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Ovarian CancerOvaClassNCT07883551

AI Analysis of CT Scans to Classify Ovarian Tumours as Benign, Borderline or Malignant Before Surgery

An observational study of Ovarian Cancer and Ovarian Tumor, run by Catharina Ziekenhuis Eindhoven at 7 sites in 2 countries.

Not yet recruiting

Opening soon. The study is approved but enrolment has not started yet. Sites may already take enquiries.

Sites and contacts
Official record
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Trial summary

The goal of this observational study is to learn if a computer program can tell what type of ovarian tumour a person has from a CT scan taken before surgery. The program uses artificial intelligence (AI). Read more about this study

Who is it for?
Ages 18 years and older, women only
How many people
1,300 participants
Where
7 sitesin 2 countries
Study dates
Nov 2026to Oct 2031
Phase
Observational
Are there results?
Not yet: the study is under way

Key requirements

Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.

  • Ages 18 years and older
  • Women only
  • No healthy volunteers
  • Adult, Older adult

Study population: Adult patients evaluated for an ovarian or adnexal mass of unknown nature at academic and teaching hospitals in the Netherlands and Belgium, who had a preoperative CT and/or MRI scan as part of routine care and subsequently underwent surgical removal of the mass with definitive histopathology. Benign, borderline and malignant tumours are included, as is advanced-stage ovarian cancer when the primary adnexal mass can be identified on imaging. CT or MRI was performed in routine care, mostly after indeterminate or suspicious ultrasound findings or for staging. The case mix therefore reflects a second-line population referred for cross-sectional imaging rather than all patients with an adnexal mass. Data come from a previous multicentre CADx cohort, the OVIDETECT registry and additional participating centres.

Who may be able to join

  • Age 18 years or older at the time of imaging
  • Ovarian or adnexal mass on clinical and/or radiological assessment that can be reliably identified as the index lesion on CT and/or MRI
  • Preoperative CT and/or MRI scan available, acquired as part of routine clinical care
  • Surgical removal of the ovarian or adnexal mass, with definitive postoperative histopathology available as reference standard
  • Bilateral ovarian tumours are eligible. If histopathology differs between sides, a predefined rule is applied (for example, selection of the lesion with the highest malignant potential)
  • Advanced ovarian malignancy, including ascites or peritoneal disease, is eligible if the primary adnexal mass can be clearly identified on imaging

Who cannot join

  • No definitive postoperative histopathology available
  • Imaging of insufficient diagnostic quality (for example incomplete series, corrupted files or non-diagnostic sequences)
  • Extra-ovarian disease that prevents reliable identification or attribution of the adnexal lesion as the index tumour (for example diffuse peritoneal carcinomatosis or a confirmed non-ovarian primary malignancy)
  • Previous ovarian malignancy or prior oncological treatment affecting the adnexal region
  • Pathology report judged indefinite or inconclusive by the reviewing clinician

Trial locations and contacts

7 sites in 2 countries. Contact the study team or a site near you to ask about taking part.

Basiel Weyers, Medical Doctor contact

+3140 239 93 00

basiel.weyers@catharinaziekenhuis.nl

7 sites in 2 countries

Netherlands6 sites

  • Netherlands Cancer Institute - Antoni van Leeuwenhoek

    Amsterdam, 1066 CX

  • Amsterdam University Medical Centre

    Amsterdam, 1081 HV

  • Amphia Ziekenhuis

    Breda, 4818 CK

  • Catharina Ziekenhuis

    Eindhoven, 5623 EJ

  • Leiden University Medical Centre

    Leiden, 2333 ZA

  • Maastricht UMC+

    Maastricht, 6229 HX

Other trials in Netherlands

Belgium1 site

  • Ghent University Hospital

    Ghent, 9000

Other trials in Belgium

About this study

Official title: Foundation Model-based AI for Preoperative Three-class Ovarian Tumour Classification: Using Computer Aided Diagnosis (CADx) to Predict Whether an Ovarian Tumour is Benign, Malignant or Borderline

The goal of this observational study is to learn if a computer program can tell what type of ovarian tumour a person has from a CT scan taken before surgery. The program uses artificial intelligence (AI). It sorts tumours into three groups:

  • benign: not cancer
  • borderline: abnormal cells that usually behave less aggressively than cancer
  • malignant: cancer
Read more

Before surgery, doctors try to judge which group a tumour belongs to. This guides where and how the operation is done. This judgement is often hard, especially for borderline tumours. An AI program that does it well could help doctors plan surgery.

