The first Australian clinical trial of 3D breast imaging technology - or tomosynthesis - in the assessment of breast cancer has produced highly promising results.
The trial, undertaken over a 14-month period from January 2013 at BreastScreen Victoria’s Maroondah service in outer eastern Melbourne, involved 560 women. All the women had been recalled for further tests after routine screening mammograms using conventional 2D x-rays had detected breast abnormalities.
The trial did not explore the use of tomosynthesis for the initial mammograms undertaken as part of general population screening for breast cancer amongst women attending BreastScreen.
The findings were unveiled today by the trial’s Principal Investigator, Dr Darren Lockie, the Designated Radiologist of Maroondah BreastScreen, at the annual conference of BreastScreen Australia in Melbourne.
The trial found:
- Tomosynthesis provides a more detailed, 3D image of the breast, reducing the risk of missing cancers
- Tomosynthesis could reduce the need for further assessment tests - biopsies by 27% and ultrasound by 11%
- Four in five participants (81%) found the assessment experience, including the compression, with tomosynthesis much better, better or the same as for their 2D screening mammogram
- Four new cancers not detected in the original screening mammograms were identified
- Used in place of regular 2D mammograms, the radiation dose is comparable, and often less than existing X-ray practice and within the guidelines.
Digital breast tomosynthesis (DBT) uses a specifically designed digital mammography unit to produce 3D images. A number of low dose conventional x-rays of the compressed breast are taken from different angles and then reconstructed into a 3D volume of thin “slices” through the breast using mathematical algorithms.
Dr Lockie said: “In the assessment of women from screening programs identified as needing further investigations it’s unequivocal that tomosynthesis absolutely has a role. There’s growing evidence now that it’s a valuable test.”