GE Senographe SecondLook Operator's Manual page 32

GE Healthcare Senographe SecondLook Digital CAD System
Revision 1 Operator Manual 5189820-5-C-1EN
ROSE-2
The second pivotal study, ROSE-2, was a multi-institutional prospective trial designed to show that the
use of the original Second Look Analog system did not appreciably increase the number of suspicious
regions recommended for further work-up by radiologists reading screening mammograms. The work-
up rates of radiologists were prospectively determined before and after the use of SecondLook. In
addition, the interpreting radiologists estimated the additional time associated with the use of
SecondLook as a percentage of total reading time.
Ten (10) experienced mammographers at 5 institutions prospectively interpreted a total of 3,946
sequential screening mammograms. Each mammogram was then processed by SecondLook, and the
same radiologist then re-evaluated the mammogram with the CAD marks. Of the 3,946 cases, 657 were
recommended for work-up by radiologists before the use of SecondLook. After the use of SecondLook
an additional 20 cases were recommended for work-up, for a total of 677 cases. Therefore, the work-up
rate of radiologists was 16.6% (657 of 3,946) before use of SecondLook and 17.2 % (677 of 3,946)
afterward. The 95% confidence intervals for these work-up rates were (15.5% - 17.8%) before
SecondLook use and (16.0% - 18.4%) with it. This demonstrated that the 0.5% (20 of 3,946) increase in
work-up rate due to the use of SecondLook was insignificant.
In 3,631 of 3,946 prospective cases (92%) the estimated additional reading time to use SecondLook was
20% or less.
In addition, historical work-up rates for the same radiologists in the months prior to the prospective cases
were compared to their rates before the use of SecondLook to illustrate the variability inherent in the
process of reading screening mammograms. For this study, work-up included additional mammographic
views, short-interval follow-up, ultrasound, other advanced imaging modalities, or recommendation for
biopsy. Of the 3,876 historical cases, 516 were worked-up by radiologists without the use of
SecondLook for a 13.3% historical work-up rate. The 95% confidence interval on this work-up rate was
(12.3% - 14.4%). Thus, there was no overlap in the confidence intervals between the historical work-up
rate and the work-up rate prior to use of SecondLook compared to the considerable overlap of
confidence intervals between the work-up rates before and after SecondLook use. Consequently, the
inherent variability in radiologist work-up rates was larger than the increase due to the use of
SecondLook. This adds further evidence that the increase in work-up rate due to the use of SecondLook
is insignificant.
Page no. 32
CAD.fm