The therapeutic use of heat has in the past engendered great enthusiasm and occasionally great disappointment. However, it now holds promise as an effective and durable, minimally invasive treatment for symptomatic benign prostatic hyperplasia (BPH). The increasing population age and the greater attention paid by older men to the symptoms of BPH means that the demand for treatment is almost limitless. Current studies of the natural history of prostatic enlargement suggest that it has relatively few serious connotations, and so great efforts have been made to lower the therapeutic burden for the patient. Transurethral resection of the prostate (TURP) in now being questioned as the "gold standard" treatment for every patient with symptomatic BPH because of the minor but significant rate of morbidity and failure in unselected patients. A host of interventional nonsurgical alternative treatments have emerged in the last 5 years [1][2][3][4][5][6]. The majority use thermal energy applied to the prostatic adenoma by the rectal, urethral or even an extracorporeal route. Energy sources include laser, focused ultrasound, radiofrequency and microwave energy. Treatmentsmay be divided into those which demand some form of general or regional anaesthesia, often with a consequent need for an inpatient hospital stay, and those which can be easily accomplished without. For a treatment to truly not require anaesthesia, the energy must be precisely targeted, not require the use of rigid urethral instrumentation, and the treatment session must be of short duration. Transurethral microwave thermotherapy (TUMT) complies with all these conditions.
Microwave energy was first applied to the prostate for the purpose of treating cancer, because of the selective sensitivity of malignant cells to heat [7]. The basic principle was subsequently used to treat symptomatic BPH. It became apparent that higher temperatures were required to irreversibly damage BPH cells [6]. The treatments were soon applied via the urethral route and developed from