K Number
K251351

Validate with FDA (Live)

Device Name
AccuContour 4.0
Date Cleared
2026-01-23

(268 days)

Product Code
Regulation Number
892.2050
Age Range
21 - 100
Reference & Predicate Devices
Predicate For
N/A
AI/MLSaMDIVD (In Vitro Diagnostic)TherapeuticPediatricDiagnosticis PCCP AuthorizedThirdpartyExpeditedreview
Intended Use

It is used by radiation oncology department to segment CT images, to generate needed information for treatment planning, treatment evaluation and treatment adaption.

Device Description

The proposed device, AccuContour 4.0 Family, is a standalone software with the following variants: AccuContour and AccuContour-Lite. The functions of AccuContour-Lite is a subset of AccuContour.

AccuContour:
It is used by oncology department to register multi-modality images and segment (non-contrast) CT images, to generate needed information for treatment planning, treatment evaluation and treatment adaptation.

The product has two image processing functions:

  1. Deep learning contouring: it can automatically contour organs-at-risk, in head and neck, thorax, abdomen and pelvis (for both male and female) areas,
  2. Automatic registration: rigid and deformable registration, and
  3. Manual contouring.

It also has the following general functions:

  • Receive, add/edit/delete, transmit, input/export, medical images and DICOM data;
  • Patient management;
  • Review tool of processed images;
  • Extension tool;
  • Plan evaluation and plan comparison;
  • Dose analysis.

AccuContour-Lite:
It is used by oncology department to segment (non-contrast) CT images, to generate needed information for treatment planning, treatment evaluation and treatment adaptation.

The product has one image processing function:
Deep learning contouring: it can automatically contour organs-at-risk, in head and neck, thorax, abdomen and pelvis (for both male and female) areas,

It also has the following general functions:

  • Receive, add/edit/delete, transmit, input/export, medical images and DICOM data;
  • Patient management;
  • Review tool of processed images.
AI/ML Overview

Here's an analysis of the acceptance criteria and study details for the AccuContour 4.0, extracted and organized from the provided FDA 510(k) clearance letter.


1. Table of Acceptance Criteria and Reported Device Performance

The acceptance criteria are derived from the "Pass Criteria" columns in Tables 1, 2, 3, and 4, which specify minimum DSC and maximum HD95 values. The reported device performance is represented by the "Lower Bound 95% CI" for both DSC and HD95, and the "Average Rating" for clinical applicability.

Table A: Performance for Synthetic CT (sCT) Contouring Function (Derived from MR Images)

Organ & StructureSizeDSC Pass CriteriaHD95 Pass Criteria (mm)Reported DSC (Lower Bound 95% CI)Reported HD95 (Lower Bound 95% CI, mm)Average Rating (1-5)Meet Criteria? (DSC)Meet Criteria? (HD95)
TemporalLobe_LMedium0.65N/A0.8864.319 (N/A criteria)4.5YesN/A
TemporalLobe_RMedium0.65N/A0.8784.382 (N/A criteria)4.6YesN/A
BrainLarge0.8N/A0.9861.877 (N/A criteria)4.7YesN/A
BrainStemMedium0.65N/A0.8434.999 (N/A criteria)4.5YesN/A
SpinalCordMedium0.65N/A0.8673.030 (N/A criteria)4.8YesN/A
OpticChiasmSmall0.5N/A0.8044.771 (N/A criteria)4.1YesN/A
OpticNerve_LSmall0.5N/A0.8222.235 (N/A criteria)4.1YesN/A
OpticNerve_RSmall0.5N/A0.7942.422 (N/A criteria)4.2YesN/A
InnerEar_LSmall0.5N/A0.8432.164 (N/A criteria)4.2YesN/A
InnerEar_RSmall0.5N/A0.8062.102 (N/A criteria)4.4YesN/A
MiddleEar_LSmall0.5N/A0.8243.580 (N/A criteria)4.5YesN/A
MiddleEar_RSmall0.5N/A0.7923.700 (N/A criteria)4.4YesN/A
Eye_LSmall0.5N/A0.9061.659 (N/A criteria)4.8YesN/A
Eye_RSmall0.5N/A0.8971.584 (N/A criteria)4.9YesN/A
Lens_LSmall0.5N/A0.8363.368 (N/A criteria)4.5YesN/A
Lens_RSmall0.5N/A0.8413.379 (N/A criteria)4.2YesN/A
PituitarySmall0.5N/A0.8012.267 (N/A criteria)4.4YesN/A
MandibleSmall0.5N/A0.9131.844 (N/A criteria)4.3YesN/A
TMJ_LSmall0.5N/A0.8302.819 (N/A criteria)4.4YesN/A
TMJ_RSmall0.5N/A0.8172.722 (N/A criteria)4.5YesN/A
OralCavityMedium0.65N/A0.9163.677 (N/A criteria)4.7YesN/A
LarynxMedium0.65N/A0.7952.196 (N/A criteria)4.4YesN/A
TracheaMedium0.65N/A0.8702.452 (N/A criteria)4.5YesN/A
EsophagusMedium0.65N/A0.8002.680 (N/A criteria)4.7YesN/A
Parotid_LMedium0.65N/A0.8512.386 (N/A criteria)4.6YesN/A
Parotid_RMedium0.65N/A0.8682.328 (N/A criteria)4.6YesN/A
Submandibular_LMedium0.65N/A0.8334.920 (N/A criteria)4.5YesN/A
Submandibular_RMedium0.65N/A0.7832.348 (N/A criteria)4.3YesN/A
ThyroidMedium0.65N/A0.8031.911 (N/A criteria)4.8YesN/A
BrachialPlexus_LMedium0.65N/A0.8285.347 (N/A criteria)4.4YesN/A
BrachialPlexus_RMedium0.65N/A0.8005.062 (N/A criteria)4.3YesN/A
Lung_LLarge0.8N/A0.9681.635 (N/A criteria)4.5YesN/A
Lung_RLarge0.8N/A0.9761.516 (N/A criteria)4.7YesN/A
HeartLarge0.8N/A0.9592.496 (N/A criteria)4.5YesN/A
LiverLarge0.8N/A0.9412.439 (N/A criteria)4.0YesN/A
Kidney_LLarge0.8N/A0.8922.748 (N/A criteria)4.7YesN/A
Kidney_RLarge0.8N/A0.8952.797 (N/A criteria)4.5YesN/A
StomachLarge0.8N/A0.7824.754 (N/A criteria)4.1No*N/A
PancreasMedium0.65N/A0.8276.271 (N/A criteria)4.0YesN/A
DuodenumMedium0.65N/A0.8156.447 (N/A criteria)4.1YesN/A
RectumMedium0.65N/A0.7962.047 (N/A criteria)3.9YesN/A
BowelBagLarge0.8N/A0.8087.380 (N/A criteria)4.0YesN/A
BladderLarge0.8N/A0.9432.082 (N/A criteria)4.5YesN/A
MarrowLarge0.8N/A0.8891.842 (N/A criteria)4.6YesN/A
FemurHead_LMedium0.65N/A0.9502.261 (N/A criteria)4.5YesN/A
FemurHead_RMedium0.65N/A0.9412.466 (N/A criteria)4.6YesN/A

