Cryosurgery as primary treatment for localized prostate cancer: a community hospital experience

The incidence proportion of erectile dysfunction in patients treated with cryotherapy for prostate cancer: a meta-analysis

OBJECTIVES

With the maturity of cryotherapy for prostate cancer, the complications after operation are also decreasing, which can improve the prognosis of patients. However, erectile dysfunction (ED) is still one of the main complications after cryotherapy. Therefore, we performed a meta-analysis to evaluate the incidence of erectile dysfunction in patients after cryotherapy.

MATERIALS AND METHODS

A comprehensive literature search was performed in August 2018. PUBMED and EMBASE databases were searched to collect studies reporting the incidence rate of ED after cryotherapy from 2002 to 2018. Two reviewers independently screened the literatures, extracted data and assessed the risk of bias of included studies. Pooled ratio and its 95% confidence intervals (95% CIs) were performed by Stata 12.1.

RESULTS

Of the 157 articles identified on August 1st 2018, 23 studies which reported ED after cold ablative therapy were identified, however, only 12 used validated outcome measures and met inclusion criteria. A total of 12 studies were included in this meta-analysis. Overall, the results of this meta-analysis showed that the pooled incidence rate of ED was 0.27 (95% CI 0.26-0.28) which means that the incidence rate of ED after cryotherapy for prostate cancer was not high, but we still found that there are great heterogeneity between the 12 articles. By subgroup analysis, we found a statistically significant incidence rate of ED in primarily localized PCa which was 0.49 (95% CI 0.30-0.68), which is clearly lower than the incidence of recurrent prostate cancer after failed primary radiotherapy 0.61 (95% CI 0.43-0.79).

CONCLUSION

ED is one of the major complications after cryotherapy for PCa. Furthermore, subgroup analysis revealed a higher incidence rate in PCa undergoing radiotherapy. Significantly, with the development of cryotherapy technology, the incidence of ED after cryotherapy for prostate cancer is decreasing. While we still need further researches to advance knowledge in this field.

An efficient technique for estimating the two-dimensional temperature distributions around multiple cryo-surgical probes based on combining contributions of unit circles

This study presents an efficient, fast and accurate method for estimating the two-dimensional temperature distributions around multiple cryo-surgical probes. The identical probes are inserted into the same depth and are operated simultaneously and uniformly. The first step in this method involves numerical derivation of the temporal performance data of a single probe, embedded in a semi-infinite, tissue-like medium. The results of this derivation are approximated by algebraic expressions that form the basis for computing the temperature distributions of multiple embedded probes by combining the data of a single probe. Comparison of isothermal contours derived by this method to those computed numerically for a variety of geometrical cases, up to 15 inserted probes and 2-10 min times of operation, yielded excellent results. Since this technique obviates the solution of the differential equations of multiple probes, the computational time required for a particular case is several orders of magnitude shorter than that needed for obtaining the full numerical solution. Blood perfusion and metabolic heat generation rates are demonstrated to inhibit the advancement of isothermal fronts. Application of this method will significantly shorten computational times without compromising the accuracy of the results. It may also facilitate expeditious consideration of the advantages of different modes of operation and the number of inserted probes at the early design stage.

Current approaches, challenges and future directions for monitoring treatment response in prostate cancer

Prostate cancer is the most commonly diagnosed non-cutaneous neoplasm in men in the United States and the second leading cause of cancer mortality. One in 7 men will be diagnosed with prostate cancer during their lifetime. As a result, monitoring treatment response is of vital importance. The cornerstone of current approaches in monitoring treatment response remains the prostate-specific antigen (PSA). However, with the limitations of PSA come challenges in our ability to monitor treatment success. Defining PSA response is different depending on the individual treatment rendered potentially making it difficult for those not trained in urologic oncology to understand. Furthermore, standard treatment response criteria do not apply to prostate cancer further complicating the issue of treatment response. Historically, prostate cancer has been difficult to image and no single modality has been consistently relied upon to measure treatment response. However, with newer imaging modalities and advances in our understanding and utilization of specific biomarkers, the future for monitoring treatment response in prostate cancer looks bright.

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.

Minimally invasive ablative therapies for definitive treatment of localized prostate cancer in the primary setting

Traditionally, the patient with a new diagnosis of localized prostate cancer faces either radical therapy, in the form of surgery or radiation, or active surveillance. A growing subset of these men may not be willing to accept the psychological burden of active surveillance nor the side effects of extirpative or radiation therapy. Local ablative therapies including cryotherapy, high-intensity focused ultrasound, and vascular-targeted photodynamic therapy have emerged as a means for minimally invasive definitive treatment. These treatments are well tolerated with decreased morbidity in association with improvements in technology; however, long-term oncologic efficacy remains to be determined.

Predicting biopsy-proven prostate cancer recurrence following cryosurgery

OBJECTIVES

Prostate cancer (CaP) cryosurgery utilizes PSA nadir level and radiotherapy criteria as surrogates for success. We attempted to correlate PSA doubling time (PSAdt) and time of undetectable PSA (TUPSA) with biopsy-proven cancer recurrence (BPR) in men treated with primary third-generation cryotherapy for clinically localized CaP.

