Prostate high-dose-rate brachytherapy as salvage treatment of local failure after previous external or permanent seed irradiation for prostate cancer

Salvage stereotactic body radiation therapy for locally recurrent prostate cancer following primary radiation therapy, are benefits worth toxicity risks?: A systematic review

INTRODUCTION

Salvage stereotactic body radiation therapy (SBRT) for localized prostate cancer recurrence following radiation therapy remains controversial. We performed a systematic review to assess the efficacy and side effect profile of salvage SBRT for locally recurrent prostate cancer to define the role of salvage SBRT in clinical practice.

METHODS

A systematic review was carried out using Pubmed (MEDLINE) and Scopus databases. Inclusion and exclusion criteria were satisfied if studies reported on patients with prior radiation therapy for prostate cancer who had subsequently had a local recurrence. Those studies included were quality assessed using the ROBINS-I checklist.

RESULTS

Five studies in total met criteria for inclusion and included all reportable outcomes. A total of 265 participants are reported on in total. Median doses for SBRT ranged from 30 to 36 Gy delivered over 5-6 fractions. Recurrence free survival ranged from 40% to 76% at 2 years. Genitourinary toxicity was more prevalent than gastrointestinal toxicities. Grade 2 and 3 genitourinary complication rates ranged from 5% to 22% and 0% to 9%, respectively. Gastrointestinal grade 2 complication rates ranged from 0% to 11% and no grade 3 complications were recorded.

DISCUSSION

Salvage SBRT appears to be comparable and potentially superior in some aspects to other salvage therapies, taking into account the limitations in cross-study comparisons. This systematic review serves as one of the first to characterize SBRT as a salvage option for locally recurrent prostate cancer.

Efficacy and toxicity following salvage high-dose-rate brachytherapy for locally recurrent prostate cancer after radiotherapy

INTRODUCTION

The management of local relapse after prostate cancer radiotherapy is frequently based on androgen deprivation therapy. The aim of the study was to report Gustave Roussy's experience with salvage prostate brachytherapy.

PATIENTS AND METHODS

All cases of localized prostate cancer presenting in an irradiated area who received salvage high dose rate (HDR) brachytherapy from 2013 to 2020 were retrospectively reviewed.

RESULTS

A total of 64 patients were included. Median follow up was 30.5 months. Median initial EBRT dose was 70 Gy [Q1-Q3: 70 - 74]. Median PSA at brachytherapy was 6.8 ng/mL [Q1-Q3: 4.4 - 8.7] with a median interval between first and salvage irradiation of 10 years [Q1-Q3: 6.9 - 12.6]. The modality of the first irradiation was an exclusive EBRT in 73% of the cases, mostly with a 3D technique (82%). Dose prescription was two fractions of 12 Gy or 13 Gy associated with androgen deprivation therapy for 63% of the patients. About 23% of the patients were castrate-resistant. Disease free survival at 2 years was 58% in the whole population and 66% in hormone sensitive patients. The only factors associated with disease free survival on multivariate analysis was a high-risk disease at initial diagnosis (HR = 3.59, IC95 [1.75; 7.39], p = 0.0005). Grade 3 urinary and rectal toxicities occurred in 1.5% and 1.5% of the patients, respectively.

CONCLUSION

HDR salvage brachytherapy seems to be a safe option for patients presenting with an isolated local relapse of prostate cancer.

High-dose-rate brachytherapy for prostate cancer: Rationale, current applications, and clinical outcome

Background

High‐dose‐rate brachytherapy (HDR BRT) has been enjoying rapid acceptance as a treatment modality offered to selected prostate cancer patients devoid of risk group, employed either in monotherapy setting or combined with external beam radiation therapy (EBRT) and is currently one of the most active clinical research areas.

Recent findings

This review encompasses all the current evidence to support the use of HDR BRT in various clinical scenario and shines light to the HDR BRT rationale, as an ultimately conformal dose delivery method enabling safe dose escalation to the prostate.

Conclusion

Valid long‐term data, both in regard to the oncologic outcomes and toxicity profile, support the current clinical indication spectrum of HDR BRT. At the same time, this serves as solid, rigid ground for emerging therapeutic applications, allowing the technique to remain in the spotlight alongside stereotactic radiosurgery.

