To what extent does the prostate-specific antigen nadir predict subsequent treatment failure after transrectal high-intensity focused ultrasound therapy for presumed localized adenocarcinoma of the prostate?

Focal high-intensity focused ultrasound therapy for localized prostate cancer: An interim analysis of the multinational FASST study

BACKGROUND

High-intensity focused ultrasound (HIFU) emerged as a novel approach for the treatment of localized prostate cancer (PCa). However, prospective studies on HIFU-related outcomes and predictors of treatment failure (TF) remain scarce.

MATERIALS AND METHODS

We conducted a multinational prospective cohort study among patients undergoing HIFU therapy for localized, low- to intermediate-risk PCa. Follow-up data on serial prostate specific antigen (PSA), multi-parametric magnetic resonance imaging (mpMRI), targeted/systematic biopsies, adverse events and functional outcomes were collected. The primary endpoint was TF, defined as histologically confirmed PCa requiring whole-gland salvage treatment. Uni- and multi-variable adjusted hazard ratios (HRs) were calculated using Cox proportional hazard regression models.

RESULTS

At baseline, mean (standard deviation) age was 64.14 (7.19) years, with the majority of patients showing T-stage 1 (73.9%) and International Society of Urological Pathology grading system Grade 2 (58.8%). PSA nadir (median, 1.70 ng/mL) was reached after 6 months. Of all patients recruited, 16% had clinically significant PCa, as confirmed by biopsy, of which 13.4% had TF. Notably, T-stage and number of positive cores at initial biopsy were independent predictors of TF during follow-up (HR [95% CI] 1.27 [1.02-1.59] and 5.02 [1.80-14.03], respectively). Adverse events were minimal (17% and 8% early and late adverse events, respectively), with stable or improved functional outcomes in the majority of patients.

CONCLUSIONS

This interim analysis of a multinational study on HIFU therapy for the management of low-to-intermediate-risk PCa reveals good functional outcomes, minimal adverse events and low incidence of TF over the short-term. Data on long-term outcomes, specifically as it relates to oncological outcomes, are awaited eagerly.

Ablative therapy for people with localised prostate cancer: a systematic review and economic evaluation

BACKGROUND

For people with localised prostate cancer, active treatments are effective but have significant side effects. Minimally invasive treatments that destroy (or ablate) either the entire gland or the part of the prostate with cancer may be as effective and cause less side effects at an acceptable cost. Such therapies include cryotherapy, high-intensity focused ultrasound (HIFU) and brachytherapy, among others.

OBJECTIVES

This study aimed to determine the relative clinical effectiveness and cost-effectiveness of ablative therapies compared with radical prostatectomy (RP), external beam radiotherapy (EBRT) and active surveillance (AS) for primary treatment of localised prostate cancer, and compared with RP for salvage treatment of localised prostate cancer which has recurred after initial treatment with EBRT.

DATA SOURCES

MEDLINE (1946 to March week 3, 2013), MEDLINE In-Process & Other Non-Indexed Citations (29 March 2013), EMBASE (1974 to week 13, 2013), Bioscience Information Service (BIOSIS) (1956 to 1 April 2013), Science Citation Index (1970 to 1 April 2013), Cochrane Central Register of Controlled Trials (CENTRAL) (issue 3, 2013), Cochrane Database of Systematic Reviews (CDSR) (issue 3, 2013), Database of Abstracts of Reviews of Effects (DARE) (inception to March 2013) and Health Technology Assessment (HTA) (inception to March 2013) databases were searched. Costs were obtained from NHS sources.

REVIEW METHODS

Evidence was drawn from randomised controlled trials (RCTs) and non-RCTs, and from case series for the ablative procedures only, in people with localised prostate cancer. For primary therapy, the ablative therapies were cryotherapy, HIFU, brachytherapy and other ablative therapies. The comparators were AS, RP and EBRT. For salvage therapy, the ablative therapies were cryotherapy and HIFU. The comparator was RP. Outcomes were cancer related, adverse effects (functional and procedural) and quality of life. Two reviewers extracted data and carried out quality assessment. Meta-analysis used a Bayesian indirect mixed-treatment comparison. Data were incorporated into an individual simulation Markov model to estimate cost-effectiveness.

RESULTS

The searches identified 121 studies for inclusion in the review of patients undergoing primary treatment and nine studies for the review of salvage treatment. Cryotherapy [3995 patients; 14 case series, 1 RCT and 4 non-randomised comparative studies (NRCSs)], HIFU (4000 patients; 20 case series, 1 NRCS) and brachytherapy (26,129 patients; 2 RCTs, 38 NRCSs) studies provided limited data for meta-analyses. All studies were considered at high risk of bias. There was no robust evidence that mortality (4-year survival 93% for cryotherapy, 99% for HIFU, 91% for EBRT) or other cancer-specific outcomes differed between treatments. For functional and quality-of-life outcomes, the paucity of data prevented any definitive conclusions from being made, although data on incontinence rates and erectile dysfunction for all ablative procedures were generally numerically lower than for non-ablative procedures. The safety profiles were comparable with existing treatments. Studies reporting the use of focal cryotherapy suggested that incontinence rates may be better than for whole-gland treatment. Data on AS, salvage treatment and other ablative therapies were too limited. The cost-effectiveness analysis confirmed the uncertainty from the clinical review and that there is no technology which appears superior, on the basis of current evidence, in terms of average cost-effectiveness. The probabilistic sensitivity analyses suggest that a number of ablative techniques are worthy of further research.