MATERIALS AND METHODS

Demographic, clinical, and pathologic data was retrieved including age, race, use of preoperative hormones or 5-α reductase inhibitors (5-ARIs), initial biopsy PSA, biopsy Gleason score, cT stage, prostate volume, presence/absence median lobe, and follow-up. Post-cryotherapy biopsy was considered for PSA levels ≥ 0.5 ng/ml. PSAdt was determined by the log-slope method. TUPSA was defined as time from surgery to a PSA value ≥ 0.2 ng/ml or most recent follow-up if undetectable.

RESULTS

Ninety-seven patients were identified. Preoperative hormonal manipulation was used in 25 (26%); 5 (5%) were using a 5-ARI. Twenty-seven (29%) underwent post-cryotherapy biopsy, 12 (12%) had a BPR. In 41 (42%), PSAdt was calculated (median 11.9 months, IQR 6.6-34.8); no significant difference between patients with BPR and without CaP was found (P = 0.46). TUPSA was a median of 4.9 months (IQR 3.2-9.9) vs. 15.6 months (IQR 6.1-30.3) for BPR or no CaP, respectively (P = 0.005). On proportional hazards regression, TUPSA was the only independent predictor of BPR (P = 0.03, OR 0.91).

CONCLUSIONS

Post-cryosurgery PSAdt does not appear to be associated with BPR risk, whereas TUPSA reduces the risk of BPR by 9% per month. This may help guide management if local failure is suspected.

Correlation of thermocouple data with voiding function after prostate cryoablation

OBJECTIVES

To identify possible correlations of thermocouple recorded data with altered postoperative voiding function after prostate cryosurgery.

METHODS

A retrospective analysis of the records of 58 patients treated with prostate cryoablation from October 2005 through April 2009 was conducted. Multivariate analysis of patient age, presenting prostate-specific antigen level, Gleason score, clinical T stage, prostate volume, maximum low temperature thermocouple recordings, history of radiation and or hormonal therapy, were studied as possible correlative factors for altered postoperative voiding function.

RESULTS

Of 58 patients, 22 (37.9%) manifested postcryoablation urgency and frequency (n = 13) requiring medical therapy or retention (n = 9). On multivariate analysis, age (P = .037) and an external sphincter temperature < or = 23 degrees C (P = .012) were associated with voiding frequency, urgency, or retention (odds ratio = 6.26, 95% CI: 1.62-24.16), whereas anterior rectal wall temperature (Denon) was weakly associated (P = .079).

CONCLUSIONS

Thermocouple data provide an objective means of assessing cryosurgical outcomes. This is the first report of a correlation of such data to post-treatment voiding function. A total of 37.9% of patients experienced urgency and/or frequency or urinary retention after cryoablation of the prostate for localized disease. Older age and external sphincter temperature < or = 23 degrees C were statistically significant predictors of these events. The data suggest that limiting the degree of freezing at the external sphincter may decrease procedure related morbidity. Further study is warranted to better delineate temperature-related data on treatment outcomes.

Contemporary analysis of erectile, voiding, and oncologic outcomes following primary targeted cryoablation of the prostate for clinically localized prostate cancer

PURPOSE

To evaluate erectile function (EF) and voiding function following primary targeted cryoablation of the prostate (TCAP) for clinically localized prostate cancer (CaP) in a contemporary cohort.

MATERIALS AND METHODS

We retrospectively reviewed all patients treated between 2/2000-5/2006 with primary TCAP. Variables included age, Gleason sum, pre-TCAP prostate specific antigen (PSA), prostate volume, clinical stage, pre-TCAP hormonal ablation, pre-TCAP EF and American Urologic Association Symptom Score (AUASS). EF was recorded as follows: 1 = potent; 2 = sufficient for intercourse; 3 = partial/insufficient; 4 = minimal/insufficient; 5 = none. Voiding function was analyzed by comparing pre/post-TCAP AUASS. Statistical analysis utilized SAS software with p < 0.05 considered significant.

RESULTS

After exclusions, 78 consecutive patients were analyzed with a mean age of 69.2 years and follow-up 39.8 months. Thirty-five (44.9%) men reported pre-TCAP EF level of 1-2. Post-TCAP, 9 of 35 (25.7%) regained EF of level 1-2 while 1 (2.9%) achieved level 3 EF. Median pre-TCAP AUASS was 8.75 versus 7.50 postoperatively (p = 0.39). Six patients (7.7%) experienced post-TCAP urinary incontinence. Lower pre-TCAP PSA (p = 0.008) and higher Gleason sum (p = 0.002) were associated with higher post-TCAP AUASS while prostate volume demonstrated a trend (p = 0.07). Post-TCAP EF and stable AUASS were not associated with increased disease-recurrence (p = 0.24 and p = 0.67, respectively).

CONCLUSIONS

Stable voiding function was observed post-TCAP, with an overall incontinence rate of 7.7%. Further, though erectile dysfunction is common following TCAP, 25.7% of previously potent patients demonstrated erections suitable for intercourse. While long-term data is requisite, consideration should be made for prospective evaluation of penile rehabilitation following primary TCAP.

Prospective evaluation of sexual function in patients receiving cryosurgery as a primary radical treatment for localized prostate cancer

OBJECTIVE

To evaluate prospectively the sexual function of patients undergoing cryosurgery as a primary radical treatment for localized prostate cancer, as the development of 17 G cryotherapy probes has improved the delivery of this treatment, but one of the side-effects of cryosurgery is the development of erectile dysfunction (ED).

