Microwave applicators for thermotherapy of benign prostatic hyperplasia: a primer

Microwave thermotherapy for treatment of benign prostatic hyperplasia (BPH) is becoming increasingly more common. This article provides an introduction to the functional principles of microwave antennas for delivery of energy to the prostatic gland. Different antenna designs (monopole, dipole, and helical coil types) and impedance matching are discussed.     

Transurethral microwave thermotherapy in the armamentarium of therapeutic modalities for benign prostatic hyperplasia

Transurethral microwave thermotherapy (TUMT) has gained a firm place in the spectrum of therapeutic modalities for management of patients with lower urinary tract symptoms suggestive of bladder outflow obstruction. To achieve optimum results following TUMT, intense research focuses on appropriate patient selection, heat-tissue interactions, and modification of technical specifications. Results of TUMT are good to excellent for the majority of patients, but there is a non-negligible number of patients who respond poorly. The selection of favorable candidates for TUMT aims to improve the therapeutic results, and both clinical baseline parameters and intrinsic characteristics of the prostate (histologic composition and vasculature) may influence treatment outcome. TUMT achieves therapeutic response through coagulative necrosis of the hyperplastic tissue, but additional theories have been proposed recently, suggesting that TUMT may cause neural destruction and induce apoptosis. Individualization of the treatment is expected to offer the best results, and because the temperature achieved inside the prostate determines the actual parenchymal necrosis, thermal monitoring during treatment will permit application of microwave energy in a feedback mode. Various microwave devices differ in technical specifications (operating frequency, design of antenna, cooling system), and recently introduced software programs (high-energy protocols, heat-shock strategy, short-duration protocols) aim at better efficacy, providing a more patient-friendly procedure. TUMT has survived the "test of time" that other, initially promising, modalities have failed. What remains to be determined is the maximum benefit that patients and health systems can gain from such a technique.     

Transurethral microwave thermotherapy for treatment of benign prostatic hyperplasia: results obtained with the Prostalund device

The 6-month results of treatment with transurethral microwave thermotherapy (Prostalund) of 28 patients with lower urinary tract symptoms (LUTS) due to benign hyperplasia of the prostate are reported. The median International Prostate Symptom Score (I-PSS) fell from 16.5 (range 9–33) to 10.5 (range 3–30; P < 0.00005). Quality-of-life assessment improved from a median value of 4 (range 2–6) to 2 (range 1–5; P = 0.0001). In the Danish Prostate Symptom Score (DAN-PSS) the median total score fell from 20 (range 5–55) to 5 (range 0–43; P = 0.001). The median peak urinary flow increased from 10.6 to 11.5 ml/s (P = 0.20). Pressure-flow studies revealed no decrease in the median detrusor pressure at peak uroflow (Pdet_Qmax) from 56 cmH₂O preoperatively to 56 cmH₂O after 6 months (P = 0.36). No change was found in postvoid residual urinary volume or in the calculated prostate volume. Complications included hematuria in most patients, urinary tract infections in 6 (21.4%) patients, and transient retention in 3 (10.7%) patients. In all, 20 (71.4%) patients responded to treatment with good symptomatic relief, but only minor changes were observed in urodynamic parameters.     

A comparison of transrectal hyperthermia,transurethral thermotherapy,urolume wallstent,and prostatic spiral for benign prostatic hyperplasia patients at poor operative risk

Transrectal hyperthermia, transurethral thermotherapy, prostatic stent, and prostatic spiral were used to treat 120 poor operative risk patients with symptomatic benign prostatic hyperplasia. The preoperative subjective and objective conditions of the four groups (each of 30 patients) were comparable. None of the patients had an indwelling catheter, but according to flow nomograms, all were obstructed. The greatest increase in peak flow rate was observed after stent placement, while the greatest decrease of residual urine volume was seen after the insertion of the stent and transrectal hyperthermia. According to maximum flow nomograms, only the placement of the stent resolved bladder outlet obstruction. The greatest improvement in subjective symptoms was the result of stent insertion, but the heating procedures also caused a significant reduction of symptom scores. The spiral produced satisfactory results only in the short term. © 1994 Wiley-Liss, Inc.     