LIMITATIONS

The main limitations were the quantity and quality of the data available on cancer-related outcomes and dysfunction.

CONCLUSIONS

The findings indicate that there is insufficient evidence to form any clear recommendations on the use of ablative therapies in order to influence current clinical practice. Research efforts in the use of ablative therapies in the management of prostate cancer should now be concentrated on the performance of RCTs and the generation of standardised outcomes.

STUDY REGISTRATION

This study is registered as PROSPERO CRD42012002461.

FUNDING

The National Institute for Health Research Health Technology Assessment programme.

High Intensity Focused Ultrasound versus Brachytherapy for the Treatment of Localized Prostate Cancer: A Matched-Pair Analysis

Purpose. To evaluate postoperative morbidity and long term oncologic and functional outcomes of high intensity focused ultrasound (HIFU) compared to brachytherapy for the treatment of localized prostate cancer. Material and Methods. Patients treated by brachytherapy were matched 1 : 1 with patients who underwent HIFU. Differences in postoperative complications across the two groups were assessed using Wilcoxon's rank-sum or χ (2) test. Kaplan-Meier curves, log-rank tests, and Cox regression models were constructed to assess differences in survival rates between the two groups. Results. Brachytherapy was significantly associated with lower voiding LUTS and less frequent acute urinary retention (p < 0.05). Median oncologic follow-up was 83 months (13-123 months) in the HIFU cohort and 44 months (13-89 months) in the brachytherapy cohort. Median time to achieve PSA nadir was statistically shorter in the HIFU. Biochemical recurrence-free survival rate was significantly higher in the brachytherapy cohort compared to HIFU cohort (68.5% versus 53%, p < 0.05). No statistically significant difference in metastasis-free, cancer specific, and overall survivals was observed between the two groups. Conclusion. HIFU and brachytherapy are safe with no significant difference in cancer specific survival on long term oncologic follow-up. Nonetheless, a randomized controlled trial is needed to confirm these results.

High-intensity focused ultrasound for the treatment of prostate cancer: A prospective trial with long-term follow-up

OBJECTIVE

High-intensity focused ultrasound (HIFU) is a minimally invasive treatment for prostate cancer. Data from the literature show promising oncological outcomes with a favourable side-effect profile. The aim of this study was to re-evaluate and bring up to date the follow-up of a previously published, prospective trial on HIFU as the primary treatment for prostate cancer.

MATERIALS AND METHODS

Between 2004 and 2007, 163 consecutive men with T1-T3N0M0 prostate cancer underwent HIFU with the Sonablate 500. Follow-up included prostate-specific antigen (PSA) tests every 3 months after treatment and a random prostate biopsy at 6 months. Failure was defined according to positive findings at the 6 month biopsy and biochemical failure was defined according to the Phoenix criteria. Biochemical-free survival, metastasis-free survival and cancer-specific survival were calculated by Kaplan-Meier curves.

RESULTS

Median follow-up was 72.0 months. Of the 160 evaluable patients, 104 (65%) were biochemically disease free; in low- to intermediate-risk disease, on Kaplan-Meier analysis the 8 year biochemical-non-evidence of disease (bNED), metastasis-free survival and cancer-specific survival rates were 69.6%, 81.3%, 100% and 40.5%, 60.6%, 100%, respectively. A PSA nadir below 0.40 ng/ml and risk stratification have an independent predictive value for bNED and metastasis-free survival.

CONCLUSIONS

A long-term favourable outcome of HIFU is associated with careful patient selection, with low- to intermediate-risk disease being the ideal case. A low postoperative PSA nadir is a predictor of long-term bNED.

Single high intensity focused ultrasound session as a whole gland primary treatment for clinically localized prostate cancer: 10-year outcomes

Objectives. To assess the treatment outcomes of a single session of whole gland high intensity focused ultrasound (HIFU) for patients with localized prostate cancer (PCa). Methods. Response rates were defined using the Stuttgart and Phoenix criteria. Complications were graded according to the Clavien score. Results. At a median follow-up of 94months, 48 (44.4%) and 50 (46.3%) patients experienced biochemical recurrence for Phoenix and Stuttgart definition, respectively. The 5- and 10-year actuarial biochemical recurrence free survival rates were 57% and 40%, respectively. The 10-year overall survival rate, cancer specific survival rate, and metastasis free survival rate were 72%, 90%, and 70%, respectively. Preoperative high risk category, Gleason score, preoperative PSA, and postoperative nadir PSA were independent predictors of oncological failure. 24.5% of patients had self-resolving LUTS, 18.2% had urinary tract infection, and 18.2% had acute urinary retention. A grade 3b complication occurred in 27 patients. Pad-free continence rate was 87.9% and the erectile dysfunction rate was 30.8%. Conclusion. Single session HIFU can be alternative therapy for patients with low risk PCa. Patients with intermediate risk should be informed about the need of multiple sessions of HIFU and/or adjuvant treatments and HIFU performed very poorly in high risk patients.

