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

Feedback microwave thermotherapy with the ProstaLund Compact Device for obstructive benign prostatic hyperplasia: 12-month response rates and complications

PURPOSE

To evaluate the effectiveness of the ProstaLund Compact Device in the treatment of benign prostatic hyperplasia (BPH).

PATIENTS AND METHODS

A series of 38 consecutive patients with a mean age of 72.6+/-8.2 years, 19 with an indwelling catheter, underwent transurethral microwave thermotherapy (TUMT) with the ProstaLund Compact Device. Pretreatment evaluation included transrectal ultrasonography (TRUS), urodynamics, and cystoscopy for all patients and flow rate (Qmax), postvoiding residual urine volume (PVR), International Prostate Symptom Score (IPSS), and quality-of-life (QoL) assessment for those without a catheter. The mean prostate volume was 63.5+/-30 cc. The Qmax, IPSS, and QoL studies were repeated at 3, 6, and 12 months, while urodynamics, cystoscopy, and TRUS were repeated at 6 and 12 months.

RESULTS

The treatment lasted a mean of 43.1+/-17.1 minutes, achieved a maximal intraprostatic temperature of 58.7+/-7.2 degrees C, and destroyed 18.4+/-14.3 g of prostatic tissue. Twelve months post-treatment, for the patients without a catheter preoperatively, the IPSS was improved from 21.5+/-6.3 to 6.5+/-3.1 (P<0.001), Qmax from 7.2+/-3.1 mL/sec to 18.1+/-7.4 mL/sec (P<0.001), detrusor pressure at Qmax from 87.5+/-15 cm H2O to 48.4+/-16.4 cm H2O (P<0.001), and PVR from 113.2+/-78.2 mL to 34.6+/-36.7 mL (P<0.01). The good-response rates for IPSS (<or=7 or >or=50% improvement), Qmax (>or=15 mL/sec or >or=50% improvement), PVR (<50 mL or >or=50% decrease), and QoL (<or=2) were 73.7%, 84.2%, 73.7%, and 94.7%, respectively. For the patients with a catheter preoperatively, the IPSS improved from 9.5+/-6 at 3 months to 5.1+/-5.3 (P<0.05) at the end of the follow-up period. The Qmax was 13.2+/-6.4 mL/sec at 3 months and remained stable throughout the follow-up period. Patient good-response rates for IPSS (<or=7), PVR (<150 mL), and QoL (<or=2) were 75%, 87.5% and 75%, respectively. Only two patients were unable to void after the treatment. Complications were similar to those presented in the literature, and bladder stone formation was noted as well (five patients).

CONCLUSIONS

ProstaLund thermotherapy is a highly promising alternative treatment for BPH, improving substantially both objective and subjective measures of bladder outflow obstruction.

Application of External Microwave Thermotherapy in Urology: Past, Present, and Future

The excellent clinical results of transurethral microwave thermotherapy (TUMT) for the treatment of symptomatic benign prostatic hyperplasia (BPH) gave to TUMT the leading position among the microwave thermotherapy modalities available for the treatment of different urologic conditions. Research in TUMT has focused on operating software, temperature monitoring, intraprostatic heat distribution, cell-kill calculations, and correlations with clinical variables. Randomized comparisons of TUMT with other established therapies for BPH, including transurethral resection, have facilitated the evaluation of the clinical outcome, durability, morbidity, and costs of the treatment. The applications of microwave thermotherapy in other urologic diseases are also presented in this review.

Efficacy and safety of intraprostatic temperature-controlled microwave thermotherapy in patients with benign prostatic hyperplasia: results of a prospective, open-label, single-center study with 1-year follow-up

BACKGROUND AND PURPOSE

Different devices for transurethral microwave thermotherapy (TUMT) are currently available for the treatment of benign prostatic hyperplasia (BPH). We evaluated the efficacy and safety of the Prostalund Feedback Treatment (PLFT), which continuously records the intraprostatic temperature, and its impact on sexual function of the patients.

PATIENTS AND METHODS

A total of 41 patients with lower urinary tract symptoms attributed to BPH were entered in this prospective open-label, single-center study of PLFT. The initial evaluation was performed according to a standard protocol. At 3, 6, and 12 months, the International Prostate Symptom Score (IPSS), bother score, sexual function, and peak flow rate (Qmax) were recorded. In addition, determination of prostate volume by transrectal ultrasonography (TRUS) and measurement of residual urine volume were repeated at the 6- and 12-month visits. All adverse events were also recorded. Patients with IPSS of < or =7, > or =50% improvement in IPSS from baseline, a Qmax of > or =15 mL/sec, or > or =50% improvement in Qmax from baseline were judged responders to the treatment.