The role of salvage brachytherapy for local relapse after external beam radiotherapy for prostate cancer

Prostate cancer is the most prevalent cancer amongst men. For localized disease, there currently exist several reliable treatment modalities including surgery, radiotherapy and brachytherapy. Our growing understanding of this disease indicates that local control plays a very important role in prevention of subsequent dissemination. Many improvements to external beam radiotherapy over recent years have decreased toxicity and improved outcomes, but nonetheless, local relapse remains common. Many salvage options exist for locally recurrent prostate cancer, but are rarely offered, partly because of the fear of toxicity. Many men with isolated local recurrence therefore do not receive potentially curative second line treatment and are instead treated with palliative androgen suppression. Selection plays an important role in determining which individuals are likely to benefit from salvage. Those at high risk of pre-existing micro-metastatic disease despite negative staging scans are unlikely to benefit. Prostate brachytherapy has evolved over the more than 3 decades of experience. Modern techniques allow more precise tumor localization and dose delivery. Better understanding of dosimetric parameters can distinguish optimal from suboptimal implants. Salvage brachytherapy can be an effective treatment for locally recurrent prostate cancer after prior external beam radiotherapy. We review the literature pertaining to both low dose rate (LDR) and high dose rate (HDR) salvage brachytherapy and discuss patient selection, optimal dose, treatment volume and toxicity avoidance.

Salvage High Dose Rate Brachytherapy after Primary External Beam Irradiation in Localized Prostate Cancer: A Case Report

No standard treatment exists for locally relapsed prostate cancer after primary external beam radiotherapy with no evidence of distant metastases. Radical prostatectomy, brachytherapy, cryotherapy and high-intensity focused ultrasound are currently used as local salvage treatments. Data on the safety and effectiveness of high dose rate (HDR) brachytherapy in this scenario are limited. We report on a patient who has no evidence of disease and no late urinary or gastrointestinal toxicity 33 months after receiving HDR treatment for recurrent prostate cancer.

Image-Guided Robotic Radiosurgery as Salvage Therapy for Locally Recurrent Prostate Cancer after External Beam Irradiation: Retrospective Feasibility Study on Six Cases

Aims and background

Technological advances in treatment planning and execution are providing new potential opportunities in the treatment of recurrent prostate cancer. This study was conducted to evaluate the feasibility and safety of reirradiation with image-guided radiosurgery using CyberKnife, a robotic arm-driven compact linear accelerator, for intraprostatic recurrence after external beam radiotherapy (EBRT).

Methods

Between September 2007 and May 2008, 6 patients diagnosed with locally recurrent prostate cancer after EBRT were treated using the CyberKnife system. The total reirradiation dose was 30 Gy in five fractions. Prior to radiosurgery four patients were treated with androgen-deprivation therapy. Radiation Therapy Oncology Group/European Organization for Research and Treatment of Cancer criteria and the Houston-Phoenix definition (PSA nadir + 2 ng/mL) were used for toxicity and biochemical failure evaluation, respectively.

Results

After a median follow-up of 11.2 months (range, 9.6–18.6 months), all patients are alive with no evidence of severe urinary or rectal acute morbidity. Local control cannot be exactly determined due to the short follow-up and the bias of the use of androgen ablation. Four patients had biochemical failure, three of them with clinical failure evidence (lymph node, bone and lung metastasis, respectively): none of these patients had clinical evidence of tumor persistence in the prostate.

Conclusions

Salvage radiosurgery with CyberKnife after irradiation is feasible with low urinary and rectal morbidity. A longer follow-up and a larger number of patients are necessary to evaluate its effectiveness and optimal patient selection criteria.

