Kryoablation des lokalisierten Prostatakarzinoms

Due to continuous technical developments for more than half a century followed by better clinical results with minimal side effects, cryoablation of the prostate for localized prostate cancer has evolved as a true alternative therapeutic option in selected cases. The current version of cryoablation has almost nothing in common with those versions established in the 1960s and 1970s and further developed in the 1980s and 1990s. The present version is minimally invasive and has a high efficacy for treatment of high risk carcinomas and failure of other therapeutic modalities. Cryoablation of the prostate is indicated if there are absolute or relative contraindications for radical surgery. In salvage cases cryoablation is the therapy of choice for localized prostate cancer. Standardization of the procedure, definition of freeze-thaw cycles and structured training programs have led to this status.     

Die Kryoablation des Prostatakarzinoms

Because of continuous technical development for more than half a century, followed by better clinical results with minimal side effects, cryoablation of the prostate for localized prostate cancer has evolved as a true alternative therapeutic option in selected cases. Today's form of cryotherapy has almost nothing in common with those versions established in the 1970s and further developed in the 1990s. Nowadays it shows minimal invasiveness and high efficacy for treatment of high-risk carcinomas and failures of other therapeutic modalities. Cryoablation of the prostate is indicated if there are absolute or relative contraindications for radical surgery. In localized prostate cancer, cryoablation is the therapy of choice for salvage cases; standardisation of the procedure, definition of freeze-thaw cycles, and structured training programs have led to this status.     

Cryoablation of renal and prostate tumors

During the past decade, cryoablation has been applied to benign and malignant conditions within the prostate and kidney. The essence of cryosurgery lies in producing temperatures low enough to cause necrosis in target tissues while avoiding lethal conditions in healthy peripheral tissues. It works by two main mechanisms: (1) at the cellular level via solute damage and intracellular ice formation; and (2) at the vascular level as a result of thrombosis and subsequent coagulative and ischemic necrosis. Investigation of cryoablation for renal tumors began in 1964, and by the 1990s, attention was turning to its use as a means of treating renal tumors. Modern renal cryosurgery is applied using minimally invasive techniques. Cryotherapy was first applied in the prostate in 1966 and soon thereafter was used to treat prostate cancer. Today, prostate cryosurgical techniques employ ultrasound monitoring and urethral warming to minimize urethral and rectal complications.     

Prostate cryoablation without an insertion kit using direct transperineal placement of ultrathin freezing probes

A modified technique for prostate cryoablation is described. Prostate cryoablation was performed with a gas-based cryomachine using multiple 17-gauge probes. The 17-gauge probes were inserted via a transperineal route directly into the prostate without using an insertion kit. Probe insertion and positioning are simplified, and operative time is reduced. The perineum is less crowded with devices and tubes. Miniaturizing the cryoprobes and their tubing is feasible. The smaller diameter enables direct insertion without an insertion kit. The surgical result does not seem to be inferior to that of conventional ablation, and penetrating trauma to the prostate is minimal. To the best of our knowledge, this is the first report of transperineal prostate cryoablation performed without an insertion kit.     

The pattern of prostate cancer local recurrence after radiation and salvage cryoablation

Objective:

We assessed the pattern of local recurrence after salvage cryoablation of the prostate, and the impact of local recurrence on intermediate-term outcome.

Methods:

One hundred twenty-two patients who underwent salvage cryoablation were studied after a mean follow-up of 56 months. Serial prostate biopsy was carried out after cryoablation. The histopathology of prostate biopsies before and after cryoablation were compared. The prognostic value of post-cryoablation biopsy was assessed with the Cox regression method.

Results:

23.1% of patients had a positive biopsy for prostate cancer following salvage cryoablation. Most cancer recurrences occurred in the apex (51.5%), base (21.2%) and seminal vesicles (18.2%). The presence of cancer at the base of the prostate was found to be a prognostic factor for eventual biochemical failure. Overall 5-year biochemical disease-free survival (bDFS) was 28%, however patients with cancer at the base of the prostate had a 5-year bDFS of 0%.

Conclusion:

Cancer recurrences occurred in areas where aggressive freezing was avoided as it might result in serious problems (e.g., urethro-rectal fistula and incontinence). Post-cryoablation biopsies and the location of persistent disease are of prognostic value.     

