inc. % Patricia Setti-Laperch Director of Regulatory Compliance and Quality 242 West 38th Street, 14th Floor NEW YORK NY 10018
December 16, 2021
Re: K212616
Trade/Device Name: Koios DS Regulation Number: 21 CFR 892.2060 Regulation Name: Radiological computer-assisted diagnostic software for lesions suspicious of cancer Regulatory Class: Class II Product Code: POK, QIH Dated: November 12, 2021 Received: November 15, 2021
Dear Patricia Setti-Laperch:
We have reviewed your Section 510(k) premarket notification of intent to market the device referenced above and have determined the device is substantially equivalent (for the indications for use stated in the enclosure) to legally marketed predicate devices marketed in interstate commerce prior to May 28, 1976, the enactment date of the Medical Device Amendments, or to devices that have been reclassified in accordance with the provisions of the Federal Food, Drug, and Cosmetic Act (Act) that do not require approval of a premarket approval application (PMA). You may, therefore, market the device, subject to the general controls provisions of the Act. Although this letter refers to your product as a device, please be aware that some cleared products may instead be combination products. The 510(k) Premarket Notification Database located at https://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfpmn/pmn.cfm identifies combination product submissions. The general controls provisions of the Act include requirements for annual registration, listing of devices, good manufacturing practice, labeling, and prohibitions against misbranding and adulteration. Please note: CDRH does not evaluate information related to contract liability warranties. We remind you, however, that device labeling must be truthful and not misleading.
If your device is classified (see above) into either class II (Special Controls) or class III (PMA), it may be subject to additional controls. Existing major regulations affecting your device can be found in the Code of Federal Regulations, Title 21, Parts 800 to 898. In addition, FDA may publish further announcements concerning your device in the Federal Register.
Please be advised that FDA's issuance of a substantial equivalence determination does not mean that FDA has made a determination that your device complies with other requirements of the Act or any Federal statutes and regulations administered by other Federal agencies. You must comply with all the Act's requirements, including, but not limited to: registration and listing (21 CFR Part 807); labeling (21 CFR Part 801); medical device reporting of medical device-related adverse events) (21 CFR 803) for
1
devices or postmarketing safety reporting (21 CFR 4, Subpart B) for combination products (see https://www.fda.gov/combination-products/guidance-regulatory-information/postmarketing-safety-reportingcombination-products); good manufacturing practice requirements as set forth in the quality systems (QS) regulation (21 CFR Part 820) for devices or current good manufacturing practices (21 CFR 4, Subpart A) for combination products; and, if applicable, the electronic product radiation control provisions (Sections 531-542 of the Act); 21 CFR 1000-1050.
Also, please note the regulation entitled, "Misbranding by reference to premarket notification" (21 CFR Part 807.97). For questions regarding the reporting of adverse events under the MDR regulation (21 CFR Part 803), please go to https://www.fda.gov/medical-device-safety/medical-device-reportingmdr-how-report-medical-device-problems.
For comprehensive regulatory information about mediation-emitting products, including information about labeling regulations, please see Device Advice (https://www.fda.gov/medicaldevices/device-advice-comprehensive-regulatory-assistance) and CDRH Learn (https://www.fda.gov/training-and-continuing-education/cdrh-learn). Additionally, you may contact the Division of Industry and Consumer Education (DICE) to ask a question about a specific regulatory topic. See the DICE website (https://www.fda.gov/medical-device-advice-comprehensive-regulatoryassistance/contact-us-division-industry-and-consumer-education-dice) for more information or contact DICE by email (DICE@fda.hhs.gov) or phone (1-800-638-2041 or 301-796-7100).
Sincerely.
For
Thalia T. Mills, Ph.D. Director Division of Radiological Health OHT7: Office of In Vitro Diagnostics and Radiological Health Office of Product Evaluation and Quality Center for Devices and Radiological Health
Enclosure
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Indications for Use
510(k) Number (if known) K212616
Device Name
Koios DS
Indications for Use (Describe)
Koios DS is an artificial intelligence (Al)/machine learning (ML)-based computer-aided diagnosis (CADx) software device intended for use as an adjunct to diagnostic ultrasound examinations of lesions or nodules suspicious for breast or thyroid cancer.
Kolos DS allows the user to select or confirm regions of interest (ROIs) within an image representing a single lesion or nodule to be analyzed. The software then automatically characterizes the selected image data to generate an AI/MLderived cancer risk assessment and selects applicable lexicon-based descriptors designed to improve overall diagnostic accuracy as well as reduce interpreting physician variability.
Koios DS may also be used as an image viewer of multi-modality digital images, including ultrasound and mammography. The software includes tools that allow users to adjust, measure and document images, and output into a structured report.
Koios DS software is designed to assist trained interpreting physicians in analyzing the breast ultrasound images of adult (>= 22 years) female patients with soft tissue breast lesions and/or thyroid ultrasounds of all adult (>= 22 years) patients with thyroid nodules suspicious for cancer. When utilized by an interpreting physician who has completed the prescribed training, this device provides information that may be useful in recommending appropriate clinical management.
Limitations:
· Patient management decisions should not be made solely on the results of the Koios DS analysis.
