HT2003-47505 A NUMERICAL STUDY OF MICROWAVE THERMOTHERAPY FOR BENIGN PROSTATIC HYPERPLASIA

ABSTRACT Transurethral resection of the prostate is the conventional therapy used for relieving bladder-outflow obstruction that typically occurs in older men due to benign prostatic hyperplasia (BPH). Due to the complications and side effects involved, other therapies that are less invasive have been in use over the last few years. The current study examines one such therapy, namely, the transurethral thermal therapy, and its effectiveness as a treatment modality for BPH. The system considered here is capable of delivering microwave energy preferentially into the prostatic tissue. The heat generated inductively increases the temperature of the tissue to well above 40°C and causes necrosis when applied for adequate times. As both heating times and temperatures dictate the process, a transient analysis of the Pennes bio-heat transfer equation was performed for applicable parameter values. Based on the calculated temperature distributions, necrosis zones are estimated using the existing cell-death data and possible heating protocols are suggested. INTRODUCTION Benign prostatic hyperplasia (BPH) is a condition in men that is characterized by non-malignant proliferation of the tissue within the prostate, leading to bladder outflow obstruction. Transurethral resection of the prostate has been the conventional therapy used for relieving these symptoms, with symptomatic improvement rates of about 85% [1,2]. Despite the success rates of this procedure, post-surgery complications such as urinary-tract infection, urethral stricture, incontinence, and impotence, and surgical risk in the elderly [2] do not make it an attractive option. These concerns and the increasing numbers of aging patients with BPH problems have led to alternative medical and minimally invasive therapies over the past few years. Hyperthermia is one such modality that utilizes heat from microwave, radio-frequency, and other similar sources to cause coagulation in the tissue. The aim of hyperthermia is to destroy the BPH tissue without damaging the tissue surrounding the treated organ, namely the bladder wall