Patient selection for salvage cryotherapy for locally recurrent prostate cancer after radiation therapy

The history of cryosurgery in Canada: A tale of two cities

Although not commonly available in Canada, cryosurgery (cryoablation) for prostate cancer has been practiced in many countries. The field of cryoablation has evolved significantly over the past 30 years. Two prostate cryoablation programs were started in Canada in the early 1990s, in London, ON and Calgary, AB, focusing, respectively, on salvage therapy following radiation failure and primary local treatment. This article chronicles the development of the two programs and outlines the scientific and clinical contributions by investigators at the two centers.

Salvage Cryoablation for Radiorecurrent Prostate Cancer: Initial Experience at a Regional Health Care System

CONTEXT

Local recurrence after radiotherapy for prostate cancer remains challenging to treat effectively. Although oncologic control is highest with salvage prostatectomy, the procedure is associated with substantial morbidity.

OBJECTIVE

To identify factors associated with successful salvage cryoablation for radiorecurrent prostate cancer.

DESIGN

We retrospectively reviewed the medical records of patients who underwent salvage cryoablation at our institution between 2005 and 2015. All patients had biopsy-proven local recurrence after radiotherapy. Patients with seminal vesicle invasion or metastases were excluded. Complete follow-up was obtained for all patients.

MAIN OUTCOME MEASURES

Primary study endpoint was biochemical progression-free survival based on the Phoenix criteria.

RESULTS

Seventy-five patients underwent salvage cryotherapy. Mean patient age was 69.3 years. The overall biochemical salvage rate was 50.7% at a median follow-up of 3.9 years. The following factors were independently associated with successful cryotherapy: Precryotherapy Gleason score of 3 + 3 or 3 + 4, low precryotherapy prostate-specific antigen (PSA), low precryotherapy PSA density, longer time to PSA nadir after radiotherapy, and low postcryotherapy PSA nadir. A postcryotherapy PSA nadir of 0.5 ng/mL or less was associated with a biochemical progression-free survival of 79.7% at 3 years and 64.7% at 5 years, whereas a postcryotherapy PSA nadir above 0.5 was associated with a biochemical progression-free survival of 5.6% at 3 years and 0% at 5 years (p < 0.0001).

CONCLUSION

Approximately 50% of the patients achieved biochemical salvage with cryoablation at 5 years. Nadir PSA after salvage was the strongest predictor of biochemical progression-free survival in our cohort.

Current Status of Salvage Cryoablation for Prostate Cancer following Radiation Failure

The role of salvage cryoablation of the prostate for patients with clinically localized prostate cancer that have failed radiotherapy to the prostate is reviewed with reference to alternatives including salvage radical prostatectomy and brachytherapy. The diagnosis and work-up of local recurrence/persistence of cancer in the prostate are reviewed and the patient selection criteria for salvage cryoablation is discussed. Technical aspects of the cryoablation procedure along with the outcome in terms of cancer control and treatment-related complications are detailed. The five-year biochemical disease-free rate is approximately 40%. The complication rate is acceptable. Salvage cryoablation definitely has a role in the management of localized prostate cancer treatment failure following radiotherapy, especially in older patients and those with some comorbidities.

Cryosurgery would be An Effective Option for Clinically Localized Prostate Cancer: A Meta-analysis and Systematic Review

Cryosurgery (CS) has been used on patients with clinically localized PCa for more than 10 years. However, clinical studies evaluating its effectiveness and safety have reported conflicting results. This systematic assessment was performed to obtain comprehensive evidence regarding the potential benefits and safety of CS compared with those of radiotherapy (RT) and radical prostatectomy (RP), respectively. All controlled trials comparing CS with RT or RP and single-arm studies reporting results of CS therapy were identified through comprehensive searches of PubMed, the Cochrane Library and Embase. Ten publications from seven trials, with totally 1252 patients, were included in the meta-analysis, which revealed no significant differences in comparisons of CS vs RT and CS vs RP for overall survival and disease specific survival. However, a significantly lower disease-free survival could be observed for CS than RP. Moreover, a systematic review of literature focusing on comparative data of databases and materials of single-arm trials revealed satisfactory survival results in both primary and salvage CS. Our results showed that cryosurgery would be a relatively effective method for clinically localized prostate cancer with survival results comparable to radiotherapy and radical prostatectomy. However, the large percentage of complications caused by cryosurgery should be carefully monitored.

Population-based comparative effectiveness of salvage radical prostatectomy vs cryotherapy

OBJECTIVE

To characterize population-based practice patterns, disease-specific and overall mortality, and cost associated with salvage cryotherapy (SCT) vs salvage radical prostatectomy (SRP).