· Koios DS software is not to be used for the evaluation of normal tissue, on sites of post-surgical excision, or images with doppler, elastography, or other overlays present in them.
· Koios DS software is not intended for use on portable handheld devices (e.g. smartphones or tablets) or as a primary diagnostic viewer of mammography images.
• The software does not predict the thyroid nodule margin descriptor, extra-thyroidal extension. In the event that this condition is present, the user may select this category manually from the margin descriptor list.
Type of Use (Select one or both, as applicable)
X Prescription Use (Part 21 CFR 801 Subpart D)
Over-The-Counter Use (21 CFR 801 Subpart C)
CONTINUE ON A SEPARATE PAGE IF NEEDED.
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510(k) Summary of Safety and Effectiveness
K212616
This 510(k) summary of safety and effectiveness information is submitted as part of the Premarket Notification in accordance with the requirements of 21 CFR Part 807, Subpart E and Section 807.92.
1. Identification of Submitter:
Submitter: | Koios Medical Inc. |
---|---|
Address: | 242 West 38th Street, 14th Floor |
New York, NY 10018 | |
Phone: | 732-529-5755 |
Fax: | 732-529-5757 |
Contact: | Patricia Setti-Laperch |
Title: | Director of Regulatory Compliance and Quality |
Phone: | 732-529-5755 |
Fax: | 732-529-5757 |
Summary Date: | December 16, 2021 |
2. Identification of Product:
Device Name: | Koios DS, Version 3.0 |
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Device Common Name: | |
Device Classification: | Radiological Computer-Assisted Diagnostic Software |
21 CFR 892.2060, Class II, POK (primary) | |
21 CFR 892.2050, Class II, QIH (secondary) | |
Classification Name: | Radiological Computer-Assisted Diagnostic Software (CADx) for |
Lesions Suspicious for Cancer | |
Manufacturer: | Koios Medical, Inc. |
3. Marketed Devices
In terms of safety and performance, this software medical device is substantially equivalent to the devices listed below:
Model: | Koios DS for Breast |
---|---|
Manufacturer: | Koios Medical, Inc. |
510(k) Number: | K190442 |
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4. Device Description
Koios DS is a software application designed to assist trained interpreting physicians in analyzing breast and thyroid ultrasound images. The software device is a web application that is deployed to a Microsoft IIS web server and accessed by a user through a compatible client. Once logged in and granted access to the Koios DS application, the user examines selected breast or thyroid ultrasound DICOM images. The user selects Regions of Interest (ROls) of orthogonal views of a breast lesion or thyroid nodule for processing by Koios DS. The ROI(s) are transmitted electronically to the Koios DS server for image processing and the results are returned to the user for review.
Breast Functionality:
Koios DS software automatically classifies breast lesions suspicious for cancer based on image data into one of four ACR BI-RADS® Atlas32 or European U1-U53 Classification System-aligned categories (Benign, Probably Benign, Suspicious or Indeterminate, or Probably Malignant) and also displays a continuous graphical Confidence Level Indicator depicting where the lesion falls within its respective category and its relation to neighboring categories. The software automatically classifies the shape (Round, Oval, Irregular) and orientation (Parallel, Not Parallel) of the selected lesion.
Thyroid Functionality:
Koios DS is a software medical device used to analyze ultrasound data to classify user-selected regions containing thyroid nodules suspicious for cancer. The software generates a set of user-editable sonographic nodule descriptor recommendations (Composition, Echogenicity, Shape, Margin, Echogenic Foci) along with an optional, deep-learning derived cancer risk assessment of the suspected nodule from two orthogonal views. Nodule descriptor recommendations are subsequently mapped to a categorical assessment and risk level rating via the ACR TI-RADS ATLAS™45 or American Thyroid Association (ATA) risk stratification systems (RSSs) based on user preference. The software's direct, non-descriptor-based cancer risk assessment is presented as the Koios "AI Adapter" that, when used in conjunction with the ACR TI-RADS or ATA guidelines for nodule risk stratification, is shown to improve overall diagnostic performance of both systems. The Al Adapter operates as an optional lexicon-specific input used to modify the final categorization in the ACR TI-RADS and ATA RSS. The Al adapter positively impacts performance through either a point-based modification (either positive or negative) or a risk-shift modification (either positive or negative) for ACR TI-RADS and the ATA systems,
4 BI-RADS® ATLAS is a registered trademark of American College of Radiology. All Rights Reserved.
² ACR BI-RADS Atlas: https://www.acr.org/-/media/ACR/Files/RADS/BI-RADS/US-Reporting.pdf
³ European Guidelines for Quality Assurance in Breast Cancer Screening and Diagnosis (Health & Consumer Protection Directorate – General). Fourth Edition. Editors: N. Perry, M. Broeders, C. de Wolf, S. Törnberg
4 TI-RADS™ ATLAS is a trademark of American College of Radiology. All Rights Reserved.
ా ACR Thyroid Imaging, Reporting and Data System (TI-RADS): White Paper of the ACR TI-RADS Committee. Tessler, Franklin N. et al. Journal of the American College of Radiology, Volume 14, Issue 5, 587 - 595
6 2015 American Thyroid Association Management Guidelines for Adult Patients with Thyroid Nodules and Differentiated Thyroid Cancer: The American Thyroid Association Guidelines Task Force on Thyroid Cancer. Haugen, Alexander, et al., Thyroid. Jan 2016, 26(1): 1-133.