Urodynamic indices change as a result of transrectal microwave thermotherapy (TMT) in benign prostatic hyperplasia (BPH)

Fifty-three patients with BPH have been evaluated and treated with TMT with a follow-up at 7 months. The prostate was heated transcrectally to 42–43°C and the treatment consisted of 5 to 6 sessions. The duration of each session was 60 minutes. The urodynamic parameters studied revealed an increase of the maximum flow rate and a decrease of the detrusor opening pressure as well as the detrusor pressure at maximum flow. A significant improvement in the amount of residual urine was seen in all patients. Based on the above, we propose TMT as a viable alternative to open surgical or transurethral removal of the prostate. Futhermore, TMT may serve as a preferred treatment option in patients with indwelling urethral catheters and highly increased surgical risk.     

Lower-energy thermotherapy in the treatment of benign prostatic hyperplasia: long-term follow-up results of a multicenter international study

The purpose of the present study was to evaluate the long-term results of lower-energy transurethral microwave thermotherapy (TUMT) and to determine predictors for a favorable treatment outcome in an international multicenter study. A total of 1092 patients treated between April 1990 and September 1993 in 6 different centers in different countries were evaluated. All patients were treated in a nonblinded, noncontrolled fashion with the Prostatron thermotherapy device using the lower-energy treatment protocol Prostasoft 2.0. Collected data included voiding parameters, Madsen symptom scores, retreatments, types of retreatment, and dates of retreatment. Instrumental retreatment served as the end point for further evaluation. The average age of our patients was 67 years. At baseline the average uroflow rate was 8.7 ml/s. After treatment the improvement in uroflow was 2–3 ml/s. This was maintained for up to 5 years after treatment for the patients remaining in follow-up. The overall improvement in the Madsen symptom score was 5–6 points for these patients. There was no significant difference between the different centers. During follow-up, however, the number of patients remaining in follow-up decreased rapidly. The absolute instrumental retreatment rate appeared to be 26%; however, when patients no longer in follow-up were taken into account, the calculated retreatment rate was 39.6% (Kaplan-Meier survival analysis). Patients undergoing retreatment were younger at baseline and had a higher Madsen score, a bigger prostate, and a greater postvoid residual. No major complication was seen. Lower-energy TUMT gives a sustained objective and subjective improvement in patients with moderate symptoms and a low-grade bladder outflow obstruction. Patients with bigger prostates, severe symptoms, low rates of maximal uroflow, and large residuals are prone to have a higher degree of prostatic obstruction and are not the ideal candidates for this treatment. The absolute instrumental retreatment rate after 5 years was 26%. Moreover, no significant international difference in treatment outcome was found.     

Vascular damage as a risk factor for benign prostatic hyperplasia and erectile dysfunction

OBJECTIVE: To assess benign prostatic hyperplasia (BPH) and erectile dysfunction (ED), both considered to be associated with urogenital ageing, in ageing men in a cross-sectional population study, comparing them with healthy controls by using symptom scores and contrast-enhanced colour Doppler ultrasonography (CDUS). PATIENTS, SUBJECTS AND METHODS: Transrectal CDUS and quantitative measurement of colour pixel intensity (CPI) are excellent minimally invasive techniques for assessing normal and pathological blood flow. CDUS was performed using the microbubble-based ultrasound enhancer for evaluating prostate, bladder neck and corpus cavernosum vascularity in young healthy men, men with BPH, and men with severe vascular damage (diabetes mellitus type 2). Resistive index measurements and computer-assisted quantification of CPI were used to objectively evaluate perfusion. The International Prostate Symptom Score (IPSS) and the International Index of Erectile Function (IIEF) were applied to quantify the symptoms. RESULTS: In patients with BPH, perfusion of the transition zone (TZ) of the prostate was significantly lower and the resistive index of the TZ significantly higher (both P < 0.001) than in healthy controls. The perfusion patterns of men with BPH and those who also had severe vascular damage (diabetes mellitus type 2) showed that vascularity in the latter group was lower in the prostatic TZ and the corpora cavernosa. In patients with BPH the IPSS, quality-of-life and IIEF scores were significantly worse than in the control group. Men with concomitant atherosclerosis had even worse symptom scores. CONCLUSION: These results strongly support the hypothesis that age-related impairment of blood supply to the lower urinary tract is important in the development of BPH and ED. Vascular damage may cause chronic ischaemia and thus be a contributing factor in the pathogenesis of BPH and ED.     

