A study of prostate multiprobe cryoablation near urethra for precision treatment planning.

The simplified preoperative planning of multiprobe prostate cryoablation limits its efficiency. In order to improve it, the thermal history prediction software is being developed. However, the problem of high risks at the prostate-urethra boundary has not been solved yet. The urethral warming system is used to protect the urethral canal from freezing. On the one hand it is used to reduce the risk of damage to the urethra; on the other hand it increases the risk of insufficient ablation of the tumor. This paper presents a step towards the possibility of carrying out the precision prostate cryoablation in this region. For the experimental part, three cases of arrangement of one and two argon cryoprobes and a heating catheter have been considered. Freezing zone shape and dimensions, and temperature at control points depending on time have been obtained. Experimental results have clearly shown the effect of the heating catheter, the second cryoprobe, and the initial temperature of the biotissue phantom on the freezing zone. After, the thermal aspects of treatment simulation have been developed and verified. A series of calculations have been carried out with the goal to get the information about optimizing the prostate cryoablation on the prostate-urethra boundary. The arrangement of cryoprobes has been proposed for three different variants for prostate cryoablation (sectors of 90, 180° and 360°). The area of prostate tissues near the urethra that cannot be cooled below the necrosis temperature is shown. This information is expected to be useful for improving the quality of cryosurgery planning algorithms (e.g. for tumor treatment).

[One-stage cryoablation of two renal tumors]. / Odnomomentnaia krioablatsiia dvukh opukholei u patsienta s pochechno-kletochnym rakom.

The progressive development of medical technologies allowed the introduction of alternative methods of treatment of localized renal cell carcinoma with a tendency to organ-sparing approach. Cryoablation, radiofrequency ablation, and some experimental methods of treatment (microwave and laser ablation, therapy with high-intensity focused ultrasound) are referred to minimally invasive treatment of renal cell carcinoma. Cryoablation is highly effective alternative method of treatment of renal cell carcinoma. The main advantages of this technique are tumor visualization and formation of 'ice ball' in real time, fewer complications compared with other methods, as well as the possibility of cryotherapy in critically ill patients. Compared to other ablative technologies, cryoablation is followed by low percentage of redo treatment and good intermediate oncological results. We described the experience of one-stage cryoablation of two kidney tumors in this report.

[Current methods of early diagnosis of prostate cancer].

Prostate cancer is the most common cancer among men, except for lung cancer. Therefore, it is imperative to identify diagnostic methods for early detection of prostate cancer to determine patients from healthy populations, which helps guide a timely treatment at an initial stage of the disease. The article provides an in-depth review of the most current diagnostic biomarkers of prostate cancer, their role in clinical practice as a means of the early detection and screening for prostate cancer.