Correlation of pretreatment clinical parameters and PSA nadir after high-intensity focused ultrasound (HIFU) for localised prostate cancer

OBJECTIVE

To determine which pretreatment clinical parameters were predictive of a low prostate-specific antigen (PSA) nadir following high-intensity focused ultrasound (HIFU) treatment.

PATIENTS AND METHODS

Retrospective study of patients with clinically localised prostate cancer undergoing HIFU at a single centre between December 1997 and September 2009. Whole-gland treatment was applied. Patients also included if they had previously undergone transurethral resection of the prostate (TURP). TURP was also conducted simultaneously to HIFU. Biochemical failure based on Phoenix definition (PSA nadir + 2). Univariate and multivariate analysis of pretreatment clinical parameters conducted to assess those factors predictive of a PSA nadir ≤0.2 and >0.2 ng/ml.

RESULTS

Mean (SD) follow-up was 6.2 (2.8) years; median (range) was 6.3 (1.1-12.2) years. Kaplan-Meier estimate of biochemical disease-free survival rate at 8 years was 83 and 48 % for patients achieving a PSA nadir of ≤0.2 and >0.2 ng/ml, respectively. Prostate volume and incidental finding of cancer were significant predictors of low PSA nadir (≤0.2 ng/ml).

CONCLUSIONS

Prostate volume and incidental finding of cancer could be predictors for oncologic success of HIFU based on post-treatment PSA nadir.

Sonablate®-500: transrectal high-intensity focused ultrasound for the treatment of prostate cancer

Prostate cancer (PCa) is the most common cancer in men and the second leading cause of death from malignancy in the UK. The number of men diagnosed with PCa is increasing, due in part to an increased willingness of men to visit their family doctors with lower urinary tract symptoms, and also a willingness of physicians to test for it. As the demographic of men diagnosed with PCa becomes younger and better informed, so the demand for a less-invasive alternative to standard therapies becomes greater. The Sonablate-500 is one of only two high-intensity focused ultrasound (HIFU) devices commercially available to treat PCa. HIFU is an attractive treatment option as it is the only form of therapy that neither involves direct instrumentation of the prostate nor ionizing radiation. This article describes the unique features of both the Sonablate-500 system hardware and software, and the outcome data from this device in the context of current standard therapies. Finally, a view into the future attempts to outline where this technology is heading and how a paradigm shift in the way that PCa is considered may make HIFU even more relevant.

Single session of high-intensity focused ultrasound for localized prostate cancer: treatment outcomes and potential effect as a primary therapy

Purpose

To investigate the treatment outcomes of a single-session high-intensity focused ultrasound (HIFU) using the Sonablate^® for patients with localized prostate cancer.

Methods

Biochemical failure was defined according to the Stuttgart definition [a rise of 1.2 ng/ml or more above the nadir prostate-specific antigen (PSA)] and the Phoenix definition (a rise of 2 ng/ml or more above the nadir PSA). Disease-free survival rate was defined using the Phoenix criteria and positive follow-up biopsy.

Results

A total of 171 patients were identified. Fifty-two (30.4 %) patients were identified to be with D’Amico low risk, 47 (27.5 %) with intermediate risk, and 72 (42.1 %) with high risk. In the median follow-up time of 43 months, there was 44 (25.7 %) and 36 (21.1 %) patients experienced biochemical failure for Stuttgart and Phoenix definition with mean (±SD) time to failure of 17.8 ± 2.1 and 19.4 ± 2.3 months, respectively. A total of 44 (25.7 %) patients were diagnosed as disease failure. Cox multivariate analysis revealed PSA nadir level (PSA cutoff = 0.2 ng/ml; HR = 9.472, 95 % CI 4.527–19.820, p < 0.001) and D’amico risk groups [HR = 3.132 (95 % CI 1.251–6.389), p = 0.033] were the predictor for failure in single-session HIFU.

Conclusions

Single-session HIFU treatment using the Sonablate^® seems to be potentially curative approach. When treated carefully with neoadjuvant hormonal therapy or preoperative transurethral resection of the prostate, higher-risk disease might be able to choose this minimally invasive procedure as primary therapy.

Prostatic cancer surveillance following whole-gland high-intensity focused ultrasound: comparison of MRI and prostate-specific antigen for detection of residual or recurrent disease

OBJECTIVE

This retrospective study compares dynamic contrast-enhanced (DCE) MRI with the serial prostate-specific antigen (PSA) measurement for detection of residual disease following whole-gland high-intensity focused ultrasound (HIFU) therapy of prostate cancer.