The cost of feedback microwave thermotherapy compared with transurethral resection of the prostate for treating benign prostatic hyperplasia

OBJECTIVE: To compare the efficacy of a new microwave thermotherapy for treating benign prostatic hyperplasia (BPH), the ProstaLund Feedback Treatment (PLFT, ProstaLund Operations AB, Lund, Sweden) and transurethral resection of the prostate (TURP) in a clinical trial to their effectiveness in clinical practice over 1 year, to estimate their cost over 1 year, and to evaluate the cost of re-interventions over a longer period (2-3 years). PATIENTS AND METHODS: In a large randomized international 1-year clinical trial PLFT was as effective as TURP in improving symptoms of BPH and urinary flow. Because PLFT is an outpatient procedure it was less costly than TURP. However, the cost-effectiveness of the new procedure depends on its long-term effectiveness in clinical practice. All 146 patients in the randomized clinical trial were included in the present analysis. The outcome was based on the International Prostate Symptom Score (IPSS) and the bother score, and costs were estimated from treatment-related adverse events and hospitalization. To validate the estimates based on the clinical trial 1-year data on effectiveness and complete resource use in clinical practice were collected in a retrospective observational study from hospital charts and patient questionnaires of 88 patients who had undergone either TURP or PLFT. To assess the number of re-interventions after TURP after the first year information was obtained from hospital and surgical procedure data in the Swedish inpatient registry. The 3-year data for a total of 52,010 patients who had an index hospitalization for TURP between 1990 and 1995 were available for the analysis. The estimate of long-term consequences of PLFT was based on complication and re-intervention data for 87 patients who had undergone PLFT between 1997 and 1999. RESULTS: The mean 1-year costs in the clinical trial were estimated at [symbol: see text] 1763 for PLFT and [symbol: see text] 3209 for TURP. When all treatment-related resource use in clinical practice for 88 patients was included the costs were estimated at [symbol: see text] 1924 and [symbol: see text] 3264 for PLFT and TURP, respectively. The IPSS and bother scores were not significantly different between the groups in both datasets. Using the registry data the cost of TURP including re-interventions (TURP and bladder neck incisions) was estimated at [symbol: see text] 3159 over 2 years and [symbol: see text] 3185 over 3 years; the respective costs for PLFT were [symbol: see text] 2121 and at [symbol: see text] 2151. CONCLUSIONS: In the 1-year clinical trial PLFT was as effective but less costly than TURP, but long-term data are still lacking. However, the preliminary analysis over 3 years indicates that the average cost of the procedure remains lower than the total cost of TURP for the same period.     

Sham treatment compared with 30 or 60 min of thermotherapy for benign prostatic hyperplasia: a randomized study.

OBJECTIVE: To study the differences in subjective and objective results after 30 or 60 min of transurethral thermotherapy (TUMT) or sham treatment in men with benign prostatic hyperplasia (BPH). PATIENTS AND METHODS: Forty-four patients with lower urinary tract symptoms caused by BPH were randomized to undergo 30 or 60 min of TUMT or sham treatment (14, 16 and 14 patients, respectively). The patients were evaluated using symptom scores, timed micturition, free flow rates and urodynamics before and after treatment. They were followed for 1 year, at the end of which they rated the treatment results on a self-administered visual analogue scale. RESULTS: Forty-two patients completed the study. The treatment failed in some patients in all groups, but the improvement in maximum and median flow rates, timed micturition and micturition frequency (day and night) was greater after TUMT than in the sham-treated group. Symptom scores also improved more after TUMT, although not significantly. There was a good correlation between the decrease in urinary frequency, especially nocturnal, and the patients' perception of a successful treatment, whereas the increase in maximum urinary flow rate was apparently of little importance. CONCLUSIONS: TUMT had a better effect than the placebo treatment, having a greater impact on irritative than on obstructive symptoms. More patients were satisfied after the 30-min than after the 60-min treatment.     

