ABSTRACT
OBJECTIVE: This study assessed the usefulness of the AutoPap 300 QC System in identifying of detection false negative(DFN) smears in a slide population previously screened as "within normal limits" and compared the rate of identification of DFN to that using 10% random selection. MATERIALS AND METHODS: From December 1996 to August 1998, we utilized the AutoPap 300 QC System at 30% selection rate to select cases for manual review. During the study period, 1,040(83.4%) among 1,247 smears and 7,848(84.0%) among 9,343 smears were screened as "within normal limits" and were included for the AutoPap 300 QC System and 10% random selection studies, respectively. RESULTS: 357(34.3%) among 1,040 were selected by the AutoPap 300 QC System at 30% QC selection rate and reviewed manually. Overall, 63 among 357 were determined to be abnormal including 47 ASCUS, 2 AGUS, and 14 LSIL. 785(10%) among 7,848 were selected by 10% random selection and reviewed manually. 96 among 785 were determined to be abnormal including 69 ASCUS, 3 AGUS, and 24 LSIL. These results represented an increase in pick up rate of DFN(detection false negative) of 5.1 and 4.4 fold for ASCUS/AGUS and LSIL, respectively and of 1.5 and 1.3 fold when accounting for the volume differences measured. CONCLUSIONS: The study demonstrated that the AutoPap 300 QC System is superior to 10% human random screening for the identification of DFN smears. Further studies are required using variable selection rates and a larger number of smears to fully assess the value of the device in quality control mode.
Subject(s)
Humans , Mass Screening , Quality Control , Vaginal SmearsABSTRACT
OBJECTIVES: To estimate false-negative rate of cervical smears using Autopap 300 QC system in rescreening modality. METHODS: From September 1997 to December 1997, Total 26,983 cervical smears were obtained and 18,592 cervical smears were rescreened by Autopap 300 QC system with 10% review rate. The 274 cases of total 26,983 cervieal smears were confirmed histologically by colposcopic biopsy, cone biopsy and hysterectomy. The 274 cases of cervical smears, which obtained prior to pathologic diagnosis made, were evaluated based on cyto-histologic correlation and then the false negative rate were estimated. The cervical smears were reviewed, researching for the cause of false negative. RESULTS: (1) Histologic diagnosis of 274 cases include 65 cases of Low SIL, 173 cases of High SIL, 29 cases of SCC, 2 cases of adenocarcinoma in situ, and 5 cases of invasive adenocarcinoma. (2) The false negative rate were 3% (9/274). Those were 6.2%(4/65) of LSIL, 2.3% (4/173) Of HSIL, none of SCC and AIS, and 20%(5/1) of invasive adenocarcinoma. (3) The false negative cases were reviewed. The 6 cases were sampling enor and 3 cases were screening error. CONCLUSION: Using AutoPap 300 QC system in rescreening modality, The false negative rate of cervical smears were decreased, compared with our previous study.
Subject(s)
Adenocarcinoma , Biopsy , Diagnosis , Hysterectomy , Mass Screening , Vaginal SmearsABSTRACT
OBJECTIVE: False negatives of cervical smears due to screening errors pose a significant and persistent problem. AutoPap 300 QC System, an automated screening device, is designed to rescreen conventionally prepared Pap smears initially screened by cytotechnologists as normal. Clinical experience and sensitivity of the AutoPap 300 QC System were assessed and compared with current 10% random quality control technique. MATERIALS AND METHODS: In clinical practice, a total of 18,592 "within normal limits" or "benign cellular changes" cases classified by The Bethesda System were rescreened by the AutoPap System. In study for sensitivity of The AutoPap System to detect false negatives, a total of 1,680 "within normal limits" or "benign cellular changes" cases were rescreened both manually and by the AutoPap System. The sensitivity of the AutoPap System to these false negatives was assessed at 10% review rate to compare 10% random manual rescreen. RESULTS: In clinical practice, 38 false negatives were identified by the AutoPap System and we had achieved 0.2% reduction in the false negative rate of screening error. In study for sensitivity, 37 false negatives were identified by manual rescreening, and 23 cases(62.2%) of the abnormal squamous cytology were detected by the AutoPap System at 10% review rate. CONCLUSONS: The AutoPap 300 QC System is a sensitive automated rescreening device that can detect potential false negatives prior to reporting and can reduce false negative rates in the laboratory. The device is confirmed to be about eight times superior to the 10% random rescreen in detecting false negatives.
Subject(s)
Mass Screening , Quality Control , Vaginal SmearsABSTRACT
The AutoPap 300 QC System is an automated device for the analysis and classification of conventional cervical cytology slides for quality control purpose. These studies evaluated the sensitivity of the AutoPap 300 QC System, and estimated morphologic features other than epithelial abnormality to identify a high quality control(QC) score with the AutoPap 300 QC System. The sensitivity of the AutoPap 300 QC System at 10% review rate for 210 cases of cervicovaginal cytology with low grade squamous intraepithelial lesion(LSIL) and higher grade lesion was assessed, and compared with a 10% random rescreening. The morphologic features, such as presence of endocervical component, dirty background, atrophy, abnormal cell size, and cellularity of single atypical cells were estimated in 45 cases of no review and 30 cases of QC review cases. The AutoPap 300 QC System identified 119(56.7%) out of 210 cases with LSIL and higher grade lesion at 10% review rate. It was more sensitive to squamous cell lesions(50-62%) than to glandular lesions(10%). The dirty background and the scanty cellularity of single atypical cells were significantly related to low QC score. Conclusively, AutoPap 300 QC System is superior to human random rescreen for the identification of false negative smears. The upgrading of this device is required to enhance the detection of glandular lesion and certain inadequate conditions of the slides.