Implementation of the ThinPrep imaging system in a high-volume metropolitan laboratory

The Papanicolaou test has proven to be the most effective cancer screening test ever developed. However, with a declining number of skilled cytotechnologists, there is an increased need for computer assistance in cervical cancer screening. The ThinPrep Imaging System (Cytyc Corporation, Marlborough, MA) is a unique system that combines computer imaging technology and human interpretive expertise in the review of ThinPrep Pap test slides. The purpose of this study is to report on the introduction and validation of this technology and present data related to the performance and productivity in our laboratory. Following completion of the ThinPrep Imaging System validation protocol, all imaged ThinPrep Pap test results were tracked and compared with year-2003 manually screened results to identify whether the Imaging System was effective in aiding human interpretive skills. Cases rescreened in the 10% random quality control (QC) program from the negative population that showed abnormal cells consistent with low-grade squamous intraepithelial lesion (LSIL) and above were compared with imaged versus non-imaged cases to establish an estimated laboratory false-negative (F/N) rate. The study compared results of 82,063 manually screened ThinPrep Pap tests in 2003 with 84,473 imaged ThinPrep Pap tests in 2004. Results demonstrated a significant increase in LSIL (37%) and high-grade squamous intraepithelial lesion (HSIL) (42%) detection on the Imager cohort. The F/N rate was reduced by half. The evaluation period after validation of the Imager showed a significant increase in LSIL and HSIL detection with the ThinPrep Imaging System compared to manual screening. These results demonstrate that the Imager has the potential to allow the cytotechnologists to detect more disease and reduce the false-negative rate for the laboratory. Although not evaluated in this study, cytotechnologists reported increased job satisfaction.