The economic impact of introducing transurethral microwave thermotherapy in the treatment of benign prostatic hyperplasia: a scenario analysis

The goal of this study was to assess the economic impact of introducing transurethral microwave thermotherapy (TUMT) in the treatment of benign prostatic hyperplasia (BPH). Different scenarios were constructed using both randomized clinical trial data and observational data on resource use related to BPH treatments. These include a baseline scenario, demand scenarios reflecting the number of men who will be treated by TUMT when it is introduced, and supply scenarios reflecting the number of hospitals that will provide TUMT. In the baseline scenario, costs of BPH treatment equal Netherlands guilders (NLG) 203 million. If the demand for BPH treatment does not increase following the adoption of TUMT, costs may vary between NLG 187 and 189 million, depending on how TUMT is provided. If the demand increases up to 25% following the introduction of TUMT, costs may vary between NLG 457 and 466 million, depending on how TUMT is provided. The introduction of TUMT seems to be cost-saving, but savings depend on the number of men who seek treatment for BPH. There is no indication for a controlled provision.     

花粉提取物对前列腺增生细胞作用的研究

将前列腺增生来源的上皮细胞和成纤维细胞在体外进行培养，并观察花粉提陂物对细胞的体外作用。结果证明花粉提取物可明显地抑制前列腺增生的上皮细胞或成纤维细胞的增殖，且上皮细胞的反应更为敏感。本结果对进一步研究花粉类物质对前列腺细胞的作用机理提供一定的帮助。     

Stromal/epithelial interactions of murine prostatic cell lines in vivo: a model for benign prostatic hyperplasia and the effect of doxazosin on tissue size

BACKGROUND: One of the major constraints in elucidating the mechanisms involved in the etiology of benign prostatic hyperplasia (BPH) is the lack of suitable model systems that are readily manipulable in vitro and in vivo. To address this issue, we have used murine prostatic cell lines to establish a novel in vivo model for studying prostatic cell interactions. METHODS: Luminal, basal, and smooth muscle (SM) cell lines were inoculated alone or in combinations under the renal capsule of intact or castrated male mice, and the growth and composition of prostatic tissue in the absence or presence of doxazosin was determined. RESULTS: Both the luminal and basal cell lines reconstituted prostatic tissue if co-inoculated under the renal capsule with normal SM cells, whereas none of the lines formed significant tissue when inoculated alone. Luminal cells produced and secreted prostatic secretory products. The growth of prostatic tissue formed from co-inoculation of basal and SM cells was androgen responsive. In addition, a significant reduction in prostatic tissue was noted in animals treated with doxazosin. CONCLUSION: We have established an in vivo model that uses prostatic epithelial and SM cell lines for investigating cellular interactions between epithelial and SM cells that regulate prostatic growth and function. This model will be useful for delineating the mechanisms by which prostatic cells interact and in determining the efficacy of new approaches aimed at interfering with prostatic stromal/epithelial interactions that result in abnormal cellular proliferation.     

