Categories
Uncategorized

Digital Breast tomosynthesis

1119

3-dimensional digital mammographic technique.

Involves image acquisition from an x-ray source that moves over an arc of excursion with reconstruction of thin slices minimizing the influence of overlapping breast tissue.

Projection images are then used to generate thin image slices of the breast, thereby reducing the overlapping effect of breast tissue that occurs in digital mammography, which can hide a tumor and lead to false negative results or give the appearance of a tumor, leading to put false positive results.

Associated with decreased false-positive test results and increased breast cancer detection in screening for breast cancer compared with digital mammography.

It allows acquisition of multiple low-dose x-ray images across a limited arc and digital detector, with data reconstructed using computer algorithms to generate thin sections displayed in a quasi-3-D format.

DBT studies report modest increases in recall rate among screened women with dense and non densse breasts, and modest iincreases in invasive cancer detection and biopsy rates.

It is used in combination with standard digital mammography for breast cancer screening.

Digital mammography plus tomosynthesis improves over conventional screening mammography by increasing the diagnosis of invasive cancers while reducing the findings of false positive results.

Digital breast tomosynthesis has a better specificity for detecting a higher number of breast cancers than digital mammography, especially in women aged 40 to 49 years.

Digital Breast Tomosynthesis Detects Higher Proportion of Breast Cancers Than Digital Mammography

Population-based Research Optimizing Screening Through Personalized Regimens (PROSPR) consortium: 180,340 breast cancer screening examinations, 129,369 (71.7%) were conducted via digital mammography and 50,971 (28.3%) were done using DBT.

Smaller invasive cancers that were node- and HER2-negative were detected more often via DBT 73.7% than with digital mammography 65.4%.

DBT was tied to lower recall and a higher rate of cancer detection than digital mammography for all age groups, even when stratified by breast density.

The largest increase in cancer detection rate and the greatest shift toward smaller, node-negative invasive cancers detected with DBT was for women aged 40 to 49 years.

The rate of cancer detection in women with nondense breasts was 1.70 per 1000 women higher with DBT than with digital mammography.

For women with dense breasts, the cancer detection rate was 2.27 per 1000 women higher with DBT than with digital mammography.

Screening with DBT is associated with increased specificity and an increased proportion of breast cancers detected with better prognosis compared with DM.

The addition of tomosynthesis mammography adds approximately 2 times the total radiation dose of current digital mammography.

Each tomosynthesis image has an effective dose of ionizing radiation of 0.7 mSv the same as standard 2D mammography view.

The technique obtains up to 60 images of the breast rather than 1-2 images obtained with the stationary scanner used in standard digital mammography.

The addition of tomosynthesis to digital mammography reduces recall rate and increases cancer detection rate (Friedenwald SM et al).

There is a reported 40% increase in detection of invasive cancers and a 15% reduction in false positive results with the use of digital mammography and tomosynthesis compared to digital mammography alone (Skaane P et al).

Its use in conjunction with standard mammography in routine screening helps eliminate tissue overlap that obscures masses.

Breast cancer screening with digital breast tomosynthesis might increase both sensitivity and specificity in comparison with digital mammography.

Women presenting for their first screening examination are particularly important to prioritize for DBT, regardless of breast density or age.

 

The investigators compared the performance of 1,273,492 DMs with 310,587 DBTs across the four Breast Imaging Reporting and Database System density types: almost entirely fatty, scattered fibroglandular density, heterogeneously dense, and extremely dense.

 

In women aged 50-59 years, screening recalls per 1,000 exams dropped from 241 with DM to 204 with DBT with a relative risk of 0.84.

 

Cancer detection rates per 1,000 exams in this age group increased from 5.9 with DM to 8.8 with DBT with a relative risk of 1.50.

 

Recall rates were lower with DBT for women with scattered fibroglandular density and heterogeneously dense breasts in all age groups, as well as in women with almost entirely fatty breasts aged 50-79 years.

 

There were no significant differences in recall rates in women with extremely dense breasts in any age group

 

Cancer detection rates are  higher with DBT than with DM in women with heterogeneously dense breasts in all age groups and in women with scattered fibroglandular density at 50-59 years of age and 60-79 years of age. 

 

Cancer detection rates are  not significantly different with DBT or DM for women with almost entirely fatty breasts or extremely dense breasts of any age.

In a large study including 504,427 women and the going 1,379,089 screening mammograms interval cancer rates were not significantly different for DBT versus digital mammography (Kerlikowske K).

In the above study women with extremely dense breasts and high risk of breast cancer, the advanced cancer rates for DBT versus digital mammography was 0.27 versus 0.8 per thousand examinations over 12 months, a statistically significant difference.

Among women with non-dense breasts, heterogeneously dense breasts or with extremely dense breasts there was no significant difference in advanced cancer rates.

The above study indicates that with extremely dense breasts and high risk of breast cancer, screening with DBT compared with digital mammography was associated with a lower risk of advanced breast cancer.

 

 

One reply on “Digital Breast tomosynthesis”

Leave a Reply

Your email address will not be published. Required fields are marked *