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respectively. This process creates an Al-augmented categorization that is meant to be used with no other modifications to the decision-making pathway of either RSS. A trained interpreting physician may choose to incorporate or exclude the Koios Al Adapter from the overall assessment when finalizing their diagnostic interpretation.
Koios DS enables the following functionality:
- Breast and Thyroid diagnostic core AI engines enabled by state-of-the-art computer vision and machine learning techniques capable of reading, interpreting, analyzing, classifying and generating findings from ultrasound image data resulting in an automated risk assessment for breast lesions and thyroid nodules suspicious for cancer
- Automatic classification of thyroid nodules aligned to both TI-RADS and ATA descriptors of: Composition, Echogenicity, Shape, Margin, and Echogenic Foci based on user-selected regions of interest (ROIs)
- Automatic classification of breast lesion BI-RADS and U1-U5 Descriptors Shape and Orientation based on user-selected or confirmed regions of interest (ROIs)
- Annotation and description of ultrasound images based on ACR BI-RADS Breast Imaging Atlas and U1-U5 for Koios DS Breast
- Annotation and description of ultrasound images based on and ACR TI-RADS Atlas and ATA classification guidelines for Koios DS Thyroid
- Reporting forms for breast lesion or thyroid nodule identification and tracking in the Electronic Health Record
- Smart Calipers - extraction of user-supplied ROI data (alternately referred to as Calipers) embedded in DICOM SR files from the ultrasound modality
- . Smart Click (Breast only) - generation of automated ROI based on user-supplied position (click on a lesion) within the image
- Ability to save findings to PACS
- Ability to export findings to reporting software
- Remote analysis interface to generate and view results within compatible software (e.g. ultrasound equipment or PACS workstation software)
- Installer and Configuration Wizard
- Single Sign-on (SSO) Windows and LDAP Authentication
- Operating system and platform-agnostic usage
- Zero-footprint web-based HTML5 DICOM image viewer with image manipulation and annotation tools
User Profile:
Koios DS is for use by trained professionals only. Koios DS is not for use by patients. Users must have appropriate medical professional competence, such as trained sonographers and interpreting physicians.
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Use Environment:
Koios DS is a software application for use within a healthcare setting for the examination and assessment of breast lesions or thyroid nodules using ultrasound. It is a platform-agnostic web application that queries and accepts DICOM compliant digital medical files from any compliant device subject to the specified DICOM Conformance Statement for Koios DS. Processing of the image(s) occurs in conjunction with a trained interpreting physician's typical diagnostic case read. The output of the system is a digital display to be used as a concurrent read and report input that may be added as an addendum to the DICOM series selected for processing or exported directly into a patient's draft report.
Operating Principle:
Koios DS is an ASP.NET web application deployed to a Microsoft IIS web server inside a Windows operating system environment accessed by a user through a compatible client. The application provides image-derived data via web triggering and remote analysis.
Once logged in and granted access to the Koios DS application, the user examines selected breast and thyroid ultrasound DICOM images. The user selects or confirms up to two orthogonal views that represent a single breast lesion for processing by the system. For thyroid functionality, two ROIs are required for analysis by the system. The first ROI must be drawn on the transverse view, with the second on the longitudinal view of the nodule. For breast functionality, bench testing has verified a single ROI does not significantly decrease system AUC performance. The ROI(s) are transmitted electronically to the Koios DS server by the Koios DS Breast or Koios DS Thyroid software for image processing and the results are returned to the user for review in the respective interface. Images and data can be stored, communicated, processed, and displayed within the system and/or across computer networks at distributed locations.
The software does not require any specialized hardware to return a diagnostic output, but the time to process ROIs will vary depending on the hardware specifications.
Koios DS contains two distinct AI/ML engines to characterize breast lesions and thyroid nodules. Based on the structured data that exists within the DICOM header for a patient study, the Koios DS system calls the corresponding engine for analysis of the identified lesion or nodule. Each system uses computer vision and machine learning techniques embedded within an engine capable of reading, interpreting, and generating findings from ultrasound data. The underlying breast and thyroid engines draw upon knowledge learned from a large database of known cases, tying image features to their eventual diagnosis, to form a predictive model.
Koios DS results can be saved or transferred in three separate ways: in-transmission, saving to Picture Archiving and Communication System (PACS), and exporting results to third-party reporting software. In-transit transmission may be utilized when users wish to share analyses across viewing workstations. Results can be stored in in-transit memory for a preset period of time defined by a system administrator. After that preset period of time, all results are wiped from the local memory. Another method of saving a report in the patient study on the PACS. After single or multiple lesion or nodule analyses have been performed and ultimately accepted by a trained interpreting physician, Koios DS can export a summary report to PACS as an
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addendum to the DICOM study that was selected for processing. This report serves as future reference and aid in the comparison of cases requiring follow up. This functionality is strictly reserved for approved users and must be configured by a site administrator.