影像引导经皮冷冻消融术治疗肿瘤应用进展

影像引导经皮冷冻消融术(PICA)是在CT、MR以及超声引导下对肿瘤进行快速降温和复温,从而彻底破坏肿瘤组织的一种新兴的治疗技术。与其他消融技术相比,PICA具有独特优势,如局部麻醉下操作、可利用多模态影像介导、术中及术后疼痛症状轻微、对胶原组织损伤较小等。近年来,PICA已用于临床治疗肺、肝、肾、乳腺、前列腺等部位的肿瘤。本文主要对冷冻消融的原理及PICA在肿瘤治疗中的应用进展进行综述。     

超声导向经会阴穿刺冷冻治疗中晚期前列腺癌(附20例报告)

目的：探讨冷冻治疗中晚期前列腺癌的有效性和安全性。方法：在B超引导下,对20例中晚期前列腺癌患者经会阴穿刺液氮冷冻前列腺肿瘤组织,检测冷冻前后PSA,穿刺病理活检以及前列腺和肿瘤体积的影像学变化。结果：20例随访2－48个月,PSA术前平均39．2ng/ml（16．1－98．2ng/ml),术后3、6、9、12、24、48个月分别为4．2、3．8、3．5、3．6、3．0、3．1ng/ml。肛诊、B超、CT及MRI示前列腺体积缩小并基本保持稳定,术后3个月瘤体基本消失,仅有少量瘢痕组织。前列腺前体积由术前平均64．2ml降至25．5ml,术后6个月行前列腺多点穿刺活检,仅1例阳性。全组均未出现冷冻并发症。结论超声导向经会阴穿刺冷冻治疗中晚期前列腺癌是一种安全有效的方法。     

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.     

Salvage prostate cryoablation after primary interstitial brachytherapy failure: a feasible approach

Salvage treatment for recurrent prostate cancer remains a very difficult and challenging field in urologic oncology. The introduction of minimally invasive surgical procedures such a targeted cryoablation brings some hope with its feasibility and efficacy to become a potentially curable treatment. We present the case of a 75-year-old male with prostate cancer treated primarily by brachytherapy, who developed late locally recurrent disease that was successfully treated with targeted salvage cryoablation.     

On-demand use of erectile aids in men with preoperative erectile dysfunction treated by whole gland prostate cryoablation

Prostate cryoablation is an established minimally invasive treatment for localized prostate cancer (PCa). However, the impairment of erectile function (EF) is considered a serious complication of the procedure. To investigate the efficacy of erectile aids following cryotherapy, 93 patients who underwent whole gland prostate cryoablation with required complete medical records were analyzed. The changes in postoperative EF were evaluated using the International Index of Erectile Function (IIEF-5) questionnaire. Additionally, independent factors that could have a correlation to the postoperative IIEF-5 score or postoperative Expanded Prostate Cancer Index Composite (EPIC) score were assessed. In the entire cohort, the mean preoperative IIEF-5 score was 7.0 ± 6.2. A total of 72 (77.4%) patients had moderate-to-severe preoperative erectile dysfunction. In longitudinal investigation, the patients using erectile aids showed the ability to recover to baseline after 24 months from cryoablation compared with the patients not using erectile aids. There were significant differences of IIEF-5 scores between these groups at 24 months (7.5 vs 3.0; P = 0.025) and 36 months (8.5 vs 3.5; P = 0.010). In multivariate analysis, the use of erectile aids correlated with restoration of IIEF-5 scores (odds ratio, 5.11; confidence interval (CI), 1.87-13.96; P < 0.001) and lower EPIC sexual bother (coef, 19.61; CI, 0.32-38.89; P = 0.046). Our data indicate that on-demand use of erectile aids could help restore EF and reduce sexual bother after whole gland prostate cryoablation. Although, erectile aids could not play a role as an adequate treatment for ED after whole gland prostate cryoablation, these results may aid in the decision-making process for PCa patients with preoperative and postoperative ED who have concern about sexual health-related quality of life.     

