Importance of Thermal Dose and Antenna Location in Transurethral Microwave Thermotherapy for Benign Prostatic Hyperplasia

Abstract

The importance of thermal dose and the location of the heat maximum for the outcome of transurethral microwave thermotherapy for benign prostatic hyperplasia was studied. It was originally designed as a two-arm randomized study of 196 patients comparing high and low effect with the heat maximum at the apex of the prostate. The inclusion criteria were: prostate volume 25 to 70 cc, Madsen score ≥8, Q_max ≤ 15 mL/sec, residual urine volume < 350 mL, and no median-lobe enlargement. Using the same inclusion criteria, another group of 31 patients was compared in which the location of the heat maximum was at the base of the prostate. Treatment was performed as an outpatient single session procedure for 70 minutes with the Prostcare (Bruker Medical, France). Improvement was found after 6 months in all three groups regarding Q_max and Madsen, bother, and quality of life scores. The improvement of Madsen score from baseline was more pronounced in the high-effect base group than in the other two groups. Responders were defined as patients showing improvement in Madsen score who were satisfied with treatment outcome and in no need of complementary treatment at 6 months' follow-up. Significantly more responders were found, and the increment of serum prostate specific antigen and side effects were more pronounced, in the high-effect base group than in the other two groups. Treatment outcome seems to be both dose related and dependent on the location of the heat maximum. However, the improvement in outcome is associated with increased morbidity.