*Note: For Stomach, the reported DSC (0.782) is below the pass criteria (0.8). However, the document states, "The results indicate that the auto-segmentation performance of the AccuContour system for sCT images derived from both CBCT and MR modalities meets the requirements for geometric accuracy." This suggests there might be an overall or combined assessment, or other factors led to acceptance despite this single instance. The average clinical rating is 4.1, which is above the threshold of 3.

Table B: Performance for Synthetic CT (sCT) Contouring Function (Derived from CBCT Images)

Organ & StructureSizeDSC Pass CriteriaHD95 Pass Criteria (mm)Reported DSC (Lower Bound 95% CI)Reported HD95 (Lower Bound 95% CI, mm)Average Rating (1-5)Meet Criteria? (DSC)Meet Criteria? (HD95)
TemporalLobe_LMedium0.65N/A0.8543.451 (N/A criteria)4.8YesN/A
TemporalLobe_RMedium0.65N/A0.8593.258 (N/A criteria)4.6YesN/A
BrainLarge0.8N/A0.9861.804 (N/A criteria)4.7YesN/A
BrainStemMedium0.65N/A0.9034.678 (N/A criteria)4.5YesN/A
SpinalCordMedium0.65N/A0.8692.088 (N/A criteria)4.8YesN/A
OpticChiasmSmall0.5N/A0.7955.252 (N/A criteria)4.4YesN/A
OpticNerve_LSmall0.5N/A0.8152.373 (N/A criteria)4.2YesN/A
OpticNerve_RSmall0.5N/A0.8162.210 (N/A criteria)4.1YesN/A
InnerEar_LSmall0.5N/A0.8002.144 (N/A criteria)4.5YesN/A
InnerEar_RSmall0.5N/A0.7942.171 (N/A criteria)4.2YesN/A
MiddleEar_LSmall0.5N/A0.8003.301 (N/A criteria)4.5YesN/A
MiddleEar_RSmall0.5N/A0.7973.888 (N/A criteria)4.5YesN/A
Eye_LSmall0.5N/A0.9441.553 (N/A criteria)4.8YesN/A
Eye_RSmall0.5N/A0.9411.678 (N/A criteria)4.9YesN/A
Lens_LSmall0.5N/A0.8203.532 (N/A criteria)4.5YesN/A
Lens_RSmall0.5N/A0.8213.370 (N/A criteria)4.7YesN/A
PituitarySmall0.5N/A0.8022.496 (N/A criteria)4.4YesN/A
MandibleSmall0.5N/A0.8702.227 (N/A criteria)4.3YesN/A
TMJ_LSmall0.5N/A0.7742.775 (N/A criteria)4.3YesN/A
TMJ_RSmall0.5N/A0.8002.791 (N/A criteria)4.5YesN/A
OralCavityMedium0.65N/A0.8853.794 (N/A criteria)4.8YesN/A
LarynxMedium0.65N/A0.7932.827 (N/A criteria)4.8YesN/A
TracheaMedium0.65N/A0.8732.545 (N/A criteria)4.5YesN/A
EsophagusMedium0.65N/A0.8002.811 (N/A criteria)4.5YesN/A
Parotid_LMedium0.65N/A0.8912.415 (N/A criteria)4.6YesN/A
Parotid_RMedium0.65N/A0.8942.525 (N/A criteria)4.6YesN/A
Submandibular_LMedium0.65N/A0.7455.026 (N/A criteria)4.8YesN/A
Submandibular_RMedium0.65N/A0.7972.192 (N/A criteria)4.7YesN/A
ThyroidMedium0.65N/A0.8232.182 (N/A criteria)4.8YesN/A
BrachialPlexus_LMedium0.65N/A0.8053.922 (N/A criteria)4.4YesN/A
BrachialPlexus_RMedium0.65N/A0.8233.529 (N/A criteria)4.2YesN/A
Lung_LLarge0.8N/A0.9471.587 (N/A criteria)4.5YesN/A
Lung_RLarge0.8N/A0.9711.635 (N/A criteria)4.3YesN/A
HeartLarge0.8N/A0.8961.823 (N/A criteria)4.5YesN/A
LiverLarge0.8N/A0.9142.595 (N/A criteria)4.6YesN/A
Kidney_LLarge0.8N/A0.9222.645 (N/A criteria)4.7YesN/A
Kidney_RLarge0.8N/A0.9062.611 (N/A criteria)4.5YesN/A
StomachLarge0.8N/A0.8584.681 (N/A criteria)4.2YesN/A
PancreasMedium0.65N/A0.8225.548 (N/A criteria)4.4YesN/A
DuodenumMedium0.65N/A0.8185.252 (N/A criteria)4.1YesN/A
RectumMedium0.65N/A0.7974.253 (N/A criteria)4.3YesN/A
BowelBagLarge0.8N/A0.8505.028 (N/A criteria)4.0YesN/A
BladderLarge0.8N/A0.9263.322 (N/A criteria)4.7YesN/A
MarrowLarge0.8N/A0.8372.148 (N/A criteria)4.7YesN/A
FemurHead_LMedium0.65N/A0.8931.639 (N/A criteria)4.8YesN/A
FemurHead_RMedium0.65N/A0.9271.807 (N/A criteria)4.9YesN/A

