[The assessment of the impact of a double reading by expert readers in a mass mammographic study].

Purpose: To evaluate the role of double reading of screening mammograms by expert radiologists.
Material and Methods: We analyzed the results of independent readings of a proficiency test of screening mammography (140 cases, 32 cancers) performed by four expert radiologists. Double reading was simulated by matching the four original readings in 6 possible combinations. The impact of double reading over single reading was evaluated in terms of increased sensitivity and increased recall rate.
Results: Of 32 carcinomas 22, 6, or 4 were identified by 4, 3, or 2 readers, respectively. Of 108 cases negative for cancer a recall for further investigations was suggested by 4, 3, 2, 1 or no reader(s) in 3, 3, 9, 14, or 79 cases, respectively. Inter-reader diagnostic repeatability was good (k = 0.65). Single readers achieved an average sensitivity of 89% (range 87.5-90.6%) and an average recall rate of 12.2% (range 7.4-16.6%). Simulated double reading achieved an average increase in sensitivity of 8.8% (range 6.2-10.95%) and an average increase of recall rate of 6.2% (range 3.8-8.3%).
Conclusions: Even though the relative increase of recall rate is relevant (+53.2%), the corresponding gain in sensitivity justifies the use of double reading, which was confirmed to be worthwhile also when expert radiologists are involved. This study confirms the opportunity of adopting double reading as a routine procedure in mammographic screening.