Koios DS also supports exporting results to third-party reporting software to facilitate the reporting process. Saving or exporting preferences can be configured by the system administrator and user.
5. Indications for Use
Koios DS is an artificial intelligence (Al)/machine learning (ML)-based computer-aided diagnosis (CADx) software device intended for use as an adjunct to diagnostic ultrasound examinations of lesions or nodules suspicious for breast or thyroid cancer.
Koios DS allows the user to select or confirm regions of interest (ROIs) within an image representing a single lesion or nodule to be analyzed. The software then automatically characterizes the selected image data to generate an AI/ML-derived cancer risk assessment and selects applicable lexicon-based descriptors designed to improve overall diagnostic accuracy as well as reduce interpreting physician variability.
Koios DS may also be used as an image viewer of multi-modality digital images, including ultrasound and mammography. The software includes tools that allow users to adjust, measure and document images, and output into a structured report.
Koios DS software is designed to assist trained interpreting physicians in analyzing the breast ultrasound images of adult (>= 22 years) female patients with soft tissue breast lesions and/or thyroid ultrasounds of all adult (>= 22 years) patients with thyroid nodules suspicious for cancer. When utilized by an interpreting physician who has completed the prescribed training, this device provides information that may be useful in recommending appropriate clinical management.
Limitations:
• Patient management decisions should not be made solely on the results of the Koios DS analysis.
• Koios DS software is not to be used for the evaluation of normal tissue, on sites of post-surgical excision, or images with doppler, elastography, or other overlays present in them.
• Koios DS software is not intended for use on portable handheld devices (e.g. smartphones or tablets) or as a primary diagnostic viewer of mammography images.
• The software does not predict the presence of the thyroid nodule margin descriptor, extra-thyroidal extension. In the event that this condition is present, the user may select this category manually from the margin descriptor list.
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6. Substantial Equivalence Chart
| Product | Koios DS for Breast
(K190442) | Koios DS
(subject device) |
|---------------------------------------------------------------------------|---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| Physical
Characteristics | Software Package
Operates on off-the-shelf hardware | Software Package
Operates on off-the-shelf hardware |
| Storage | Storage not supported | Storage not supported |
| Image Input
Characteristics | DICOM | DICOM |
| Intended
Use/Indications
for Use | Decision support device used to assist in
the assessment and
characterization of breast lesions
using US image data. | Decision support device used to assist in
the assessment and characterization of
breast lesions and thyroid nodules using US
image data. |
| | Koios Decision Support (DS) for Breast
is a software application designed to
assist trained interpreting physicians
in analyzing the breast ultrasound
images of patients with soft tissue
breast lesions who are being referred
for further diagnostic ultrasound
examination. | Koios Decision Support (DS) is an artificial
intelligence (AI)/machine learning (ML)- based computer-aided diagnosis (CADx)
software device intended for use as an
adjunct to diagnostic ultrasound
examinations of lesions suspicious for
breast or thyroid cancer. |
| | Koios DS for Breast is a machine
learning-based decision support
system, indicated as an adjunct to
diagnostic ultrasound for breast
cancer. | Koios DS allows the user to select or
confirm regions of interest (ROIs) within an
image representing a single lesion or
nodule to be analyzed. The software then
automatically characterizes the selected
image data to generate an AI/ML-derived
cancer risk assessment and selects
applicable lexicon-based descriptors
designed to improve overall diagnostic
accuracy as well as reduce interpreting
physician variability. |
| | Koios DS for Breast automatically
classifies user-selected region(s) of
interest (ROIs) containing a breast
lesion into four BI-RADS-aligned
categories (Benign, Probably Benign,
Suspicious, Probably Malignant), and
displays a continuous graphical
confidence level indicator of where
the lesion falls across all categories.
Koios DS for Breast also automatically
classifies lesion shape and orientation
according to BI-RADS descriptors. | Koios DS software may also be used as an
image viewer of multi-modality digital
images, including ultrasound and
mammography. The software includes
tools that allow users to adjust, measure
and document images, and output into a
structured report. |
| | The software requires a user to select
up to two ROIs, from up to two
orthogonal views, that represent a
single lesion to be selected and
processed. When utilized by an
interpreting physician who has
completed the prescribed training | Koios DS software is designed to assist
trained interpreting physicians in analyzing
the breast ultrasound images of adult (>=
22 years) female patients with soft tissue
breast lesions and/or thyroid ultrasounds
of all adult (>= 22 years) patients with
thyroid nodules suspicious for cancer. |
| | this device provides information that
may be useful in rendering an
accurate diagnosis.
Patient management decisions should
not be made solely on the results of
the Koios DS for Breast analysis. This
device is intended to help trained
interpreting physicians improve their
overall accuracy as well as reduce
inter- and intra-operator variability.