METHODS

Patients in whom post-HIFU DCE-MRI was followed within 3 months by ultrasound-guided transrectal biopsy were selected from a local database. 26 patients met the study inclusion criteria. Serial PSA levels following HIFU and post-HIFU follow-up MRI were retrieved for each patient. Three radiologists unaware of other investigative results independently assessed post-HIFU MRI studies for the presence of cancer, scoring on a four-point scale (1, no disease; 2, probably no disease; 3, probably residual disease; and 4, residual disease). Sensitivity, specificity and receiver operating characteristic (ROC) analysis were performed for each reader, post-HIFU PSA nadir and pre-biopsy PSA level thresholds of >0.2 and >0.5 ng ml(-1).

RESULTS

The sensitivity of DCE-MRI for detection of residual disease for the three readers ranged between 73% and 87%, and the specificity between 73% and 82%. There was good agreement between readers (κ = 0.69-0.77). The sensitivity and specificity of PSA thresholds was 60-87% and 73-100%, respectively. The area under the ROC curve was greatest for pre-biopsy PSA (0.95).

CONCLUSION

DCE-MRI performed following whole-gland HIFU has similar sensitivity and specificity and ROC performance to serial PSA measurements for detection of residual or recurrent disease.

High-intensity focused ultrasound therapy for prostate cancer

Recent advances in high-intensity focused ultrasound, which was developed in the 1940s as a viable thermal tissue ablation approach, have increased its popularity. High-intensity focused ultrasound is currently utilized the most in Europe and Japan, but has not yet been approved by the Food and Drug Administration, USA, for this indication. The purpose of the present report is to review the scientific foundation of high-intensity focused ultrasound technology and the clinical outcomes achieved with commercially available devices. Recently published articles were reviewed to evaluate the current status of high-intensity focused ultrasound as a primary or salvage treatment option for localized prostate cancer. Improvements in the clinical outcome as a result of technical, imaging and technological advancements are described herein. A wide range of treatment options for organ-confined prostate cancer is available. However, high-intensity focused ultrasound is an attractive choice for men willing to choose less invasive options, although establishing the efficacy of high-intensity focused ultrasound requires longer follow-up periods. Technological advances, together with cultural and economic factors, have caused a dramatic shift from traditional open, radical prostatectomy to minimally invasive techniques. High-intensity focused ultrasound is likely to play a significant role in the future of oncology practice.

High-intensity focused ultrasound for prostate cancer: a practice guideline

OBJECTIVE

The aim of this practice guideline was to develop evidence-based recommendations for clinicians on the use of high-intensity focused ultrasound (HIFU) in patients with localized prostate cancer.

METHODS

The guideline was developed using the methods of Cancer Care Ontario's Program in Evidence-Based Care (PEBC). The core methodology of the PEBC's guideline development process is systematic review. A comprehensive literature search was undertaken to identify high-quality studies, reviews and other practice guidelines on the use of HIFU in prostate cancer. The evidence formed the basis of the recommendations, which were reviewed and amended where necessary, by clinical experts in medical and radiation oncology and urology.

RESULTS

The literature review yielded limited evidence. No randomized controlled trials or meta-analyses comparing HIFU with currently accepted management approaches were identified. The body of evidence is primarily based on data from case series. Internal feedback was provided by the PEBC Genitourinary Disease Site Group membership and the Report Approval Panel. External peer review included targeted review by clinical experts specifically requested to comment on the guideline, and professional consultation through an online survey of health care professionals.

CONCLUSION

HIFU is currently not recommended as an alternative to accepted curative treatment approaches for localized prostate cancer.

Transrectal high-intensity focused ultrasound for the treatment of prostate cancer: past, present, and future

Upon a review of recently published articles on high-intensity focused ultrasound (HIFU) in the treatment of prostate cancer, we evaluated the current status of HIFU as a primary treatment option for localized prostate cancer and its use as salvage therapy when radiation failed. We also briefly discuss current issues in indications, definition of response, and finally the future of HIFU development.

Correlation of prostate-specific antigen nadir and biochemical failure after high-intensity focused ultrasound of localized prostate cancer based on the Stuttgart failure criteria - analysis from the @-Registry

OBJECTIVE

•To determine if the prostate-specific antigen (PSA) nadir after high-intensity focused ultrasound (HIFU) can be used as a predictor of the biochemical disease-free survival rate (DFSR).

PATIENTS AND METHODS

•Patient data were derived from the multicentre-based @-Registry, the largest registry to report outcomes in patients with localized prostate cancer after Ablatherm® HIFU. •PSA level was measured at 3-month intervals. Patients were stratified into four PSA nadir groups: group 1, ≤0.2 ng/mL; group 2, 0.21-0.5 ng/mL; group 3, 0.51-1 ng/mL; and group 4, >1 ng/mL. •Biochemical treatment failure was defined according to the Stuttgart definition (PSA nadir + 1.2 ng/mL) and the Phoenix definition (PSA nadir + 2 ng/mL). •Biopsy was performed at 3-6 months post-HIFU or if a PSA level was recorded that was considered clinically relevant.