PATIENTS AND METHODS

Between July 2003 and May 2008, 53 patients were treated using an argon-based third-generation cryotherapy system (Oncura, Arlington Heights, IL, USA). Prospective data were collected at 6 weeks, 3 months, then 3-monthly up to 1 year and subsequently 6-monthly. Patients were followed up for up to 54 months, with a median (mean) follow-up 36 (30.5) months.

RESULTS

All 53 patients were followed after receiving cryosurgery as primary treatment for prostate cancer; 51 (96.3%) had ED at 6 weeks while two (3.7%) were experiencing partial erections. By 9 months one (2.4%) of 42 patients was fully potent using phosphodiesterase type-5 inhibitors, and six (14.3%) were experiencing partial erections. By 18 months eight (21%) of 39 patients followed up had regained full potency and by 24 months eight (24%) of 33 patients were fully potent and three (9%) experienced partial erections.

CONCLUSION

While ED is a significant side-effect of cryotherapy, a considerable proportion of patients who have no ED before treatment (39%) recover full sexual function afterward. Focal nerve-sparing cryosurgery might be the way forward in an attempt to preserve erectile function in men who had no ED before treatment. Erectile aids should be made available for those patients for whom sexual dysfunction compromises the quality of their life and relationships.

Single center experience with third-generation cryosurgery for management of organ-confined prostate cancer: critical evaluation of short-term outcomes, complications, and patient quality of life

BACKGROUND AND PURPOSE

Technical refinements such as improved ultrasonographic localization and the routine use of urethral warmers and small-gauge needle delivery systems have renewed interest in cryosurgical treatment as a minimally invasive option for selected patients with localized prostate cancer. Only three reports of quality of life (QoL) in prostate cryoablation exist, and none report on patients treated with third-generation cryoablative technology. We critically examine our initial series of consecutive patients at a single institution undergoing primary third-generation cryosurgical treatment of localized prostate cancer with respect to treatment outcome, morbidity profile, and QoL parameters. To our knowledge, this is the first QoL report on third-generation cryoablation of the prostate.

PATIENTS AND METHODS

We retrospectively review the records of 89 consecutive patients with median followup of 11 months (1-32) who have undergone third-generation cryosurgical ablation of the prostate as primary treatment for localized prostate cancer with intention to cure. Patients were risk stratified according to preprocedural parameters of prostate-specific antigen (PSA), clinical stage, and Gleason score. PSA trends were recorded and treatment effectiveness was observed using different definitions of biochemical failure. Charts were reviewed for postprocedure complications. Quality of life was measured prospectively using the University of California, Los Angeles, Prostate Cancer Index as well as American Urological Association symptom scores. We compare a percent of baseline score (%BS) for various domains between our series of patients treated with primary cryoablation with a series of patients undergoing brachytherapy for localized prostate cancer.

RESULTS

Treatment success was defined by achievement of a PSA nadir of < or =0.1 ng/mL and by biochemical disease-free survival (BDFS) assessed with both a PSA threshold of < or =0.4 ng/dL over time and the American Society for Therapeutic Radiology and Oncology (ASTRO) definition of three consecutive rises in PSA. According to risk stratification, 86%, 81.5%, and 78% of low-, intermediate-, and high-risk patients, respectively, achieved a PSA nadir of < or =0.1 ng/mL. Overall, at 12 months follow-up, 94% of patients achieved BDFS using ASTRO criteria while 70% achieved BDFS using a PSA threshold of < or =0.4 ng/mL. With risk stratification, 74%, 70%, and 60% of low-, intermediate-, and high-risk patients, respectively, achieved BDFS defined by PSA threshold of < or =0.4 ng/mL. Complications were rare. The response rate for Health Related Quality of Life (HRQoL) questionnaires was 71% for cryoablation patients and 51% for brachytherapy patients. At 12 months follow-up, patients undergoing cryoablation on average achieved urinary and bowel domain scores comparable to baseline, but sexual domains remained well below baseline. When compared with a brachytherapy series with better baseline sexual function (P = 0.04) and urinary function (P = 0.03), cryotherapy patients experienced more negative impact on sexual function steadily for up to 12 months (P = 0.02). Urinary function was similar between the groups until 18 months, at which time cryoablation patients fared better (P = 0.01); this was sustained up to 24 months (P = 0.04).

CONCLUSIONS

Treatment success with cryosurgery varies with definition; however, our results are comparable to other series with regard to short-term cancer control. Complication rates in this series of third-generation cryosurgical patients are low. QoL characteristics of third-generation cryoablation are similar to those described in second-generation cryoablation series. Compared with brachytherapy, cryotherapy results in less irritative and obstructive voiding symptoms in the early post-treatment period and may improve urinary function up to 24 months after treatment. In a small group of older patients with baseline erectile dysfunction undergoing cryoablation, sexual function returns to 20% of its baseline value with up to 12 months follow-up.