Koios DS for Breast may also be used
as an image viewer of multi-modality
digital images, including ultrasound
and mammography. The software
includes tools that allow users to
adjust, measure and document
images, and output into a structured
report. | When utilized by an interpreting physician
who has completed the prescribed
training, this device provides information
that may be useful in recommending
appropriate clinical management. |
| Target Population
(subset of above
for comparison
purposes) | Koios Decision Support (DS) for Breast
is a software application designed to
assist trained interpreting physicians
in analyzing the breast ultrasound
images of patients with soft tissue
breast lesions who are being referred
for further diagnostic ultrasound
examination. | Koios DS software is designed to assist
trained interpreting physicians in analyzing
the breast ultrasound images of adult (>=
22 years) female patients with soft tissue
breast lesions and/or thyroid ultrasounds
of all adult (>= 22 years) patients with
thyroid nodules suspicious for cancer. |
| Limitations for
Use
(subset of above
for comparison
purposes) | Limitations:
Koios DS for Breast is not to be used
on sites of post-surgical excision, or
images with doppler, elastography, or
other overlays present in them.
Koios DS for Breast is not intended for
the primary interpretation of digital
mammography images.
Koios DS for Breast is not intended for
use on mobile devices. | Limitations:
• Patient management decisions should
not be made solely on the results of the
Koios DS analysis.
• Koios DS software is not to be used for
the evaluation of normal tissue, on sites of
post-surgical excision, or images with
doppler, elastography, or other overlays
present in them.
• Koios DS software is not intended for use
on portable handheld devices (e.g.
smartphones or tablets) or as a primary
diagnostic viewer of mammography
images.
• The software does not predict the
presence of the thyroid nodule margin
descriptor, extra-thyroidal extension. In
the event that this condition is present, the
user may select this category manually. |
| | | from the margin descriptor list. |
| Modality Used for
Analysis | Breast Ultrasound Data | Breast Ultrasound Data
Thyroid Ultrasound Data |
| Input | Medical images provided in a DICOM
format | Medical images provided in a DICOM
format |
| ROI
Requirements | The software requires a user to select
up to two ROIs, from up to two
orthogonal views, that represent a
single lesion to be selected and
processed. | Breast
The software requires a user to select up to
two ROIs, from up to two orthogonal
views, that represent a single lesion to be
selected and processed.
Thyroid
Two ROIs that represent a single lesion to
be selected and processed are required for
analysis.
The first ROI is drawn on the transverse
view of the nodule. The second is drawn on
the longitudinal view. |
| Output (Breast) | Koios defined categorical and
continuous outputs (confidence level
indicator) that align to BI-RADS and
auto-classified shape and orientation | Koios DS Breast defined categorical and
continuous outputs (confidence level
indicator) that align to BI-RADS, U1-U5, and
auto-classified shape and orientation. |
| Output (Thyroid) | N/A | Koios DS Thyroid software automatically
classifies thyroid nodules suspicious for
cancer based on image data generating an
output aligned to either the TI-RADS or
ATA classification guidelines. The system
automatically generates user-modifiable
nodule descriptors (Composition,
Echogenicity, Shape, Margin, Echogenic
Foci) and a direct, image-derived cancer
risk assessment that is translated into an
optional lexicon-specific modifier. |
| Comparative
Clinical
Performance
Testing (Breast) | Metric: AUC
Cases: 900
Readers: 15 | Metric: AUC
Cases: 900
Readers: 15 |
| Comparative
Clinical
Performance
Testing (Thyroid) | N/A | Metric: AUC
Cases: 650
Readers: 15 |
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11
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7. Description of Similarities and/or Differences
Intended Use/Indications for Use (IFU)
Comparing the IFU of the predicate device Koios DS Breast (K190442) and Koios DS, there are several key similarities and differences outlined below:
Both devices are intended to be utilized as diagnostic aids that operate on user-supplied Regions of Interest (ROIs). Koios DS Thyroid functionality requires two ROIs representing a single lesion to be selected and processed for analysis. The first ROI is drawn on the transverse view of the second is drawn on the longitudinal view.
The Koios DS system also contains the Smart Click (breast only) and Smart Caliper functionalities for streamlining the previously manual ROI selection process. The Smart Click functionality enables the user to click on the center of a lesion in order to activate a system-generated region of interest surrounding the selected lesion for the user. The Smart Calipers functionality ingests caliper data from compatible ultrasound devices with the capability to use a calculation package when drawing calipers on lesions. Koios DS can automatically generate ROIs and resulting analyses for the user based on this caliper data. Both Smart Caliper-generated ROIS can be edited or deleted by the user and have been demonstrated to have no adverse impact on the diagnostic outputs of the Koios DS engines.
The intended use and indications for use statements have been updated from those of the predicate device in order to enhance labeling clarity and to detail the additional breast and thyroid cancer decision support functionality and limitations. These differences do not affectiveness of the device when used as a labeled Computer-Assisted Diagnostic software for lesions suspicious for cancer.
Target Patient Population
Both the Koios DS Breast predicate and the subject device are software applications designed to assist trained interpreting physicians in analyzing the ultrasound images of patients with soft tissue lesions who are being referred for further diagnostic ultrasound examination.
Additional detail has been included to clarify the Koios DS Breast product indications for females, as well as to exclude pediatric use for Koios DS Breast and Koios DS Thyroid.
Technological Characteristics
Modality
Koios DS shares the ultrasound modality requirements of Koios DS Breast and provides additional functionality for Thyroid ultrasound images.