METHODS

We retrospectively identified 440 men who failed primary radiation therapy and subsequently underwent SCT (n = 341, 77.5%) or SRP (n = 99, 22.5%) between 1992 and 2009 from Surveillance, Epidemiology, and End Results-Medicare linked data. Propensity score analyses were used to compare overall and prostate cancer-specific mortality and associated Medicare expenditures for SRP vs SCT.

RESULTS

Men undergoing SCT were more likely to be white (P <.001), less likely to be high school graduates (P = .008), and experienced shorter median time from diagnosis to salvage therapy (44.1 vs 60.1, P <.001) and from primary radiotherapy to salvage therapy (38.7 vs 55.8 months, P <.001). In adjusted analyses, overall mortality was higher (21.6 vs 6.1 deaths/100 person years, P <.001) for SRP vs SCT. There was a trend for higher prostate cancer-specific death rates with SRP vs SCT (6.5 vs 1.4 deaths/100 person years, P = .061). Medicare expenditures for SRP vs SCT were more than 2-fold higher ($19,543 vs $8,088, P <.001).

CONCLUSION

SRP vs SCT is associated with higher overall mortality and greater health care expenditures. However, longer follow-up is needed to assess long-term functional outcomes and cancer control.

Focal salvage therapy for locally recurrent prostate cancer: a review

Objectives: To evaluate the current status of focal therapy as the salvage treatment option for patients with recurrent prostate cancer after established therapy (radiation, surgery) failure for localized tumor.
Methods: A MedLine search using specified search terms was done on December 23, 2011. This research rendered 346 papers related to High-Intensity Focused Ultrasound (HIFU), 644 papers related to cryosurgery, 180 related to photodynamic therapy and 3 articles related to radio frequency ablation. Very few of these papers presented original outcome data and are included in the present review.
Results: No controlled trial was available for analysis. 
Conclusions: Salvage HIFU in patients with local recurrence of prostate cancer after radical EBRT indicate is a reasonable treatment option, but better patient selection criteria are needed. It is a promising treatment option for local recurrence after radiation therapy, with morbidity comparable with other forms of salvage treatment. The side effects are not negligible but comparable with other forms of salvage treatment. Photodynamic therapy is a new option that could be suitable for organ-confined PC recurrence after radiotherapy, but the data are very few.

Predictors of biochemical failure in patients undergoing prostate whole-gland salvage cryotherapy: a novel risk stratification model

What's known on the subject? and what does the study add?: Previous studies have identified the most important prognostic factors of the likely outcomes of salvage prostate whole-gland ablation, including initial clinical stage, biopsy Gleason score, and PSA (total and doubling time). There is potential for further optimization of candidate selection for salvage cryoablation with curative intent and nadir PSA achieved after whole-gland cryotherapy may provide additional prognostic value. The study shows that the most important prognostic factors of biochemical progression-free survival for patients who have undergone whole-gland salvage prostate cryotherapy are nadir PSA achieved after therapy and pre-therapy biopsy Gleason score. Based on these two prognostic variables, we have identified risk stratification groups (low, intermediate and high) which help predict the expected outcomes of salvage whole-gland prostate cryotherapy in a given patient. This risk stratification constitutes a useful clinical tool in defining which patients maybe best suited for this local salvage treatment method.

OBJECTIVE

To assess the prognostic variables predicting the risk of biochemical progression-free survival (bPFS) after salvage prostate whole-gland cryotherapy using the Phoenix definition of bPFS.

PATIENTS AND METHODS

A total of 132 patients underwent prostate whole-gland salvage cryotherapy with curative intent. No patient underwent neoadjuvant/adjuvant hormonal ablative therapy, and all had extended post-salvage prostate-specific antigen (PSA) follow-up data. Cox univariate and multivariate logistic regression analyses of potential predictors of bPFS were conducted. Kaplan-Meier analyses of bPFS was also performed.

RESULTS

At a mean (range) follow-up of 4.3 (0.9-12.7) years, the median (range) post-cryotherapy nadir PSA achieved was 0.17 (0-33.9) ng/mL. On multivariate analysis, predictors of bPFS were nadir PSA post-cryotherapy and pre-salvage biopsy Gleason score (P < 0.001 and 0.009, respectively). Risk stratification groups (low, intermediate and high) were developed based on the presence of zero, one or two adverse risk factors, the risk factors being either a nadir PSA >2.5 ng/mL or biopsy Gleason score ≥ 7, with the Kaplan-Meier bPFS curves of these risk groups being significantly different (P = 0.02 and <0.001, respectively).

CONCLUSIONS

Post-salvage nadir PSA and pre-salvage biopsy Gleason score are important predictors of outcome in this patient cohort. Low-, intermediate- and high-risk groups can be determined based on these variables and can define patients best suited for prostate cryotherapy.