Focal or subtotal therapy for early stage prostate cancer

Focal treatment for prostate cancer is highly intriguing, but poorly supported by the published literature. Further studies, preferably randomized controlled trials, are needed before this can be considered standard therapy. Focal treatment should be reserved for patients with focal disease. Even "clinically insignificant" synchronous tumors are malignant, and carry risk of progression if not treated with the index lesion. Whether these are likely to progress in this setting compared to those managed with active surveillance is unknown. The limited data regarding subtotal or focal cryotherapy suggest that patients properly evaluated for presence of satellite tumors have a low risk of having large unknown satellite tumors. The author requires office-based saturation biopsy prior to considering focal cryotherapy. Observation of prostatic intraepithelial neoplasia (PIN), atypical findings (ASAP), or cancer on the contralateral biopsy cores excludes the patient from consideration of subtotal therapy. MRI offers a potential additional ability to detect occult contralateral tumors. Younger men paradoxically seem to have greater interest in focal therapy while having a higher risk of future malignancy in the untreated areas based on the years of potential risk. However, no age cutoff is established. Without published data to support its use, lumpectomy or freezing only the focus where cancer is believed to exist, will remain limited. Hemispheric or subtotal treatment decreases the amount of untreated tissue. As a result, the local failure rate would be predicted to be lower but is unknown. When performing subtotal treatment, the author freezes almost the entire gland, sparing only the aspect adjacent to the contralateral neurovascular bundle, and has found this practice to be of highly limited utility based on the issues described. Biopsy should be performed following any treatment that fails to target the entire gland. A positive biopsy should be dealt with based on clinical factors as if the patient had not been treated, and a positive biopsy should not preclude active surveillance if deemed appropriate.

Focal cryosurgery followed by penile rehabilitation as primary treatment for localized prostate cancer: initial results

The study reported here was undertaken to assess medium short-term efficacy of focal cryoablation as primary therapy for localized prostate cancer and to determine the rate of morbidity in patients who undergo this treatment. Patients were treated with focal cryoablation with argon cryoprobes under ultrasonographic visualization with temperature monitoring. Men who were potent at the time of intervention were encouraged to use a vacuum erectile dysfunction device on a regular basis after treatment. Incontinence was defined as any urine leakage regardless of the number of pads worn (if any). Potency was defined as the ability to achieve an erection sufficient to complete intercourse with or without oral pharmaceuticals. Biochemical failure was defined as 3 successive rises in serum prostate-specific antigen (PSA) concentration. A total of 60 consecutive patients were treated. Mean patient age was 69.0 years; mean PSA was 7.2 ng/mL, median Gleason score was 6, and median stage was T1c. Before treatment was initiated, all patients were continent and 72.7% were potent. Mean follow-up for the entire population was 15.2+/-7.4 months. Of those patients who were continent before receiving treatment, 3.6% were incontinent at 6 months, but none used any absorbent pads. At last follow-up, 80.4% of patients were biochemically disease free; mean time to failure was 3.5 months among those for whom treatment failed. The positive biopsy rate after first treatment was 23.3%, and mean time to failure was 12.0 months. Of those who underwent a second focal cryoablation procedure after positive biopsy, 66% were subsequently cancer free. All patients who were potent after the first cryoablation procedure regained their potency after the second cryoablation procedure. Focal cryoablation combined with penile rehabilitation as primary treatment for localized prostate cancer is a minimally morbid procedure with acceptable morbidity and the potential for retreatment of a patient if cancer is subsequently detected. Further study is warranted.

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.

Short-term cancer control after primary cryosurgical ablation for clinically localized prostate cancer using third-generation cryotechnology

OBJECTIVES

Percutaneous perineal cryoablation of the prostate is a promising technique in the treatment armamentarium for clinically localized prostate carcinoma. We report our initial experience using a transrectal ultrasound-guided, third-generation, argon/helium cryosurgical system.

METHODS

From January 2002 to July 2005, 50 men underwent primary cryosurgery for clinically localized prostate carcinoma. The median patient age was 68 years (range 50 to 83), and the median follow-up period was 18 months (range 3 to 43). According to the D'Amico risk stratification system, 36 patients (72%) had low-risk, 9 (18%) had intermediate-risk, and 5 (10%) had high-risk prostate cancer. All patients underwent a dual freeze-thaw cycle using third-generation cryotechnology with ultrathin 17-gauge cryoneedles.

RESULTS

The prostate-specific antigen (PSA) level for all patients at the last follow-up visit was less than 0.5 ng/mL in 45 patients (90%) and 0.5 ng/mL or more in 5 (10%). Two patients had persistent prostate cancer confirmed by prostate biopsy and were treated with salvage cryotherapy or external beam radiotherapy. Three other patients had an elevated PSA level after cryotherapy despite negative posttreatment biopsies and a metastatic evaluation. Of these 3 patients, 2 had their postcryotherapy PSA level normalize, and 1 patient, with intermediate-risk disease preoperatively, had a consistent increase in PSA up to 1.2 ng/mL. The overall survival rate was 100%.

CONCLUSIONS

Cryoablation of the prostate is a feasible and safe treatment option in patients with organ-confined prostate cancer. Additional studies with longer follow-up are necessary to determine the sustained efficacy of this procedure.

Cryotherapy for localised prostate cancer

BACKGROUND

Prostate cancer is a common cancer in elderly men and in some will prove fatal. Standard treatments for localised disease include surgery ( radical prostatectomy), radiotherapy and active monitoring. New emerging therapies are being evaluated with the aim of reducing the complication rate associated with standard therapies, as well as developing an effective treatment. One such modality is cryotherapy, a procedure that introduces probes directly into the prostate tumour and kills the malignant cells by a freezing process.

