Studies using the following schedule distinguish between false malign (C) and false benign (B) results instead of false clinically relevant and not relevant diagnoses.
„golden standard“
Sometimes, the year of test was not give. Then the year was estimated.
4th column: S = static system; D = dynamic system; DLM = direct light microscope;
5th column: amount without brackets = examined cases + deferred cases; amount in brackets = finally diagnosed cases (=all correct and incorrect cases);
6th-9th column: Accurate diagnosed cases, distinguished in malign and benign - in total and in %; in some lines the amount of correct diagnoses is given as one total and not distinguished in malign and benign.
10th-13th column: Incorrect diagnosed cases of TP, distinguished in malign and benign - in total and %;
6th-13th column: The percentage is based on the correct / incorrect part of benign and malign diagnoses;
14th-15th column: Deferred diagnoses in total and in %;
16th -column: amount of images per case in average;
17th column: time needed per examination; the number in the brackets give the range of time/case.
Schedule II - Accuracy Based on the Golden Standard 13 Heidelberg 1993 S 600 Telepathology was used for panel
discussions between experts - final concordant diagnoses could be given in about 80 % of the cases
No. Description of the Executed Tests of Schedule II 1 Source: [Prasse, 1995, pp. 259-266];
Test design: Test was executed in Georgia; communication bandwidth varied from 56 kbps to 384 kbps; 640 x 480 x 256 colors; cases: 99 cytology, 80 hematology, 66 histology;
Result: There occurred diagnostic problems due to transmission speed and image quality. The desktop video conference system in Georgia was judged as not satisfactory for definitive diagnostic purposes, but seen as a good tool for general illustrations and case discussions between pathologists [Prasse, 1995, p. 264].
2 Source: [Ito, 1994, p. 801].
Test design: 10 kidney biopsies and 10 liver cases at Tottori / Japan;
Result: 2 cases were not accurate due to field selection and case communication.
3 Source: [Martin, 1996, p. 460; Martin, 1995, p. 194];
Test design: 790 cases were examined during a period of 4 years in 11 laboratories;
Results: tele-discussions last about 15 minutes, the whole examination about 30-60 minutes.
A telediagnosis was established on 3 to 20 transmitted images (mean 7); nearly 80 % of the diagnoses could have been confirmed immediately; 15 % were more or less modified; in the remaining 5 % of the cases the problem remained unsolved after the initial discussion - in these cases it was necessary either to send new images after additional investigation or to forward the slides and paraffin blocks to the expert [Martin, 1996, p. 460]. Two more studies were executed: Fine-needle biopsies taken from 50 liver nodules and 50 prostate lesions - concordance of the diagnosis reached 97,5%; 200 surgical specimens were tele-examined between the University of Dijon and Boston’s Brigham and Women’s Hospital.
4 Source: [Weinstein, 1997/(1), p. 34]
Test design: 46 skin specimen - frozen section examinations;
Result: 1 % = margin was not selected for diagnosis; 4 % = the tumor extended to a cleft in the tissue that was misinterpreted by the transmitting operator and selected as the deep margin; in no instance was diagnostic interpretation limited by poor fidelity of the video images.
No. Description of the Executed Tests of Schedule II 5 Source: [Fujita, 1995, pp. 105-110].
Result: There was one borderline case with an atypical ductal hyperplasia of the breast;
of the conclusive cases 2 were benign and one 1 malignant by paraffin section examination.
6 Source: [Fujita, 1995, p. 105 ff.]
Test design: Static imaging, images selected by referring cyto-technologist, 135 cases;
Result: There were no serious misdiagnoses. Only a few minor mismatches occurred, again due to insufficient interpretation and field selection. However, the mismatched cases were very specific.
They are described by Fujita, 1995, pp. 108-109. The cyto-technician at the remote site was very reliable; macroscopic images were sent via FAX; no wrong diagnosis occurred;
Considering liability: reliable in Japan is always the telepathologist!
7 Source: [Eide, 1992/(2), p. 411; Nordrum, 1991, p. 517, Eide, 1994, p. 885].
Results: No false positive; two false negative diagnoses- one due to sampling error, the second was diagnosed as sclerosing and intraductal adenosis, but showed infiltrating carcinoma on paraffin embedded material; 2 inconclusive diagnoses were (both) given on thyroid tumor tissues.
8 Source: [Eide, 1992/(1), pp. 405 ff.];
Test design: 80 cases, mix of frozen sections from different organs; two examining pathologists.
Result: Two false negative diagnoses due to quality of video images and missing information of a case; one false positive - a biopsy of the pancreas with irregular proliferating ducts in chronic pancreatitis was diagnosed to be an adenocarcinoma.
The overall agreement within the final diagnosis was 91 %.
9 Source: [Steffen, 1997/(1), pp. 25-27, 37];
Test design: From 1992 to 1996, 93 frozen sections from different organs had been examined;
Result: In average, per examination 2 (0-8) macroscopical and 6 (2-17) microscopical images were transferred from Samedan to Basel. The time needed for a telepathological examination was 30 minutes up to a maximum of 45 minutes, measured from the time when the first image was transferred till the diagnosis was made [Steffen, 1997/(1), p. 37].
10 Source: [Nordrum, 1995, p. 255; Nordrum, 1997, p. 172];
Test design: Test of different organ specimens - breast (52) and thyroid tissues (22), lymph nodes (5), ovary (5), and other.
11 Source: [Schmid, 1996/(2), p. 480].
Test design: Image transfer by ISDN lines; three pathologists tested 118 frozen sections on lung surgery.
12 Source: [Schmid, 1996/(2), p. 480].
Test design: 8 B-ISDN channels, 139 frozen sections cases, tested by 2 pathologists at the University of Tuebingen/Germany and Stuttgart/Germany.
13 Source: [Kayser, 1993/(2), p. 395; Kayser, 1995/(1), pp. 52-59];
Test design: Hospital Baumgartnerhoehe (Vienna, Austria), Klinikum Heckeshorn (Berlin, Germany), and Thoraxklinik (Heidelberg, Germany). Each participating institute was obliged to send HE- and PAS-stained histopathological slides comprising 100 bronchial biopsy cases and 100 surgical specimens with primary lung cancer to the participating partners - all in all 300 biopsy cases and 300 surgical specimens were included in the study. Finally 120 cases with a broad variety of lung tumors have been discussed intraoperatively. Reclassification of the bronchial carcinomas was performed independent of each other, based on the criteria of the WHO. Statements of the staining and fixation quality as well as of the characteristic areas of the slides were noted. A time schedule was defined for expert consultations of difficult cases and panel discussions [Kayser, 1995/(1), p. 55].
Result: No technical problems occur during the transmission of images. The quality of the transmitted images (contrast and color) was sufficient to permit an accurate diagnosis; spatial resolution was poor in case of low magnification - sufficient at magnifications x 25 or higher. Average time for
transmission was 95 seconds (range 40 to 180 seconds) with a transmission rate of 9,600 baud;
1 to 3 images were necessary for a diagnosis [Kayser, 1993/(2), p. 397]. Unfortunately unexpected breakdowns of the ISDN connection occurred in 4/25 transmissions. Failures of the modems could be excluded.
In all, telepathology demonstrated to be effective in panel discussions. Final concordant diagnoses could be given in about 80 % of the cases - biopsy: 236 correct, 64 discrepant; surgical cases: 212 correct, 88 discrepant.