Cryotherapy and its applications in the management of urologic malignancies: a review of its use in prostate and renal cancers

Cryotherapy has been established as an ablative modality for the treatment of a wide range of malignancies. Being minimally invasive, it is associated with less morbidity than conventional extirpative surgical procedures. In recent years, it has been used with success for treating two of the common urologic malignancies, that is, prostate and renal cancer. In this review, we highlight the role of cryotherapy as a treatment modality, the proposed destructive mechanisms of action and the risks of its use in the management of prostate and renal malignancy.

Salvage cryotherapy for radiation-recurrent prostate cancer: outcomes and complications

Potentially curative salvage options for radio-recurrent prostate cancer include prostatectomy, brachytherapy, high-intensity focused ultrasound, and cryotherapy. Salvage cryoablation technology, surgical technique, oncologic outcomes, and complication rates have improved dramatically over the past few decades, shifting this treatment modality from investigational status to an established therapeutic option. In this review, we focus on the most up-to-date oncologic and functional outcomes, as well as complications of salvage cryotherapy for radiation-recurrent prostate cancer.

A pretreatment nomogram predicting biochemical failure after salvage cryotherapy for locally recurrent prostate cancer

OBJECTIVE

To gather a pooled database from six tertiary-care referral centres using salvage cryotherapy (SC) for locally recurrent prostate cancer, and develop a pretreatment nomogram allowing a prediction of the probability of biochemical failure after SC, based on pretreatment clinical variables.

PATIENTS AND METHODS

We retrospectively analysed 797 men treated at six tertiary-care referral centres with SC for locally recurrent disease after primary radiotherapy with curative intent. The median duration of follow-up from the time of SC to the date of last contact was 3.4 years. The primary study endpoint was biochemical failure, defined as a serum prostate-specific antigen (PSA) level after SC of >0.5 ng/mL.

RESULTS

Overall, the rate of biochemical failure was 66% with a median of 3.4 years of follow-up. A logistic regression model was used to predict biochemical failure. Covariates included serum PSA level at diagnosis, initial clinical T stage, and initial biopsy Gleason score. On the basis of these results, a pretreatment nomogram was developed which can be used to help select patients best suited for SC. Our pretreatment nomogram was internally validated using 500 bootstrap samples, with the concordance index of the model being 0.70.

CONCLUSION

A pretreatment nomogram based on several diagnostic variables (serum PSA level at diagnosis, biopsy Gleason grade, and initial clinical T stage) was developed and might allow the selection of ideal candidates for SC.

Locally recurrent prostate cancer after initial radiation therapy: a comparison of salvage radical prostatectomy versus cryotherapy

PURPOSE

We compared the treatment outcomes of salvage radical prostatectomy and salvage cryotherapy for patients with locally recurrent prostate cancer after initial radiation therapy.

MATERIALS AND METHODS

We retrospectively reviewed the medical records of patients who underwent salvage radical prostatectomy at the Mayo Clinic between 1990 and 1999, and those who underwent salvage cryotherapy at M. D. Anderson Cancer Center between 1992 and 1995. Eligibility criteria were prostate specific antigen less than 10 ng/ml, post-radiation therapy biopsy showing Gleason score 8 or less and prior radiation therapy alone without pre-salvage or post-salvage hormonal therapy. We assessed the rates of biochemical disease-free survival, disease specific survival and overall survival in each group. Biochemical failure was assessed using the 2 definitions of 1) prostate specific antigen greater than 0.4 ng/ml and 2) 2 increases above the nadir prostate specific antigen.

RESULTS

Mean followup was 7.8 years for the salvage radical prostatectomy group and 5.5 years for the salvage cryotherapy group. Compared to salvage cryotherapy, salvage radical prostatectomy resulted in superior biochemical disease-free survival by both definitions of biochemical failure (prostate specific antigen greater than 0.4 ng/ml, salvage cryotherapy 21% vs salvage radical prostatectomy 61% at 5 years, p <0.001; 2 increases above nadir with salvage cryotherapy 42% vs salvage radical prostatectomy 66% at 5 years, p = 0.002) and in superior overall survival (at 5 years salvage cryotherapy 85% vs salvage radical prostatectomy 95%, p = 0.001). There was no significant difference in disease specific survival (at 5 years salvage cryotherapy 96% vs salvage radical prostatectomy 98%, p = 0.283). After adjusting for post-radiation therapy biopsy Gleason sum and pre-salvage treatment serum prostate specific antigen on multivariate analysis salvage radical prostatectomy remained superior to salvage cryotherapy for the end points of any increase in prostate specific antigen greater than 0.4 ng/ml (HR 0.24, p <0.0001), 2 increases in prostate specific antigen (HR 0.47, p = 0.02) and overall survival (HR 0.21, p = 0.01).