RESULTS

•The present study included 804 patients. Biochemical treatment success rates at 5 years according to the Stuttgart definition for the four PSA nadir sub-groups were as follows: 84, 64, 40 and 30% for groups 1-4, respectively. •The equivalent 5-year biochemical success rates using the Phoenix definition were 94, 74, 66 and 47%, respectively. •Significantly more patients had a negative biopsy in the lowest PSA nadir group than in the other sub-groups (91.6 vs 73.1%; P < 0.001). •The present study is limited by its retrospective nature and variations in clinical practice across participating centres.

CONCLUSION

•This multicentre analysis confirms that PSA nadir after HIFU predicts biochemical DFSR in a statistically significant manner.

High-intensity focused ultrasound for prostate cancer: a systematic review

High-intensity focused ultrasound (HIFU) has recently been promoted as a non-invasive treatment option for prostate cancer. This systematic review sought to evaluate the evidence comparing it with standard treatment in patients with localised prostate cancer. The literature review included searches of MEDLINE, EMBASE, the Cochrane Library, annual meetings' abstracts and websites of evidence-based practice guideline producers. Studies were included if they were randomised controlled trials comparing HIFU with current management approaches, or were meta-analyses, systematic reviews or practice guidelines addressing HIFU. No randomised controlled trials or meta-analyses were identified. Seven systematic reviews and two practice guidelines were identified; neither contained randomised controlled trials. Adjusting the selection criteria to include case series found 34 clinical studies of HIFU. Twenty-nine evaluated HIFU as the primary treatment and five examined HIFU as salvage treatment for recurrence after radiotherapy. In most studies the outcomes used to determine efficacy were negative biopsy rates or prostate-specific antigen (PSA) levels. Among the 29 studies of HIFU as the primary treatment, negative biopsy rates ranged from 35 to 95% in 21 studies, a PSA nadir of ≤0.5 ng/ml ranged from 55 to 91% in 10 studies and mean PSA nadirs ranged from 0 to 1.9 ng/ml in 17 studies. Five studies reported 5-year disease-free survival rates ranging from 55 to 95%. Among five studies of HIFU as salvage treatment, negative biopsy rates ranged from 73 to 84% in four studies, a PSA nadir of ≤0.5 ng/ml ranged from 57 to 66% in three studies and mean PSA nadirs were 1.97 and 2.38 ng/ml in two studies, respectively. Current evidence on HIFU use in prostate cancer patients is of low quality, rendering it difficult to draw conclusions about its efficacy. Until results from case series are confirmed in prospective studies, the widespread use of HIFU is not supported.

Anterior perirectal fat tissue thickness is a strong predictor of recurrence after high-intensity focused ultrasound for prostate cancer

OBJECTIVE

To evaluate if and why obesity affects the clinical outcome in patients undergoing high-intensity focused ultrasound (HIFU) treatment for prostate cancer (CaP).

METHODS

115 patients who underwent HIFU treatment for localized CaP were categorized as obese, overweight or normal according to body mass index (BMI). The thickness of the anterior perirectal fat tissue (APFT) was measured by transrectal ultrasonography. Treatment was considered to have failed in the case of biochemical failure according to the Phoenix definition, positive follow-up biopsy or initiation of salvage therapy. Cox proportional hazards analyses were used to identify possible predictors for disease free survival (DFS), and an experimental fat tissue model was made to evaluate the ablation effect at the target tissue.

RESULTS

According to the classification by the Western Pacific Regional Office of WHO, 43 patients were of normal weight, 24 were overweight and 48 were obese. The BMI groups did not differ in Gleason score, prostate-specific antigen level at diagnosis or clinical stage. There were, however, significant correlations between BMI and prostate-specific antigen nadir (P < 0.001), and BMI and APFT thickness (P < 0.01). Multivariate analyses showed that BMI fails to be an independent predictor of DFS when APFT (P < 0.0001) is included as a variable.

CONCLUSIONS

Our results suggest that APFT thickness, for which obesity could be a useful surrogate, might represent the causative factor for poor clinical outcome after transrectal HIFU treatment for CaP.

High-intensity focused ultrasound: where are we and where to from here?

High-intensity focused ultrasound (HIFU) has evolved significantly from early work treating cerebral lesions. The ability to treat deep soft-tissue lesions without damaging superficial structures led to it being used for prostate cancer treatment both in the primary and salvage setting. Primary HIFU treatment for prostate cancer leads to 5-year disease free survival rates of up to 70-80% in selected patients with little morbidity; however, comparative studies with established treatment modalities are lacking. Salvage treatment with HIFU leads to significantly more morbidity than primary treatment yet the morbidity appears the same or less than other salvage treatments following external-beam radiation treatment. We believe that with the development of more advanced imaging techniques combined with multimodality prostate imaging that HIFU's future lies in focal treatment of prostate cancer.

