For breast cancer patients, detecting and diagnosing their condition is traditionally a lengthy process requiring multiple imaging scans. A source of frustration and anxiety for women, this process can take several weeks from initial mammogram to final diagnosis.
This lengthy time period from initial mammogram to final diagnosis can cause anxiety in women and frustration with the overall process. Current protocols at many breast centers involve an initial screening mammogram followed by a diagnostic mammogram and/or ultrasound to further characterize the lesions and determine if a biopsy is needed. The additional diagnostic mammogram, often inclusive of spot and magnification views, can increase the patient’s exposure to radiation–a growing concern in the radiology community.
Digital breast tomosynthesis (DBT) is a novel imaging modality that builds on the success of mammography to provide 3D imaging. DBT has garnered attention of late for its promise in reducing the recall rate associated with 2D mammography. However, questions remain as to the improved performance and “need” for an additional imaging modality in an already crowded space.
A new study published in Radiology compares the performance of DBT and mammography spot views for the characterization of lesions detected and diagnosed during earlier exams. The authors found that there was no statistical difference in radiologist performance for characterizing lesions using these two modalities. The radiologists stated improved visibility using DBT, though this only reached statistical significance for one reader. The study authors note that if DBT is involved in the initial work-up, spot views may not be needed. However, further analysis with larger studies is needed to make a definitive judgment.
There is an increasing body of evidence showing that DBT is as good or superior to 2D mammography, implying that DBT could become a “one-stop” imaging modality for breast cancer screening if the dose is decreased. The dose associated with Hologic’s Selenia Dimensions system (the only DBT platform currently FDA approved) is still higher than that of screening mammography, deterring some from moving forward with purchasing.
In contrast, both Siemens’ and GE Healthcare’s systems will likely not be released in the US until their doses are similar to that of 2D mammography. While use of DBT in a clinical protocol will likely decrease the number of downstream exams and the cumulative dose to the patient, this is not the guarantee some physicians require to purchase the technology.
Many of the hospitals we have spoken with recently indicate that they are in a “wait and see mode” with regard to purchasing DBT. Since current studies do not definitively show superiority of DBT over 2D mammography, it will be difficult for many administrators to move forward, particularly without incremental payment.
RSNA, the largest annual imaging conference, is quickly approaching, causing some to speculate that larger studies or product launches will be revealed. Stay tuned to the Pipeline for live updates during the 2011 conference.