CONCLUSIONS

Young, healthy patients with recurrent prostate cancer after radiation therapy should consider salvage radical prostatectomy as it offers superior biochemical disease-free survival and may potentially offer the best chance of cure.

Clinical significance and treatment of biochemical recurrence after definitive therapy for localized prostate cancer

PURPOSE

Radical prostatectomy and external beam radiation therapy are the established and definitive interventions for clinically localized prostate cancer. These treatment modalities are yet subject to failure observed first by biochemical recurrence, defined by increases in the serum PSA level. We investigated the significance of biochemical recurrence after definitive therapy and the available salvage therapy options for cancer recurrence.

METHODS

A literature search was performed in PubMed, and applicable studies addressing biochemical recurrence and salvage options after radical prostatectomy or external beam radiation therapy were reviewed.

RESULTS

After radical prostatectomy, a detectable serum PSA level indicates biochemical recurrence. Whether to administer salvage therapy locally or systemically depends largely on prognostic factors including PSA doubling time, Gleason's score, pathologic stage, and the time interval between radical prostatectomy and biochemical recurrence. Early initiation of salvage therapy has been shown to significantly impact on cancer outcomes. After external beam radiation therapy, no single PSA level can define biochemical recurrence. Instead, it has been defined by increases in the PSA level above the nadir. Following radiation therapy, PSA doubling time and Gleason score play important roles in determining the need for local versus systemic salvage therapy.

CONCLUSIONS

After the diagnosis of biochemical recurrence, it is critical to perform a timely clinical assessment using the prognostic factors mentioned above. Prompt initiation of salvage therapy may prevent subsequent clinical progression and prostate cancer-specific mortality.

Review of primary and salvage cryoablation for prostate cancer

BACKGROUND

Cryosurgery has gained popularity as a minimally invasive treatment option for primary and recurrent prostate cancer. Herein we present a review and summary reports on primary cryoablation for prostate cancer and salvage cryoablation following radiation failure.

METHODS

We reviewed the current published literature in the English language on these topics, along with some historic articles dating back to the 1960s for background and development of the procedure. The material is supplemented by some commentary based on our own 13-year experience with cryoablation for prostate cancer. The review is divided into two sections: primary and salvage cryoablation.

RESULTS

For primary cryoablation, success rates are proportional to the risk categories of the primary cancers. A pretreatment prostate-specific antigen (PSA) <or= 10 ng/mL and an undetectable PSA nadir following cryoablation are associated with a more favorable long-term outcome. Safety profile and quality of life are acceptable in carefully selected patients. Similarly, for salvage cryoablation following radiation failure, patient selection is of paramount importance. The most consistently identified predictive factors for poor cryoablation outcomes were pre-cryoablation PSA > 10 ng/mL and post-cryoablation nadir PSA > 1 ng/mL for salvage procedures. Side effects are more prevalent and serious than with primary cryoablation but for carefully selected patients, the long-term results are favorable.

CONCLUSIONS

Patient selection is the key to success with cryoablation, in both the primary and salvage setting. The modality can offer long-term cancer control in carefully selected patient with properly executed techniques.

[Cryosurgery in the management of prostate cancer]

This article reviews the current status of the prostatic cryosurgery in the management of patients with prostate cancer. Recent advances in cryoablative technology have allowed to treat these patients successfully with decreased morbidity. Using transrectal high-resolution ultrasound imaging, prostate cryotherapy is delivered with multiple ultrathin (17-gauge) cryo-needles, via percutaneous transperineal approach. The extent of freezing can be precisely controlled and monitored with thermic devices, tissue destruction is monitored with real-time visualization of the prostate and surrounding structures, and urethral warming is used to avoid urethral sloughing. However, the results with the second and third-generation cryosurgical equipment will have to be confirmed by means of prospective and randomized trials, because up to now we only have data based on retrospective analyses, which are very heterogeneous. The ability of prostate-specific antigen (PSA) to predict long-term outcome after cryotherapy for localized prostate cancer is not well known because experience with this treatment modality is still limited; however, it seems that a PSA value of 0.5 ng/ml or less after 6 months or longer after cryotherapy would be associated with a high probability (greater than 95%) of negative post-treatment biopsy. Cryosurgery could also be an option of treatment for men with recurrent local disease who have undergone radiotherapy or radical prostatectomy. We have to keep in mind possible complications (incontinence, impotency, urethrorectal fistula or bladder outlet obstruction. The favorable side effect profile and preliminary oncologic and funtional results could suggest that cryosurgery will have a role in the minimally invasive management of selected patients with prostate cancer.

