Biomedical subjects

Stefano Ciatto

Publications and source records attributed to Stefano Ciatto.

40 records · Page 3Linked to original sources

PubMedDate not supplied

Quality control of the autopap screening system employed as a primary screening device: rapid review of smears coded as no further review.

AIMS AND BACKGROUND: Automated reading of smears is increasingly used in cervical screening, and quality control procedures to check its performance are required. The aim of the present study was to evaluate the usefulness of rapid review of all smears coded as "no further review" (NFR) by the AutoPap system as a quality control procedure. METHODS: From 2002-2005, 153,269 smears were processed by AutoPap at the Centro per lo Studio e la Prevenzione Oncologica of Florence, Italy, and 24,503 (15.9%) were coded as NFR. All NFR smears underwent immediate rapid review by expert readers. RESULTS: Sixty-five of 118 NFR cases reviewed as ASCUS-R complied to recommended 6 months cytology, and 25 of 30 NFR cases reviewed as ASCUS-SIL or more severe accepted immediate colposcopy. As a result of such assessment, one single case of microinvasive carcinoma was detected in a woman aged 34 years: NFR smear had been reviewed as AGCUS, was followed by repeat AGCUS cytology and repeat negative colposcopy, and finally underwent conization. CONCLUSIONS: NFR report at AutoPap was associated with an extremely high negative predictive value, which might suggest using AutoPap as a primary screening tool, with NFR report prompting a "return to screening" recommendation. Rapid review of NFR smears is not recommended as a quality control measure for the negligible yield of high-grade lesions detected.

Adult↗

PubMedDate not supplied

Association of endometrial thickness assessed at trans-vaginal ultrasonography to endometrial cancer in postmenopausal women asymptomatic or with abnormal uterine bleeding.

PURPOSE: To define the normal cut off of endometrial thickness as measured at transvaginal ultrasonography (TVUS) in order to define postmenopausal women without symptoms or with abnormal uterine bleeding (AUB) at risk of endometrial carcinoma (EC). MATERIALS AND METHODS: 3460 postmenopausal women (2240 asymptomatic, 1220 with AUB) undergoing TVUS. These series was linked with the Tuscany Cancer Registry archives in order to identify subjects who developed EC subsequent (within two years) to TVUS. RESULTS: Thickness (half layer) was significantly reduced in 2234 subjects not developing EC (1.68 mm; range = 0-20, SD 3.14) as compared to 6 subjects developing EC (4.67 mm, range = 0-10, SD 3.67) (p=0.02). A 4 mm cut off was associated with a sensitivity of 66.7%, a specificity of 92.1%, a positive predictive value of 2.2% and a negative predictive value of 99.9%. Similarly, in subjects with AUB, thickness (half layer) was significantly smaller in the 1175 subjects not developing EC (2.46 mm, range 0-20, SD 3.59) as compared to 45 subjects developing EC (8.0 mm, range 0-44, SD 6.76) (p<0.001). The best cut off for clinical purposes was 4 mm, with a sensitivity of 91.1%, a specificity of 79.8%, a positive predictive value of 14.8% and a negative predictive value of 99.6%. CONCLUSIONS: The study confirms the usefulness of measuring endometrial thickness (half layer cut off = 4 mm) with TVUS in asymptomatic postmenopausal women, both in asymptomatic subjects to indicate further special surveillance and in subjects with AUB to indicate immediate invasive assessment.

Aged↗

PubMedDate not supplied

Comparison of standard reading and computer aided diagnosis (CAD) on a proficiency test of screening mammography.

PURPOSE: To evaluate the role of computer aided diagnosis (CAD) to improve screening mammograms interpretation. MATERIALS AND METHODS: Six radiologists underwent a screening mammography proficiency test first by conventional, then by CAD assisted reading. Sensitivity and recall rate at conventional and CAD reading were compared. Independent conventional double reading was simulated (15 pair combinations) and compared to single CAD reading. RESULTS: CAD marked 31 of 32 cancers (case-based sensitivity=96.8%). On a film and lesion basis, CAD identified 31 of 32 (96.8%) malignant calcifications and 29 of 42 (69.0%) malignant opacities, the only cancer not identified by CAD being depicted as an isolated opacity. CAD marked 348 areas (153 microcalcifications and 195 opacities) in 88 of 108 non cancer cases, with a case-based specificity of 18.5% (20/108). Considering all six readings, cancer was identified in 164 or 174 of 192 readings (85.4 vs 90.6%, c2 2.03, df=1, p=0.15) and recalls of non-cancer cases were 108 or 159 of 648 readings (16.6 vs 24.5%, c2 11.7, df=1, p<0.001) at conventional or CAD reading, respectively. CAD reading (average of 6 readings, 192 cancer, 648 non-cancer readings) was slightly, non significantly less sensitive (sensitivity 90.6 vs 92.9%, c2 0.73, df=1, p=0.39) and slightly, but not significantly more specific (recall rate 24.5 vs 26.1%, c2 0.56, df=1, p=0.45) as compared to simulated independent double reading (average of 15 combinations, 480 cancer, 1620 non-cancer readings). CONCLUSION: CAD seems to allow for a limited absolute increase (+5.2%) in sensitivity and for a limited absolute increase (+7.9%) in recall rate, the latter difference only reaching statistical significance. CAD reading showed no significant difference in diagnostic accuracy as compared to conventional (simulated) double reading, although further studies are needed to confirm it as possible alternative to double reading in the current screening practice.

