The predictive value of baseline variables in the treatment of benign prostatic hyperplasia using high-energy transurethral microwave thermotherapy.

OBJECTIVE

To evaluate the combination of patient age, prostate size, grade of outlet obstruction and total amount of energy, all independent predictive variables of treatment outcome in patients with lower urinary tract symptoms (LUTS) and benign prostatic hyperplasia (BPH) treated with high-energy transurethral microwave thermotherapy (HE-TUMT), and thus provide nomograms for predicting treatment outcome after HE-TUMT.

PATIENTS AND METHODS

Between October 1993 and July 1996, 247 patients with LUTS and BPH were treated with HE-TUMT using the Prostatron device, software version 2.5 (EDAP Technomed, Lyon, France). The World Health Organisation Response Evaluation Criteria were used to evaluate the outcome. Patient age, prostate volume, total amount of energy and grade of outlet obstruction were categorized using the Akaike information criterion (AIC). The probabilities of a good/intermediate vs a poor response at 26 weeks according to the AIC were calculated.

RESULTS

Nomograms are presented providing the estimated probability (95% confidence interval) for a good/intermediate response of the evaluation of the International Prostate Symptom Score at 26 weeks by categories of prostate volume, total amount of TUMT energy and age, and of maximum urinary flow rate by categories of bladder outlet obstruction (linear passive urethral resistance ratio, linPURR) and total amount of energy, and of linPURR by categories of prostate volume and total amount of energy. The total amount of energy appeared to have the most impact in the prediction of good/intermediate and poor response in all three response evaluation criteria.

CONCLUSIONS

These nomograms may assist urologists in making clinical recommendations for the treatment of men with LUTS and BPH using HE-TUMT.