OBJECTIVES

This review aims to evaluate the relative clinical and economic benefits of cryotherapy compared to standard therapies for the primary treatment of localised prostate cancer.

SEARCH STRATEGY

Our search strategy included an electronic search of MEDLINE from 1996 to December 2006, plus EMBASE (Excerpta Medica Database), the Cochrane library, ISI Science Citation Index, Database of Abstracts and Reviews of Effectiveness (DARE), and LILACS to identify all relevant published randomised trials of cryotherapy for localised prostate cancer. Cancerlit and HealthSTAR databases were searched to their final date. Handsearching of relevant journals was undertaken.

SELECTION CRITERIA

Only published randomised trials comparing the effectiveness of cryotherapy with radical prostatectomy, radiotherapy or active monitoring for the primary treatment of men with localised prostate cancer were eligible for inclusion in this review.

DATA COLLECTION AND ANALYSIS

Data were extracted from eligible studies, and included study design, participants, interventions and outcomes. Primary outcome measures were biochemical disease-free survival, disease-free survival and treatment-induced complications. Secondary outcomes included disease-specific survival, overall survival, quality-of-life outcome measures and economic impact measures.

MAIN RESULTS

There were no randomised trials found comparing cryotherapy with other therapies for the primary treatment of localised prostate cancer. All studies identified were case series. To indicate the level of the available evidence, studies that evaluated cryotherapy as a primary therapy, using transrectal ultrasound guidance and urethral warming in at least 50 patients with localised prostate cancer, and a minimum of one year follow up, were reviewed. Eight case series were identified that complied with these criteria; two were retrospective. The patients recruited (n = 1483) had an age range from 41 to 84 years, stages T1 = 0 to 43%, T2 = 24 to 88%, T3 = 1 to 41%, and T4 = 0 to 14%. The mean preoperative PSA level ranged from 9.7 to 39 ng/mL, with Gleason scores < 7 and ranging from 6 to 37%. One additional study that compared cryotherapy (total cryotherapy and standard cryotherapy with urethral preservation) with radical prostatectomy was also identified and reviewed. In this study the success rates, defined as a post-treatment PSA of 0.2 ng/mL or less, were reported as 96% for total cryotherapy, 49% for standard cryotherapy and 73% for radical prostatectomy. Four studies did not monitor the temperature of the cyro-procedure and reported 17 to 28% of patients had a positive biopsy following cryotherapy with a mean PSA nadir of 0.55 to 1.75 ng/mL (median 0.4 to 1.85 ng/mL). The other four studies used thermocouples to monitor the temperature of the cryo-procedure and reported progression-free survival rates of 71 to 89% with 1.4 to 13% of patients having a positive biopsy post-cryotherapy. At 5 years, overall survival was reported as 89 to 92% in two studies, and disease-specific survival as 94% in one study. The major complications observed in all studies included impotence (47 to 100%), incontinence (1.3 to 19%), and urethral sloughing (3.9 to 85%), with less common complications of fistula (0 to 2%), bladder-neck obstruction (2 to 55%), stricture (2.2 to 17%) and pain (0.4 to 3.1%). Most patients were sent home the following day (range 1 to 4 days).

AUTHORS' CONCLUSIONS

Cryotherapy offers a potential alternative to standard therapies for the primary treatment of localised prostate cancer. However, the poor quality of the available studies makes it difficult to determine the relative benefits of this modality. Randomised trials are needed to fully evaluate the full potential of cryotherapy in men with this disease. Patients selecting cryotherapy as their therapeutic option should be made fully aware of the reported efficacy, complications and the low-grade evidence from which these data are derived.

Ultrasound probe positioning to minimize the risk of recto-urethral fistula during cryosurgical ablation of prostate cancer

OBJECTIVE

To evaluate the ability to increase the distance between the rectal mucosa and prostate, and thus decrease the risk of recto-urethral fistula, and to improve the ability to adequately freeze beyond the prostatic capsule during cryosurgical ablation for prostate cancer.

PATIENTS AND METHODS

The transrectal ultrasound probe was manipulated to increase the distance from the rectal mucosa to prostate in 28 men scheduled for cryosurgical ablation for localized prostate cancer. Ten patients were treated for local recurrence after previous definitive radiotherapy, and cryosurgery was chosen as the primary treatment for the remainder.

RESULTS

The mean (range) distance from the rectal mucosa to the prostate when the probe was securely applied to the rectal wall was 2.5 (1-7) mm, and could be extended to 9.6 (7-14) mm before the ultrasonogram quality diminished enough to impede accurate placing of the cryoprobe. The mean distance gained as a margin of error was 7.1 (4-12) mm (P < 0.001). In no patient was it felt that visualization during the freezing cycles was impaired. No recto-urethral fistula was identified.

CONCLUSION

The manoeuvres described here allow the surgeon to freeze beyond the prostatic capsule while maintaining a visible distance from rectal wall. The extra distance created by this manoeuvre might reduce the risk of recto-urethral fistula, and potentially improve tumour control in the posterior aspect of the prostate, based on the ability to freeze beyond the capsule to reach lethal temperatures in all prostatic tissue.