The clinical applications of high intensity focused ultrasound in the prostate

PURPOSE

To review the current status of high intensity focused ultrasound (HIFU) therapy in the prostate, in particular the treatment of prostate cancer.

MATERIALS AND METHODS

Two trans-rectal devices are currently in clinical use; the SonablateR500 and AblathermR. These devices are compared and similarities and differences highlighted.

RESULTS

Outcomes from the primary treatment of prostate cancer, and HIFU as a salvage therapy are discussed. The rate of adverse events are described after each of these, and the role and safety of other therapies after primary HIFU failure are outlined. Factors which may influence outcome such as use of neo-adjuvant androgen suppression are discussed.

CONCLUSIONS

Trans-rectal HIFU for prostate cancer is a promising technique with medium-term oncological results broadly comparable to standard therapies. It is the only form of therapy which is non-invasive and does not utilise ionising radiation. This is an exiciting field undergoing rapid developments, both in the technology and the way in which prostate cancer as a disease is managed.

High-intensity focused ultrasound and prostate cancer: technology, state of the art and future

Background.

The potential applications of the high-intensity focused ultrasound (HIFU) as a minimally invasive therapy of the localized prostate cancer explain the growing interest of the urologic community towards this technique. HIFU has been assessed for its role in the treatment of localized prostate cancer in patients who otherwise would not have benefited from surgery, and in local recurrences after radiation failure.

Methods.

Relevant information on HIFU treatment was identified through a literature search of published studies.

Results.

High biochemical efficacy, excellent tumor local control and favorable mid- and long-term oncological data with a low morbidity rate have been shown in many series of patients.

Conclusions.

Although HIFU is a recent and emerging technology, it has been well studied and developed to a point that HIFU will undoubtedly be an effective alternative to radiation therapy.

Eight years' experience with high-intensity focused ultrasonography for treatment of localized prostate cancer

OBJECTIVES

To report on the long-term results of high-intensity focused ultrasonography (HIFU) in the treatment of localized prostate cancer.

METHODS

Patients with clinical Stage T1-T2N0M0, biopsy-proven, localized prostate cancer, with a serum prostate-specific antigen (PSA) level of <or=20 ng/mL, Gleason score of <or=7, and with no previous curative prostate cancer treatment, were included. All patients underwent HIFU using the Ablatherm device and were required to have a minimal follow-up of 3 years after the last HIFU session to be included in this analysis. Follow-up included PSA measurement and biopsy performed 3-6 months after treatment and in conjunction with an increasing PSA level. Biochemical failure was defined according to the Phoenix definition (PSA nadir + 2 ng/mL). In determining the disease-free survival rate, treatment was considered to have failed if any of the following occurred: biochemical failure, positive biopsy findings, or the initiation of salvage treatment.

RESULTS

The study included 163 patients. Within the 4.8 +/- 1.2 years of follow-up, no patient died of prostate cancer. Of the 163 patients, 86.4% achieved a PSA nadir of <1 ng/mL and 92.7% had negative post-treatment biopsy findings. The actuarial biochemical survival rate at 5 years was 75%. The actuarial disease-free survival rate at 5 years was 66%, with salvage treatment initiated for 12% of the patients. On multivariate analysis, the pretreatment PSA level was the only statistically significant predictive factor of recurrence (P = .005).

CONCLUSIONS

The results after long-term follow-up have indicated that HIFU is an efficient and safe treatment for patients with localized prostate cancer.

Endorectal magnetic resonance imaging and magnetic resonance spectroscopy to monitor the prostate for residual disease or local cancer recurrence after transrectal high-intensity focused ultrasound

OBJECTIVE

To assess the role of magnetic resonance imaging (MRI) for evaluating changes in the prostate after transrectal high-intensity focused ultrasound (HIFU) for treating prostate cancer, correlating the findings with histology to assess its possible role in predicting the outcome, evaluating residual cancer or local recurrence of disease.

PATIENTS AND METHODS

Ten patients with prostate cancer were assessed with MR and MR spectroscopy (MRS) before and at 1, 4 and 12 months after HIFU, assessing the glandular volume and MRI and MRS data after HIFU. These data were correlated with the prostate-specific antigen (PSA) levels at each examination (suspicious for residual cancer if >0.5 ng/mL) and with histological findings of prostate biopsy sampling at 6-8 months (random or targeted at suspicious MR areas).

RESULTS

Variations in volume during the follow-up were not associated with treatment outcome. MRI was suspicious for residual cancer in one patient at 1 month and in another two at 4 months; in all three patients (one with a PSA level of <0.5 ng/mL) targeted biopsies were positive for cancer. MRI was negative in seven patients; in six of these (one with a PSA level of >0.5 ng/mL) random biopsies were negative, and in one the random biopsies were positive for residual cancer. At 4 months there was a statistically significant difference (P = 0.015) between patients responsive to treatment and those with persistent disease, by combining negative MRI with a PSA level of <0.5 ng/mL; MRS data were suitable for analysis only in three patients with partial necrosis.

