Thermal Distribution of Canine Prostate Using Hyperthermia Combining with Balloon Catheter

Abn, Jong Hoon; Kwang, Tae Kon

Abstract

Nonsurgical alternatives such as urethral stents, balloon dilation, laser therapy and thermal therapy for the treatment of symptomatic benign prostatic hyperplasia(BPH) have been encouraged by the current trend due to socioeconomic concern and patient's demand. But most thermal techniques involving the hyperthermia for the treatment of BPH have shown limited efficacy and lack of objective results. One of the questions raised regarding the use of hyperthermia in the treatment of BPH is whether there is a uniform and safe temperature distribution within the prostate. Our study was performed under the idea that intraprostatic urethral pressure balloon(8 mm in diameter, 5atm)may reduce the blood perfusion in the canine prostate, so it can prevent the self cooling mechanism by circulation resulting in even heating by hyperthermia. We compared the thermal distribution using the catheter which has helical radiofrequency(RF) antenna with or without balloon. Heating was performed with 13.56MHz, contact RF generator for 60 minutes and the temperatures were recorded at 20, 40 and 60 minutes respectively through eight, 0.2mm sized K-type thermocouples, which were placed at regular array, 4mm and 8mm distance from the urethra, totally 16 points. The results were as follows: 1) The mean temperature was significantly higher in hyperthermia using the balloon catheter than using the simple catheter. 2) The temperatures in 4mm and 8mm distances using the balloon catheter were significantly higher than using the simple catheter. 3) The mean temperatures along 20, 40 and 60 minutes in using the balloon catheter were significantly higher than in using the simple catheter 4) The isothermal curve made with mean temperatures of each points shows higher(mean 4.5 degrees C) and more even distribution in using the balloon catheter. 5) Histologic findings in 2 weeks after hyperthermia demonstrated varying degrees of coagulation necrosis, hemorrhage and increased interacinar fibrosis in treated area. In conclusion, these studies demonstrate the better effect of the pressure balloon catheter and hyperthermia in the canine prostate, so balloon catheter could be applied to human prostate for the better results.