RESULTS

Thirty-three of the patients completed the 12-month visit. The response rate was 88% (29 of 33 patients). There was a statistically significant decrease in IPSS at the 12-month visit, the mean IPSS being 7.1 v 21.9 at baseline (P<0.001). The mean IPSS was 10.3 and 7.6 at the 3- and 6-months' follow-up, respectively. The bother score presented a similar improvement, with a decrease from a mean of 4.2 at baseline to a mean of 1.4 after 12 months (P<0.001). The mean Qmax improved from 8.4 mL/sec at baseline to 15.9 mL/sec, 19.2 mL/sec, and 17.8 mL/sec at 3, 6, and 12 months, respectively (P<0.001). The mean change in prostate volume, as determined by TRUS, was 16 mL at 6 months and 19 mL at 12 months (P<0.001). The procedure was well tolerated. The mean post-treatment catheterization time was 17.90 days. Bladder spasms and urinary tract infection were the most common adverse events. Coitus ability remained practically unchanged after treatment (from 71% to 74.3%), but the number of patients with ejaculation decreased (from 78% to 51.4%).

CONCLUSION

Our results indicate that PLFT is an effective and safe treatment for most patients with BPH.

High-energy transurethral microwave thermotherapy: symptomatic vs urodynamic success

OBJECTIVE

To evaluate the subjective and objective treatment results of high-energy transurethral microwave thermotherapy (TUMT) for symptomatic benign prostatic hyperplasia (BPH), and investigate the possible variables for predicting symptomatic and/or urodynamic success.

PATIENTS AND METHODS

Between October 1998 and October 2000, 40 men with BPH underwent high-energy TUMT using the Targis device (Urologix, Inc., Minneapolis, MN, USA). Evaluation after treatment included a clinical determination of the symptom score, a urodynamic assessment by peak flow rate and pressure-flow, magnetic resonance imaging (MRI), transrectal ultrasonography and endoscopy. The objective and subjective success was correlated with several variables before, during and after treatment.

RESULTS

All patients completed at least 1 year of follow-up after TUMT as monotherapy. The symptom score improved from a median (range) of 20.5 (11-28) initially to 9 (0-28) (P < 0.001). Twenty-two patients (55%) had a marked and 11 (28%) a moderate response, giving an overall subjective success rate of 83%. Similarly, there was a significant improvement in peak flow rate, from 9.2 (4.4-13.4) to 15 (3.3-22.9) mL/s (P < 0.001). Twenty-one patients (53%) had a maximum flow rate of > 15 mL/s while in eight (20%) it was 10-15 mL/s. Only 20 patients changed from unobstructed on the pressure-flow nomogram, i.e. an overall objective success rate of 50%. Gadolinium-enhanced T1-weighted MRI 1 week after treatment showed a median (range) perfusion defect of 20.7 (5.5-76.6)% of the total gland volume. Despite this persisting in all patients, a well-defined cavity was apparent in only in seven (18%) at the final evaluation. Cystoscopy 1 month after therapy showed evidence of necrotic tissue occupying the prostatic fossa in all patients. Younger patients were more likely to be urodynamically successful, and a higher grade of obstruction predicted symptomatic success.

CONCLUSION

High-energy TUMT can induce considerable necrosis of the prostate, as shown by MRI and cystoscopy. Although there was an adequate improvement in most patients' symptoms, there was a successful urodynamic change to unobstructed in only half the patients. Younger patients and those with a higher grade of obstruction were more likely to have urodynamic and symptomatic success, respectively.

Heat versus drugs in the treatment of benign prostatic hyperplasia

The improvement in symptoms and voiding function is greater with transurethral microwave thermotherapy than with drug therapy, and the associated morbidity is low. Transient urinary retention necessitating catheterization is of short duration after targeted microwave thermotherapy. The short-term effect of microwave thermotherapy can be improved by neoadjuvant and adjuvant alpha-blockade. Microwave treatment offers greater versatility than drug therapy, allowing patients with severe baseline symptoms and small prostates to be treated successfully. Medical management improves symptoms to a more modest extent than does microwave treatment. Finasteride gives comparatively small symptom and flow rate improvements and requires several months for the maximum responses. With alpha-blockers the onset of action is fast and side-effects reversible, although they limit their utility. Finasteride or alpha-blockers must be continued indefinitely to maintain improvements in patients with BPH, but they have a favourable safety and tolerability profile.