Table C: Performance for 4DCT Registration Function (Rigid Registration)

Organ & StructureSizeDSC Pass CriteriaReported DSC (Lower Bound 95% CI)Average Rating (1-5)Meet Criteria?
TracheaMedium0.650.8884.5Yes
EsophagusMedium0.650.8364.5Yes
Lung_LLarge0.80.9324.7Yes
Lung_RLarge0.80.9294.8Yes
Lung_AllLarge0.80.9304.8Yes
HeartLarge0.80.9174.6Yes
SpinalCordMedium0.650.9434.6Yes
LiverLarge0.80.8884.6Yes
StomachLarge0.80.7914.5No*
A_AortaLarge0.80.9174.4Yes
SpleenLarge0.80.7864.5No*
BodyLarge0.80.9954.9Yes

*Note: For Stomach (0.791) and Spleen (0.786), the reported DSC is below the pass criteria (0.8). However, the document states, "According to the results, the accuracy of 4DCT image registration images meets the requirements and all structure models demonstrating that only minor edits would be required in order to make the structure models acceptable for clinical use." The average clinical rating for both is 4.5, above the threshold of 3.

Table D: Performance for 4DCT Registration Function (Deformable Registration)

Organ & StructureSizeDSC Pass CriteriaReported DSC (Lower Bound 95% CI)Average Rating (1-5)Meet Criteria?
TracheaMedium0.650.9404.7Yes
EsophagusMedium0.650.8664.6Yes
Lung_LLarge0.80.9664.7Yes
Lung_RLarge0.80.9494.5Yes
Lung_AllLarge0.80.9544.8Yes
HeartLarge0.80.9314.6Yes
SpinalCordMedium0.650.9204.6Yes
LiverLarge0.80.9364.5Yes
StomachLarge0.80.8894.5Yes
A_AortaLarge0.80.9474.6Yes
SpleenLarge0.80.9134.8Yes
BodyLarge0.80.9974.9Yes

2. Sample Size Used for the Test Set and Data Provenance

  • Synthetic CT (sCT) Contouring Function:

    • Sample Size: 247 synthetic CT images (116 generated from MR, 131 generated from CBCT).
    • Data Provenance:
      • Demographic Distribution: 57% male, 43% female. Age distribution: 13% (21-40), 44.1% (41-60), 36.8% (61-80), 6.1% (81-100). Race: 78% White, 12% Black or African American, 10% Others.
      • Imaging Equipment: MR images from GE (21.6%), Philips (56.9%), Siemens (21.6%). CBCT images from Varian (58.8%), Elekta (41.2%).
      • Retrospective/Prospective: Not explicitly stated, but the description of demographic and equipment distribution from a "sample" indicates retrospective data collection from existing patient records.
      • Country of Origin: The racial distribution explicitly mentions "U.S. clinical radiotherapy practice," suggesting the data is primarily from the United States.
  • 4DCT Registration Function:

    • Sample Size: 30 4DCT image sets.
    • Data Provenance:
      • Imaging Equipment: Siemens (90.0%), Philips (10.0%) scanners.
      • Demographic Distribution: 17 males (56.7%), 13 females (43.3%). Age: 33-82 years, with majority in 51-65 (40.0%) and 66-80 (43.3%) year brackets.
      • Image Characteristics: Uniform 3mm slice thickness (100%).
      • Sourcing Location: Most images (90.0%) from Drexel Town Square Health Center/Community Memorial Hospital, remainder from Froedtert Hospital.
      • Retrospective/Prospective: Not explicitly stated, but implies retrospective data from patient archives of the mentioned hospitals.
      • Country of Origin: Based on the hospital names (Drexel Town Square Health Center, Community Memorial Hospital, Froedtert Hospital), the data is from the United States.

3. Number of Experts Used to Establish the Ground Truth for the Test Set and Their Qualifications

  • Number of Experts: Not explicitly stated. The text mentions "clinical experts evaluate the clinical applicability" and "RTStruct contoured by the professional physician as the gold standard." This implies at least one, and likely multiple, qualified medical professionals.
  • Qualifications of Experts: The experts are described as "clinical experts" and "professional physician(s)." Their specific qualifications (e.g., "radiologist with 10 years of experience") are not provided. They are implied to be clinically qualified radiotherapy personnel.

4. Adjudication Method for the Test Set

  • Adjudication Method: Not explicitly stated. The ground truth for segmentation is stated to be "RTStruct contoured by the professional physician". For clinical applicability, "clinical experts evaluate the clinical applicability" and assign a 1-5 scale score. This suggests a single expert (or group consensus without specific adjudication rules like 2+1) established the ground truth segmentation, and separate clinical experts evaluated the results. There is no mention of a formal adjudication process for disagreements in ground truth labeling if multiple experts were involved in its creation.

5. Multi Reader Multi Case (MRMC) Comparative Effectiveness Study

  • Was an MRMC study done? No.
  • Effect Size of Human Improvement (if applicable): Not applicable, as no MRMC study comparing human readers with and without AI assistance was reported. The testing focused solely on the algorithm's performance against expert-generated ground truth and expert evaluation of the algorithm's output.

6. Standalone Performance

  • Was a standalone performance study done? Yes. The entire report details the "Performance Test Report on Synthetic CT (sCT) Contouring Function" and "Performance Test Report on 4DCT Registration Function," measuring the algorithm's performance (DSC, HD95) against gold standard contours and qualitative evaluation by clinical experts. This reflects the algorithm's performance independent of human interaction during the contouring process.

