Breast Cancer Screening: Digital Breast Tomosynthesis Versus Digital 2D Mammography (TOSYMA)

January 21, 2026 updated by: University Hospital Muenster

Prospective Randomized Comparison of Digital Breast Tomosynthesis Plus Synthesized Images Versus Standard Full-field Digital Mammography in Population-based Screening (TOSYMA)

This study is a randomized, multicenter, multivendor, controlled, diagnostic superiority trial to compare digital breast tomosynthesis plus synthesized 2D mammograms (DBT+s2D) versus standard 2D full-field digital mammography (2D-FFDM) regarding the effectiveness as screening modality.

Study Overview

Status

Active, not recruiting

Conditions

Intervention / Treatment

Detailed Description

The primary objective of the study is to evaluate whether digital breast tomosynthesis plus synthesized 2D mammograms leads to a relevant increase in the detection rate of screening-detected invasive cancers compared to 2D full-field digital mammography in routine screening according to the European Guidelines. Furthermore, the incidence rate of interval cancers within a 24 months interval after screening will be compared between both study arms in order to investigate the potential for overdiagnosis.

According to the pre-defined order of both primary endpoints and the primary objective of the study in the planning phase, the initial sample size calculation was based solely on the first primary endpoint (invasive breast cancer detection rate). Given the increasing national and international attention of interval cancers to assess the impact of potential overdiagnosis caused by tomosynthesis, we have planned a sample size increase from 80,000 to 120,000 study participants to achieve a reasonable statistical power for the evaluation of both primary endpoints. The revised sample size calculation was carried out without knowledge of the data from the currently recruiting TOSYMA study, i.e. all planning assumptions were based on external data that do not belong to the ongoing study.

Study Type

Interventional

Enrollment (Actual)

99689

Phase

  • Not Applicable

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Locations

  • Germany
    • Lower Saxony
      • Hanover, Lower Saxony, Germany, 30449
        • Screening-Einheit Hannover; Mammographie-Einheit Hannover
      • Lüneburg, Lower Saxony, Germany, 21337
        • Screening-Einheit Niedersachsen Nordost; Mammographie-Einheit Lüneburg
      • Stade, Lower Saxony, Germany, 21680
        • Screening-Einheit Niedersachsen Nord; Mammographie-Einheit Stade
      • Vechta, Lower Saxony, Germany, 49377
        • Screening-Einheit Niedersachsen Mitte; Mammographie-Einheit Vechta
      • Wilhelmshaven, Lower Saxony, Germany, 26382
        • Screening-Einheit Niedersachsen Nordwest; Mammographie-Einheit Wilhelmshaven
    • North Rhine-Westphalia
      • Aachen, North Rhine-Westphalia, Germany, 52062
        • Screening-Einheit Aachen-Düren-Heinsberg; Mammographie-Einheit Aachen
      • Ahlen, North Rhine-Westphalia, Germany, 59227
        • Referenz-Screening-Einheit Münster-Nord/Warendorf; Mammographie-Einheit Ahlen
      • Bergisch Gladbach, North Rhine-Westphalia, Germany, 51429
        • Screening-Einheit Köln rechtsrheinisch, Leverkusen, Rhein.-Berg. Kreis, Oberbergischer Kreis; Mammographie-Einheit Bergisch Gladbach
      • Bielefeld, North Rhine-Westphalia, Germany, 33062
        • Screening-Einheit Bielefeld, Gütersloh; Mammographie-Einheit Bielefeld
      • Coesfeld, North Rhine-Westphalia, Germany, 48653
        • Screening-Einheit Münster-Süd; Mammographie-Einheit Coesfeld
      • Duisburg, North Rhine-Westphalia, Germany, 47057
        • Screening-Einheit Duisburg; Mammographie-Einheit Duisburg
      • Gelsenkirchen, North Rhine-Westphalia, Germany, 45894
        • Screening-Einheit Gelsenkirchen, Kreis Recklinghausen, Bottrop; Mammographie-Einheit Gelsenkirchen
      • Herford, North Rhine-Westphalia, Germany, 32052
        • Screening-Einheit Minden-Lübbecke, Herford; Mammographie-Einheit Herford
      • Krefeld, North Rhine-Westphalia, Germany, 47805
        • Screening-Einheit Mönchengladbach, Krefeld, Viersen; Mammographie-Einheit Krefeld
      • Lippstadt, North Rhine-Westphalia, Germany, 59555
        • Screening-Einheit Höxter, Paderborn, Soest; Mammographie-Einheit Lippstadt
      • Münster, North Rhine-Westphalia, Germany, 48143
        • Referenz-Screeening-Einheit Münster-Nord/Warendorf; Mammographie-Einheit Münster-Nord
      • Münster, North Rhine-Westphalia, Germany, 48153
        • Screening-Einheit Münster-Süd; Mammographie-Einheit Münster
      • Paderborn, North Rhine-Westphalia, Germany, 33098
        • Screening-Einheit Höxter, Paderborn, Soest; Mammographie-Einheit Paderborn
      • Schwerte, North Rhine-Westphalia, Germany, 58239
        • Screening-Einheit Märkischer Kreis, Hamm, Unna; Mammographie-Einheit Schwerte
      • Solingen, North Rhine-Westphalia, Germany, 42651
        • Screening-Einheit Raum Bergisch Land/Kreis Mettmann; Mammographie-Einheit Solingen-Mitte
      • Wuppertal, North Rhine-Westphalia, Germany, 42109
        • Screening-Einheit Raum Bergisch Land/Kreis Mettmann; Mammographie-Einheit Wuppertal-Elberfeld

