SIGNIFICANCE OF ADC MEASUREMENTS AS RADIOLOGICAL MRI MARKER IN DETECTION OF METASTATIC LYMPH NODE INVOLVEMENT IN PATIENTS WITH PROSTATE CANCER.

BACKGROUND: In spite of significant advances in diagnosis of prostate cancer (PCa), the detection and differential diagnosis of metastatic lymph node involvement remains an important clinical dilemma in a large number of cases. Contrast-enhanced abdominal computed tomography and magnetic resonance imaging (MRI), in part when using T1-weighed images (T1-WI and T2-WI), allow evaluating indirectly the presence of invasion in regional lymph nodes by assessing their diameter and morphology. Nonetheless, these techniques do not appear to be sufficiently sensitive for direct identification of lymph nodes with metastatic lesions. AIM: To study the significance of the apparent diffusion coefficient (ADC) of diffusion-weighted MRI in detection of metastatic lymph node involvement in PCa patients. MATERIALS AND METHODS: The study involved 35 patients with histologically verified PCa. Based on multiparametric prostatic MRI findings and pathomorphological reports, we have performed ADC measurements for pelvic lymph nodes either with (n = 15, mean size 1.78 ± 0.59 cm) or without metastases (n = 20, mean size: 0.94 ± 0.06 cm) in PCa patients who underwent radical prostatectomy with lymph node dissection. RESULTS: No significant diffe-rences were observed when comparing mean sizes of N+ and N- pelvic lymph nodes. At the same time, when comparing mean ADC values for N+ and N- pelvic lymph nodes, we observed a statistically significant difference: 0.74 ± 0.09 · 10-3 mm2/s in metastatic lymph node vs 1.05 ± 0.23 · 10-3 mm2/s in lymph nodes without metastatic involvement (p < 0.001). CONCLUSION: The use of ADC for diffusion-weighted MRI may provide valuable information for detection of metastatic lymph node involvement in patients with PCa.

THE ROLE OF THE APPARENT DIFFUSION COEFFICIENT OF THE BIPARAMETRIC MRI AS AN IMAGING MARKER OF PROSTATE CANCER. / ROL' VYMIRIuVANOGO KOEFITsIIeNTA DYFUZIÏ BIPARAMETRYChNOÏ MRT IaK PROMENEVOGO MARKERA RAKU PEREDMIKhUROVOÏ ZALOZY.

Prostate cancer (PCa) is the most common malignancy in men. The role of the apparent diffusion coefficient (ADC)of biparametric MRI (biMRI) which is a study without the use of dynamic contrast enhancement (DCE), in detectionof PCa is still not comprehensively investigated. OBJECTIVE: The goal of the study was to assess the role of ADC of biMRI as an imaging marker of clinically significant PCaMaterials and methods. The study involved 78 men suspected of having PCa. All patients underwent a comprehensive clinical examination, which included multiparametric MRI of the prostate, a component of which was biMRI. TheMRI data was evaluated according to the PIRADS system version 2.1. RESULTS: The distribution of patients according to the PIRADS system was as follows: 1 point - 9 (11.54 %)patients, 2 points - 12 (15.38 %) patients, 3 points - 25 (32.05 %) patients, 4 points - 19 (24.36 %) patients and5 points - 13 (16.67 %) patients. In a subgroup of patients with 5 points, clinically significant PCa was detected in 100 % of cases. In the subgroup of patients with tumors of 4 points clinically significant PCa was diagnosed in 16of 19 (84.21 %) cases, and in 3 (15.79 %) patients - clinically insignificant tumor. In the subgroup of patients with3 points, clinically significant PCa was diagnosed in 11 of 25 (44.0 %) cases, in 8 (32.0 %) patients - clinicallyinsignificant tumor and in 6 (24.0 %) patients - benign prostatic hyperplasia. PCa with a score of 7 on the Gleasonscale showed significantly lower mean values of ADC of the diffusion weighted MRI images compared to tumors witha score of < 7 on the Gleason scale: (0.86 ± 0.07) x 103 mm2/s vs (1.08 ± 0.04) x 103 mm2/s (р < 0.05). CONCLUSIONS: The obtained results testify to the high informativeness of biMRI in the diagnosis of prostate cancer.The use of ADC allowed to differentiate clinically significant and insignificant variants of the tumor, as well asbenign changes in prostate tissues and can be considered as a potential imaging marker of PCa.

A modern view on the effect of ionizing radiation on patients with diagnosis of nuclei cell cancer and its dischariationn. / SUChASNYY̆ POGLIaD NA DIIu IONIZUIuChOGO VYPROMINIuVANNIa NA KhVORYKh PRY DIAGNOSTYTsI NYRKOVO-KLITYNNOGO RAKU I ShLIaKhY Y̆OGO UNYKNENNIa.

One of the effects of the ionizing radiation on the cell is the emergence of genetic mutations which may lead to cancer development. The patients' exposure dose during diagnostics of renal cell carcinoma (RCC) by means of ordinary CT amounts to 5 mGy (5 mSv) and it can rise up to 50 mGy (5mSV) in the setting of multiphase scan. Until recent times, the evaluation of a risk for the cancer development caused by such relatively small doses of radiation exposure has been considered unnecessary. Nowadays, the influence of ionizing radiation during diagnostic pro cedures has been proved to increase the risk of cancer development significantly. The multiphase CT, routinely used in RCC diagnostics, results in 1 case of radiation induced cancer per 250 (180-370) scans in female and per 330 (240-490) scans in male individuals. There is a proved association between CN scans in dose > 7,5 mSv and patients' DNA damage. Thus, one of the ways to avoid radiation exposure of the patients with RCC is wider appli cation of MRI and X ray tubes of decreased voltage, however, further investigations in this field are still required.