This is a prospective clinical trial aiming to determine the ability of an AI pipeline to identify women who would benefit from supplemental MRI in terms of decreasing the number of cancers having a significantly delayed detection
All women attending mammography screening at Karolinska University Hospital will have their mammograms analyzed by AI (Figure 1). The specific AI-implementation (AI tool) in this study is a result of AI predictions from three equally weighted component AI models analyzing mammograms: (i) masking predictor, (ii) risk predictor and (iii) cancer signs predictor (by one commercial CAD model and one in-house academic CAD model); the age of the woman is also taken into account by multiplying the score with (110-age)/70. The purpose of the age factor is to attain a relatively similar proportion of MRI exams in the lower and higher age groups. The aim of the AI tool is to identify women with the highest probability of having a delay in cancer detection, i.e., having had a false negative screening mammogram. An AI-based framework has been developed by researchers at Karolinska Institute (led by Dr. Fredrik Strand) and Royal Institute of Technology (led by Dr: Kevin Smith). The specific AI-implementation (AI tool) in this study is a result of AI predictions from three equally weighted component AI models analyzing mammograms: (i) masking predictor, (ii) risk predictor and (iii) cancer signs predictor (by one commercial CAD model and one in-house academic CAD model); the age of the woman is also taken into account by multiplying the score with (110-age)/70. The purpose of the age factor is to attain a relatively similar proportion of MRI exams in the lower and higher age groups. The aim of the AI tool is to identify women with the highest probability of having a delay in cancer detection, i.e., having had a false negative screening mammogram. The specific AI tool and its settings will remain the same during the study. For each examination, the AI tool will produce an AI Joint Score and an AI Masking Score. The AI Masking Score cut-off point was defined by the median of examinations collected during the initial period of March 1 to March 24, 2021. The cut-off point of the AI Joint Score was defined by the 92nd percentile of the initial population. Women meeting these criteria will be invited to the study, and randomized to MRI or no-MRI (standard-of-care). A Signa Premier 3T MRI scanner from GE Healthcare will be used. The MRI protocol will contain a T2-weighted Dixon sequence and a T1-weighted dynamic contrast enhanced series, and will remain the same through the course of the study. All MRI exams will be assessed by two radiologists, where the second reader will have access to the assessment of the first reader. In case of disagreement, a consensus discussion between two radiologists will be held. The MRI exams will be assessed according to BI-RADS, and follow-up will depend on the BI-RADS category (Figure 2). Women with BI-RADS 1-2 will have no further diagnostics and will be sent a 'healthy letter'. Women with BI-RADS 3 to 5 will be recalled for 2nd look ultrasound. Women with BI-RADS 4-5 will be included in the regular process for established cancer suspicion and be discussed in a multidisciplinary team conference. For women with BI-RADS 3, the follow-up will be handled within the breast radiology unit.
Study Type
INTERVENTIONAL
Allocation
RANDOMIZED
Purpose
SCREENING
Masking
NONE
Enrollment
2,500
An AI tool will generate scores used to determine eligibility. Women randomized to MRI will be examined in an MRI scanner.
Karolinska University Hospital
Stockholm, Sweden
Significantly Delayed Breast Cancer Detection per 1000 women
Composite end-point defined by either: 1. Interval Cancer, 2. Cancer with lymph node metastasis, 3. Cancer with invasive component larger than 15 mm
Time frame: Until 27 months from study inclusion (includes cancer detected at subsequent screening within this time frame). Cancer detected at the initial screening mammography or MRI shall not be included.
MRI-detected breast cancer
Breast cancer detected at the initial screening MRI for women in the Intervention arm of the study
Time frame: Diagnosis during work-up within 2 months of the initial screening MRI
Invasiveness
In situ and/or Invasive cancer
Time frame: All diagnosed breast cancer within 27 months of study inclusion
Histology
Ductal, Lobular, Mucinous, Tubular, Other
Time frame: All diagnosed breast cancer within 27 months of study inclusion
Lymph node metastasis
0 nodes, 1-3 nodes, 4 or more nodes
Time frame: All diagnosed breast cancer within 27 months of study inclusion
Tumor size
Size (in millimetre) for the invasive and the in situ component
Time frame: All diagnosed breast cancer within 27 months of study inclusion
Receptor status
ER positive/negative, PR positive/negative, HER2 positive/negative
Time frame: All diagnosed breast cancer within 27 months of study inclusion
This platform is for informational purposes only and does not constitute medical advice. Always consult a qualified healthcare professional.
Age
Age of the woman
Time frame: At study inclusion
Distribution of AI scores
Histogram, mean, median and dispersion measures for the AI Scores
Time frame: At study inclusion
BI-RADS codes
For each MRI examination, the BI-RADS code for fibroglandular volume, background enhancement and breast lesions
Time frame: At study inclusion and until end of 27 month follow-up
Biopsy result
Pathology assessment of biopsy: normal tissue, benign lesion, cancer in situ, invasive cancer
Time frame: Diagnosis during work-up within 2 months of the MRI examination
Participant questionnaire
Participant questionnaire replies for MRI contraindications and for Breast cancer-related history
Time frame: At study inclusion