The evolution of brachytherapy for prostate cancer

Brachytherapy (BT), using low-dose-rate (LDR) permanent seed implantation or high-dose-rate (HDR) temporary source implantation, is an acceptable treatment option for select patients with prostate cancer of any risk group. The benefits of HDR-BT over LDR-BT include the ability to use the same source for other cancers, lower operator dependence, and - typically - fewer acute irritative symptoms. By contrast, the benefits of LDR-BT include more favourable scheduling logistics, lower initial capital equipment costs, no need for a shielded room, completion in a single implant, and more robust data from clinical trials. Prospective reports comparing HDR-BT and LDR-BT to each other or to other treatment options (such as external beam radiotherapy (EBRT) or surgery) suggest similar outcomes. The 5-year freedom from biochemical failure rates for patients with low-risk, intermediate-risk, and high-risk disease are >85%, 69-97%, and 63-80%, respectively. Brachytherapy with EBRT (versus brachytherapy alone) is an appropriate approach in select patients with intermediate-risk and high-risk disease. The 10-year rates of overall survival, distant metastasis, and cancer-specific mortality are >85%, <10%, and <5%, respectively. Grade 3-4 toxicities associated with HDR-BT and LDR-BT are rare, at <4% in most series, and quality of life is improved in patients who receive brachytherapy compared with those who undergo surgery.

High-dose-rate brachytherapy as salvage modality for locally recurrent prostate cancer after definitive radiotherapy : A systematic review

PURPOSE

To review the current status of interstitial high-dose-rate brachytherapy as a salvage modality (sHDR BRT) for locally recurrent prostate cancer after definitive radiotherapy (RT).

MATERIALS AND METHODS

A literature search was performed in PubMed using "high-dose-rate, brachytherapy, prostate cancer, salvage" as search terms. In all, 51 search results published between 2000 and 2016 were identified. Data tables were generated and summary descriptions created. The main outcome parameters used were biochemical control (BC) and toxicity scores.

RESULTS

Eleven publications reported clinical outcome and toxicity with follow-up ranging from 4-191 months. A variety of dose and fractionation schedules were described, including 19.0 Gy in 2 fractions up to 42.0 Gy in 6 fractions. The 5‑year BC ranged from 18-77%. Late grade 3 genitourinary and gastrointestinal toxicity was 0-32% and 0-5.1%, respectively.

CONCLUSIONS

sHDR BRT appears as safe and effective salvage modality for the reirradiation of locally recurrent prostate cancer after definitive RT.

Salvage prostate re-irradiation using high-dose-rate brachytherapy or focal stereotactic body radiotherapy for local recurrence after definitive radiation therapy

Background

Optimal management of locally recurrent prostate cancer after definitive radiation therapy is still challenging. With the development of highly accurate radiotherapy devices, prostate salvage re-irradiation might generate lower toxicity rates than classical salvage therapies. We retrospectively evaluated the toxicity and the feasibility of a prostate re-irradiation after definitive radiation therapy failure. Two modalities were investigated: high-dose-rate brachytherapy (HDRB) on whole prostate gland and focal stereotactic radiotherapy (SBRT) using CyberKnife® linac.

Methods

Between 2011 and 2015, 28 patients with imaged and/or biopsy-proven intra-prostatic recurrence of cancer after definitive radiation therapy underwent a salvage re-irradiation using HDRB (n = 10) or focal SBRT (n = 18). The schedule of re-irradiation was 35 Gy in 5 fractions.

Biological response (defined as post-salvage radiation PSA variation) and biochemical no-evidence of disease (bNED) were evaluated in the whole cohort. For patients who had a positive biological response after salvage radiation, biochemical recurrence (BCR) and survival after salvage radiotherapy were evaluated. Post-salvage toxicities were assessed according to the Common Terminology Criteria for Adverse Events (CTCAE) v4.03 and were compared to baseline status.

Results

Within a median follow-up of 22.5 months (IQR = 8–42), 9 (90%) patients experienced a positive biological response after salvage HDRB and 5 (50%) remained bNED at the end of the follow-up. Among patients who initially responded to salvage HDRB, the BCR rate was 44.4% after a median interval of 19.5 months (IQR = 11.5–26). Only one patient experienced a transient grade 3 urinary complication.

In the SBRT group, the median follow-up was 14.5 months (IQR = 7–23) and 10 (55.6%) out of the 18 patients remained bNED. Among the 15 patients who initially responded to salvage SBRT, 5 (33.3%) experienced a BCR. One patient experienced a transient grade 4 urinary complication.

At the end of the follow-up, all evaluated patients had a urinary status grade variation ≤ +1 grade. No grade 3–4 digestive toxicity was observed.