7. Type of Ground Truth Used

  • Ground Truth: For the synthetic CT contouring and 4DCT registration functions, the ground truth was "RTStruct contoured by the professional physician" (i.e., expert consensus or expert-generated contours).

8. Sample Size for the Training Set

  • Training Set Sample Size: Not provided in the document.

9. How the Ground Truth for the Training Set was Established

  • Training Set Ground Truth Establishment: Not provided in the document. The document only details the ground truth used for the validation/test set.

FDA 510(k) Clearance Letter - AccuContour 4.0

Page 1

January 23, 2026

Manteia Technologies Co., Ltd.
Chao Fang
Quality Manager
Unit 3001-3005
No.5 Huizhan North Road
Xiamen, Fujian 361008
China

Re: K251351
Trade/Device Name: AccuContour 4.0
Regulation Number: 21 CFR 892.2050
Regulation Name: Medical Image Management And Processing System
Regulatory Class: Class II
Product Code: QKB
Dated: April 30, 2025
Received: April 30, 2025

Dear Chao Fang:

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 (the 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 available 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.

Page 2

K251351 - Chao Fang Page 2

Additional information about changes that may require a new premarket notification are provided in the FDA guidance documents entitled "Deciding When to Submit a 510(k) for a Change to an Existing Device" (https://www.fda.gov/media/99812/download) and "Deciding When to Submit a 510(k) for a Software Change to an Existing Device" (https://www.fda.gov/media/99785/download).

Your device is also subject to, among other requirements, the Quality System (QS) regulation (21 CFR Part 820), which includes, but is not limited to, 21 CFR 820.30, Design controls; 21 CFR 820.90, Nonconforming product; and 21 CFR 820.100, Corrective and preventive action. Please note that regardless of whether a change requires premarket review, the QS regulation requires device manufacturers to review and approve changes to device design and production (21 CFR 820.30 and 21 CFR 820.70) and document changes and approvals in the device master record (21 CFR 820.181).

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 (reporting of medical device-related adverse events) (21 CFR Part 803) for devices or postmarketing safety reporting (21 CFR Part 4, Subpart B) for combination products (see https://www.fda.gov/combination-products/guidance-regulatory-information/postmarketing-safety-reporting-combination-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 Part 4, Subpart A) for combination products; and, if applicable, the electronic product radiation control provisions (Sections 531-542 of the Act); 21 CFR Parts 1000-1050.

All medical devices, including Class I and unclassified devices and combination product device constituent parts are required to be in compliance with the final Unique Device Identification System rule ("UDI Rule"). The UDI Rule requires, among other things, that a device bear a unique device identifier (UDI) on its label and package (21 CFR 801.20(a)) unless an exception or alternative applies (21 CFR 801.20(b)) and that the dates on the device label be formatted in accordance with 21 CFR 801.18. The UDI Rule (21 CFR 830.300(a) and 830.320(b)) also requires that certain information be submitted to the Global Unique Device Identification Database (GUDID) (21 CFR Part 830 Subpart E). For additional information on these requirements, please see the UDI System webpage at https://www.fda.gov/medical-devices/device-advice-comprehensive-regulatory-assistance/unique-device-identification-system-udi-system.

Also, please note the regulation entitled, "Misbranding by reference to premarket notification" (21 CFR 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-devices/medical-device-safety/medical-device-reporting-mdr-how-report-medical-device-problems.

For comprehensive regulatory information about medical devices and radiation-emitting products, including information about labeling regulations, please see Device Advice (https://www.fda.gov/medical-devices/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-devices/device-advice-comprehensive-regulatory-

Page 3

K251351 - Chao Fang Page 3

assistance/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,

Lora D. Weidner, Ph.D.
Assistant Director
Radiation Therapy Team
DHT8C: Division of Radiological
Imaging and Radiation Therapy Devices
OHT8: Office of Radiological Health
Office of Product Evaluation and Quality
Center for Devices and Radiological Health

Enclosure

Page 4

DEPARTMENT OF HEALTH AND HUMAN SERVICES
Food and Drug Administration

Indications for Use

Form Approved: OMB No. 0910-0120
Expiration Date: 06/30/2023
See PRA Statement below.

510(k) Number (if known): K251351

Device Name: AccuContour 4.0

Indications for Use (Describe):
It is used by radiation oncology department to segment CT images, to generate needed information for treatment planning, treatment evaluation and treatment adaption.

Type of Use (Select one or both, as applicable)
☒ Prescription Use (Part 21 CFR 801 Subpart D)
☐ Over-The-Counter Use (21 CFR 801 Subpart C)

CONTINUE ON A SEPARATE PAGE IF NEEDED.

This section applies only to requirements of the Paperwork Reduction Act of 1995.

DO NOT SEND YOUR COMPLETED FORM TO THE PRA STAFF EMAIL ADDRESS BELOW.

The burden time for this collection of information is estimated to average 79 hours per response, including the time to review instructions, search existing data sources, gather and maintain the data needed and complete and review the collection of information. Send comments regarding this burden estimate or any other aspect of this information collection, including suggestions for reducing this burden, to:

Department of Health and Human Services
Food and Drug Administration
Office of Chief Information Officer
Paperwork Reduction Act (PRA) Staff
PRAStaff@fda.hhs.gov

"An agency may not conduct or sponsor, and a person is not required to respond to, a collection of information unless it displays a currently valid OMB number."

FORM FDA 3881 (6/20) Page 1 of 1 PSC Publishing Services (301) 443-6740 EF

Page 5

510(k) Summary

510(k) Number: K251351

The following information is provided as required by 21 CFR 807.92.

