Use of Tomosynthesis in Intraoperative Digital Specimen Radiography - Is a Reduction of Breast Re-excision Rates Possible?

A prospective clinical study was done to see whether it is possible to reduce the rate of re-excisions using digital breast tomosynthesis (DBT) compared commercial FFDM. Between 1/2011 and 5/2011 we diagnosed an invasive breast cancer (BI-RADS 5) in 100 patients. After histological verification we performed breast-conserving therapy with intraoperative imaging using one of 2 different systems: 1. Tomosynthesis (Siemens, Erlangen, Germany), amorphous selenium, Tungsten source, focus 0.1 mm, resolution 85 µm, pixel pitch, 8 l/mm, range: 50°, 25 projections, time for scanning > 20 s, geometry: same scanning scope, reconstruction: filtered back projection; or 2. Inspiration™ (Siemens, Erlangen, Germany), amorphous selenium, tungsten source, focus 0.1 mm, resolution 85 µm, pixel pitch, 8 l/mm as the standard. The 100 radiograms obtained with both systems were prospectively shown on a monitor to 3 radiologists. Out of a total of 100 patients with histologically proven breast cancer (BI-RADS 6) no re-excision was necessary in 78 patients. A retrospective analysis (n = 22) demonstrated an increase in sensitivity of tomosynthesis compared to the Inspiration™ at a magnification of 1.0 : 1.0 of 8 % (p < 0.05), i.e., in 8 patients re-excision would not have been necessary with tomosynthesis. Tomosynthesis has a significant higher sensitivity (p < 0.05) compared with a commercial FFDM system. Studies with higher numbers of patients will be necessary to evaluate this method.