Conclusions

Salvage prostate re-irradiation for locally recurrent cancer is feasible and generate low toxicities rates when using with HDRB or focal SBRT. However, further investigations are necessary to confirm these findings and to determine predictive features for patients who might benefit from such an approach.

Salvage high-dose-rate brachytherapy for locally recurrent prostate cancer after primary radiotherapy failure

BACKGROUND AND PURPOSE

To evaluate high-dose-rate brachytherapy (HDR BT) as a salvage modality for locally recurrent prostate cancer after primary radiotherapy failure.

MATERIALS AND METHODS

Eighty-three prostate cancer patients, who locally relapsed after radiotherapy, were treated with salvage HDR BT. The schedule was three implantations, every two weeks, with 10Gy per implant, to a total dose of 30Gy. Acute and late toxicity rates were evaluated. Overall survival (OS) and biochemical control were calculated using Kaplan-Meier method.

RESULTS

Median follow-up after salvage HDR was 41months. The 3-year and 5-year OS were 93% and 86%, respectively. The 3-year and 5-year biochemical disease-free survival (bDFS) were 76% and 67%, respectively. The single factor associated with biochemical control was time to achieve salvage PSA nadir (p-.006). OS was linked significantly with primary nadir level (p-.001) while primary biochemical relapse interval was of borderline significance (p-.07).

CONCLUSIONS

Salvage HDR BT is a promising treatment option for patients with localized relapse of previously irradiated prostate cancer. Lower PSA nadir after primary radiotherapy and longer primary disease-free interval influence the outcome.

Salvage Brachytherapy for Biochemically Recurrent Prostate Cancer following Primary Brachytherapy

Purpose. In this study, we evaluated our experience with salvage brachytherapy after discovery of biochemical recurrence after a prior brachytherapy procedure. Methods and Materials. From 2001 through 2012 twenty-one patients treated by brachytherapy within University of Kentucky or from outside centers developed biochemical failure and had no evidence of metastases. Computed tomography (CT) scans were evaluated; patients who had an underseeded portion of their prostate were considered for reimplantation. Results. The majority of the patients in this study (61.9%) were low risk and median presalvage PSA was 3.49 (range 17.41-1.68). Mean follow-up was 61 months. At last follow-up after reseeding, 11/21 (52.4%) were free of biochemical recurrence. There was a trend towards decreased freedom from biochemical recurrence in low risk patients (p = 0.12). International Prostate Symptom Scores (IPSS) increased at 3-month follow-up visits but decreased and were equivalent to baseline scores at 18 months. Conclusions. Salvage brachytherapy after primary brachytherapy is possible; however, in our experience the side-effect profile after the second brachytherapy procedure was higher than after the first brachytherapy procedure. In this cohort of patients we demonstrate that approximately 50% oncologic control, low risk patients appear to have better outcomes than others.

Comparative Oncologic and Toxicity Outcomes of Salvage Radical Prostatectomy Versus Nonsurgical Therapies for Radiorecurrent Prostate Cancer: A Meta-Regression Analysis

CONTEXT

In the absence of randomised controlled trials comparing the oncologic, toxicity, and functional outcomes of salvage radical prostatectomy (SRP), salvage high-intensity focused ultrasound (SHIFU), salvage brachytherapy (SBT), and salvage cryotherapy (SCT), controversy exists as to the optimal salvage modality in radiorecurrent prostate cancer.

OBJECTIVE

We carried out a meta-regression analysis to determine whether there is a difference in oncologic, toxicity, and functional outcomes using data from original publications of salvage modalities in the postradiation setting.

EVIDENCE ACQUISITION

We performed a systematic review of PubMed/Medline citations according to the Preferred Reporting Items for Systematic Review and Meta-analysis (PRISMA) statement. We included 63 articles in the analysis (25 on SRP, 8 on SHIFU, 16 on SCT, 14 on SBT).