Thermotherapy and thermoablation for benign prostatic hyperplasia

PURPOSE OF REVIEW

From all the available thermoablative methods for the treatment of symptomatic benign prostatic hyperplasia, transurethral microwave thermotherapy is considered as standard in minimally invasive management. The literature is enriched by several new studies on transurethral microwave thermotherapy, and thus this review presents up-to-date information about thermotherapy.

RECENT FINDINGS

New studies have provided significant information regarding differences in outcome for devices with different protocols and selection criteria, confirming the superiority of high-energy programmes. Furthermore, monitoring of the intraprostatic temperature promises better clinical results by means of individualization of the treatment. Long-term results have been available and allow the evaluation of the fundamental issue of treatment durability. Improvement after high-energy transurethral microwave thermotherapy remains durable for more than 2.5 years. Randomized studies comparing this treatment with other established therapies for benign prostatic hyperplasia, including medical treatment and transurethral resection of the prostate, have also contributed to an evaluation of the morbidity, and costs of treatment. Clinical outcomes with transurethral microwave thermotherapy are in the range of those obtained with transurethral resection of the prostate and are superior to those of medical management. Retreatment after transurethral resection of the prostate emerges because of complications following the procedure, whereas retreatment after transurethral microwave thermotherapy is as a result of treatment failure. In addition, the rate of failure of medical management is almost seven times higher than that for transurethral microwave thermotherapy. Thus, the latter seems to play a dominant role in the economic models used to assess the cost-efficiency of different treatment modalities for benign prostatic hyperplasia.

SUMMARY

The recent innovations in high-energy transurethral microwave thermotherapy provide better and more durable clinical outcomes and lower morbidity, and strengthen its position as an established treatment for benign prostatic hyperplasia. However, there is always room for improvement, so further research on therapeutic protocols, treatment monitoring and selection criteria are to be welcomed.

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.

Impact of interventional therapy for benign prostatic hyperplasia on quality of life and sexual function

Considering the epidemiologic impact of benign prostatic hyperplasia (BPH), the use of minimally invasive surgery in the treatment of this condition is one of the main ambitions of contemporary urology. Compared with the prevalence of BPH and LUTS in elderly men, only a small percentage of patients requires surgery for indications such as renal insufficiency, chronic retention, and infection. The majority of patients seek treatment because of the bothersome nature of their symptoms and expect improvement in their quality of life. The goal of interventional therapy is to restore the comfort and well being of the patients, including preserving their sexuality. Therefore, there is increased focus on the quality of life and sexual function in the evaluation of the outcome of interventional therapy for BPH.

Minimally invasive procedures as an alternative to medical management for lower urinary tract symptoms of benign prostatic hyperplasia

Data are reviewed relating to the safety and efficacy of minimally invasive transurethral microwave thermotherapy and medical management in patients with lower urinary tract symptoms of benign prostatic hyperplasia. Recent evidence is summarized indicating more pronounced long-term beneficial effects of microwave treatment. alpha-Blockade, however, offers the advantage of more rapid action than microwave treatment. Neoadjuvant and adjuvant alpha-blocker therapy can accelerate symptom and flow rate improvement in patients receiving microwave treatment. Compared with medical management, microwave treatment possesses greater versatility, allowing patients with severe baseline symptoms and small prostate sizes to be treated with a high probability of success.

Heat treatment of the prostate: where do we stand in 2000?

Various minimally invasive modalities that are aimed at alleviating lower urinary tract symptoms employ heat-induced ablation of hyperplastic prostatic tissue. Following extensive studies, most of these modalities were eventually abandoned. High-energy transurethral microwave thermotherapy has survived, however, and has gained a firm position as a therapeutic modality, along with transurethral resection of the prostate. Recent research addressed fundamental issues of mode of action of microwave treatment, and revealed the overall efficacy of this treatment, determined new indications, and rendered high-energy transurethral microwave thermotherapy more acceptable to the patients. Insights into intraprostatic vascularization and treatment monitoring were also gained as a result of these global research efforts.

Targeted transurethral microwave thermotherapy versus alpha-blockade in benign prostatic hyperplasia: outcomes at 18 months

OBJECTIVES

To compare directly the efficacy, safety, and durability of targeted transurethral microwave thermotherapy with that of alpha-blocker treatment for lower urinary tract symptoms of benign prostatic hyperplasia.