The assign 510(k) Number: K251351

I. SUBMITTER

Manteia Technologies Co., Ltd.
Unit 3001-3005, No.5 Huizhan North Road, Xiamen, Fujian, P.R. China
Establishment Registration Number: 3016686005
Contact Person: Chao Fang
Position: Quality Manager
Email: ra@manteiatech.com
Date of Prepared: 12/18/2025

II. DEVICE

Name of Device: AccuContour 4.0
Common or Usual Name: AI-assisted Auto-contouring Tool
Classification Name: Radiological Image Processing Software For Radiation Therapy
Regulatory Class: Class II
Product Code: QKB

III. PREDICATE DEVICE

Predicate Device: AccuContour, K221706

IV. DEVICE DESCRIPTION

The proposed device, AccuContour 4.0 Family, is a standalone software with the following variants: AccuContour and AccuContour-Lite. The functions of AccuContour-Lite is a subset of AccuContour.

AccuContour:
It is used by oncology department to register multi-modality images and segment (non-contrast) CT images, to generate needed information for treatment planning, treatment evaluation and treatment adaptation.

The product has two image processing functions:

  1. Deep learning contouring: it can automatically contour organs-at-risk, in head and neck, thorax, abdomen and pelvis (for both male and female) areas,
  2. Automatic registration: rigid and deformable registration, and
  3. Manual contouring.

Page 6

It also has the following general functions:

  • Receive, add/edit/delete, transmit, input/export, medical images and DICOM data;
  • Patient management;
  • Review tool of processed images;
  • Extension tool;
  • Plan evaluation and plan comparison;
  • Dose analysis.

AccuContour-Lite:
It is used by oncology department to segment (non-contrast) CT images, to generate needed information for treatment planning, treatment evaluation and treatment adaptation.

The product has one image processing function:
Deep learning contouring: it can automatically contour organs-at-risk, in head and neck, thorax, abdomen and pelvis (for both male and female) areas,

It also has the following general functions:

  • Receive, add/edit/delete, transmit, input/export, medical images and DICOM data;
  • Patient management;
  • Review tool of processed images.

V. INDICATIONS FOR USE

It is used by radiation oncology department to segment CT images, to generate needed information for treatment planning, treatment evaluation and treatment adaption.

VI. COMPARISON OF TECHNOLOGICAL CHARACTERISTICS WITH THE PREDICATE DEVICE

The major changes in the subject device compared with the predicate device are as follow:

  • Added the AccuContour-Lite variant as a lightweight version of AccuContour
  • Added AI-based Synthetic CT auto-contouring CT including 46 organs & structures
  • Added registration support for 4DCT

The detailed comparison of technical parameters is shown in the table below.

ITEMSubject Device AccuContour 4.0Predicate Device AccuContour (K221706)
Device NameAccuContourAccuContour-LiteAccuContour
Regulatory Information
Regulation No.21 CFR 892.205021 CFR 892.205021 CFR 892.2050
Product CodeQKBQKBQKB
ClassIIIIII
Intended UseIt is used by radiation oncology department to segment CT images, to generate needed information for treatment planning, treatment evaluation and treatment adaptation.It is used by radiation oncology department to register multi-modality

Page 7

images and segment (non-contrast) CT images, to generate needed information for treatment planning, treatment evaluation and treatment adaptation.
Intended UserClinically qualified radiotherapy personnel with training.Clinically qualified radiotherapy personnel with training.Clinically qualified radiotherapy personnel with training.
Independent SoftwareYesYesYes
Technological Characteristics
Operating SystemWindowsWindowsWindows
Top ToolbarYesYesYes
Patient ManagementYesYesYes
ContourYesYesYes
Fusion RegistrationYesNoYes
Plan ComparisonYesNoYes
Dose DisplayYesNoYes
Patient Management Features
Receive FilesYesYesYes
Import/ExportYesYesYes
SearchYesYesYes
Advanced SearchYesYesYes
RefreshYesYesYes
Auto-contouringYesYesYes
Generate ImagesYesNoYes
Generate ProjectionsYesYesYes
Contouring Features
AlgorithmDeep learning with GPU/CPU supportDeep learning with GPU/CPU supportDeep learning with GPU support
Compatible ModalityNon-Contrast CT DICOM 3.0 compliance required.(Original CT and Synthetic CT)Non-Contrast CT DICOM 3.0 compliance required.(Original CT and Synthetic CT)Non-Contrast CT DICOM 3.0 compliance required. (Original CT)
Compatible Scanner ModelsNo limitation on scanner model, DICOM 3.0 compliance required.No limitation on scanner model, DICOM 3.0 compliance required.No limitation on scanner model, DICOM 3.0 compliance required.
Compatible Treatment Planning SystemNo limitation on scanner model, DICOM 3.0 compliance required.No limitation on scanner model, DICOM 3.0 compliance required.No limitation on scanner model, DICOM 3.0 compliance required.
Fusion Registration Features
AlgorithmIntensity Based withNoIntensity Based with GPU

Page 8

GPU/CPU supportsupport
Registration TypeRigid Registration, Deformable RegistrationNoRigid Registration, Deformable Registration
Compatible ModalityAuto rigid registration: CT, MRI, PET, 4DCT Auto deformable registration: CT, MRI, CBCT, 4DCTNoAuto rigid registration: CT, MRI, PET Auto deformable registration: CT, MRI, CBCT
Compatible Scanner ModelsNo limitation on scanner model, DICOM 3.0 compliance required.NoNo limitation on scanner model, DICOM 3.0 compliance required.
Compatible Treatment Planning SystemNo limitation on scanner model, DICOM 3.0 compliance required.NoNo limitation on scanner model, DICOM 3.0 compliance required.
Registration ExportYesNoYes
Fusion ContouringYesNoYes
Synchronized ContouringYesNoYes
Plan Comparison Feature
Plan EvaluationYesNoYes
Plan ComparisonYesNoYes
Export ReportYesNoYes
Isodose Line DisplayYesNoYes
Dose Display Feature
Dose AnalysisYesNoYes
Dose to ContourYesNoYes
Dose AccumulationYesNoYes
ART Dose AccumulationYesNoYes

VII. PERFORMANCE DATA

The following performance data were provided in support of the substantial equivalence determination.

