Transrectal ultrasonography to predict the clinical outcome of transurethral microwave thermotherapy in patients with benign prostatic hyperplasia

Morphological and biological predictors for treatment outcome of transurethral microwave thermotherapy

The proliferation of prostatic tissue as a result of ageing typically leads to prostatic enlargement, which often causes obstruction of urine outflow from the bladder, clinically lower urinary tract symptoms, detrusor instability, incomplete bladder emptying, urinary infection, and finally acute urinary retention. The first approach to therapy depending on the severity of the symptoms is usually medical management (phytotherapy, alpha-blockers, 5 alpha-reductase inhibitors) before surgical procedures are performed. The reference standard for treatment of benign prostatic hyperplasia is transurethral resection of the prostate, although the introduction of minimally invasive alternatives such as transurethral microwave thermotherapy has led to a new era in surgical management. Suitable patients must be selected carefully on the basis of individual parameters that predict a favourable result.

Microwave thermotherapy for benign prostatic hyperplasia with the Dornier Urowave: response durability and variables potentially predicting response

OBJECTIVES

To evaluate the clinical efficacy and durability of transurethral microwave thermotherapy (TUMT) in the treatment of benign prostatic hyperplasia. The clinical variables useful in predicting outcome were identified.

METHODS

From October 1996 to March 2000, 58 patients with symptomatic benign prostatic hyperplasia were treated with TUMT using the Urowave device. Treatment outcome was evaluated by the International Prostate Symptom Score (IPSS), quality-of-life assessment score, and urodynamic investigation. The patients were divided into those having a good and poor response on the basis of the degree of IPSS decrease at 3 months.

RESULTS

The mean IPSS significantly decreased from 19.2 at baseline to 13.3 at 3 months (P <0.0001). The mean quality-of-life score changed from 4.6 at baseline to 2.9 at 3 months (P <0.0001). No statistically significant differences in peak flow rate, postvoid residual volume, Schäfer's obstruction scale, or detrusor pressure at peak flow were noted before or after TUMT. The pretreatment IPSS of the good response group was significantly higher than that of the poor response group (P=0.017). A more significant difference was obtained for the obstructive score (P = 0.002), and no difference was observed in the irritative score (P = 0.631). The Schäfer grading scale score of the good response group was significantly smaller than that of the poor response group (P = 0.047).

CONCLUSIONS

TUMT with the Urowave was effective in eliminating symptoms associated with benign prostatic hyperplasia, but did not markedly improve the objective voiding parameters. Patients with urodynamically less obstructive symptoms but subjectively more obstructive symptoms are therefore probably good candidates for TUMT.

Pretreatment prostate-specific antigen as an outcome predictor of targeted transurethral microwave thermotherapy

OBJECTIVES

To evaluate pretreatment serum prostate-specific antigen (PSA) as an outcome predictor of targeted microwave thermotherapy.

METHODS

Seventy-one patients with lower urinary tract symptoms of benign prostatic hyperplasia underwent targeted transurethral microwave thermotherapy using the Targis system. Outcomes 12 months after treatment were evaluated by the International Prostate Symptom Score (IPSS), peak urinary flow rate (Qmax), and quality-of-life (QOL) score. The ability of PSA to predict outcomes was evaluated by linear and logistic regression and receiver operating characteristic curve analysis.

RESULTS

Higher pretreatment PSA levels were significantly predictive of an absolute IPSS change of -7.5 or less for patients with moderate baseline symptoms or - 15 or less for those with severe baseline symptoms; an absolute Qmax change of 5 mL/s or greater; an absolute QOL score change of -3 or less; an IPSS at 12 months of 7 or less; a Qmax at 12 months of greater than 12 mL/s; and a QOL score at 12 months of 1 or less. Nevertheless, even without taking pretreatment PSA into account, most patients benefitted substantially from targeted microwave thermotherapy. Thus, 74%, 71%, and 79% of all eligible patients improved 50% or more in IPSS, Qmax, and QOL score, respectively, at 12 months compared with baseline. No significant association between PSA and either prostate or transition zone volume could be demonstrated.

CONCLUSIONS

Most patients benefit substantially from targeted microwave thermotherapy. However, higher PSA levels are significantly predictive of more favorable outcomes. This association may reflect patient-to-patient differences in the relative abundance of PSA-producing epithelial cells in the transition zone of the prostate.

Long-term follow-up of transurethral microwave thermotherapy

OBJECTIVES

To evaluate the long-term results of transurethral microwave thermotherapy (TUMT) for benign prostatic hyperplasia (BPH) with up to 5 years of follow-up at our institution.

METHODS

From October 1991 to November 1993, 106 patients were treated for BPH with TUMT using the Prostatron 2.0. Of the 106 patients, 64 were available for evaluation of symptoms (Madsen-Iverson score), uroflow, residual urine, and retreatment rate at a mean follow-up of 50+/-5.4 months (mean+/-SD).

RESULTS

The mean age of the patients was 65.2+/-9.8 years. Thirty-two patients (50.0%) were treated with one session of TUMT. Additional treatments were required for 32 patients (50.0%). Three patients had two sessions of TUMT, 14 underwent transurethral resection of prostate, and 3 had laser prostatectomy. Twelve patients received medical therapy. The mean symptom score decreased significantly from 12.9+/-2.5 to 5.7+/-3.6 (P = 0.001). The mean peak flow rates and postvoid residual volume showed little difference before and after TUMT. On the basis of the criteria described by Poincelet and Cathaud the overall clinical efficacy rate was 39.1% (15.6% complete response and 23.5% partial response). No obvious clinical parameter was useful to predict favorable outcome after TUMT.

CONCLUSIONS

The present study showed that the efficacy rate of TUMT with the Prostatron 2.0 at 50 months was 39.1 %. None of the preoperative clinical factors was predictive of a favorable outcome.