Randomized trial comparing cryoablation and external beam radiotherapy for T2C-T3B prostate cancer

The objective was to evaluate the relative efficacy of cryoablation (CRYO) versus external beam radiation (EBRT) for clinically locally advanced prostate cancer in a randomized clinical trial. Patients with histologically proven, clinically staged as T2C, T3A or T3B disease were randomized with 6 months of perioperative hormone therapy to one of the two procedures. Owing largely to a shift in practice to longer term adjuvant hormonal therapy and higher doses of radiation for T3 disease, only 64 out of the planned 150 patients were accrued. Twenty-one of 33 (64%) in the CRYO group and 14 of 31 (45%) in the EBRT-treated group who had met the ASTRO definition of failure were also classified as treatment failure. The mean biochemical disease-free survival (bDFS) was 41 months for the EBRT group compared to 28 months for the CRYO group. The 4-year bDFS for EBRT and CRYO groups were 47 and 13%, respectively. Disease-specific survival (DSS) and overall survival (OS) for both groups were very similar. Serious complications were uncommon in either group. EBRT patients exhibited gastrointestinal (GI) adverse effects more frequently. Taking into account the relative deficiency in numbers and the original trial design, this prospective randomized trial indicated that the results of CRYO were less favorable compared to those of EBRT, and was suboptimal primary therapy in locally advanced prostate cancer.

Cryoablation as Primary Treatment for Localized Prostate Cancer Followed by Penile Rehabilitation

OBJECTIVES

To determine the medium term efficacy and morbidity of patients who underwent cryoablation as primary therapy for localized prostate cancer followed by a penile rehabilitation regimen.

METHODS

Patients were treated with whole gland cryoablation. Those potent at intervention were encouraged to use a vacuum erection device regularly after treatment. Incontinence was defined as any leakage of urine. Potency was defined as the ability to achieve an erection sufficient to complete intercourse with or without oral pharmaceutical agents. Biochemical failure was defined as three successive rises in prostate-specific antigen, with a final value greater than 1.0 ng/mL.

RESULTS

A total of 416 consecutive patients were treated. The mean patient age was 69.4 years, mean prostate-specific antigen level was 8.7 ng/mL, median Gleason score was 6, and median stage was T1c. The mean follow-up of the entire population was 20.4 +/- 14.7 months. Of those continent before treatment, 4.0% were incontinent at 6 months but only 2 (0.6%) used any absorbent pads. Kaplan-Meier analysis demonstrated progressive recovery of sexual function of preoperatively potent men, with 41.4% +/- 4.3% and 51.3% +/- 5.9% potent 1 and 4 years after treatment, respectively. No patients had rectal fistula. The actuarial probability of remaining biochemically disease free at 4 years was 79.6% +/- 2.4%, with a mean time to failure of 4.2 months. After therapy, 168 patients underwent biopsy; 17 had positive findings (10.1%). The positive biopsy rate for the entire population was 4.1% (17 of 416).

CONCLUSIONS

The results of our study have indicated that cryoablation as a primary treatment of localized prostate cancer is effective with acceptable morbidity. The use of a penile rehabilitation regimen after treatment appeared to substantially increase postcryoablation potency.

Minimally Invasive Approaches to Localized Prostate Carcinoma

Prostate cancer is an increasing medical problem. Radical prostatectomy and radiation therapy are effective treatments, but have the risk of significant morbidity. Clinicians have strived to develop new modalities of treatment that can maintain the excellent treatment outcomes of radical prostatectomy, but diminish the morbidity. Improved instrumentation, optics, and robotic technology have allowed the application of laparoscopic techniques to radical prostatectomy. Patients can have less blood loss and expect more rapid recovery. Intermediate oncologic outcomes appear similar to radical prostatectomy with good functional results. Cryotherapy and HIFU are tissue ablative approaches rather than extirpative approaches to prostate cancer treatment. They attempt to use nonsurgical methods to treat prostate cancer with the hope of providing oncologic control comparable to surgery and radiation while minimizing morbidity.

Feasibility of nerve-sparing prostate cryosurgery: applications and limitations in a canine model

BACKGROUND AND PURPOSE

In a canine model, we evaluated the feasibility of nerve-sparing cryosurgery by active warming of the neurovascular bundle (NVB). Furthermore, our aim was to determine if NVB warming increases the risk of acinar gland and stromal-tissue preservation in adjacent areas of the prostate. The effects of a single versus double freeze-thaw cycle on prostate tissue were also assessed.

MATERIALS AND METHODS

Ten prostate lobes from five dogs were evaluated. Nine lobes from five dogs were treated with cryoablation using 17-gauge gas-driven cryoneedles. Seven lobes wre treated with active warming of the NVB using helium gas, and two lobes were treated without active warming. A single or double freeze-thaw cycle was utilized. Prostate tissue ablation and NVB preservation were evaluated in histologic sections.

RESULTS

All seven prostate lobes treated with active warming demonstrated complete or partial NVB preservation. Four of these lobes had adjacent gland preservation. All lobes treated with a double freeze-thaw cycle showed complete and uniform ablation of prostate tissue. One of the three lobes treated with a single freeze-thaw cycle demonstrated incomplete ablation of the tissue.

CONCLUSIONS

This is the first study investigating the feasibility of NVB preservation under controlled experimental conditions. In our canine model, NVB preservation with active warming was possible but not consistently reproducible. In some cases, NVB preservation with active warming may result in incomplete peripheral tissue ablation. A double, but not a single, freeze-thaw cycle induces complete and effective necrosis of prostatic tissue. These results have significant clinical applications when attempting nerve-sparing cryosurgical ablation of the prostate.