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 prostate cryoablation: initial results show cancer control and potency preservation

BACKGROUND: Focal prostate cryoablation is the less-than-complete ablation of the gland with ice. Known tumor is ablated aggressively, whereas contralateral prostate tissue and surrounding structures are spared. This method offers targeted local cancer control aiming at sexual potency and urinary continence preservation in patients whose prostate cancer is believed to be unilateral. PATIENTS AND METHODS: Patients who had a strong desire for preservation of sexual function and continence were informed of focal prostate cryoablation as an investigational treatment option for clinically organ-confined, unilateral tumor identified by color Doppler ultrasonography and confirmed by targeted and systematic biopsy. Only stage, not preoperative serum prostate specific antigen concentration (PSA) or tumor differentiation, was considered a potential contraindication. Thirty-one men with a mean age of 63 years underwent the procedure. Follow-up consisted of PSA measurement every 3 months for 1 year and every 6 months thereafter, with biopsies at 6 months and 1, 2, and 5 years and following any three consecutive PSA rises. Potency was determined with a patient questionnaire filled in without the physician present. RESULTS: At a mean follow-up of 70 months, biochemical disease-free status, according to the ASTRO definition, was maintained by 92.8% of patients (26/28) and a 96.0% negative-biopsy rate (24/25) was observed. The one biopsy-positive patient was subsequently treated with full-gland cryoablation and remains disease free. Potency was maintained by 48.1% of patients (13/27) and another 40.7% (11/27) were potent with oral pharmaceutical assistance, yielding a total potency-preservation rate of 88.9%. No complications were observed. CONCLUSION: Focal cryoablation can provide biochemical and local control of prostate cancer while preserving potency and continence. Further investigation is needed.     

Salvage prostate cryoablation for recurrent localized prostate cancer after radiotherapy

Salvage prostate cryoablation (SCA) for recurrent localized prostate cancer after radiotherapy has been studied in Western countries for more than a decade. We present our experience of SCA in a Taiwanese medical center. We performed four cases of SCA for recurrent localized prostate cancer after radiotherapy. The data recorded included age, cancer stage, prostate-specific antigen (PSA) level, Gleason score, prostate volume and patient outcome. The median follow-up period was 17 months. All cases were biopsy-proven to have residual cancer before cryoablation. After SCA, 25% of the patients reached undetectable PSA levels, 50% showed response but did not reach undetectable levels, and 25% showed no decrease in PSA. The median recurrence-free duration after SCA was 18 months in the patients who experienced a decrease in PSA. ADT was initiated after SCA for the patient who did not show any response, and bone metastasis was later diagnosed in that patient. Most patients experienced obstructive voiding problems after SCA, which improved over time. SCA is a safe salvage option for prostate cancer patients with local recurrence after RT. The preliminary results are encouraging. More extensive imagery to exclude extra-glandular disease is warranted before SCA. A longer follow-up period and larger sample size are necessary to delineate the benefits more conclusively.     

冷冻消融治疗恶性肿瘤后机体细胞免疫功能变化的研究进展

冷冻消融术适用于各种恶性肿瘤,包括肝癌、肺癌、前列腺癌、肾癌等,冷冻消融术治疗恶性肿瘤与外科手术切除不同,冷冻消融在破坏肿瘤组织的同时,坏死肿瘤碎片存留在体内,可刺激机体免疫系统诱导抗肿瘤免疫反应。本文就冷冻消融治疗恶性肿瘤后对机体细胞免疫功能的影响进行综述。     

Prostate cryoablation using direct transperineal placement of ultrathin probes through a 17-gauge brachytherapy template—technique and preliminary results

Objectives. To describe a new surgical approach to third-generation cryoablation of the prostate and present our preliminary results.Methods. The technique is detailed and demonstrated in a Web-based video- clip tutorial. Ninety-two men underwent prostate cryoablation (71 primary ablations, 19 salvage procedures, and 2 repeated cryoablations), using direct transperineal placement of ultrathin probes through a 17-gauge brachytherapy template.Results. No fistulous or major complications were observed. Eight patients (8.3%) had minor complications. In 36 patients, the follow-up period was long enough to permit nadir prostate-specific antigen (PSA) evaluation. In 31 (86%), the nadir PSA was 0.5 ng/mL or less. In 5 patients, the nadir PSA was greater than 0.5 ng/mL. The workup revealed systemic failure in 3 patients and inadequate eradication of the prostate gland in 2 patients. In 18 (86%) of 21 androgen-ablation-naive patients, the nadir PSA was 0.5 ng/mL or less. Nine (43%) had an undetectable nadir PSA and 3 had a nadir PSA of greater than 0.5 ng/mL.Conclusions. A modified, less-invasive approach to cryoablation of the prostate is presented. The preliminary results do not show an increased rate of complications compared with other published series. The clinical outcome data are preliminary. Longer follow-up data are required to draw conclusions concerning efficacy.     