The main questions it aims to answer are:

  • How well does the AI program sort ovarian tumours into benign, borderline and malignant on CT scans?
  • Does the AI program work as well on scans from hospitals it did not learn from?

Researchers will compare the AI program's results with the final diagnosis from the tumour tissue removed during surgery. They will also compare the program with methods doctors use today, such as ultrasound-based risk scores and the radiologist's report. In a smaller group, researchers will test the program on MRI scans.

This study only uses information that already exists. It includes adults who had surgery for a mass in or near the ovary at hospitals in the Netherlands and Belgium. Researchers will use:

  • CT or MRI scans made before surgery as part of regular care
  • information from medical records
  • the tissue diagnosis after surgery

Participants will not be contacted. They will not have any extra scans, tests or visits. Each hospital codes the data before sharing them, so researchers cannot see participants' names. The study does not change anyone's care.

Read the detailed description
  • Background and rationale Preoperative distinction between benign, borderline and malignant ovarian tumours determines referral, surgical approach and extent of surgery. Ultrasound-based models such as IOTA-ADNEX and the Risk of Malignancy Index (RMI) are the current triage tools, but their performance varies between populations and users. CT is often performed in indeterminate cases or for staging. There are no validated diagnostic criteria for CT, and interpretation depends on the reader. Published CT-based computer-aided diagnosis (CADx) models are mostly single-centre, binary (benign versus malignant), dependent on manual tumour segmentation and rarely externally validated. Borderline tumours need different management but are usually excluded or merged with malignant tumours. Earlier work from the Catharina Cancer Institute and Eindhoven University of Technology (TU/e) showed considerable domain shift between hospitals in a multicentre CT dataset (Koch et al., 2026).
  • Index test The index test is a CADx pipeline built on SPECTRE, a CT foundation model developed at TU/e and pre-trained with self-supervised learning on more than 250,000 CT scans. SPECTRE is fine-tuned with parameter-efficient adaptation. The pre-trained encoder is kept frozen or partially unfrozen, and lightweight task heads are trained for tumour localisation and three-class classification. The pipeline works directly on the CT volume. Tumour localisation is learned within the model, so no tumour masks or bounding boxes are needed for training or evaluation. An uncertainty quantification module produces calibrated confidence estimates alongside each prediction. The overall architecture is fixed. Training details such as the fine-tuning schedule, loss weighting and calibration method may be adapted based on interim results. Radiomics-based machine learning (handcrafted features with classifiers such as logistic regression, support vector machines, random forests or gradient boosting) is used only as a benchmark comparator. The model is applied retrospectively and its output is never available to treating clinicians.
  • Reference standard Definitive postoperative histopathology, classified as benign, borderline or malignant according to the 2020 WHO Classification of Female Genital Tumours. Ambiguous cases are adjudicated by an experienced gynaecological pathologist to keep labelling consistent across centres. In bilateral tumours with discordant histology, a predefined rule is applied (for example, selection of the lesion with the highest malignant potential).
  • Data acquisition and preprocessing Participating centres identify eligible patients and pseudonymise and code imaging, clinical and pathology data locally before transfer under formal data-sharing agreements. The key linking codes to identities stays at the local centre. Images are exported in DICOM format and may be converted to volumetric formats (NIfTI or NRRD). CT preprocessing includes intensity windowing (for example -100 to +300 HU), normalisation and voxel resampling to a standard resolution. Scanner manufacturer and model, slice thickness, contrast phase and reconstruction kernel are recorded for analysis of domain shift. For the MRI pilot, T2-weighted, T1-weighted with and without fat suppression, diffusion-weighted with ADC maps and contrast-enhanced T1-weighted sequences are used when available.
  • Model development and validation Within the development cohort, stratified cross-validation (or an equivalent resampling method adapted to the final sample size) is used, stratified by outcome class. Hyperparameter tuning and model selection take place only within the training data of each resampling iteration. All scans and lesions from one patient are kept in the same split to prevent data leakage. External validation uses one or more centres that are excluded entirely from model development. The allocation of centres to development and external validation is documented before any performance analysis. Calibration methods such as Platt scaling or temperature scaling may be applied.
  • Statistical analysis Discrimination is assessed with one-vs-rest AUROC per class and macro- and micro-averaged multiclass AUROC. Classification metrics include sensitivity, specificity, positive and negative predictive values, F1-score, balanced accuracy and confusion matrices. 95% confidence intervals are estimated by bootstrapping where appropriate. Calibration is assessed with calibration curves and the Brier score. Net benefit across clinically relevant risk thresholds is assessed with decision curve analysis. Comparison with RMI, IOTA-ADNEX, radiologist reports and, in the MRI pilot, O-RADS MRI is restricted to patients in whom the comparator is available or can be reconstructed. Paired comparisons use the DeLong test for ROC curves, McNemar's test for paired proportions, kappa statistics for agreement and the Brier score for probabilistic predictions. Baseline characteristics are compared with chi-squared or Fisher's exact tests and t-tests or Mann-Whitney U tests as appropriate. Two-sided p-values are reported with a nominal significance level of 0.05, with emphasis on effect sizes and confidence intervals. Missing clinical data are described and not imputed. Model behaviour is explored with attention and saliency maps (for example Grad-CAM).
  • Exploratory analyses Where data can be linked in coded form and are covered by ethics approval and data-sharing agreements, exploratory analyses will assess whether adding blood-based biomarkers (CA-125, CA-125 glycovariants, CEA, ctDNA, proteomics) or radiologist report content to CT imaging changes classification performance. In a subset with digitised histopathology slides, AI-based analysis of whole slide images will be explored to find histological correlates of CT-based tumour characteristics. These analyses do not change the primary imaging-based objective.
  • Reporting Results will be reported following TRIPOD+AI, supplemented by CLAIM and STROBE where applicable.
Keywords
Ovarian neoplasms, adnexal mass, borderline ovarian tumour, ovarian cancer, artificial intelligence, deep learning, transfer learning, foundation model, computer-aided diagnosis, computed tomography, magnetic resonance imaging, preoperative diagnosis, diagnostic accuracy, multiclass classification, external validation, domain shift
Medical subject headings
Ovarian Neoplasms