Critical review of the efficacy and safety of cryotherapy of the prostate

Modern cryoablation of the prostate is a procedure that has evolved since the early 1990s into a safer and more successful treatment of adenocarcinoma of the prostate. The improvement of this technique has taken place secondary to advancement in engineering, procedure refinement, temperature monitoring, and a better understanding of physiologic events during the freezing process. Long-term results are available that demonstrate durable efficacy equivalent to other therapies in low-risk groups. In moderate to high risk groups, results point toward equal to superior results than other standard therapies. New ideas on potency preservation using vacuum erection devices have improved men's return to function over the course of the postoperative year. Early morbidity issues, such as fistula formation and incontinence, have become much less problematic, with results between 0% and 1% in some series. Cryoablation of the prostate now offers significantly improved outcomes with a parallel decrease in morbidity.

THE SPEED OF ICE GROWTH AS AN IMPORTANT INDICATOR IN CRYOSURGERY

PURPOSE

We consider the speed of ice growth as an indicator of the speed of cooling and investigated its impact on the factors at the cell death boundary in an in vitro simulated cryosurgical system.

MATERIALS AND METHODS

PC-3 cells were cultured in culture plates and simulated cryosurgery was performed under different speeds of ice growth using an in vitro simulated cryosurgical system. The freezing front was closely monitored. Cells were fixed and stained 24 hours after cryosurgery. The distance from the cell death boundary to the ice front was measured and defined as the distance gap. It was correlated with the speed of ice growth. Temperature history at the cell death boundary was retrieved and also correlated with the speed of ice growth.

RESULTS

A high correlation between the speed of ice growth and the temperature gradient plus an inverse correlation between the speed of ice growth and the distance gap were found. The distance gap narrowed when the speed of ice growth was around 3 mm per minute but widened when the speed of ice growth was slower than 1.5 mm per minute.

CONCLUSIONS

Changes in ice growth speed indicate changes in the temperature gradient, and the distance between the ice front and the cell death boundary. Different treatment end points should be chosen according to the speed of ice growth to increase accurate cell killing.

Cryotherapy

TRUS-guided transcutaneous cryotherapy in the treatment of the prostatic carcinoma is performed by perineal approach, the intraoperatory monitoring of temperatures and a mechanical hydraulic sonorguided separation between prostate and the anterior rectal wall. Six to eight probes are used, the Argon gas in the freezing phase (-10 °C and -40 °C) and Helio gas for heating phase.

TRUS-guided cryoterapy is a possible therapeutich option in the treatment of localized or locally advanced prostatic carcinoma and after RT, in case of the relapse in alternative to the rescue prostatectomy.

We examined in both procedures the most significant series concerning the oncologic results and morbility.

At present, TRUS-guided cryotherapy represents a mininvasive therapeutic option in selected patients (ASA 2–3).

For the future an evaluation of the survival years compared with quality of life and randomized studies will be necessary.

Prostate cancer: cryotherapy

The incidence of prostate cancer has more than doubled in the last 10 years, and 220,900 new cases will be detected in 2003. This increase is due in large part to increased use of prostate-specific antigen (PSA)-based screening, transrectal ultrasonography, and random biopsy of the prostate. The treatment of prostate cancer, however, remains controversial, and no consensus has been established as to what constitutes appropriate treatment for any stage of disease, especially for localized cancers. Radical prostatectomy, radiation therapy, or watchful waiting all have their advocates, and the risks and benefits of these approaches are discussed frequently. Skepticism about conventional treatments has stimulated patients and physicians to search for alternatives that are effective and associated with limited morbidity. Technologic developments have rekindled interest in cryotherapy as a viable alternative to other, more conventional localized therapies. Given the relative paucity of alternatives for patients who experience biochemical progression after radiotherapy, cryosurgery also may prove to be a good alternative for those patients whose tumors appear to remain localized despite progression. In addition, it appears that cryosurgery will play an increased role in the future management of prostate cancer.

Comparison of health-related quality of life and prostate-associated symptoms after primary and salvage cryotherapy for prostate cancer

PURPOSE

Recent advances in cryosurgery of the prostate have led to the ability to treat tumors successfully with decreased morbidity. The patients' perspectives of this relatively new technique, however, have not yet been addressed. The purpose of this study was to compare health related quality of life (QoL) as well as prostate-associated symptoms in patients after primary and salvage cryoablation for clinically localized prostate cancer using a self-administered questionnaire.

METHODS

A total of 131 consecutive patients who underwent cryoablation of the prostate between 1997 and 2001 were included in this confidential mailing study. The patients were either (a) patients with localized prostate cancer with contraindications for radical surgery, including patients refusing other forms of therapy, or (b) had locally recurrent prostate cancer after failure of radiation therapy. All patients received 3 months of neoadjuvant androgen deprivation therapy prior to cryosurgery and were surgically treated by the same surgeon using an argon-based system. We used the EORTC QLQ-C30, a commonly used, multidimensional instrument together with a supplementing, prostate-cancer-specific module.