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=50% improvement), Qmax (>or=15 mL/sec or >or=50% improvement), PVR (<50 mL or >or=50% decrease), and QoL (相似文献   

土贝母皂甙对大鼠前列腺增生模型影响的实验研究

目的　探讨中药土贝母对前列腺增生 (BPH)的影响及作用机制。方法　将 4 0只SD大鼠去势 7天后皮下注射丙酸睾酮 5mg/kg,同时土贝母大、小剂量组分别腹腔注射土贝母注射液 4mg/kg、2mg/kg ,前列通瘀胶囊组给前列通瘀胶囊溶液 10 0mg/kg。于给药 30天后处死 ,观察前列腺重量和组织细胞结构改变 ,并通过免疫组化法检测PCNA和bFGF表达的变化。结果　 3个治疗组大鼠前列腺重量、PCNA指数及bFGF表达水平均明显低于模型组 ,其中尤以土贝母大剂量组最为明显 (P <0 .0 1)。土贝母大剂量组与前列通瘀胶囊组比较差异亦有显著性 ,而土贝母小剂量组与前列通瘀胶囊组比较差异无显著意义。结论　土贝母能明显抑制模型大鼠的BPH ,其机制可能是通过抑制前列腺细胞的增殖及减少前列腺组织中bFGF的表达而实现的。     

输精管结扎用于预防和治疗前列腺增生症的研究

目的：探讨输精管结扎对前列腺增生症的预防和治疗作用。方法：临床系列输精管结扎组16例，行双侧输精管及输精管静脉结扎；设对照1组40例，口服安宫黄体酮2mg，3次／d，长期服用；对照2组40例，口服保列治5mg，1次／d，长期服用。调查系列采用大样本抽样方法，调查了55岁以上男性l240例，其中结扎组850例，对照组390例。对其前列腺症状评分、生活质量指数、直肠指诊、前列腺体积及残余尿等指标分年龄段进行了综合分析与比较。结果：临床系列输精管结扎组有效率66.7％，对照l组35.5％，对照2组68.8％。调查系列结扎组各年龄段BPH的发病率明显低于对照组。结论：输精管结扎可明显降低人在老年期BPH的发病率和减轻临床症状；并对人BPH有治疗作用，远期疗效优于性激素治疗。     

改良的Madigan前列腺切除术的临床疗效

目的 探讨改良的Madigan前列腺切除术的疗效。方法 对2001年9月～2006年9月42例前列腺增生患者行改良的Madigan前列腺切除术的临床资料进地回顾性分析。结果 本组手术均成功。恢复均顺利。平均手术时间80min,平均出血量120ml,均未输血,平均切除前列腺组织重量78．3g。拔除导尿管后均排尿通畅。其中38例获随访,随访时间18～60个月。IPSS自术前平均29．5分下降至7．5分,残余尿≤20ml。未发现严重的 并发症,疗效满意。结论 改良的Madigan前列腺切除术为理想的良性前列腺增生症开放手术治疗方法,值得推广。     

Atamestane, a new aromatase inhibitor for the management of benign prostatic hyperplasia.

Atamestane is a new, competitive, and irreversible inhibitor of estrogen biosynthesis. Its pharmacologic action has been evaluated in mice, rats, rabbits, dogs, monkeys, and humans. In rats, atamestane leads to a decrease of pregnant mare serum gonadotropin-stimulated ovarian estrogen production, and inhibits androstenedione-induced estrogenic effects such as uterine growth and abortion. In all species tested, atamestane lacks other intrinsic hormonal or antihormonal activities, and shows no inhibition of other cytochrome P450-dependent enzymes of adrenal steroidogenesis. However, it inhibits estrogen-related negative feedback. The extent and consequences of the induced counterregulation of the pituitary-hypothalamic axis show major sex- and species-specific differences. Atamestane is highly effective in inhibiting estrogen-induced hyperplastic changes in the fibromuscular stroma of the prostate in androstenedione-treated dogs and monkeys. In male volunteers and patients with benign prostatic hyperplasia (BPH), atamestane induces an expected reduction of serum (and BPH tissue) estrogen concentrations without significant changes in androgen levels. In conclusion, all available results indicate that atamestane is a selective (no inhibition of adrenal function), pure (no endocrine side effects), and highly effective steroidal aromatase inhibitor, with an excellent safety profile. Based on the discussion of its clinical potential, atamestane seems to be a promising compound for the management of BPH.