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Input
Per the respective device descriptions of Koios DS Breast and Koios DS, the input to each consists of medical images provided in a DICOM format. The technical implementation for ingesting images for processing occurs via the same DICOM-based interface. Based on the structured data that exists within the DICOM header for a patient study or a user selection, the Koios DS system calls the appropriate corresponding engine (Breast or Thyroid) for analysis of the identified lesion or nodule. The Koios DS system also contains the Smart Click and Smart Caliper functionalities for streamlining the previously manual ROI selection process. Regarding Region of Interest image input data, Koios DS Thyroid functionality requires two ROIs representing a single lesion to be selected and processed for analysis, whereas this is optional for breast.
Output
When comparing breast functionality, the predicate and subject devices differ only in the additional optional output display in alignment with the European U1-U5 Classification system for enhanced usability in international markets. Direct comparison with the Koios DS Breast v2.0 predicate engine's categorical output performance determined there is a significant increase in AUC (5%), no significant change in sensitivity, and a significant increase (24%) in specificity. Koios DS retains the identical descriptor outputs and performance for the assessment of shape and orientation.
Koios DS software contains functionality for automatically classifying thyroid nodules suspicious for cancer. Similar to Koios DS Breast, this is based on image data. The system generates an output aligned to either the TI-RADS or ATA classification guidelines (in comparison with BI-RADS and U1-U5 for breast). The system automatically generates user-modifiable thyroid nodule descriptors (Composition, Echogenicity, Shape, Margin, Echogenic Foci), analogous to the Shape and Orientation descriptors present in the breast functionality, and a direct, image-derived cancer risk assessment that is translated into an optional lexicon-specific (TI-RADS or ATA) modifier. Clinical data demonstrates that this provides a significant improvement in overall reader performance when utilizing Koios DS for the interpretation of thyroid ultrasound studies.
Performance Testing
To compare the performance of the subject device to the predicate device (K190442), a clinical study was conducted in order to assess the performance of the thyroid functionality of the subject device and bench testing was conducted on the updated breast functionality. As in the predicate device, ground truth for all breast analysis was determined by pathology or 1-year follow-up for cases that were not biopsied, whereas for thyroid it was determined exclusively via histo/cyto-pathology and/or surgical excision. The breast and thyroid engine validation sets are composed of 900 lesions from 900 different patients and 650 lesions from 650 different patients, respectively. Each was set aside from the systems' training data for the purpose of validating performance.
While operating on identical modalities, but different body regions (breast versus thyroid), similar primary endpoints were utilized in the clinical validation studies of the subject and predicate devices. Both clinical studies evaluated an Area Under the Curve (AUC) shift when comparing the performance of users alone versus users utilizing the respective software platform with a 1-month washout period. The number of cases evaluated in the predicate study was 900, while the subject device study evaluated a total of 650 cases which were both
14
determined via power estimates utilizing pilot study estimates for effect size. The number of interpreting physicians utilized in both studies was 15 readers. Additionally, bench testing was conducted to assess the standalone performance, as measured by AUC, on identical breast validation datasets.
The results of the subject device's clinical study evaluating its impact on the diagnostic performance of thyroid lesion classification successfully met all primary endpoints demonstrating a 0.083 (0.066, 0.099 95% Cl) improvement in parametric AUC on the overall dataset along with a stratified analysis of United States (US)based readers on US-based cases demonstrating an improvement of 0.074 (0.051, 0.098 95% Cl) in parametric AUC. The absolute improvement in AUC on the US-only stratification demonstrated a larger mean shift than seen in the predicate device's study (0.074 versus 0.037).
Previous clinical study evaluations reported in K190442 have demonstrated significant AUC improvements for readers utilizing Koios DS Breast. The subject device's updated breast classification engine was compared to the predicate device on the same 900 case validation set and demonstrated a statistically significant shift in AUC to 0.929 (0.913, 0.945 95% CI) from 0.882 (0.857, 0.907 95% CI). An additional 50 new cases were added to the set and evaluated to test the subject device for robustness to dataset drift. This additional test generated a resulting AUC of 0.930 [0.914, 0.946 95% Cl], demonstrating there is no degradation in performance attributable to dataset drift.
In conclusion, the subject device has demonstrated substantially equivalent performance to the predicate by showing statistically significant results against similar success criteria in both clinical and bench testing comparisons.
8. Performance Testing - Bench/Non-Clinical
Breast Engine
Malignancy Risk Classification:
Bench testing was performed on the updated breast engine to ascertain the degree of concordance with trained interpreting physicians. Ground truth for malignancy risk classification was determined by pathology or 1-year follow-up for cases that were not biopsied. The system was analyzed on 900 lesions from 900 different patients set aside from the system's training data for the purpose of validating performance. Each lesion was represented by two orthogonal images (e.g. radial and anti-radial), providing a total of 1800 images. System performance on the 900 cases reported an AUC of 92.9%, with a Sensitivity of 0.97 [0.96, 0.99] and a Specificity of 0.61 [0.57, 0.66].
