Neural network-based screening (NNS) in cervical cytology: no need for the light microscope?

Neural network-based screening (NNS) of cervical smears can be performed as a so-called "hybrid screening method," in which parts of the cases are additionally studied by light microscope, and it can also be used as "pure" NNS, in which the cytological diagnosis is based only on the digital images, generated by the NNS system. A random enriched sample of 985 cases, in a previous study diagnosed by hybrid NNS, was drawn to be screened by pure NNS. This study population comprised 192 women with (pre)neoplasia of the cervix, and 793 negative cases. With pure NNS, more cases were recognized as severely abnormal; with hybrid NNS, more cases were cytologically diagnosed as low-grade. For a threshold value > or = HSIL (high-grade squamous intraepithelial lesions), the areas under the receiver operating characteristic (ROC) curves (AUC) were 81% (95% CI, 75-88%) for pure NNS vs. 78% (95% CI, 75-81%) for hybrid NNS. For low-grade squamous intraepithelial lesions (LSIL), the AUC was significantly higher for hybrid NNS (81%; 95% CI, 77-85%) than for pure NNS (75%; 95% CI, 70-80%). Pure NNS provides optimized prediction of HSIL cases or negative outcome. For the detection of LSIL, light microscopy has additional value.