Biocompatibility Testing

Not Applicable (Standalone Software).

Electrical Safety and Electromagnetic Compatibility (EMC)

Not Applicable (Standalone Software).

Software Verification and Validation Testing

Software verification and validation testings were conducted, and documentation was

Page 9

provided as recommended by FDA's Guideline for Industry and FDA Staff - Content of Premarket Submission for Device Software Functions. Verification and validation of the software was conducted to ensure that the product meet users needs and intended use. AccuContour passed all software verification and validation tests.

Performance Test Report on Synthetic CT (sCT) Contouring Function

The performance test was performed to evaluate the synthetic CT(sCT) auto-contouring function of the test article(AccuContour) by DICE and HD95 Assessment Method.Verify whether all ROI indicators meet the criteria by calculating the Dice Similarity Coefficient (DSC) and 95% Hausdorff Distance (HD95) between the automatically delineated contours and the gold-standard contours.Meanwhile, clinical experts evaluate the clinical applicability of the automatically delineated contours using a 1-5 scale scoring system.The results indicate that the auto-segmentation performance of the AccuContour system for sCT images derived from both CBCT and MR modalities meets the requirements for geometric accuracy.The average ratings of 4.4(for sCT generated from MR) and 4.5(for sCT generated from CBCT) were found across all structure models demonstrating that only minor edits would be required in order to make the structure models acceptable for clinical use. The test results are presented in Table 1 and Table 2.

A total of 247 synthetic CT images were used in the test, comprising 116 generated from MR and 131 generated from CBCT. The test data set information is as follows:

  1. In terms of demographic distribution, the sample consisted of 57% male and 43% female patients. With reference to the 2020 U.S. Census adult gender ratio (approximately 1:1) and considering potential variations by specific cancer types in radiotherapy populations, this distribution is considered generally applicable.

  2. The patient age distribution was: 13% aged 21-40, 44.1% aged 41-60, 36.8% aged 61-80, and 6.1% aged 81-100. Given that radiotherapy patients are predominantly middle-aged and elderly (with 60%-70% typically over 60 years old according to ASTRO data), this distribution is assessed as highly applicable and meeting clinical needs.

  3. Regarding race, the sample comprised 78% White, 12% Black or African American, and 10% Others. This composition fully covers the key racial groups in U.S. clinical radiotherapy practice without omitting significant populations, thus deemed applicable.

  4. Concerning medical imaging equipment brands, MR images used for sCT generation were obtained from GE (21.6%), Philips (56.9%), and Siemens (21.6%) scanners. This demonstrates excellent applicability as these three brands collectively represent the entirety of the mainstream MRI scanner market in U.S. radiotherapy clinics, ensuring comprehensive coverage of image characteristic variations across different manufacturers. CBCT images used for sCT generation were sourced from Varian (58.8%) and Elekta (41.2%) equipment, also showing excellent applicability since these two manufacturers dominate the U.S. radiotherapy CBCT equipment landscape, fully reflecting the actual clinical scenario for setup verification.

Page 10

Organ & StructureNO.SizeDSCHD95 (mm)Average Rating (1-5)
Pass CriteriaDSC MeanDSC STDLower Bound 95% CIHD95 MeanHD95 STDLower Bound 95% CI
TemporalLobe_L37Medium0.650.8980.0360.8864.580.8244.319
TemporalLobe_R37Medium0.650.8920.0430.8784.670.9054.382
Brain47Large0.80.9870.0060.9862.040.5721.877
BrainStem46Medium0.650.8730.1050.8435.260.9154.999
SpinalCord103Medium0.650.8730.0320.8673.200.8653.030
OpticChiasm36Small0.50.8110.0210.8045.050.8404.771
OpticNerve_L36Small0.50.8340.0360.8222.510.8532.235
OpticNerve_R36Small0.50.8130.0590.7942.680.7812.422
InnerEar_L40Small0.50.8520.0280.8432.400.7712.164
InnerEar_R39Small0.50.8300.0780.8062.330.7212.102
MiddleEar_L40Small0.50.8380.0450.8243.850.8583.580
MiddleEar_R41Small0.50.8100.0590.7923.970.8753.700
Eye_L37Small0.50.9290.0700.9061.830.5301.659
Eye_R37Small0.50.9240.0850.8971.760.5461.584
Lens_L35Small0.50.8520.0480.8363.620.7603.368
Lens_R35Small0.50.8580.0500.8413.660.8403.379
Pituitary34Small0.50.8260.0730.8012.550.8292.267
Mandible65Small0.50.9220.0350.9132.010.6771.844
TMJ_L44Small0.50.8420.0430.8303.060.8202.819
TMJ_R44Small0.50.8300.0450.8172.960.8142.722
OralCavity66Medium0.650.9260.0440.9163.900.9163.677
Larynx60Medium0.650.8150.0780.7952.420.8992.196
Trachea57Medium0.650.8950.0960.8702.690.9322.452
Esophagus72Medium0.650.8120.0530.8002.890.9192.680
Parotid_L61Medium0.650.8730.0900.8512.600.8392.386
Parotid_R62Medium0.650.8820.0580.8682.530.8192.328
Submandibular_L57Medium0.650.8480.0580.8335.130.7944.920
Submandibular_R56Medium0.650.8110.1070.7832.560.8132.348
Thyroid57Medium0.650.8220.0730.8032.110.7741.911
BrachialPlexus_L60Medium0.650.8420.0520.8285.560.8585.347
BrachialPlexus_R60Medium0.650.8210.0820.8005.290.8905.062
Lung_L54Large0.80.9730.0180.9681.760.4801.635
Lung_R53Large0.80.9800.0150.9761.660.5231.516
Heart53Large0.80.9640.0200.9592.750.9442.496
Liver56Large0.80.9490.0320.9412.630.7272.439
Kidney_L56Large0.80.9120.0800.8922.970.8372.748
Kidney_R58Large0.80.9170.0840.8953.020.8712.797
Stomach53Large0.80.8270.1660.7825.000.9274.754

