3D vs 2D Mammography
3D mammography (or breast tomosynthesis) has a 40% higher rate of invasive breast cancer detection when compared with 2D mammography, with a 15% decrease in false positive rate.1 When used in conjunction with synthetic 2D software, the radiation dose of 3D mammography is comparable to 2D mammography.2
Imaging Symptomatic Women
When investigating women with breast symptoms, the usual initial breast imaging is mammography (ideally 3D mammography) with breast ultrasound. The exception to this is for women who are less than 35 years old, pregnant or breast-feeding, in which case the usual initial breast imaging is breast ultrasound +/- mammogram. If the ultrasound is normal or benign, often a mammogram will not be performed, unless the patient has significant breast cancer risk factors. If a mammogram is required, 3D mammography is preferred in this younger population.3
Mammographic Breast Density
Breasts are primarily made up of a mix of fatty and fibroglandular tissue. The more fibroglandular tissue compared to fat that a woman has, the whiter the mammogram will be, and the breast will be classified as more dense. Breast density cannot be determined by the way the breast feels or looks. It can only be determined by the radiological (mammographic) appearance. Software such as VolparaTM can provide objective measures for mammographic breast density.
Mammographic breast density is emerging as one of the strongest independent risk factors for breast cancer. Women who are in the highest category of breast density for age are at 4-6 times increased risk of breast cancer compared with women in the lowest category.4 Women with dense breasts are not only at increased risk of developing breast cancer, but are also more likely to mask breast cancer, which may result in delayed detection on mammogram.
Personalised Breast Imaging Screening
A woman’s breast cancer risk can be calculated using a risk calculator such as the IBIS Risk Evaluator (Tyrer-Cuzick model)5, which considers risk factors such as age, BMI, menstrual history, pregnancy history, HRT use, family history and mammographic breast density. Based on this risk, the woman’s age and mammographic breast density, a personalised breast imaging screening recommendation can be formulated. These usually include 3D mammogram and breast ultrasound, and may also include contrast enhanced mammography and breast MRI.
All the above mentioned services (with the exception of breast MRI) are available at Imaging Associates Mitcham in Mitcham Private Hospital. 3D Mammography and Ultrasound is available at our Box Hill and Wagga Wagga clinics also.
- Skaane, P et al. Comparison of digital Mammography Alone and Digital Mammography Plus Tomosynthesis in a Population-based Screening Program. Radiology 2013; 267(1): 47-56.
- Feng, S. Clinical Digital Breast Tomosynthesis System: Dosimetric Characterization. Radiology 2012; 263: 35-42
- Conant, E et al. Association of Digital Breast Tomosynthesis vs Digital Mammography With Cancer Detection and Recall Rates by Age and Breast Density. JAMA Oncology 2019; 5(5): 635-642
- Cancer Australia. Risk Factors for Breast Cancer: A Review of the Evidence. 2018
- https://ems-trials.org/riskevaluator
Dr Daniel Lee
Radiologist, Clinical Director at Imaging Associates Mitcham