Direct comparison with the prior (Koios DS Breast v2.0 predicate) engine's performance determined there is a significant increase in AUC (5%), no significant change in sensitivity, and a significant increase (24%) in specificity.
In summary, a comprehensive evaluation of the breast engines was conducted across key performance metrics and bench testing demonstrated that the system exceeds physician performance measured by AUC, sensitivity,
15
and specificity. The engine's shape and orientation predictions have not been modified from the previously cleared device (which demonstrated the required level of agreement with the subjective categorizations assigned by physicians). Testing characterizes the system's sensitivity to shifts in the selected region of interests (ROI) and transducer frequency. Testing characterizes the system's Positive Value (PPV), Negative Predictive Value (NPV), Positive Likelihood Ratio (PLR) and Negative Likelihood Ratio (NLR) in comparison with physicians. Testing demonstrates that the performance of the engine does not demonstrate degradation when regions of interest are provided by the Smart Click system, as compared to manually drawn regions of interest. In all tests, the Breast engine met or exceeded performance requirements.
Thyroid Engine
Bench testing was performed on the thyroid engine to ascertain the degree of concordance with trained interpreting physicians utilizing both the ACR TI-RADS and ATA classification systems. Ground truth for malignancy risk classification was determined by pathology results only. The system was analyzed on 500 lesions from 500 different patients set aside from the system's training data for the purpose of validating performance. Each lesion was represented by two orthogonal images (e.g. radial and anti-radial), providing a total of 1000 images.
When applied to diagnoses made using ACR TI-RADS guidelines, the Al Adapter and descriptor predictors achieved an AUC of 79.8%, demonstrating a significant increase over the average physician AUC. When recommending biopsy, the system's sensitivity is 0.644 [0.545, 0.744] and specificity is 0.612 [0.566, 0.658]. When recommending follow-up, the system's sensitivity and specificity are 0.879 [0.812, 0.946] and 0.495 [0.446, 0.544], respectively. In both scenarios, bench testing of the system demonstrates a non-significant improvement in sensitivity and a significant improvement in specificity over the physician average.
Tests demonstrating AI Adapter impact on ATA classifications yielded similarly improved performance. With application of the Al Adapter, physician AUC demonstrates a significant increase of 9.135% [5.975, 12.294]. Sensitivity shows a non-significant increase of 0.511% [-5.182, 6.204], while specificity shows a significant increase of 18.741% [9.885, 27.596].
Bench testing included verification of standalone performance with TI-RADS and ATA outputs, as well as performance when compared to a separate data set including data from independent sites (separate and apart from the sites/data used to train and tune the algorithm).
In summary, a comprehensive evaluation of the thyroid engine was conducted across key performance metrics and bench testing demonstrated that application of the Koios DS Al Adapter exceeds physician performance as measured by AUC, sensitivity, and specificity. Descriptor predictions were tested objectively – against ground truth pathology. Testing demonstrated that performance requirements were met under ACR TI-RADS and ATA reporting systems as well as when compared against independent site data. Outputs were additionally tested subjectively and met the requirements for agreement with readers' descriptor categorizations. Testing characterized the sensitivity of the system with respect to shifts in the region of interest and variation in performance between high and low transducer frequencies. System performance on data acquired from
16
independent sites meets performance requirements. In all tests, the Thyroid engine met or exceeded performance requirements.
9. Performance Testing - Clinical
Breast
A clinical study was previously executed (K190442) to determine the effect of Koios DS Breast on reader performance. As discussed in the prior section, the prior device's performance has been met or significantly improved across all measured metrics by the subject device. This data continues to apply to the breast functionality within the subject device, with the understanding that its performance is superior, and it would therefore provide an equivalent or greater benefit. The below summary of the clinical study data has been included for ease of reference.
The study objective was to determine the impact on Interpreting Physician (Reader) performance as defined by the area under the Receiver Operating Characteristic (ROC) Curve (AUC) when Koios DS Breast and an ultrasound examination are combined (USE + DS), compared to USE Alone in patients that present with a soft tissue breast lesion through any form of imaging or physical examination and are referred for diagnostic ultrasound.