CONCLUSION

Our preliminary data support the role of MRI in association with PSA levels as a useful and accurate tool in the follow-up of patients treated with HIFU for prostate cancer. However, considering the economic issue, it should not be used routinely and should be limited to detecting residual cancer (in patients with a PSA level of >0.5 ng/mL) with the main purpose of improving the detection rate of transrectal ultrasonography (TRUS)-guided prostate biopsy. MRS data had no additional value over MRI. Further evaluation is needed to compare the use of contrast media and other techniques (e.g. colour Doppler TRUS) in detecting residual or local recurrent cancer.

High-intensity focused ultrasound in prostate cancer; a systematic literature review of the French Association of Urology

We discuss the efficacy and safety of high-intensity focused ultrasound (HIFU) in patients with prostate cancer, to define the best indications for HIFU in daily clinical practice as primary therapy. We searched Medline and Embase for clinical studies evaluating the efficacy and safety of HIFU in prostate cancer (July 2007), and abstracts presented at the 2005-2007 annual meetings of the European Association of Urology and American Urological Association were screened. In all, 37 articles/abstracts were selected. As the data on HIFU as salvage therapy were limited, we focused on HIFU as primary therapy. Studies consisted of case series only. Included patients were approximately 70 years old with T1-T2 N0M0 disease, Gleason Score <or=7, a prostate-specific antigen (PSA) level of <or=28 ng/mL and a prostate volume of <or=40 mL. Negative biopsy rates with the Ablatherm device (EDAP TMS S.A., Vaulx-en-Velin, France) were 64-93%, and a PSA nadir of <or=0.5 ng/mL was achieved in 55-84% of patients. The 5-year actuarial disease-free survival rates were 60-70%. The most common complications were stress urinary incontinence, urinary tract infection, urethral/bladder neck stenosis or strictures, and erectile dysfunction. For the Ablatherm device, the rate of complications has been significantly reduced over the years, due to technical improvements in the device and the use of transurethral resection of the prostate before HIFU. In conclusion, HIFU as primary therapy for prostate cancer is indicated in older patients (>or=70 years) with T1-T2 N0M0 disease, a Gleason score of <7, a PSA level of <15 ng/mL and a prostate volume of <40 mL. In these patients HIFU achieves short-term cancer control, as shown by a high percentage of negative biopsies and significantly reduced PSA levels. The median-term survival data also seem promising, but long-term follow-up studies are needed to further evaluate cancer-specific and overall survival rates before the indications for primary therapy can be expanded.

PSA Nadir Is a Significant Predictor of Treatment Failure after High-Intensity Focussed Ultrasound (HIFU) Treatment of Localised Prostate Cancer

OBJECTIVES

To assess if prostate-specific antigen (PSA) nadir is an independent predictor of treatment failure and disease-free survival after high-intensity focussed ultrasound (HIFU) therapy for localised prostate cancer as defined by the new ASTRO criteria.

METHODS

One hundred three patients after HIFU treatment (Ablatherm, EDAP, Lyon, France) for localised prostate cancer without previous hormonal therapy were evaluated retrospectively. Patients attended regular follow-up visits every 3 mo. Treatment failure was defined by the revised ASTRO criteria (PSA >or=2 ng/ml above nadir PSA, positive biopsy, if salvage treatment was administered). Patients were divided into three PSA nadir subgroups (group 1, <or=0.2 ng/ml; group 2, 0.21-1 ng/ml; group 3, >1 ng/ml). The disease-free survival rate (DFSR) was calculated by using life table methods. The log-rank test was used to compare the curves based on Kaplan-Meier models.

RESULTS

The median follow-up was 4.9 (3-8.6) yr. Mean time to PSA nadir was 6.4+/-5.1 mo. A PSA nadir of <or=0.2 ng/ml, 0.21-1 ng/ml, and >1ng/ml was reached by 64%, 22.3%, and 13.6% of patients, respectively. Treatment failure rates during follow-up were 4.5%, 30.4%, and 100%, respectively, for the three groups (p<0.001). The actuarial DFSRs at 5 yr were 95%, 55%, and 0%, respectively, for the 3 groups (p<0.001).

CONCLUSIONS

The PSA nadir after HIFU correlates highly significantly with treatment failure and DFSR, and can be applied in daily clinical practice. Promising oncological outcome is obtained if a PSA nadir of <or=0.2 ng/ml is reached.

First analysis of the long-term results with transrectal HIFU in patients with localised prostate cancer

OBJECTIVE

To evaluate the long-term efficacy of high-intensity focused ultrasound (HIFU) therapy for patients with localised prostate cancer.

MATERIAL AND METHODS

Patients included in this multicentre analysis had T1-T2 NxM0 prostate cancer, a PSA<15 ng/ml, and a Gleason score (GS) < or = 7, and were treated with prototypes or first-generation Ablatherm HIFU devices between October 1997 and August 2001. The Phoenix definition of biochemical failure was used (PSA nadir+2). Treatment failure was defined as: biochemical failure or positive biopsy.