What participants receive

What participants receive. In a randomised study each person is assigned to one group by chance.

Study groups in NCT07883551
Study groupRoleWhat they receive
CT development cohort* Description: Adult patients with an adnexal mass who had preoperative CT and surgery with definitive histopathology at the development centres (Catharina Hospital Eindhoven, Amphia Hospital, Netherlands Cancer Institute-Antoni van Leeuwenhoek, Leiden University Medical Centre and Amsterdam UMC). Includes patients from a previous multicentre CADx cohort and the OVIDETECT registry, approximately 930 scans, of which around 118 are borderline tumours. Used for model training, tuning and internal cross-validation. * Intervention: SPECTRE-based CADx model
CT external validation cohort* Description: Adult patients meeting the same criteria at centres held out entirely from model development (anticipated: Maastricht UMC+ and/or Ghent University Hospital), approximately 400 scans. Used only to assess generalisability across institutions. Centre allocation is fixed and documented before analysis. * Intervention: SPECTRE-based CADx model
MRI pilot cohort (exploratory)* Description: Adult patients from participating centres with a preoperative MRI of the adnexal mass and definitive histopathology, approximately 100 to 200 scans. Used to explore preliminary CADx feasibility on MRI and to compare with O-RADS MRI. Not part of the primary CT-based objective. * Intervention: SPECTRE-based CADx model

What is being measured

The primary outcome is the main question the study is designed to answer.

  1. Discrimination of the CADx model for three-class classification (benign, borderline, malignant): macro-averaged AUROC

    Area under the receiver operating characteristic curve (AUROC) of the SPECTRE-based CADx model on preoperative CT. Calculated per class (one-vs-rest) and macro-averaged across the three classes, with histopathology according to the 2020 WHO classification as reference standard. Reported for internal cross-validation in the development cohort and for the centre-held-out external validation cohort, with 95% confidence intervals estimated by bootstrapping. Range 0 to 1, higher values indicate better discrimination.

