The accuracy of two view digital x-ray mammography (2DDM) in breast cancer screening is limited because of superimposition of normal breast structures onto a two dimensional image. Mammography signs of breast cancer may be obscured, particularly in women with dense glandular breast tissue, resulting in delay in diagnosis of cancer. Interval cancer data shows that up to 4000 women per annum (2.88 per 1000 screened) are diagnosed with breast cancer in the interval between screens. Conversely, superimposition of normal tissues may produce features on mammography which are suspicious for cancer and lead to unnecessary recall for further diagnostic tests.
Digital Breast Tomosynthesis (DBT) is an x-ray mammography technique which involves acquiring multiple low dose projection images over a limited angular range (less than 50 degrees). These projection images are reconstructed into a set of images consisting of parallel planes, typically 1mm apart throughout the breast, and provide three dimensional information to the film reader. A synthetic 2D mammogram (S 2D) has been developed using the data from the reconstructed DBT images.
Studies of DBT + 2DDM in screening have shown increased invasive cancer detection rates and lower false positive recall rates.There may be increased costs related to the technology and reading times.
The aim of this trial is to measure the impact and cost-effectiveness of DBT + 2DDM or S 2D in routine screening compared to standard 2DDM.
100,000 women will be recruited using NHS screening sites with DBT mammography equipment. At each site, through a clinic randomisation process, half the trial participants will undergo standard 2DDM (the control group) and half will undergo 2DDM + DBT (the intervention group). All cases will be double read - in the intervention group, one read will be DBT + 2DDM, and one read will be DBT + S 2D. Arbitration or consensus will be used for reader 1/2 discordance.
Project Details
Principal Investigator: Dr Alexandra Valencia
Planned End Date: 31/03/2025
Local Ref: 4441