RESULTS

A total of 140 patients with a mean (SD) age 69.1 yr (6.6) were included. Mean (SD) follow-up was 6.4 yr (1.1). Control prostate biopsies were negative in 86.4% of patients. Median PSA nadir of 0.16 ng/ml (range, 0.0-9.1) was achieved at a mean (SD) of 4.9 mo (5.2). A PSA nadir < or = 0.5 ng/ml was recorded in 68.4% of patients. The actuarial biochemical failure-free survival rates (SR) at 5 and 7 yr were 77% and 69%, respectively. The actuarial disease-free SR at 5 and 7 yr were 66% and 59%, respectively.

CONCLUSIONS

This study demonstrates the effective long-term cancer control achieved with HIFU in patients with low- or intermediate-risk localised prostate cancer.

High-intensity focused ultrasound (HIFU) for prostate cancer

BACKGROUND

The growing interest in high-intensity focused ultrasound (HIFU) is mainly due to its potential applications as a minimally invasive therapy. HIFU has been assessed for its role in the treatment of localized prostate cancer in patients who otherwise would not have benefited from surgery and in local recurrences after radiation failure.

METHODS

Relevant information on HIFU treatment was identified through a MEDLINE search using specified terms. Papers that presented original outcomes were included in the present review.

RESULTS

High biochemical efficacy, excellent tumor local control and favorable mid-term oncological data with a low morbidity rate have been proven in many series of patients.

CONCLUSIONS

Although HIFU is a recent and emerging technology, it has been well studied and developed to a point that HIFU will undoubtedly be an effective alternative to radiation therapy.

Influence of perfusion on high-intensity focused ultrasound prostate ablation: a first-pass MRI study

Our aim was to evaluate the influence of regional prostate blood flow (rPBF) on high-intensity focused ultrasound (HIFU) treatment outcome. A total of 48 patients with clinically localized prostate cancer were examined by dynamic contrast-enhanced (DCE)-MRI prior to HIFU therapy. A prostate-specific antigen (PSA) nadir threshold of 0.2 ng/ml was used to define the populations of responders and nonresponders. A dedicated tracer kinetic model, namely "monoexponential plus constant" (MPC) deconvolution, was implemented to provide quantitative estimates of rPBF. The results were compared with those obtained by semiquantitative (steepest slope, mean gradient) and quantitative (Fermi deconvolution) approaches. Of the four methods studied, quantitative rPBF obtained by MPC deconvolution proved the most sensitive to the perfusion changes encountered in this study. Furthermore, blood-flow values obtained with MPC deconvolution in the prostate and muscle (12 +/- 8 and 5 +/- 3 ml/min/100 g, respectively) were in good agreement with literature data. The mean pretreatment rPBF obtained with MPC deconvolution was significantly higher in nonresponders compared to responders (16 +/- 9 vs. 10 +/- 6 ml/min/100 g), suggesting a correlation between baseline perfusion and treatment outcome. The present work describes and validates the use of dynamic MRI to estimate rPBF in patients, which in the future may help to refine the conduct of HIFU therapy.

Visually directed high-intensity focused ultrasound for organ-confined prostate cancer: a proposed standard for the conduct of therapy

OBJECTIVE

To propose a standard for the conduct of visually directed transrectal high-intensity focused ultrasound (HIFU) and to offer a formal description of the changes observed on B-mode ultrasonography (US) during this procedure. We describe our early experience of using two different treatment methods; algorithm-based HIFU and visually directed HIFU for the treatment of organ-confined prostate cancer.

PATIENTS AND METHODS

Between November 2004 and October 2005, 34 men were treated using the Sonablate-500 (Focus Surgery, Indianapolis, IN, USA) as primary therapy for T1 or T2 prostate cancer. None had had previous hormone therapy and all had > or = 3-month PSA nadirs recorded at the follow-up. Nine men were treated using an algorithm-based protocol (group 1) and 25 using visually directed therapy (group 2). The conduct of visually directed treatment was described and changes seen using B-mode US were categorized using three 'Uchida' grades. RESULTS The mean PSA nadir achieved in group 2 was 0.15 ng/mL, vs 1.51 ng/mL in group 1 (P < 0.005). In group 2, 21 of 25 men achieved PSA nadirs of < or = 0.2 ng/mL 3 months after treatment. Seven men achieved undetectable PSA values. The occurrence rate of treatment-related toxicity was similar in both groups.

CONCLUSION

Visually directed, transrectal HIFU enables clinically important and statistically significantly lower PSA nadirs to be achieved than algorithm-based HIFU. This is the first reported experience of visually directed HIFU for the treatment of organ-confined prostate cancer. We think that this is the first attempt to standardize the conduct of therapy; such standardization facilitates teaching it, and makes it possible to derive quality standards. The standardization of the conduct of therapy is a key step in the process of health technology assessment.