METHODS

In a randomized, controlled clinical trial, 52 patients with lower urinary tract symptoms due to benign prostatic hyperplasia received terazosin treatment and 51 underwent microwave treatment under topical anesthesia. The patient evaluation included the International Prostate Symptom Score, peak flow rate, and quality-of-life score before microwave treatment or initiation of terazosin treatment and at periodic intervals thereafter up to 18 months.

RESULTS

The mean International Prostate Symptom Score, peak flow rate, and quality-of-life score all improved significantly in both groups by 6 months. However, the magnitude of improvement was significantly greater in the microwave group than in the terazosin group. The significant between-group differences observed at 6 months in the mean International Prostate Symptom Score, peak flow rate, and quality-of-life score were fully maintained at 18 months, at which time the improvements in these three outcome measures were significantly greater (P <0.0005), by 35%, 22%, and 43%, respectively, in the microwave group than in the terazosin group. The actuarial rate of treatment failure at 18 months was significantly greater by sevenfold in the terazosin group. Adverse events were generally infrequent and readily manageable in both groups.

CONCLUSIONS

Although the initial onset of terazosin action was more rapid, the longer term clinical outcomes of targeted microwave treatment were markedly superior. The more favorable results in patients who underwent microwave treatment were maintained for at least 18 months.

Microwave thermotherapy: historical overview

The application of heat with curative aim is an old and very well-known principle in medicine. A review of the history of heat use in the treatment of prostatic disease is presented. The article is based on bibliographic research (MEDLINE Search and PubMed) and focuses on treatment of benign prostatic hyperplasia (BPH) since the first clinical documentation of transrectal hyperthermia for this condition. Then, in a chronological sequence, not only the evolution toward thermotherapy but also enhancements of the latest techniques are presented. The new advances in the field of patient selection, indications, and outcome predictors, as well as new trends in treatment are briefly considered.

Transurethral microwave thermotherapy: an alternative to medical management in patients with benign prostatic hyperplasia?

Transurethral microwave thermotherapy (TUMT) is being increasingly considered as an alternative to medical management with alpha-blockers or finasteride in patients with lower urinary tract symptoms (LUTS) of benign prostate hyperplasia (BPH). Enduring clinical benefits have been demonstrated after a single 1-hour microwave treatment session under topical anesthesia, and the associated morbidity is low. Optimal results are obtained with the delivery of high thermal doses and accurate targeting of microwave energy. Extensive evidence from randomized clinical trials supports the safety and efficacy of both microwave treatment and medical management, but randomized trial data have only recently become available directly comparing these two approaches to BPH treatment. These data indicate that greater long-term improvements in symptoms, peak urinary flow rates, and quality of life are attained with microwave treatment than with alpha-blockade. Furthermore, the actuarial rate of treatment failure is markedly lower in patients undergoing microwave v alpha-blocker treatment. However, the onset of action of alpha-blocker treatment is more rapid. The principal limitations of alpha-blockade are side effects and lack of efficacy leading to treatment failure in some patients. The maximal effects of finasteride are modest and require a period of months to be manifested, although the side effect profile and tolerability of this agent are favorable. Neoadjuvant and adjuvant alpha-blocker therapy can accelerate symptom and flow rate improvement after TUMT. In contrast to medical management, microwave treatment is highly versatile, allowing patients over a broad range of baseline symptom severities and prostate sizes to be treated with a high probability of success.

Clinical results of microwave thermotherapy for benign prostatic hyperplasia

Transurethral microwave thermotherapy is a truly office procedure without the need for anesthesia for the treatment of lower urinary tract symptoms caused by benign prostatic hyperplasia. Several devices have been developed. Continuous refinement of the procedure led to higher energy protocols and high-intensity dose protocols applying the heat-shock strategy. We report on the clinical results of these protocols. Symptom scores improve around 60%, whereas maximum urinary flow rate improve from an average 9 to 10 mL/sec at baseline to 14 to 15 mL/sec during follow-up. No significant differences have been shown between the outcomes with the different devices. Long-term data show satisfactory results after 4 years. Initial clinical results with the heat-shock strategy show results comparable to those of higher-energy protocols with decreased morbidity. Treatment morbidity of higher energy protocols is moderate and consists mainly of the need for catheterization and a higher percentage of retrograde ejaculation. To improve treatment efficacy, patient selection appears to be most important. Prostate size, bladder outlet obstruction, age, and prostate composition are of predictive value for treatment outcome. Further development of the treatment protocols and refinement of the urethral applicators might enhance outcome.