The study consisted of 15 readers with varying levels of training and experience providing analysis on a randomized set of 900 patient cases presented with USE + DS and USE Alone in two reading periods separated by a 1-month wash-out, totaling 1800 cases analyzed per reader set and dataset were distributed in accordance with FDA guidance and are explained in detail below:
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Reader Background
| Reader
ID | Board
Certification/
Specialty | Breast
Fellowship
Trained
and/or
Dedicated
Breast Imager | Years of
Experience -
Mammography
and/or Breast
Ultrasound | Academic
Institution
Affiliation
(Yes/No) | MQSA
Qualified
Interpreting
Physician |
|--------------|--------------------------------------|-------------------------------------------------------------------------|------------------------------------------------------------------------|----------------------------------------------------|------------------------------------------------|
| 1 | Diagnostic
Radiology | No | 13 years | No | Yes |
| 2 | Diagnostic
Radiology | No | 4 years | No | No |
| 3 | Diagnostic
Radiology | Yes | 7 years | Yes | Yes |
| 4 | Breast
Surgeon | No | 0 years | No | No |
| 5 | OB/GYN | No | 20 years | No | No |
| 6 | Diagnostic
Radiology | No | 13 years | Yes | No |
| 7 | Diagnostic
Radiology | No | 3 years | Yes | No |
| 8 | OB/GYN | No | 0 years | No | No |
| 9 | Diagnostic
Radiology | Yes | 15 years | No | Yes |
| 10 | Diagnostic
Radiology | No | 13 years | No | No |
| 11 | Diagnostic
Radiology | Yes | 30 years | No | Yes |
| 12 | Diagnostic
Radiology | Yes | 10 years | Yes | Yes |
| 13 | Diagnostic
Radiology | No | 0 years | No | No |
| 14 | Interventional
Radiology | No | 4 years | No | No |
| 15 | Breast
Surgeon | No | 25 years | Yes | No |
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Dataset Demographic Information
The Koios DS Breast engine was tested on images sourced from a wide variety of ultrasound hardware and data with the following patient demographics to ensure the system performance is generalizable to and representative of diverse populations. Patient demographic distribution was based upon data from the Breast Cancer Surveillance Consortium (2006-2009)7.
Image /page/18/Figure/2 description: This bar chart shows the count of benign and cancer diagnoses. The x-axis represents the diagnosis type, with 'benign' and 'cancer' as the categories. The y-axis represents the count, with the benign diagnosis having a count of 470 (52.2%) and the cancer diagnosis having a count of 430 (47.8%).
The following figures represent the final validation dataset (900 cases):
Image /page/18/Figure/4 description: The image is a bar chart that shows the distribution of BI-RADS categories. The x-axis represents the BI-RADS category, and the y-axis represents the count. The bar chart shows that the most frequent category is 4A, with a count of 222 (24.7%), followed by 4C with a count of 187 (20.8%). The least frequent category is 2, with a count of 68 (7.6%).
Distribution of Malignancy in Final Validation Set
Image /page/18/Figure/6 description: The image is a bar chart showing the distribution of ethnicity. The x-axis represents different ethnicities: white, black, hispanic, asian, and other. The y-axis represents the count, with the highest count for white ethnicity at 592 (65.8%), followed by asian at 133 (14.8%), black at 77 (8.6%), hispanic at 73 (8.1%), and other at 25 (2.8%).
Distribution of BI-RADS Category in Final Validation Set
Image /page/18/Figure/8 description: The image is a bar chart showing the distribution of ages. The x-axis represents age groups, including 'n/a', '7 Data were obtained from the Breast Cancer Surveillance Consortium, funded by the National Cancer Institute (HHSN261201100031C). From the Breast Cancer Surveillance Consortium website, http://www.bcsc-research.org/
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Image /page/19/Figure/0 description: The image contains two bar charts. The first bar chart shows the distribution of tumor sizes, with the x-axis representing size in millimeters and the y-axis representing the count. The tumor sizes are categorized as n/a, 0 for all reader pairs. The standard error for USE + DS and USE Alone was computed to assess if the shifts in the metric were significant. The average Kendall Tau-B of USE Alone was .5404 (.5301, .5507) and the average Kendall Tau-B of USE + DS was .6797 (.6653, .6941) with 95% Cl demonstrating a significant increase in the metric (α = .05).
Also assessed was the effect of Koios DS on intra-operator variability leveraging 150 reads that did not switch from USE Alone to USE + DS across the washout session in the reader study (75 each). USE Alone class switching rate was 13.6% and the USE + DS class switching rate was 10.8% (p = 0.042), demonstrating a statistically significant reduction in intra-reader variability when using USE + DS.
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Thyroid
An observational case-controlled, Multi-Reader, Multi-Case (MRMC) retrospective clinical trial (CRRS-3) was executed to determine the effect of Koios DS Thyroid on reader performance.
Effect on performance was defined by measuring the area under the Receiver Operating Characteristic (ROC) Curve (AUC) when Koios DS and an ultrasound examination were combined (USE + DS), compared to unassisted TI-RADS based Reader performance (USE Alone). All data analysis cases consisted of USE Alone and USE + DS image readings in patients that presented with a thyroid abnormality through any form of imaging or physical examination and were referred for diagnostic ultrasound where a nodule was subsequently discovered.
Data analysis in the CRRS-3 study was based on 650 retrospectively collected cases that were assigned a TI-RADS Assessment Category 1 through 5 at the of initial review at study entry based upon the interpreting physician of the ultrasound evaluation. The study consisted of 15 readers reviewing and interpreting 650 cases twice (1300 total cases per reader). All data analysis was based on two randomized evaluations of each case with and without the assistance of Koios DS software with a 1-month washout period between corresponding presentations of the case and interpretations by physicians.
The study design called for a mixed population of physician readers (11/15 or 73% US based) and cases (500 or 77% US based) coming from both the US and Europe. Readers with a current medical license who met inclusion criteria and completed the study training protocol were considered trained interpreting physicians for study purposes. Readers possessed varying levels of training and experience, as detailed below:
| Reader
ID | Reader Category | Experience (post-
residency) |
|--------------|--------------------------------|---------------------------------|
| R1 | Domestic Endocrinologist (End) |