An algorithm for managing the failure of external beam radiotherapy in prostate cancer

OBJECTIVE

To present a management algorithm for men with prostate cancer recurring after external beam radiotherapy (EBRT), based on a review of published reports, to assist clinicians in identifying men who are suitable for salvage therapy and to help them to decide which type of salvage treatment is most likely to confer the desired outcome with the minimum of harm.

METHODS

Men with radiorecurrent prostate cancer require special consideration; they tend to be older, have more comorbidity and have worse disease than their contemporaries having primary treatment. Salvage treatment is compromised by the irradiated pelvis, resulting in increased treatment toxicity. Using the Pubmed database and reference lists of key articles, we identified studies relating to the management of radiorecurrent prostate cancer; the findings were incorporated into a management algorithm and summary table of treatments.

RESULTS

The American Society for Therapeutic Radiology and Oncology criteria, which define biochemical failure has now been superseded by the Phoenix definition (nadir prostate-specific antigen [PSA] plus 2 ng/mL). Biochemical follow-up after EBRT should be 3-monthly until the PSA level has reached a stable nadir after withdrawing androgen suppression. Contrast-enhanced dynamic magnetic resonance imaging (MRI) is an accurate tool and can be used for both the diagnosis and staging of patients with prostate cancer, in conjunction with prostate biopsies. Prostate biopsies should only be considered >2 years after EBRT to avoid false-positive results. In addition to MRI, high-risk cases being considered for salvage therapy should be considered for laparoscopic lymph-node dissection to exclude micrometastases. Deferred androgen suppression, laparoscopic or open radical prostatectomy, cryotherapy and high-intensity focused ultrasound all seem reasonable salvage treatment approaches.

CONCLUSION

Through improved methods of detection, including frequent PSA measurements, modern imaging and carefully obtained biopsies, those with radiorecurrent disease can be identified before their disease has spread. Rigorous staging will exclude those with micrometastases. The minimally invasive salvage therapies seem to offer an advantage over salvage surgery to patients in whom the benefits and harms are so finely balanced.

Magnetic resonance image-guided salvage brachytherapy after radiation in select men who initially presented with favorable-risk prostate cancer

BACKGROUND

The authors prospectively evaluated the late gastrointestinal (GI) and genitourinary (GU) toxicity and prostate-specific antigen (PSA) control of magnetic resonance imaging (MRI)-guided brachytherapy used as salvage for radiation therapy (RT) failure.

METHODS

From October 2000 to October 2005, 25 men with a rising PSA level and biopsy-proven, intraprostatic cancer at least 2 years after initial RT (external beam in 13 men and brachytherapy in 12 men) who had favorable clinical features (Gleason score < or =7, PSA < 10 ng/mL, negative pelvic and bone imaging studies), received MRI-guided salvage brachytherapy to a minimum peripheral dose of 137 gray on a phase 1/2 protocol. Estimates of toxicity and cancer control were calculated using the Kaplan-Meier method.

RESULTS

The median follow-up was 47 months. The 4-year estimate of grade 3 or 4 GI or GU toxicity was 30%, and 13% of patients required a colostomy and/or urostomy to repair a fistula. An interval < 4.5 years between RT courses was associated with both outcomes with a hazard ratio of 12 (95% confidence interval [95% CI], 1.4-100; P = .02) for grade 3 or 4 toxicity and 25 (95% CI, 1.1-529; P = .04) for colostomy and/or urostomy. PSA control (nadir +2 definition) was 70% at 4 years.

CONCLUSIONS

The current results indicated that MRI-guided salvage brachytherapy in men who are selected based on presenting characteristics and post-failure PSA kinetics can achieve high PSA control rates, although complications requiring surgical intervention may occur in 10% to 15% of patients. Prospective randomized studies are needed to characterize the relative cancer control and toxicity after all forms of salvage local therapy.

Management of prostate cancer recurrences after radiation therapy-brachytherapy as a salvage option

Depending on initial prognostic factors, an estimated 10%-60% of men who undergo definitive radiation therapy for prostate cancer may experience a biochemical recurrence. Even though hormonal therapy is standard for metastatic recurrences, no consensus exists on optimal salvage therapy for those recurrences thought confined to the prostate. Salvage treatment options for these local recurrences have historically been limited to salvage prostatectomy, hormonal therapy, or cryotherapy. Salvage prostate brachytherapy, however, uses a widely available technique and may provide another option for attaining disease control in patients with localized failures, although only about 110 cases have been reported in the literature. In this report, the authors have described their own series of salvage brachytherapy cases as well as presented a review of other such series reported in the literature. In addition, the authors included a comprehensive review of published experiences with surgery and cryotherapy as salvage options. It appears that salvage brachytherapy, when combined with careful patient selection, is at least as effective as other salvage options with comparable or potentially fewer treatment-related side effects.