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

50 years to 69 years (Adult, Older Adult)

Accepts Healthy Volunteers

Yes

Description

Inclusion Criteria:

  • Women eligible to participate in the National Mammography Screening Program of Germany
  • Informed decision for mammography screening
  • Written informed consent
  • No prior participation in the TOSYMA trial

Exclusion Criteria:

  • Breast cancer up to 5 years prior to study invitation
  • Previous mammography examination < 12 months,
  • Breast implants

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Screening
  • Allocation: Randomized
  • Interventional Model: Parallel Assignment
  • Masking: None (Open Label)

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
Experimental: DBT+s2D
Digital breast tomosynthesis plus synthesized 2D mammograms
Diagnostic test: DBT+s2D
Digital breast tomosynthesis plus synthesized 2D mammograms
Active Comparator: 2D-FFDM
2D full-field digital mammography
Diagnostic test: 2D-FFDM
2D full-field digital mammography

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Detection rate of invasive breast cancers
Time Frame: Routine screening visit
Number of women with screening-detected invasive breast cancer divided by the number of all women screened. A screening-detected breast cancer is classified as invasive carcinoma if the pT category (pathological tumor size) of the TNM classification falls into one of the following categories: pT1mic, pT1a, pT1b, pT1c, pT1, pT2, pT3, pT4a, pT4b, pT4c, pT4d, pT4, pTX (for evaluation purpose pTX defines histologically approved invasive breast cancer with missing tumor diameter) or the final pathological categorization has been done after neoadjuvant therapy (ypT), implying an invasive cancer prior to therapy.
Routine screening visit
Cumulative 24 months incidence of interval cancers
Time Frame: 24 months after routine screening visit
The 24 months incidence of interval cancers is defined as the number of women that develop a ductal carcinoma in situ or an invasive breast cancer in the 24 months interval after a negative screening examination divided by the number of all women with a negative screening result.
24 months after routine screening visit

Secondary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Detection rate of ductal carcinoma in situ (DCIS)
Time Frame: Routine screening visit
Number of women with screening-detected ductal carcinoma in situ (if the pT category of the TNM classification falls into the category pTis) divided by the number of all women screened.
Routine screening visit
Detection rate of tumor category pT1
Time Frame: Routine screening visit
Number of women with screening-detected invasive breast cancers of the category pT1 divided by the number of all women screened. A screening-detected breast cancer is classified as breast cancer of tumor category pT1 if tumor size is ≤ 20 mm in greatest dimension and the respective pT subcategory of the pTNM classification is one of the following: pT1mic, pT1a, pT1b, pT1c, pT1.
Routine screening visit
Recall rate for further assessment
Time Frame: Routine Screening Visit
Number of women with recalls for further assessment divided by the number of all women screened.
Routine Screening Visit
Positive predictive value of recall for further assessment (PPV1)
Time Frame: Routine screening visit
Number of women with screening-detected malignancies (ductal carcinoma in situ or invasive breast cancer) divided by the number of women with recalls for further assessment.
Routine screening visit
Cumulative 12 months incidence of interval cancers
Time Frame: 12 months after routine screening visit
The 12 months incidence of interval cancers is defined as the number of women that develop a ductal carcinoma in situ or an invasive breast cancer in the 12 months interval after a negative screening examination divided by the number of all women with a negative screening result.
12 months after routine screening visit

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

University Hospital Muenster

Collaborators

German Research Foundation

Investigators

  • Principal Investigator: Walter Heindel, MD, PhD, University Clinic for Radiology, University of Muenster / University Hospital Muenster

Publications and helpful links

The person responsible for entering information about the study voluntarily provides these publications. These may be about anything related to the study.

General Publications

Helpful Links

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Actual)

July 5, 2018

Primary Completion (Estimated)

March 31, 2027

Study Completion (Estimated)

March 31, 2027

Study Registration Dates

First Submitted

December 13, 2017

First Submitted That Met QC Criteria

December 13, 2017

First Posted (Actual)

December 19, 2017

Study Record Updates

Last Update Posted (Actual)

January 23, 2026

Last Update Submitted That Met QC Criteria

January 21, 2026

Last Verified

January 1, 2026

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

  • UKM14_0016
  • HE1646/5-1 and HE1646/5-2 (Other Grant/Funding Number: German Research Foundation (DFG))

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

UNDECIDED

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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