RESULTS

Eighty-one of the 131 patients (response rate 62%) returned the questionnaires. The two groups were comparable regarding age (mean age 72.8 vs 70.1 for the primary and the salvage group, respectively; p=0.22). The overall QoL scores were high in both groups. Primary cryotherapy patients fared significantly better regarding physical (p=0.005) and social (p=0.024) functioning compared with salvage cryotherapy patients. The most prominent prostate-related symptom in both patient groups was sexual dysfunction, followed by urinary symptoms, which were significantly more severe in the salvage group (p=0.001). Incontinence rates were 5.9 and 10% in the primary and the salvage group, respectively. Severe erectile dysfunction was reported in 86 and 90% of the primary and the salvage group, respectively.

CONCLUSIONS

The present study demonstrates that, in selected patients, cryotherapy is a treatment option which has a functional outcome comparable to traditionally used prostate cancer treatments. More information regarding QoL is necessary for appropriate patient counseling and individual decision-making in the presence of various treatment alternatives.

Active rectal wall protection using direct transperineal cryo-needles for histologically proven prostate adenocarcinomas

INTRODUCTION AND OBJECTIVES

Cryosurgical ablation of the prostate is a promising new modality for the treatment localized prostate cancer. However, better protection of the rectal wall during cryoablation of the peripheral zone of the prostate (PZP) may permit deeper freezing of the PZP and for longer time, rendering the procedure safer and more effective. We present a modified cryoablation technique of the prostate using the SeedNet system (Galil Medical, Uniondale, NY, USA), in which the rectum is actively protected during cryoablation.

PATIENTS AND METHODS

During a 12-month period, 31 patients (32 procedures) with localized and histologically proven prostate adenocarcinoma of various stages and grades were treated in this fashion. We evaluated the feasibility of a new method of active rectal wall protection during cryoablation of the prostate. Fourteen ultrathin, 17-gauge, probes, cryo-needles were percutaneously introduced under transrectal ultrasound (TRUS) guidance into the prostate. Peripheral region of the prostate and the area between the prostate and rectal wall were real time monitored for temperature changes. Two cryo-needles placed between the prostate and rectal wall served for active warming using the thawing mode when the temperatures dropped to approximately 0 degrees C, and rectal lumen washing with hot water (+40 degrees C) when the temperature reading dropped further to -8 degrees C or -10 degrees C.

RESULTS

Active protection of the rectal wall using the cryosurgical modification of active thawing by the two additional cryo-needles placed in the space between the prostate and rectum, while freezing the prostate was performed in every patient, thus enabling us a safe generation of an iceball at the peripheral zone of the prostate with an average temperature ranging from -35 degrees C to -60 degrees C, for 10 min per cycle. During a follow-up of up to 18 months (mean 13.2 months) there was a PSA decrease to values equal or less than 0.5ng/ml in 25 patients (80.6%) and to values equal or less than 1 ng/ml in 21 patients (67.7%). There were no cases of rectal injury or postoperative rectal pain in any of these patients.

CONCLUSIONS

This new cryotechnique of active rectal wall protection during cryotherapy of the prostate was safe and simple to perform, resulting in no rectal injuries. It was also very effective in ablating the prostate gland, as expressed by the low follow up PSA values.

The current and potential role of cryoablation as a primary therapy for localized prostate cancer

Targeted cryoablation of the prostate has evolved significantly since its reintroduction in the early 1990s. This evolution stems from engineering advancements, procedural refinement, introduction of temperature monitoring, and greater understanding of cryobiology. Recent publications demonstrate durable efficacy for cryoablation, equivalent to other therapies for low-risk disease and possibly superior for moderate- and high-risk prostate cancer. Morbidity following the procedure is mild in comparison with other therapies, with the exception of sexual function impairment. However, longer-term quality-of-life studies show that a significant number of patients return to having intercourse, and late-onset morbidities are not observed. These results contrast with those for radiotherapy--specifically brachytherapy--for which several recent studies document a decline in sexual function, protracted morbidity, and the emergence of late-onset morbidity. Cryoablation is an effective therapy with acceptable morbidity that should be offered as a treatment option to all patients with localized prostate cancer. Furthermore, cryoablation has the potential ability to be tailored to an individual patient's disease. As diagnostic tools and methods continue to advance, it may become possible to target the less aggressive forms of prostate cancer. Focal cryoablation may prove to be an ideal treatment modality in this setting.

The evolution and state of modern technology for prostate cryosurgery

Cryosurgery is the in situ ablation of a target tissue by application of extreme cold temperature. The ability of cryosurgery to ablate tissue is unquestioned. It is the controlled application of a cryoinjury in a manner to minimize morbidity that is problematic. Prostate cryosurgery is complicated by the proximity of the prostate to adjacent structures that are sensitive to a freeze injury, namely the urethra, rectal wall, and neurovascular bundles. Several recent technological advances have led to the development of an effective treatment protocol with acceptable morbidity. These include the advent of real-time transrectal ultrasound, cryomachines with almost instant freeze-thaw control through the use of the Joule-Thompson effect, and warming catheters to effectively preserve the integrity of the urethra and external sphincter. Further, temperature monitoring at the posterior margin of the prostate sometimes combined with an injection of saline solution into Denonvilliers fascia has reduced the occurrence of urethrorectal fistula formation to 0% to 0.5% in modern series. We review the key innovations of prostate cryosurgery that differentiate this state-of-the-art procedure from that used by early investigators to even that of the early 1990s. Potential future innovations, specifically related to image guidance of the procedure, are also addressed.