Salvage radical prostatectomy for radiorecurrent prostate cancer: Indications and results

AIMS

A rise in the incidence of radiorecurrent prostate cancer is to be expected, since approximately one third of early prostate cancer cases are nowadays treated with a radiotherapy modality. One possibility in treating radiorecurrent prostate cancer is salvage prostatectomy. Our objective was to look into our own experience with salvage radical prostatectomy and to analyse outcome and morbidity.

METHODS

A computer search through our hospital database identified 11 patients who underwent a salvage radical prostatectomy for radiorecurrent cancer over the last 15 years. All data were retrospectively analysed and confronted with the literature.

RESULTS

Although the surgery was mostly difficult, there were no intraoperative complications. Bladder neck stricture is the most common postoperative complication (18%). Continence rates are worse than in classical radical prostatectomy. All patients lost potency, since no attempt was made to spare the neurovascular bundles. With a mean follow-up of 6.9 years, biochemical disease-free survival rates was 55%, while overall and cancer-specific survival was 91%.

CONCLUSION

While most patients with radiorecurrent prostate cancer will be treated by many experts with hormonal therapy, a salvage radical prostatectomy can give a second chance for cure in carefully selected patients.

Presalvage prostate-specific antigen (PSA) and PSA doubling time as predictors of biochemical failure of salvage cryotherapy in patients with locally recurrent prostate cancer after radiotherapy

BACKGROUND

The value of presalvage cryotherapy serum PSA level in predicting biochemical failure in patients with local recurrence of prostate cancer (PCa) after radiotherapy was documented; however, little is known about the predictive value of prostate-specific antigen (PSA) doubling time (DT) in this patient group. The purpose of the current study was to evaluate serum PSA level and PSA DT as predictors of salvage cryotherapy outcomes in patients being treated for postradiotherapy locally recurrent PCa.

METHODS

The charts of patients treated with salvage cryotherapy were retrospectively reviewed for locally recurrent PCa at the M. D. Anderson Cancer Center from January 1980 to July 2004. Patients who received neoadjuvant or adjuvant hormone therapy were excluded. We assessed pre- and postradiotherapy clinical data, pre- and postsalvage cryotherapy clinical data, and other variables. Kaplan-Meier and log rank tests were performed to assess unadjusted survival probabilities and 2-group survival comparisons, respectively. Cox proportional hazards regression models were used to assess the effect of patient characteristics in predicting overall, disease-specific, and biochemical failure-free survival.

RESULTS

Forty-nine patients met the eligibility criteria. The median age of patients at diagnosis was 66 years (58-81 years) with the initial clinical stage before radiotherapy most commonly T2 (n = 25) or T3 (n = 21). The median presalvage cryotherapy serum PSA level was 5.9 ng/mL (0.4-23.1 ng/mL) and the presalvage prostatic biopsies were frequently high grade (Gleason grade > or =8 in 51% of patients). The median postsalvage cryotherapy serum PSA level was 0.1 ng/mL (0.1-9.5 ng/mL), and biochemical failure (defined as a serum PSA level > or =2 ng/mL above the postsalvage cryotherapy PSA nadir) occurred in 26 patients. In these 26 patients, there was a statistically significant difference between pre- and postsalvage cryotherapy PSA DTs (12.3 months to 5.6 months, respectively; P = .02). A presalvage cryotherapy serum PSA level >10 ng/mL (P = .002) and PSA DT < or =16 months (P = .06) were found to predict the subsequent risk of biochemical failure.

CONCLUSIONS

Presalvage PSA and PSA DT can predict biochemical failure of salvage cryotherapy, although the predictive value of PSA DT only trended toward significance. The statistically significant difference in pre- and postsalvage cryotherapy PSA DTs was reflective of aggressive tumor biology.

Role of transrectal ultrasound guided salvage cryosurgery for recurrent prostate carcinoma after radiotherapy

Despite improvements in treatment of localized prostate cancer, local recurrence remains a significant problem. A total of 46 patients with proven local cancer recurrence following external beam radiotherapy entered a prospective clinical trial using ultrasound-guided cryosurgery to ablate the residual prostate gland. Persistent complications included one urethra-rectal fistula, incontinence (2), retention (3), and treatment induced erectile dysfunction (7). Using the PSA definitions for biochemical failure as PSA>or=0.3 ng/ml, the Kaplan-Meier plots showed the incidence of patients to be free of biochemical recurrence at 51 and 44% at 1 and 2 y, respectively. For a PSA>or=1.0, the values at 1 and 2 y were 72 and 58%.

CURRENT STATUS OF LOCAL SALVAGE THERAPIES FOLLOWING RADIATION FAILURE FOR PROSTATE CANCER

PURPOSE

We reviewed the curative options available to patients with local failure after radical radiotherapy for prostate cancer and identified the patients best suited for such salvage therapies.

