Interactive CAD is intended to aid the reader in decision making and will not help to avoid perceptual oversights. The success of the interactive approach may be explained by assuming that perceptual oversights do not occur frequently. In our study this appeared to be the case. On average only 5 (12.2%) of the true-positive CAD regions were not probed by the reader. Thus, in the reader study at most 12.2% of the cancers were overlooked, while none of them were reported in the original screening. Results also show that on average 274.2 (50.2%) false-positive CAD regions were not activated, limiting the number of false positives to which the readers are exposed. It is noted that the system can easily be extended by displaying the most suspicious, non-queried CAD regions as traditional prompts after the reading is completed.