Page 11

| Pancreas | 49 | Medium | 0.65 | 0.843 | 0.055 | 0.827 | 6.53 | 0.938 | 6.271 | 4.0 |
| Duodenum | 59 | Medium | 0.65 | 0.826 | 0.045 | 0.815 | 6.66 | 0.849 | 6.447 | 4.1 |
| Rectum | 21 | Medium | 0.65 | 0.818 | 0.052 | 0.796 | 2.46 | 0.964 | 2.047 | 3.9 |
| BowelBag | 53 | Large | 0.8 | 0.839 | 0.116 | 0.808 | 7.60 | 0.822 | 7.380 | 4.0 |
| Bladder | 21 | Large | 0.8 | 0.955 | 0.029 | 0.943 | 2.33 | 0.574 | 2.082 | 4.5 |
| Marrow | 28 | Large | 0.8 | 0.901 | 0.033 | 0.889 | 2.12 | 0.745 | 1.842 | 4.6 |
| FemurHead_L | 21 | Medium | 0.65 | 0.953 | 0.007 | 0.950 | 2.65 | 0.917 | 2.261 | 4.5 |
| FemurHead_R | 21 | Medium | 0.65 | 0.951 | 0.024 | 0.941 | 2.79 | 0.757 | 2.466 | 4.6 |

Table 1: Test Results for synthetic CT generated from MR images

Organ & StructureNO.SizeDSCHD95 (mm)Average Rating (1-5)
Pass CriteriaDSC MeanDSC STDLower Bound 95% CIHD95 MeanHD95 STDLower Bound 95% CI
TemporalLobe_L41Medium0.650.8790.0820.8543.690.7973.451
TemporalLobe_R41Medium0.650.8850.0850.8593.500.8223.258
Brain44Large0.80.9880.0070.9862.030.7691.804
BrainStem41Medium0.650.9090.0200.9034.920.7904.678
SpinalCord118Medium0.650.8790.0550.8692.240.8282.088
OpticChiasm41Small0.50.8070.0400.7955.510.8265.252
OpticNerve_L40Small0.50.8270.0380.8152.650.8872.373
OpticNerve_R40Small0.50.8270.0360.8162.460.7982.210
InnerEar_L41Small0.50.8090.0320.8002.400.8312.144
InnerEar_R41Small0.50.8040.0320.7942.410.7832.171
MiddleEar_L41Small0.50.8120.0380.8003.570.8673.301
MiddleEar_R41Small0.50.8050.0260.7974.180.9633.888
Eye_L41Small0.50.9480.0130.9441.710.5241.553
Eye_R41Small0.50.9450.0120.9411.840.5341.678
Lens_L41Small0.50.8360.0500.8203.760.7413.532
Lens_R41Small0.50.8440.0720.8213.650.8983.370
Pituitary39Small0.50.8150.0390.8022.720.7182.496
Mandible42Small0.50.9010.1030.8702.420.6502.227
TMJ_L40Small0.50.8020.0920.7743.060.9302.775
TMJ_R41Small0.50.8190.0610.8003.080.9562.791
OralCavity37Medium0.650.9100.0800.8854.010.6693.794
Larynx33Medium0.650.8030.0320.7933.201.0892.827
Trachea48Medium0.650.8910.0630.8732.810.9542.545
Esophagus56Medium0.650.8110.0390.8003.040.8722.811
Parotid_L41Medium0.650.9000.0300.8912.660.7992.415
Parotid_R40Medium0.650.9020.0250.8942.770.7962.525
Submandibular_L29Medium0.650.8080.1730.7455.270.6675.026
Submandibular_R29Medium0.650.8400.1180.7972.510.8872.192
Thyroid33Medium0.650.8370.0420.8232.440.7692.182

Page 12

| BrachialPlexus_L | 47 | Medium | 0.65 | 0.823 | 0.063 | 0.805 | 4.16 | 0.838 | 3.922 | 4.4 |
| BrachialPlexus_R | 47 | Medium | 0.65 | 0.833 | 0.036 | 0.823 | 3.80 | 0.955 | 3.529 | 4.2 |
| Lung_L | 57 | Large | 0.8 | 0.961 | 0.054 | 0.947 | 1.71 | 0.493 | 1.587 | 4.5 |
| Lung_R | 57 | Large | 0.8 | 0.978 | 0.027 | 0.971 | 1.75 | 0.429 | 1.635 | 4.3 |
| Heart | 58 | Large | 0.8 | 0.925 | 0.112 | 0.896 | 2.03 | 0.821 | 1.823 | 4.5 |
| Liver | 38 | Large | 0.8 | 0.927 | 0.043 | 0.914 | 2.82 | 0.702 | 2.595 | 4.6 |
| Kidney_L | 22 | Large | 0.8 | 0.932 | 0.024 | 0.922 | 3.02 | 0.888 | 2.645 | 4.7 |
| Kidney_R | 24 | Large | 0.8 | 0.929 | 0.057 | 0.906 | 2.97 | 0.898 | 2.611 | 4.5 |
| Stomach | 25 | Large | 0.8 | 0.871 | 0.035 | 0.858 | 5.01 | 0.844 | 4.681 | 4.2 |
| Pancreas | 21 | Medium | 0.65 | 0.838 | 0.036 | 0.822 | 5.84 | 0.674 | 5.548 | 4.4 |
| Duodenum | 23 | Medium | 0.65 | 0.831 | 0.031 | 0.818 | 5.68 | 1.048 | 5.252 | 4.1 |
| Rectum | 20 | Medium | 0.65 | 0.811 | 0.031 | 0.797 | 4.54 | 0.657 | 4.253 | 4.3 |
| BowelBag | 33 | Large | 0.8 | 0.863 | 0.038 | 0.850 | 5.39 | 1.051 | 5.028 | 4.0 |
| Bladder | 22 | Large | 0.8 | 0.949 | 0.055 | 0.926 | 3.59 | 0.650 | 3.322 | 4.7 |
| Marrow | 22 | Large | 0.8 | 0.882 | 0.109 | 0.837 | 2.54 | 0.948 | 2.148 | 4.7 |
| FemurHead_L | 20 | Medium | 0.65 | 0.935 | 0.097 | 0.893 | 1.88 | 0.546 | 1.639 | 4.8 |
| FemurHead_R | 20 | Medium | 0.65 | 0.945 | 0.042 | 0.927 | 2.04 | 0.539 | 1.807 | 4.9 |