EVIDENCE SYNTHESIS

Median values of the following variables were extracted from each study: patient age, length of follow-up, prostate-specific antigen (PSA) before radiotherapy (RT), PSA before salvage therapy, Gleason score before RT, and time interval between RT and salvage therapy. Functional, toxicity, and oncologic outcomes were measured according to rates of impotence, incontinence, fistula formation, urethral strictures, and biochemical recurrence. Meta-regression adjusting for confounders found no significant difference in oncologic outcomes between SRP and nonsurgical salvage modalities. SBT, SCT, and SHIFU appeared to have better continence outcomes than SRP. No significant difference in toxicity outcomes between modalities was found, although limitations such as reporting, selection, and publication bias and between-study heterogeneity must also be considered with these conclusions.

CONCLUSIONS

Oncologic outcomes are comparable for SRP and all three nonsurgical salvage modalities. We found no significant differences in toxicity outcomes among modalities; however, SRP appears to be associated with worse rates of urinary incontinence than SBT, SCT, and SHIFU.

PATIENT SUMMARY

We performed a meta-regression analysis to compare oncologic, functional, and toxicity outcomes between salvage radical prostatectomy and nonsurgical salvage modalities. Oncologic and toxicity outcomes appear to be similar; however, all nonsurgical salvage modalities may be associated with better continence outcomes.

Focal radiotherapy as focal therapy of prostate cancer

PURPOSE OF REVIEW

Focal radiotherapy treatment procedures play an increasingly important role in function-preservation and organ-preservation treatment techniques. As an alternative to traditional whole-gland radiotherapy regimes, focal prostate radiotherapy may be of benefit for both primary tumor as well as locally recurrent disease. This is a review of the current literature on the topic, including patient selection, preliminary toxicity, and outcome data as well as a technical overview on treatment delivery techniques.

RECENT FINDINGS

Partial organ treatment in early prostate cancer (PCa) is now technically feasible with both newer external-beam and brachytherapy technology. To date, only small and generally monoinstitutional series have been published in the literature. Early feasibility and toxicity data are encouraging, and demonstrate potential advantages for the role of focal brachytherapy in early PCa. Although some advanced external-beam techniques can also be used to deliver focal therapy within the prostate, there is no relevant publication in the literature.

SUMMARY

Radiotherapy, especially interventional radiotherapy (brachytherapy), is a technically feasible treatment technique to deliver focal radiotherapy for PCa. To date, only preliminary results are available for all forms of interventional radiotherapy (high dose rate, low dose rate, and pulsed dose rate) for focal PCa treatment and no large cohort comparative results are published. As interventional radiotherapy (brachytherapy) as yet lacks any such long-term studies, comparative outcome data are not available to suggest differences in efficacy for one form of brachytherapy or another.

Salvage brachytherapy in prostate local recurrence after radiation therapy: predicting factors for control and toxicity

Purpose

To evaluate efficacy and toxicity after salvage brachytherapy (BT) in prostate local recurrence after radiation therapy.

Methods and materials

Between 1993 and 2007, we retrospectively analyzed 56 consecutively patients (pts) undergoing salvage brachytherapy. After local biopsy-proven recurrence, pts received 145 Gy LDR-BT (37 pts, 66%) or HDR-BT (19 pts, 34%) in different dose levels according to biological equivalent doses (BED_{2 Gy}). By the time of salvage BT, only 15 pts (27%) received ADT. Univariate and multivariate analyses were performed to identify predictors of biochemical control and toxicities. Acute and late genitourinary (GU) and gastrointestinal (GI) toxicities were graded using Common Terminology Criteria for Adverse Events (CTCv3.0).

Results

Median follow-up after salvage BT was 48 months. The 5-year FFbF was 77%. HDR and LDR late grade 3 GU toxicities were observed in 21% and 24%. Late grade 3 GI toxicities were observed in 2% (HDR) and 2.7% (LDR). On univariate analysis, pre-salvage prostate-specific antigen (PSA) > 10 ng/ml (p = 0.004), interval to relapse after initial treatment < 24 months (p = 0.004) and salvage HDR-BT doses BED_{2 Gy} level < 227 Gy (p = 0.012) were significant in predicting biochemical failure. On Cox multivariate analysis, pre-salvage PSA, and time to relapse were significant in predicting biochemical failure.

HDR-BT BED_{2 Gy} (α/β 1.5 Gy) levels ≥ 227 (p = 0.013), and ADT (p = 0.049) were significant in predicting grade ≥ 2 urinary toxicity.