Breast Neoplasms↗

PubMedDate not supplied

Comparison of two commercial systems for computer-assisted detection (CAD) as an aid to interpreting screening mammograms.

PURPOSE: To compare the diagnostic accuracy of two commercial CAD systems (CADx and R2) and their impact as an aid to conventional reading of screening mammograms. MATERIALS AND METHODS: The image set considered consisted of 120 mammograms, 89 confirmed negative and 31 with subsequent interval cancers (11 classified as false negatives (FN), 20 as "minimal signs" (MS)). The set was digitised and processed with CAD, and printouts obtained of the mammograms with indications of the areas warranting review. Six expert radiologists read the mammograms three times, once using conventional reading and twice using CAD reading with CADx and R2, respectively. The two CAD systems were compared in terms of diagnostic accuracy of the marks and the impact of CAD reading compared to conventional reading and to the use of independent second reading simulated by combining pairs of single conventional readings. RESULTS: R2 highlighted more calcifications (218 vs 132, +65%) and CADx highlighted more masses (208 vs 105, +98%). CADx and R2 marked 15 and 17 out of 31 cancers, respectively (sensitivity 48.3% vs 54.8%, chi squared=6.4, p=0.79), 10 and 6 out of 11 FN (90.9% vs 54.5%, chi squared=2.0, p=0.15), respectively, and 5 and 11 out of 20 MS (25.0% vs 55.0%, chi squared=2.6, p=0.10), respectively. As for specificity, the false positive markings for masses were on average (per case) 1.60 for CADx and 0.75 for R2, those for calcifications were 1.08 for CADx and 1.77 for R2 and the total false positive markings were 2.68 for CADx and 2.52 for R2. CADx and R2 marked 73 and 63 of 89 negative controls (specificity = 0.18 vs 0.29, chi squared=2.52, p=0.11), respectively. All the radiologists showed greater sensitivity with CAD reading compared to conventional reading. On average, sensitivity with conventional reading was 58.6% (109/186), as against 70.9% (132/186) for CADx or R2 (chi squared=5.71, p=0.016). Sensitivity for FN cases was 71.2% (47/66) with conventional reading, 84.8% (56/66) with CADx (chi squared=2.82, p=0.09) and 80.3% (53/66) for R2 (chi squared=1.03, p=0.30) (CADx vs R2, chi squared=0.21, p=0.64). Sensitivity for MS cases was 51.6% (62/120) for conventional reading, 63.3% (76/120) for CADx (chi squared=2.88, p=0.08) and 65.8% (79/120) for R2 (chi squared=4.40, p=0.03) (CADx vs R2, chi squared=0.07, p=0.78). The recall rates were 18.1% (97/534) for conventional reading, 29.7% (159/534) for CADx (chi squared=5.72, p=0.01) and 24.3% (130/534) for R2 (chi squared=10.11, p=10-5) (CADx vs R2, chi squared=3.71, p=0.05). Double reading was significantly more sensitive than conventional reading (chi squared=29.6, p=10-6), CADx (chi squared=5.33, p=0.02) and R2 (chi squared=5.33, p=0.02). The recall rate for double reading was significantly higher than for conventional reading (chi squared=21.5, p=10-6) whereas no significant difference was detected when compared to CADx (chi squared=0.16, p=0.68) or R2 (chi squared=3.4, p=0.06). CONCLUSIONS: Despite using different algorithms, the two CAD systems exhibit comparable levels of diagnostic accuracy and a similar positive impact on sensitivity when used as an aid to conventional reading. Single reading with either CAD system is as specific but not as sensitive to double independent reading: its use as an alternative to double reading cannot be recommended and should be investigated further by means of controlled prospective studies.

False Negative Reactions↗