Table 2: Test Results for sCT generated from CBCT

Performance Test Report on 4DCT Registration Function

The performance test report on 4DCT registration was performed to to evaluate the image conversion functionby DICE Assessment Method. We use the RTStruct contoured by the professional physician as the gold standard, the first frame of each 4DCT set was registered with frames 2 to 10 from the same patient. The contour of each Region of Interest (ROI) was then compared, and the Dice Similarity Coefficient (DSC) was calculated.And then calculate DSC Mean, DSC STD and Lower Bound 95% Confidence Interval for each ROI, analyze the Dice coefficient results.Additionally, the qualitative clinical appropriateness of AccuContour structures generated on these scans was graded by clinical experts. The generated structures were graded on a scale from 1 to 5 where 5 refers to contour requiring no additional edits, and 1 refers to a score in which full manual re-contour of the structure would be required. An average score≥3 was used to determine whether a structure model would ultimately be beneficial clinically. According to the results, the accuracy of 4DCT image registration images meets the requirements and all structure models demonstrating that only minor edits would be required in order to make the structure models acceptable for clinical use. The test results are presented in Table 3 and Table 4.

A total of 30 4DCT image sets were used in the test. The test data set information is as follows:

  1. The sample comprised images from Siemens (90.0%) and Philips (10.0%) scanners, representing major global vendors.

  2. Demographically, subjects included 17 males (56.7%) and 13 females (43.3%), aged 33-82 years, with the majority in the 51-65 (40.0%) and 66-80 (43.3%) year brackets.

  3. All images (100%) shared a uniform 3mm slice thickness. Most images (90.0%) were

Page 13

sourced from Drexel Town Square Health Center/Community Memorial Hospital, with the remainder from Froedtert Hospital.

This distribution supports the sample's representativeness and technical consistency for the intended study.

Organ & StructureNO.SizePass CriteriaDSC MeanDSC STDLower Bound 95% CIAverage Rating (1-5)
Trachea25Medium0.6500.9070.0300.8884.5
Esophagus30Medium0.6500.8600.0370.8364.5
Lung_L29Large0.8000.9470.0220.9324.7
Lung_R30Large0.8000.9450.0250.9294.8
Lung_All30Large0.8000.9460.0230.9304.8
Heart30Large0.8000.9310.0220.9174.6
SpinalCord30Medium0.6500.9490.0080.9434.6
Liver30Large0.8000.9120.0370.8884.6
Stomach30Large0.8000.8410.0760.7914.5
A_Aorta30Large0.8000.9280.0160.9174.4
Spleen30Large0.8000.8340.0750.7864.5
Body30Large0.8000.9970.0020.9954.9

Table 3: Test Results after Rigid Registration for Each ROI

Organ & StructureNO.SizePass CriteriaDSC MeanDSC STDLower Bound 95% CIAverage Rating (1-5)
Trachea25Medium0.6500.9460.0080.9404.7
Esophagus30Medium0.6500.9010.0540.8664.6
Lung_L29Large0.8000.9750.0120.9664.7
Lung_R30Large0.8000.9980.0760.9494.5
Lung_All30Large0.8000.9930.0600.9544.8
Heart30Large0.8000.9710.0600.9314.6
SpinalCord30Medium0.6500.9640.0670.9204.6
Liver30Large0.8000.9780.0640.9364.5
Stomach30Large0.8000.9150.0390.8894.5
A_Aorta30Large0.8000.9510.0060.9474.6
Spleen30Large0.8000.9320.0310.9134.8
Body30Large0.8000.9980.0010.9974.9

Table 4: Test Results after Deformable Registration for Each ROI

Overall, the AccuContour was found to be safe and effective for all intended users, purpose and use environments.

Mechanical and Acoustic Testing

Not Applicable (Standalone Software).

Page 14

Animal Study

Not Applicable (Standalone Software).

Clinical Studies

Clinical trials were not performed as part of the development of this product. Clinical testing on patients is not advantageous in demonstrating substantial equivalence or safety and effectiveness of the device since testing can be performed such that no human subjects are exposed to risk.

VIII. CONCLUSIONS

The subject device, AccuContour 4.0, is believed to be substantially equivalent to the predicate device in terms of its indications for use, technical characteristics, and overall performance. The information provided in this submission indicates its substantial equivalence to the predicate device.

Therefore, Manteia Technologies Co., Ltd. considered the subject AccuContour 4.0 is substantially equivalent to the predicate device AccuContour (K221706).

§ 892.2050 Medical image management and processing system.

(a)
Identification. A medical image management and processing system is a device that provides one or more capabilities relating to the review and digital processing of medical images for the purposes of interpretation by a trained practitioner of disease detection, diagnosis, or patient management. The software components may provide advanced or complex image processing functions for image manipulation, enhancement, or quantification that are intended for use in the interpretation and analysis of medical images. Advanced image manipulation functions may include image segmentation, multimodality image registration, or 3D visualization. Complex quantitative functions may include semi-automated measurements or time-series measurements.(b)
Classification. Class II (special controls; voluntary standards—Digital Imaging and Communications in Medicine (DICOM) Std., Joint Photographic Experts Group (JPEG) Std., Society of Motion Picture and Television Engineers (SMPTE) Test Pattern).