Conclusions

Prostate BT is an effective salvage modality in some selected prostate local recurrence patients after radiation therapy. Even, we provide some potential predictors of biochemical control and toxicity for prostate salvage BT, further investigation is recommended.

Salvage prostate HDR brachytherapy combined with interstitial hyperthermia for local recurrence after radiation therapy failure

PURPOSE

The aim of the present retrospective study is to evaluate toxicity and early clinical outcomes of interstitial hyperthermia (IHT) combined with high-dose rate (HDR) brachytherapy as a salvage treatment in patients with biopsy-confirmed local recurrence of prostate cancer after previous external beam radiotherapy.

PATIENTS AND METHODS

Between September 2008 and March 2013, 25 patients with local recurrence of previously irradiated prostate cancer were treated. The main eligibility criteria for salvage prostate HDR brachytherapy combined with interstitial hyperthermia were biopsy confirmed local recurrence and absence of nodal and distant metastases. All patients were treated with a dose of 30 Gy in 3 fractions at 21-day intervals. We performed 62 hyperthermia procedures out of 75 planned (83 %). The aim of the hyperthermia treatment was to heat the prostate to 41-43 °C for 60 min. Toxicity for the organs of the genitourinary system and rectum was assessed according to the Common Terminology Criteria for Adverse Events (CTCAE, v. 4.03). Determination of subsequent biochemical failure was based on the Phoenix definition (nadir + 2 ng/ml).

RESULTS

The median age was 71 years (range 62-83 years), the median initial PSA level was 16.3 ng/ml (range 6.37-64 ng/ml), and the median salvage PSA level was 2.8 ng/ml (1.044-25.346 ng/ml). The median follow-up was 13 months (range 4-48 months). The combination of HDR brachytherapy and IHT was well tolerated. The most frequent complications were nocturia, weak urine stream, urinary frequency, hematuria, and urgency. Grade 2 rectal hemorrhage was observed in 1 patient. No grade 3 or higher complications were observed. The 2-year Kaplan-Meier estimate of biochemical control after salvage treatment was 74 %. The PSA in 20 patients decreased below the presalvage level, while 11 patients achieved a PSA nadir < 0.5 ng/ml. All patients are still alive. Of the 7 patients who experienced biochemical failure, bone metastases were found in 2 patients.

CONCLUSION

IHT in combination with salvage HDR brachytherapy is a well tolerated and effective treatment.

Survey of high-dose-rate prostate brachytherapy practice in Australia and New Zealand, 2010-2011

INTRODUCTION

A survey was designed to establish a baseline data set for the current routine practice of high-dose-rate prostate brachytherapy (HDR-PB) in Australia and New Zealand. Existing treatment protocols and clinical implementations are not generally known.

METHODS

The survey, for the 2010 and 2011 calendar years, collected data including number of patients treated; equipment used; imaging modalities; applicator verification and correction methods; dose prescriptions and normal tissue dose constraints. The number of HDR-PB patients treated was compared with the most recently published prostate cancer incidence data in Australia and in New Zealand. Total biologically equivalent doses in 2.0 Gy fractions (EQD2) were calculated for each prescription regime reported.

RESULTS

There were reductions, of 25-60%, in patients treated with HDR-PB from 2010 to 2011 in four departments. Prostate cancer patients are two to six times more likely to be prescribed HDR-PB in Western Australia than elsewhere in the region. There were 12 different treatment prescriptions, with EQD2 doses ranging from 73.5 to 97.6 Gy, among the 18 reported by survey respondents. Normal tissue definition methodology and dose constraints varied, and 13 of 15 departments reported that no particular published external guidelines were followed in full.

CONCLUSION

The high survey response rate, 15 of 17 departments, has provided a representative baseline data set of contemporary HDR-PB practice in Australia and New Zealand that may assist government and professional bodies, such as the Australasian Brachytherapy Group, in formulating recommendations, setting standards and future planning.

American Brachytherapy Society consensus guidelines for high-dose-rate prostate brachytherapy

PURPOSE

A well-established body of literature supports the use of high-dose-rate (HDR) brachytherapy as definitive treatment for localized prostate cancer. Most of the articles describe HDR as a boost with adjuvant external beam radiation, but there is a growing experience with HDR monotherapy.

