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Abstract: ackground p16/Ki-67 dual immunocytochemical staining (DS) is considered easy to interpret if evaluators are properly trained, however, there is no consensus on what constitutes proper training. In the present study we evaluated a protocol for teaching DS evaluation on students inexperienced in cervical cytology. Methods Initial training on 40 DS conventional smears was provided by a senior cytotechnologist experienced in such evaluation. Afterwards, two students evaluated 118 cases. Additional training consisted mainly of discussing discrepant cases from the first evaluation and was followed by evaluation of new 383 cases. Agreement and accuracy of students' results were compared among the participants and to the results of the reference after both evaluations. We also noted time needed for evaluation of one slide as well as intra-observer variability of the teacher's results. Results At the end of the study, agreement between students and reference was higher compared to those after initial training (overall percent agreement [OPA] 81.4% for each student, kappa 0.512 and 0.527 vs. OPA 78.3% and 87.2%, kappa 0.556 and 0.713, respectively). However, accuracy results differed between the two students. After initial training sensitivity was 4.3% points and 2.9% points higher, respectively compared to the reference, while specificity was 30.6% points and 24.4% points lower, respectively, compared to the reference. At the end of the study, the sensitivity reached by one student was the same as that of the reference, while it was 2.6% points lower for the other student. There was a statistically significant difference in specificity between one student and the reference and also between students (16.7 and 15.1% points). Towards the end of the study, one student needed 5.2 min for evaluating one slide while the other needed 8.2 min. The intra-observer variability of the senior cytotechnologist was in the range of "very good" in both arms of the study. Conclusions In teaching DS evaluation, the students' progress has to be monitored using several criteria like agreement, accuracy and time needed for evaluating one slide. The monitoring process has to continue for a while after students reach satisfactory results in order to assure a continuous good performance. Monitoring of teacher's performance is also advisable.
Keywords: cervical cytology, cervical cancer, immunocytochemistry, accuracy
Published in DiRROS: 11.07.2024; Views: 1116; Downloads: 746
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Abstract: Standard applicators for cervical cancer Brachytherapy (BT) do not always achieve acceptable balance between target volume and normal tissue irradiation. We aimed to develop an innovative method of Targetvolume Density Mapping (TDM) for modelling of novel applicator prototypes with optimal coverage characteristics. Patients and methods. Development of Contour-Analysis Tool 2 (CAT-2) software for TDM generation was the core priority of our task group. Main requests regarding software functionalities were formulated and guided the coding process. Software validation and accuracy check was performed using phantom objects. Concepts and terms for standardized workflow of TDM post-processing and applicator development were introduced. Results. CAT-2 enables applicator-based co-registration of Digital Imaging and Communications in Medicine (DICOM) structures from a sample of cases, generating a TDM with pooled contours in applicator-eye-view. Each TDM voxel is assigned a value, corresponding to the number of target contours encompassing that voxel. Values are converted to grey levels and transformed to DICOM image, which is transported to the treatment planning system. Iso-density contours (IDC) are generated as lines, connecting voxels with same grey levels. Residual Volume at Risk (RVR) is created for each IDC as potential volume that could contain organs at risk. Finally, standard and prototype applicators are applied on the TDM and virtual dose planning is performed. Dose volume histogram (DVH) parameters are recorded for individual IDC and RVR delineations and characteristic curves generated. Optimal applicator configuration is determined in an iterative manner based on comparison of characteristic curves, virtual implant complexities and isodose distributions. Conclusions. Using the TDM approach, virtual applicator prototypes capable of conformal coverage of any target volume, can be modelled. Further systematic assessment, including studies on clinical feasibility, safety and effectiveness are needed before routine use of novel prototypes can be considered.
Keywords: cervical cancer, brachytherapy, applicators, virtual modelling
Published in DiRROS: 09.05.2024; Views: 1321; Downloads: 402
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Keywords: colposcopy, cervical cancer
Published in DiRROS: 26.05.2020; Views: 2343; Downloads: 712
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