冷冻消融治疗前列腺癌诱导肿瘤特异性免疫反应

目的:评价经皮冷冻消融治疗局限性前列腺癌前后机体抗肿瘤免疫反应。方法:10例局限性前列腺癌患者行经皮冷冻消融治疗。分别于冷冻治疗前1d、治疗后2周采取外周血,分离外周血单个核细胞(PBMCs)。穿刺活检制备前列腺自身肿瘤和非肿瘤组织溶解物。酶联免疫吸附测定(ELISA)法检测血清TNF-α、IFN-γ、IL-4、IL-10水平,以IFN-γ/IL-4计算Th1/Th2比值。酶联免疫斑点(ELISPOT)试验检测不同组织溶解物刺激下分泌IFN-γ的T细胞数。以人前列腺癌LNCaP细胞和肾癌GRC-1细胞为靶细胞,乳酸脱氢酶(LDH)释放试验检测细胞毒T淋巴细胞(CTL)特异性杀伤活性。结果:与术前比较,冷冻治疗后TNF-α、IFN-γ明显升高,IL-4、IL-10轻度下降,Th1/Th2比值明显升高(P<0.01)。肿瘤组织溶解物刺激后IFN-γ+T细胞数明显增多(P<0.01)。非肿瘤组织溶解物刺激后,IFN-γ+T细胞数无明显变化。冷冻治疗后细胞毒CTL对人前列腺癌细胞株LNCaP特异杀伤活性明显增强,而对人肾癌细胞株GRC-1无明显杀伤活性。随访3～6个月,仅1例患者肿瘤复发。结论:经皮冷冻治疗前列腺癌可诱导机体产生肿瘤特异性免疫反应。     

Targeted induction of apoptosis via TRAIL and cryoablation: a novel strategy for the treatment of prostate cancer

Adjuvant therapies contribute to the successful treatment of cancer. Our previous reports have shown that combining cryoablation with cytotoxic agents enhances cell death. Tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) is a cytotoxic agent that preferentially induces apoptosis in a variety of human cancer cells. Human prostate cancer cells (PC-3) are resistant to many cytodestructive agents, including cryoablation and TRAIL. Here, we evaluated the effects of TRAIL combined with cryoablation on PC-3 and normal prostate (RWPE-1) cell death. Exposure of PC-3 cells to freezing (-10 degrees C) or TRAIL (500 ng/ml) results in minimal cell death, whereas a complete loss of viability is observed with the simultaneous combination. The synergistic effect was found to be due to a marked increase in apoptosis. Western blot analysis revealed a significant level of caspase-8 and -3 cleavage between 12 and 24 h post-exposure. Caspase activation assays provided similar results and also indicated a role for caspase-9. Inhibitors to caspase-8 and -9 along with a pan-caspase inhibitor were incorporated to determine which pathway was necessary for the combined efficacy. Inhibition of caspase-8 significantly blocked the combination-induced cell death compared to cells that did not receive the inhibitor (63% compared to 10% viable). The addition of the caspase-9 inhibitor resulted in only a minimal protection. Importantly, the combination was not effective when applied to normal prostate cells. The results describe a novel therapeutic model for the treatment of prostate cancer and provide support for future in vivo studies.     

Therapy options in relapsing prostate cancer after external radiation therapy

In the near future, the number of young patients suffering from locoregional recurrence of their prostate cancer after external beam radiation will increase. For these patients, androgen deprivation is the most widely used therapy, but it is only palliative. Salvage radical prostatectomy, cryoablation, interstitial brachytherapy, and high-intensity focused ultrasound (HIFU) are treatment options with the potential of curing the patient. Currently, salvage radical prostatectomy offers the best chance for cure. Although a significant reduction in peri- and postoperative complication rates has been reported, surgery remains technically challenging, with a high rate of urinary incontinence. We believe that salvage prostatectomy should be considered only for patients in good general health whose life expectancy is more than 10 years and whose cancer was initially organ-confined before radiation therapy. Salvage cryotherapy might be an alternative to surgery. Complication rates have decreased as technical application has improved considerably within the last years. A major drawback of cryoablation is its lack of reliable and complete ablation of all prostate cells. HIFU and interstitial brachytherapy are minimally invasive salvage options that have been investigated in small clinical studies.     

