Computer-aided evaluation of radiologist's reproducibility and subjectivity in mammographic density assessment.

Mammographic density is an independent risk of breast cancer. This study has evaluated the radiologists' reproducibility and subjectivity in breast density estimation and in order to decrease the radiologists' subjective errors the computer software was developed. The very good reproducibility existed in the strong correlation with the first and the second mammogram assessment after three month period for each radiologist (correlation coefficient 0.73-1, p < 0.001). The strong correlation was present in the case of all 5 radiologists when compared among themselves and compared with software aided MDEST-Mammographic Density Estimation (correlation coefficient 0.651-0.777, p < 0.001). Detected differences in glandular tissue percentage determination occurred in the case of two experienced radiologists, out of 5 (one radiologist with more than 5 year experience and one with more than 10 year experience, p < 0.01), but in the case of breast type determination (American College of Radiology-ACR I-IV), the detected difference occurred in one radiologist with the least experience (less than 5 years, p < 0.001). It can be concluded that the estimation of glandular tissue percentage in breast density is rather subjective method, especially if it is expressed with absolute percentage, but the determination of type of breast (ARCI-IV) depends on the radiologist's experience. This study showed that software aided determination of glandular tissue percentage and breast type can be of a great benefit in the case of less experienced radiologists.

Statistical learning confirms the diagnostic significance of the anemia panel in breast cancer.

BACKGROUND: Diagnostic value of available tumor markers, such as cancer antigen CA 15-3 and carcinoembryonic antigen (CEA) in breast cancer is limited. There is an ongoing search for additional, potentially better diagnostic blood markers with improved clinical utility. The aim of this study is to evaluate performance of the approach based on routine blood tests accompanied by a statistical learning tool to the diagnosis of breast cancer. METHODS: Blood was collected from total of 104 subjects which were divided into two groups: breast cancer patients and a control group that consisted of asymptomatic volunteers and patients who had benign breast lesions at the time of blood collection. Random forest statistical learning method and the external method validation have been applied to evaluate diagnostic performance of 31 routine blood tests. RESULTS: The applied statistical learning approach assigned the highest diagnostic importance to the anemia panel among all analyzed blood tests that also included CA 15-3. External validation has shown utility of selected statistical approach - we were able to select tests that provide a diagnostic accuracy comparable to some diagnostic tools described in literature and based on more demanding laboratory techniques, such as gene expression microarrays. CONCLUSIONS: Inclusion of tests for anemia significantly improves diagnostic accuracy for the breast cancer in comparison to the diagnostic accuracy of the CA 15-3 alone. Application of the random forests also enables the reduction of number of laboratory tests needed for the establishment of diagnosis. Differences in relevant test values between the cancer and control group are small but application of multiparametric statistical learning ensured diagnostic accuracy of 72.0% associated by a sensitivity of 64.7% and specificity of 84.9%.

Model of total skin electron treatment using the 'six-dual-field' technique.

During implementation of the total skin electron treatment, using six-dual-field technique, at radiotherapy department a large number of measurements are needed. To assess depth dose curve required by clinicians and dose uniformity over a whole treatment plane, combinations of different irradiation parameters are used (electron energy, beam angle, scatterers). Measurements for each combination must be performed. One possible way to reduce number of measurements is to model the treatment using the Monte Carlo simulation of electron transport. We made a simplified multiple-source Monte Carlo model of electron beam and tested it by comparing calculations and experimental results. Calculated data differs less than 5 percent from measurements in the treatment plane. During the treatment patient can be approximated using cylinders with different diameters and orientations. We tried to model the depth dose variations in the total skin electron treatment not just around the body cross-section (simplified to cylinders of different diameters), but also along the body to account for the variations in body curvature longitudinally. This effect comes down to the problem of modeling distribution in different cylinders, but varying the longitudinal orientation of those cylinders. We compared Monte Carlo calculations and film measurements of depth dose curves for two orientations of the cylindrical phantom, which were the simplest for experimental arrangement. Comparison of the results proved accuracy of the model and we used it to calculate depth dose curves for a number of other cylinder orientations.

Total skin electron treatment of extensive cutaneous lesions in Kaposi sarcoma.

We report on a 62-year-old HIV-negative male patient with Kaposi sarcoma. After 8 years of treatment of smaller localized skin lesions with surgery and local radiotherapy, the patient developed extensive lesions of the whole skin. The extent of the lesions required the administration of the total skin electron therapy (TSET). Until then, TSET had been used at our Department only for the treatment of mycosis fungoides. The dose delivered was 30 Gy higher than in a conventional radiotherapy treatment, where doses are usually between 8 and 24 Gy. Six months after the TSET therapy, the lesions completely regressed, except for two large facial lesions, which were surgically removed. Major side effects were mild erythema and hyperpigmentation of the skin. Erythema disappeared a month after the therapy.