Thermal therapy for treatment of benign prostatic hyperplasia (BPH) is becoming increasingly popular due to the minimally invasive nature of the treatment. Successful management of such therapy requires accurate estimation of thermal dosage. The purpose of this study is to provide correlations for the thermal damage caused by ultrasound, microwave, and infrared devices under a range of operating conditions. A boundary-fitting finite difference method is used to examine the heat transfer in the prostate gland and surrounding tissue. The Pennes bioheat transfer model and a porous media model were utilized to calculate temperature histories. Necrosis zones were determined using published necrosis data for prostatic tissue and cells. Thermal damage correlations for the three different hyperthermia sources along with sample temperature contours and necrosis zones are presented. Results indicate that the applicator power level and heating time are the most important parameters in achieving the desired necrosis zones, while coolant parameters strongly affect the temperatures of the sensitive urethra and serve as constraints for protocol parameters. Out of the three sources evaluated, ultrasound modality appears to be the most capable of causing necrosis in the target zones, with least damage to the surrounding healthy tissues.
Magnetic resonance temperature imaging validation of a bioheat transfer model for laser‐induced thermal therapy