The Role of Cryosurgery of the Prostate for Nonsurgical Candidates

Introduction:

Technological advancements have reduced the morbidity associated with cryosurgery, leading to an increased interest in this modality for the treatment of organ-confined prostate cancer. In this study, we critically examine the current role of cryoablation of the prostate to better understand how to counsel patients regarding this treatment option.

Methods:

A database was compiled over a 3-year period (2008–2011) of 30 patients who underwent cryoablation for organ-confined prostate cancer. Indications for cryosurgery included primary treatment, focal treatment (institutional review board–approved prospective study), and salvage cryotherapy for radiation failure. The primary outcomes were biochemical response via prostate-specific antigen (PSA) measurement and morbidity associated with cryoablation. Cryotherapy failure was defined as an increasing postcryotherapy PSA level ≥ 2 ng/mL above the post-treatment nadir, a positive prostate biopsy, or radiographic evidence of metastatic disease.

Results:

Of the 30 patients who underwent cryoablation from 2008 to 2011, 26 patients had complete follow-up data for analysis. Of these patients, 17 (65.38%) had total gland cryotherapy, 5 (19.23%) had salvage cryotherapy for radiation failure, and 4 (15.38%) had focal cryotherapy. The mean patient age was 68 years (54–89); median preoperative PSA was 5.5 ng/mL (1.7–15.9); median prostate volume was 35 mL (15–54); mean Gleason score was 7; and the median PSA at study conclusion was 0.7 (0.02–3.4) ng/mL. Of the 17 patients who had total prostate cryotherapy, 11 (64.7%) had significant factors precluding primary treatment by a surgical and/or radiation approach, including neurological disorders (2), morbid obesity (1), rectal cancer treated with radiation (1), kidney/pancreas transplant (2), ileoanal pouch secondary to inflammatory bowel disease (IBD) (1), renal failure (1), and age (3).There were no intra- or postoperative complications. After a median follow-up of 18 months (1–40), none of the patients with multiple comorbidities had biochemical failures. Two patients from the salvage group experienced treatment failure requiring androgen deprivation therapy.

Conclusions:

This critical analysis of a single-surgeon experience at a large academic prostate cancer program revealed that the contemporary role of cryosurgery is, in select patients with comorbidities, preventing surgical and/or radiation therapy. Additionally, cryosurgery has a role in treating radiation failures. Further studies are necessary to investigate focal cryotherapy as an option for primary treatment, but our preliminary results are promising, without any biochemical failures in our focal therapy cohort.     

Cryosurgical Ablation of the Prostate for Localized Adenocarcinoma: A Preliminary Experience

Purpose

Cryosurgical ablation of the prostate has recently become recognized as a therapeutic option in the treatment of localized adenocarcinoma of the prostate. To assess the efficacy of cryoablation in this disease process several centers have instituted treatment protocols.

Materials and Methods

Our overall series includes 117 ultrasound guided percutaneous transperineal cryoablations performed on 104 patients with localized adenocarcinoma of the prostate. Followup consisted of digital rectal examinations and measurement of prostate specific antigen levels at 3-month intervals after cryosurgery. Additionally, prostate biopsies were obtained 3 to 6 months postoperatively.

Results

Of 63 patients who underwent initial cryosurgery and followup biopsy 47 (75 percent) had negative findings. Of the 16 patients with positive biopsies 10 consented to undergo a second cryosurgical ablation, and 7 of these patients subsequently had negative followup biopsies. Therefore, our disease-free rate at 3 months after 1 or 2 cryosurgical procedures was 95 percent. A total of 46 protocol patients in our series completed 12 months of evaluation and 40 (87 percent) had no evidence of disease. This same cohort showed only minimal disease progression, with disease-free rates of 96, 93, 87 and 87 percent at 3, 6, 9 and 12 months, respectively. Major complications were infrequent.

Conclusions

At 1-year followup our clinical experience shows cryoablation of the prostate to be an effective therapy in select cases of prostatic adenocarcinoma. Long-term efficacy is still in question but, based on current disease-free rates, this therapeutic modality merits continued clinical investigation.