METHODS AND MATERIALS

The American Brachytherapy Society has convened a group of expert practitioners and physicists to develop guidelines for the use of HDR in the management of prostate cancer. This involved an extensive literature review and input from an expert panel.

RESULTS

Despite a wide variation in doses and fractionation reported, HDR brachytherapy provides biochemical control rates of 85-100%, 81-100%, and 43-93% for low-, intermediate-, and high-risk prostate cancers, respectively. Severe toxicity is rare, with most authors reporting less than 5% Grade 3 or higher toxicity. Careful attention to patient evaluation for appropriate patient selection, meticulous technique, treatment planning, and delivery are essential for successful treatment.

CONCLUSION

The clinical outcomes for HDR are excellent, with high rates of biochemical control, even for high-risk disease, with low morbidity. HDR monotherapy, both for primary treatment and salvage, are promising treatment modalities.

Imaging techniques for local recurrence of prostate cancer: for whom, why and how?

Since there are salvage solutions, it is important to detect local recurrence of prostate cancer as early as possible. The first sign is "biochemical failure" in that the prostate specific antigen (PSA) concentration rises again. The definition of biochemical failure varies depending on the initial treatment: PSA greater than 0.2ng/mL after prostatectomy, nadir+2ng/mL after radiotherapy. There is no standardised definition of biochemical failure after cryotherapy, focused ultrasound, or brachytherapy. Magnetic resonance imaging (MRI) (particularly dynamic MRI) can detect local recurrence with good sensitivity. The role of spectroscopy is still under discussion. For the moment, ultrasound techniques are less effective than MRI.

MR imaging of treated prostate cancer

Many management options are available to patients with newly diagnosed prostate cancer. Magnetic resonance (MR) imaging plays an important role in initial staging of prostate cancer, but it also aids in tumor detection when there is clinical or biochemical suspicion of residual or recurrent disease after treatment. The purpose of this review is to describe the normal appearances of the prostatic region after different kinds of treatment for prostate cancer and to discuss how these appearances differ from those of recurrent and residual disease. Several MR imaging techniques used in evaluating patients with prostate cancer are described, including conventional MR imaging sequences (mainly T1- and T2-weighted sequences), MR spectroscopic imaging, diffusion-weighted imaging, and dynamic contrast agent-enhanced MR imaging. Clinical considerations, together with the different approaches for interpreting serum prostate-specific antigen values in the posttreatment setting, are also presented. All forms of treatment alter the MR imaging features of the prostatic region to a greater or lesser extent, and it is important to be able to recognize expected posttreatment appearances and distinguish them from the features of recurrent or residual cancer to aid subsequent clinical management.

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 as salvage therapy for patients with recurrent prostate cancer after external beam radiation, brachytherapy or proton therapy

OBJECTIVE

To investigate the use of high-intensity focused ultrasound (HIFU) as a salvage therapy in patients with recurrence of localized prostate cancer after external beam radiation (EBRT), brachytherapy, or proton therapy.

PATIENTS AND METHODS

We retrospectively reviewed the charts of all patients who had undergone salvage HIFU for biopsy-proven prostate cancer after primary radiation therapy. Patient characteristics and oncological outcomes were assessed.

RESULTS

Records of 22 patients with a median (range) follow-up of 24 (5-80) months were reviewed. Patients were men with presumed organ-confined disease who had been treated with salvage HIFU following recurrent disease after EBRT (fourteen patients), brachytherapy (five patients: four with high-dose brachytherapy using In(192) ; and one with low-dose brachytherapy using Au(98) ) or proton therapy (three patients). The median (range) age at salvage HIFU was 65 (52-80) years, with a median (range) prostate-specific antigen (PSA) level before radiation therapy of 14.3 (5.7-118) ng/mL and a median (range) PSA level of 4.0 (1.2-30.1) ng/mL before HIFU. The median (range) period to HIFU after radiation therapy was 36 (4-96) months. The biochemical disease-free survival (bDFS) rate in all patients at 5 years was 52%. Rates of bDFS in low-, intermediate- and high-risk groups were 100%, 86%, and 14%, respectively. One of the twelve patients who received post-HIFU prostate biopsy showed malignancy. Side effects included urethral stricture in four patients, grade I urinary incontinence in four patients, rectourethral fistula and epididymitis in one of each patient.