MATERIALS AND METHODS

A literature search of English language publications was done using the key terms salvage, prostatectomy, cryosurgery, brachytherapy and radiation failure.

RESULTS

Salvage radical prostatectomy offers 5-year biochemical relapse-free rates between 55 and 69%. Higher complication rates are reported with salvage compared to primary radical prostatectomy, including rectal injuries, bladder neck contracture and urinary incontinence. Cryosurgery biochemical response rates vary according to the definition of failure but they are generally lower than those of salvage radical prostatectomy. The local control rates of cryosurgery are acceptable. Major complications related to cryotherapy are urinary incontinence, impotence, pelvic pain and urinary retention. Experience with salvage brachytherapy has been limited but some success has been reported in terms of biochemical control.

CONCLUSIONS

Salvage prostatectomy for localized radiation failure is a good option in the patient with a life expectancy of at least 10 years, preradiation and preoperative prostate specific antigen less than 10 ng/ml, and localized preoperative stage with the understanding that complication risks are higher. Salvage cryotherapy is a valid option in patients with preoperative prostate specific antigen less than 10 ng/ml and Gleason score less than 8, clinical stage less than T3 who are hormonally naive. Salvage cryotherapy is especially suited for older patients with some comorbidities who are still considered to be at reasonable anesthetic risk. The study of brachytherapy remains in its infancy and the efficacy of this modality remains to be determined.

FERROMAGNETIC THERMAL ABLATION OF LOCALLY RECURRENT PROSTATE CANCER: PROSTATE SPECIFIC ANTIGEN RESULTS AND IMMEDIATE/INTERMEDIATE MORBIDITIES

PURPOSE

Curative options for locally recurrent prostate cancer following external beam radiotherapy are limited due to the significant morbidity associated with surgical therapy. ThermoRods (Ablation Technologies, San Diego, California) are permanently implantable, 14 mm cobalt-palladium alloy rods that produce heat through oscillation of a magnetic field. The rod is designed to self-regulate the temperature to 70C by a temperature dependent magnetic transition (Curie effect). We determined whether patients with prostate cancer and local failure could be treated with thermal ablation of the prostate using this novel technology.

MATERIALS AND METHODS

A total of 14 men with an average age of 72 years (range 62 to 81) were enrolled in the study. All had biopsy proven prostate cancer with increasing prostate specific antigen (PSA) (1.0 to 10.3 ng/ml). The seminal vesicles were not routinely biopsied. Metastatic disease was assayed in all men with bone scan and in later patients with abdominopelvic computerized tomography. Patients had ThermoRods placed under transrectal ultrasound guidance, similar to brachytherapy. The pre-plan was rigorously followed to produce a 3-dimensional array with rods separated by 1 cm across the short axis. Patients were treated in a magnetic field for 1 hour. Urethral and rectal temperatures were also monitored and cooled appropriately. Serial PSA measurements and 6 month posttreatment biopsies were obtained after the procedure.

RESULTS

Average time since radiation was 4.5 years. PSA nadir values after radiation were between 0.3 and 2.2 ng/ml. Prostatic temperatures were homogeneously increased greater than 50C, while rectal and urethral temperatures did not exceed 44C at any point. The urethral catheter was removed 2 weeks postoperatively in all cases. Six months after the procedure 8 of the 14 men (57%) had a PSA decrease to less than 0.1 ng/ml. Complications included urinary retention as well as incontinence. Incontinence was generally temporary and only 1 patient (7%) had long-term incontinence. Most patients were impotent after treatment. Of the patients 21% experienced urinary retention. Five patients (36%) needed to undergo secondary procedures after therapy, including transurethral prostate resection in 2, balloon dilation in 1, cystoscopic removal of necrotic tissue in 1 and bladder irrigation in 1.

CONCLUSIONS

This novel means of thermal ablation produces significant PSA decreases in patients. Morbidity is predominantly in the form of incontinence and impotence. Incontinence is generally temporary. The use of ferromagnetic rods enables the precise control of tissue destruction with the sparing of immediately adjacent structures. The technology uses skills familiar to the urologist and avoids radiation. The durability of the PSA response and incidence of late morbidity remain to be defined.

Recurrent prostate cancer after external beam radiotherapy: value of contrast-enhanced dynamic MRI in localizing intraprostatic tumor--correlation with biopsy findings

OBJECTIVES

To assess the accuracy and interobserver variability of T2-weighted (T2W) and contrast-enhanced dynamic (CE-Dyn) magnetic resonance imaging (MRI) in predicting the results of transrectal biopsy in patients with suspected recurrent prostate cancer after external beam radiotherapy.