    Measured: Preoperatively (CT scan acquired before surgery), compared with histopathology of the tumour removed at surgery

Secondary outcomes (11)

  1. Sensitivity, specificity and predictive values per tumour class

    Sensitivity, specificity, positive predictive value and negative predictive value of the CADx model for each class (one-vs-rest), against histopathology. Decision thresholds are set in the development cohort and fixed before external validation. Reported with 95% confidence intervals for internal and external validation.

    Measured: Preoperatively (CT scan acquired before surgery), compared with histopathology of the tumour removed at surgery

  2. F1-score, balanced accuracy and confusion matrix for three-class classification

    Per-class and macro-averaged F1-score, balanced accuracy and the full three-by-three confusion matrix of predicted versus histopathological class, for internal and external validation.

    Measured: Preoperatively (CT scan acquired before surgery), compared with histopathology of the tumour removed at surgery

  3. Calibration of predicted class probabilities

    Agreement between predicted probabilities and observed histopathological outcomes, assessed with calibration curves and the Brier score, before and after any recalibration (for example Platt or temperature scaling). Reported for internal and external validation.

    Measured: Preoperatively (CT scan acquired before surgery), compared with histopathology of the tumour removed at surgery

  4. Net benefit of CADx-supported triage (decision curve analysis)

    Net benefit of using the CADx model to identify borderline or malignant tumours across a range of clinically relevant risk thresholds, compared with treat-all and treat-none strategies and with IOTA-ADNEX where available.

    Measured: Preoperatively (CT scan acquired before surgery), compared with histopathology of the tumour removed at surgery

  5. Diagnostic performance of the CADx model compared with IOTA-ADNEX

    Paired comparison in patients with an available or reconstructable ADNEX result. ADNEX risk categories are collapsed to benign, borderline and malignant. Compared by AUROC (DeLong test), sensitivity and specificity (McNemar's test), Brier score and agreement (kappa).

    Measured: Preoperatively (CT scan acquired before surgery), compared with histopathology of the tumour removed at surgery

  6. Diagnostic performance of the CADx model compared with the Risk of Malignancy Index (RMI)

    Paired comparison in patients with a calculable RMI. Because RMI is a binary score, comparison is made for benign versus borderline or malignant tumours at the threshold used in routine practice (RMI ≥200). Compared by AUROC (DeLong test) and sensitivity and specificity (McNemar's test).

    Measured: Preoperatively (CT scan acquired before surgery), compared with histopathology of the tumour removed at surgery

  7. Diagnostic performance of the CADx model compared with the radiologist's CT report

    Paired comparison with the classification derived from the original clinical CT report using a predefined mapping rule. Compared by sensitivity, specificity (McNemar's test) and agreement (kappa).

    Measured: Preoperatively (CT scan acquired before surgery), compared with histopathology of the tumour removed at surgery

  8. Inter-centre generalisability of CADx performance

    Macro-averaged AUROC, sensitivity and specificity per centre, and the difference between internal cross-validated and external validation performance, to quantify domain shift related to centre, scanner and acquisition protocol.

    Measured: Preoperatively (CT scan acquired before surgery), compared with histopathology of the tumour removed at surgery

  9. CADx performance by histological subtype (exploratory)

    Proportion of correctly classified tumours and class-specific sensitivity per histological subtype (2020 WHO classification), for example serous, mucinous, endometrioid, clear cell and non-epithelial tumours.

    Measured: Preoperatively (CT scan acquired before surgery), compared with histopathology of the tumour removed at surgery

  10. CADx performance by menopausal status and tumour size

    Macro-averaged AUROC, sensitivity and specificity in subgroups by menopausal status (pre- versus postmenopausal) and by maximum tumour diameter on imaging.

    Measured: Preoperatively (CT scan acquired before surgery), compared with histopathology of the tumour removed at surgery

  11. CADx performance on MRI and comparison with O-RADS MRI (exploratory pilot)

    Within the MRI pilot cohort, AUROC, sensitivity and specificity of the CADx model on MRI against histopathology, and paired comparison with the O-RADS MRI score where available.

