Comparison of computer-assisted and manual screening of cervical cytology

The Pap smear, introduced over 50 years ago, has significantly contributed to the reduction of mortality due to cervical cancer. The shortage of skilled cytotechnologists to screen and diagnose Pap slides has always been a concern, thus driving the goal to develop an automated system. This study evaluated the diagnostic performance of an automated computer imaging system for routine cervical cancer screening in a high-volume independent laboratory.

Validation and training were conducted upon installation of the computer imaging system. Following validation, data were evaluated comparing cytologic detection rates of a six-month cohort of slides screened with computer imaging assistance versus a historic control of manually screened slides.

For each cytologic abnormal category, the Imager-assisted detection rates were significantly greater than the manually screened historic cohort. The Imager increased the detection of HSIL+ by 38% and LSIL by 46% compared to manual screening. There was an increase in the rate of ASC in the Imager cohort (6.5%) compared to manual screening (4.1%), however, the ASC rate decreased during the time of the study period suggesting learning affect.

The results indicate that computer-imaging-assisted screening significantly increased the cytologic detection of cervical abnormalities compared to manual screening. The initial increase in ASC rates is partially due to a new stain protocol that may be corrected with additional experience. The implementation of the Imager, however, did not adversely affect the ASC:SIL ratio.