METHODS

A total of 22 patients with increasing prostate-specific antigen levels after external beam radiotherapy for prostate cancer underwent T2W and CE-Dyn MRI of the prostate. The CE-Dyn sequence (acquisition time 30 seconds) was repeated three times after the injection of gadolinium. All patients underwent subsequent transrectal biopsy. Three independent readers interpreted the MRI scans. The MRI and biopsy results were correlated in 10 prostate sectors (the sextants of the peripheral zone, the two transitional zones, and the two seminal vesicles).

RESULTS

Biopsy cores were obtained in 147 prostate sectors. Of these, 63 were positive for cancer in 19 patients. On the T2W images, the three readers interpreted as positive for cancer 15, 15, and 13 of the 19 patients showing cancer at biopsy. They interpreted as negative 3, 0, and 1 of the 3 patients showing no cancer at biopsy. On CE-Dyn images, the three readers correctly classified all the patients as positive or negative for cancer. The T2W and CE-Dyn MRI findings were concordant with biopsy results in, respectively, 81 to 95 and 107 to 117 prostate sectors (P <0.001 and P <0.01 for readers 1 and 2 and was nonsignificant for reader 3). The interobserver agreement was better for CE-Dyn images (kappa = 0.63 to 0.70) than for the T2W images (kappa = 0.18 to 0.39). The MRI-calculated tumor volumes and the mean biopsy core invasion rates were significantly correlated on the CE-Dyn images for all readers. They correlated significantly on T2W images only for one reader.

CONCLUSIONS

CE-Dyn MRI depicts the intraprostatic distribution of recurrent cancer after external beam radiotherapy more accurately and with less interobserver variability than T2W MRI.

Cryotherapy for prostate cancer

Cryotherapy, or the use of freezing, is a long-established method of tumor cell destruction. Although in the past cryotherapy was widely used as a local treatment for prostate cancer, this technique was abandoned not due to lack of efficacy but because the complication rate was unacceptably high. However, there has been a re-emergence in the popularity of cryotherapy for the treatment of localized prostate cancer due to improvements in instrumentation, tumor localization and treatment delivery. Using transrectal ultrasound imaging, prostate cryotherapy is currently delivered with multiple probes via a percutaneous transperineal approach. The extent of freezing can be precisely controlled and monitored with thermocouples and tissue destruction is monitored with real-time visualization of the prostate and surrounding structures. The role of cryotherapy in localized prostate cancer is reviewed.

Selecting a secondary treatment

There is compelling evidence that early hormonal therapy prolongs life in many stages of prostate cancer. Large-scale trials to answer this question have not yet been conducted in surgically treated patients or in patients with PSA-only relapse. Thus, many physicians and patients use early hormone therapy in PSA-only relapse. Many unique new agents are being tested in this population and may offer benefits. Patients and physicians are encouraged to participate in such trials, with hormone therapy reserved for subsequent use. Following failure of primary hormone therapy, a standard algorithm of care exists: antiandrogen withdrawal, use of alternative or first-line anti-androgens. ketoconazole. and chemotherapy. At each interval, clinical trials should be offered since none of these maneuvers are proven to prolong life.

Results of salvage cryoablation of the prostate after radiation: identifying predictors of treatment failure and complications

PURPOSE

We conduct a critical evaluation of cryoablation of prostate cancer after failure of full dose radiotherapy to identify predictors of treatment failure and complications.

MATERIALS AND METHODS

A total of 125 cryoablation procedures were performed in 118 patients with proved local recurrence after full dose radiotherapy. Followup includes serial prostate specific antigen (PSA) and biopsy at 6,12 and 24 months. Kaplan-Meier plots were constructed for different PSA cutoffs. We separately analyzed different cohorts based on T stage, Gleason score, PSA before cryoablation and endocrine therapy status.

RESULTS

Of the 118 patients 114 had serum PSA nadir less than 0.5 ng./ml. Median followup was 18.6 months (range 3 to 54). Of the biopsy cores 3.1% (23 of 745) from 7 patients contained persistent viable cancer. Kaplan-Meier plots showed patients free of histological failure leveling at 87% and free from biochemical failure at 68%, 55% and 34%, respectively, with PSA greater than 4, 2 and 0.5 ng./ml. PSA greater than 10 ng./ml. before cryoablation, Gleason score 8 or greater before radiation and stage T3/T4 disease appeared to predict an unfavorable biochemical outcome. Serious complications included 4 rectourethral fistulas (3.3%) and severe incontinence (6.7%). Strong predictors of complications included bulky disease for fistulas and prior transurethral surgery.

CONCLUSIONS

Salvage cryoablation after radiation can achieve reasonable biochemical and histological results with acceptable morbidity. Cryoablation appears to be a reasonable treatment option for this patient population with few viable therapeutic options, provided vigorous patient selection criteria are adhered to.