    Measured: Preoperatively (MRI scan acquired before surgery), compared with histopathology of the tumour removed at surgery

Timeline

From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.

  1. First posted20 Oct 2026
  2. Study startNov 2026 (estimated)
  3. Primary completionOct 2031 (estimated)
  4. Study completionOct 2031 (estimated)

Resources

More details

For doctors and researchers: how the study is designed, who runs it, and its registry IDs.

Study design
Study type
Observational
Observational model
Cohort
Time perspective
Retrospective
Enrolment
1,300 participants (estimated)
IDs, dates and publications
ClinicalTrials.gov ID
NCT07883551
Sponsor's protocol ID
nWMO-2026.058
Other IDs
W26.002
Acronym
OvaClass
Status last verified
Oct 2026
First submitted
9 Oct 2026
Last updated
20 Oct 2026
Results posted
No
Data monitoring committee
No
FDA-regulated drug
No
FDA-regulated device
No
Individual data sharing
No: Individual participant data will not be shared outside the study consortium. The dataset consists of retrospective CT and MRI scans with linked clinical and pathology data from several hospitals in the Netherlands and Belgium. Data are shared within the consortium under a research agreement with joint controllership and the ethics approvals of each centre. Neither these agreements nor the consent obtained cover sharing with other researchers. Volumetric CT data also carry a residual risk of re-identification after pseudonymisation. Any reuse beyond the protocol would need new ethics review and agreement from all participating centres. Where these agreements allow, the study team plans to share model code, trained model weights and derived, non-identifiable features through public or institutional repositories. Researchers interested in collaboration can contact the study team.

Publications

  • Koch AH, Claessens CHB, Nies I, Schultz EWR, Hellstrom TAE, Boers T, Dekker EML, Muntinga CLP, Hoogstad-van Evert JS, Niers-Stobbe I, Bruining A, Lok CAR, Nederend J, van der Sommen F, Piek JMJ. Evaluating Performance of a Deep Learning-based Artificial Intelligence Model for Ovarian Tumor Classification Using a Multicenter CT Dataset. Radiol Imaging Cancer. 2026 Mar;8(2):e250027. doi: 10.1148/rycan.250027.

    PubMed 41686074

  • Koch AH, Jeelof LS, Muntinga CLP, Gootzen TA, van de Kruis NMA, Nederend J, Boers T, van der Sommen F, Piek JMJ. Analysis of computer-aided diagnostics in the preoperative diagnosis of ovarian cancer: a systematic review. Insights Imaging. 2023 Feb 15;14(1):34. doi: 10.1186/s13244-022-01345-x.

    PubMed 36790570

Questions about this trial

What is this clinical trial studying?

An observational study of Ovarian Cancer and Ovarian Tumor, run by Catharina Ziekenhuis Eindhoven at 7 sites in 2 countries.

The full registered description is in the About this study section and the official record.

Who may be eligible to take part?

The sponsor lists 6 inclusion and 5 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.

Is this clinical trial currently recruiting?

The record says: opening soon, as of the sponsor's last update on 20 Oct 2026. Status can change between updates, so confirm with the study contact before making plans.

Where is the study taking place?

The record lists 7 sites in Netherlands, Belgium. Whether a site is taking part right now should be confirmed with that site. See every site.

What are the possible benefits and risks?

They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.

Are results available for this study?

This study is still under way. Results are not available in the source record yet.

How can a doctor refer a patient or contact the research team?

Contact Basiel Weyers, Medical Doctor (+3140 239 93 00, basiel.weyers@catharinaziekenhuis.nl), or a site near the patient. AzTrials does not enrol participants or take referrals.

What does the primary outcome measure?

Discrimination of the CADx model for three-class classification (benign, borderline, malignant): macro-averaged AUROC (time frame: Preoperatively (CT scan acquired before surgery), compared with histopathology of the tumour removed at surgery). It is what the study was designed to measure, not a finding.

Where can I read the original study information?

On the ClinicalTrials.gov record for NCT07883551, which also lists 2 linked publications.

Does a listing mean the treatment is approved or proven to work?

No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.

How often is this information updated?

AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 20 Oct 2026; AzTrials last refreshed its copy on 26 Oct 2026.

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