CONCLUSION

Salvage HIFU is a promising treatment option for local recurrence after radiation therapy, with morbidity comparable with other forms of salvage treatment.

[Which modality for prostate brachytherapy?]

Brachytherapy techniques by permanent implant of radioactive sources or by temporary high-dose-rate (HDR) fractions are nowadays extensively used for the treatment of prostatic carcinoma. Long-term results (at 20 years) concerning large amount of patients have been published by major centers confirming both in terms of efficacy and toxicities that permanent implant of radioactive iodine-125 seeds yields at least the same good results of surgery and of external beam irradiation when proposed to patients affected by low-risk disease. For intermediate to high-risk tumors, HDR temporary implants are proposed as a boost for dose escalation. For both techniques, several topics still need to be clarified dealing with a recent enlargement of indications (HDR alone for low-risk, iodine-125 seeds boost for intermediate-high-risk cancers), or with technical aspects (loose seeds versus linked ones, number of fractions and dose for HDR protocols), while dosimetric issues have only recently been addressed by cooperatives groups. Last but not least, there is a real need to address and clearly characterize the correct definition of biochemical disease control both for iodine permanent implant and for HDR implant. New challenges are facing the prostate-brachytherapy community in the near future: local relapse after external beam radiotherapy are currently managed by several salvage treatments (prostatectomy, cryo, high intensity focused ultrasounds [HIFU]) but the role of reirradiation by brachytherapy is also actively investigated. Focal therapy has gained considerable interest in the last 5 years aiming at treating only the area of cancer foci inside the prostate and preserving nearby healthy tissues. Encouraging results have been obtained with the so-called "minimally invasive" approaches and both permanent seed implantation and HDR brachytherapy techniques may be worthwhile testing in this setting because of their capability of exactly sculpting the dose inside the prostatic gland.

Current salvage methods for recurrent prostate cancer after failure of primary radiotherapy

We reviewed the current salvage methods for patients with local recurrent prostate cancer after primary radiotherapy (RT), using a search of relevant Medline/PubMed articles published from 1982 to 2008, with the following search terms: 'radiorecurrent prostate cancer, local salvage treatment, salvage radical prostatectomy (RP), salvage cryoablation, salvage brachytherapy, salvage high-intensity focused ultrasound (HIFU)', and permutations of the above. Only articles written in English were included. The objectives of this review were to analyse the eligibility criteria for careful selection of appropriate patients and to evaluate the oncological results and complications for each method. There are four whole-gland re-treatment options (salvage RP, salvage cryoablation, salvage brachytherapy, salvage HIFU) for RT failure, although others might be in development or investigations. Salvage RP has the longest follow-up with acceptable oncological results, but it is a challenging technique with a high complication rate. Salvage cryoablation is a feasible option, especially using third-generation technology, whereby the average biochemical disease-free survival rate is 50-70% and there are fewer occurrences of severe complications such as recto-urethral fistula. Salvage brachytherapy, with short-term cancer control, is comparable to other salvage methods but depends on cumulative dosage limitation to target tissues. HIFU is a relatively recent option in the salvage setting. Both salvage brachytherapy and HIFU require more detailed studies with intermediate and long-term follow-up. As these are not prospective, randomized studies and the definitions of biochemical failure varied, there are limited comparisons among these different salvage methods, including efficacy. In the focal therapy salvage setting, the increased use of thermoablative methods for eligible patients might contribute to reducing complications and maintaining quality of life. The problem to effectively salvage patients with locally recurrent disease after RT is the lack of diagnostic examinations with sufficient sensitivity and specificity to detect local recurrence at an early curable stage. Therefore, a more strict definition of biochemical failure, improved imaging techniques, and accurate specimen mapping are needed as diagnostic tools. Furthermore, universal selection criteria and an integrated definition of biochemical failure for all salvage methods are required to determine which provides the best oncological efficacy and least comorbidity.