Short-term outcomes after cryosurgical ablation of the prostate in men with recurrent prostate carcinoma following radiation therapy

Image-guided percutaneous cryo-ablation of peri-urethral unresectable recurrent pelvic malignancy: A case report and brief review

Recurrent or metastatic peri-urethral pelvic malignancies are a difficult-to-treat entity. Re-resection is recommended when possible but is frequently unfavorable due to scar tissue, fibrosis, and obliteration of tissue planes following previous interventions such as surgical resection and/or radiation therapy. Curative options for patients that have unresectable cancer are limited. Cryo-ablation has been extensively studied in the treatment of unresectable renal, liver and lung malignancies and has the potential to provide definitive treatment for recurrent pelvic malignancy. There is a paucity of reports of salvage cryo-ablation in patients with recurrent pelvic malignancies, as most of these tumors are located close to critical structures that could be irreversibly injured by thermal ablation and are hence treated with some form of radiation therapy. But, for patients who fail surgical and radiation treatments, options are limited. Here, we describe two cases of regional tumor recurrence in the pelvis treated with percutaneous cryoablation using protective techniques to avoid thermal injury to adjacent structures. In each case, cryo-ablation was performed successfully despite extensive previous surgical and radiation interventions. Salvage cryo-ablation resulted in a positive clinical and imaging response with an improvement in quality of life and absence of recurrence on follow-up imaging which continues to persist at the writing of this manuscript about 8 and 12-months following treatment.

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.

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.

Focal therapy in the management of prostate cancer: an emerging approach for localized prostate cancer

A widespread screening with prostate-specific antigen (PSA) has led increased diagnosis of localized prostate cancer along with a reduction in the proportion of advanced-stage disease at diagnosis. Over the past decade, interest in focal therapy as a less morbid option for the treatment of localized low-risk prostate cancer has recently been renewed due to downward stage migration. Focal therapy stands midway between active surveillance and radical treatments, combining minimal morbidity with cancer control. Several techniques of focal therapy have potential for isolated ablation of a tumor focus with sparing of uninvolved surround tissue demonstrating excellent short-term cancer control and a favorable patient's quality of life. However, to date, tissue ablation has mostly used for near-whole prostate gland ablation without taking advantage of accompanying the technological capabilities. The available ablative technologies include cryotherapy, high-intensity focused ultrasound (HIFU), and vascular-targeted photodynamic therapy (VTP). Despite the interest in focal therapy, this technology has not yet been a well-established procedure nor provided sufficient data, because of the lack of randomized trial comparing the efficacy and morbidity of the standard treatment options. In this paper we briefly summarize the recent data regarding focal therapy for prostate cancer and these new therapeutic modalities.

Long-term cancer-specific and overall survival for men followed more than 10 years after primary and salvage cryoablation of the prostate

INTRODUCTION

Ten-year disease-specific survival for clinically localized prostate cancer after radiation is 93%, 88%, and 80% for low-, medium-, and high-risk groups, respectively. The objective of this study was to report long-term cancer survival outcomes for patients who had undergone prostate cryotherapy at our institution more than 10 years ago. To date, this is the longest reported follow-up after cryotherapy.

MATERIALS AND METHODS

A retrospective patient chart review, conducted of an Institutional Review Board (IRB)- approved cryotherapy database, identified 76 men who had undergone prostate cryotherapy before January 1999. Pre-, intra-, and posttreatment data were collected. Primary study endpoints were overall mortality and prostate-cancer-specific death. Secondary endpoints were disease recurrence and clinical progression.

RESULTS

Mean patient age was 69.2 (47.4-86.3) years; median preoperative prostate-specific antigen was 5.3 (0.2-208.0); mean Gleason score was 7. Forty of 76 (52.6%) were confirmed D'Amico high risk. Median follow-up was 10.1 (0.2-14.9) years; 25 patients underwent primary treatment; 51 postradiation. After 10 years of follow-up, 43 of 76 men (56.6%) were still alive; 33 men (43.4%) had died-10 (13.2%) from prostate cancer, 18 (22.4%) from noncancerous causes, and 5 (6.6%) unknown.

CONCLUSIONS

The long-term results of prostate cryotherapy in our series indicate an 87% overall 10-year prostate-cancer-specific survival, despite early cryotherapy technology and the majority of patients being D'Amico high risk.

Minimally invasive surgical approaches and management of prostate cancer

For clinically localized prostate cancer, radical prostatectomy remains the "gold standard" treatment. New forms of minimally invasive therapies are sought out by patients, however, because of the potential morbidity associated with open surgery. With quality-of-life aspects influencing patient decision making, minimally invasive therapeutic modalities have generated great interest among patients. Laparoscopic radical prostatectomy, robotic-assisted laparoscopic prostatectomy, brachytherapy, cryotherapy, and high-intensity focused ultrasound are all considered to be minimally invasive treatment options for the management of clinically localized prostate cancer.

Initial clinical experience with real-time transrectal ultrasonography-magnetic resonance imaging fusion-guided prostate biopsy

OBJECTIVE

To evaluate the feasibility and utility of registration and fusion of real-time transrectal ultrasonography (TRUS) and previously acquired magnetic resonance imaging (MRI) to guide prostate biopsies.

PATIENTS AND METHODS

Two National Cancer Institute trials allowed MRI-guided (with or with no US fusion) prostate biopsies during placement of fiducial markers. Fiducial markers were used to guide patient set-up for daily external beam radiation therapy. The eligible patients had biopsy-confirmed prostate cancer that was visible on MRI. A high-field (3T) MRI was performed with an endorectal coil in place. After moving to an US suite, the patient then underwent TRUS to visualize the prostate. The US transducer was equipped with a commercial needle guide and custom modified with two embedded miniature orthogonal five-degrees of freedom sensors to enable spatial tracking and registration with MR images in six degrees of freedom. The MRI sequence of choice was registered manually to the US using custom software for real-time navigation and feedback. The interface displayed the actual and projected needle pathways superimposed upon the real-time US blended with the prior MR images, with position data updating in real time at 10 frames per second. The registered MRI information blended to the real-time US was available to the physician who performed targeted biopsies of highly suspicious areas.

RESULTS

Five patients underwent limited focal biopsy and fiducial marker placement with real-time TRUS-MRI fusion. The Gleason scores at the time of enrollment on study were 8, 7, 9, 9, and 6. Of the 11 targeted biopsies, eight showed prostate cancer. Positive biopsies were found in all patients. The entire TRUS procedure, with fusion, took approximately 10 min.

CONCLUSION

The fusion of real-time TRUS and prior MR images of the prostate is feasible and enables MRI-guided interventions (like prostate biopsy) outside of the MRI suite. The technique allows for navigation within dynamic contrast-enhanced maps, or T2-weighted or MR spectroscopy images. This technique is a rapid way to facilitate MRI-guided prostate therapies such as external beam radiation therapy, brachytherapy, cryoablation, high-intensity focused ultrasound ablation, or direct injection of agents, without the cost, throughput, or equipment compatibility issues that might arise with MRI-guided interventions inside the MRI suite.

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.

Salvage Cryosurgery for Recurrent Prostate Carcinoma after Radiotherapy

Cryotherapy is a salvage treatment for patients with biopsy-proved prostatic adenocarcinoma recurrent after radiotherapy. Proper sampling, labeling, and analysis of prostate biopsies allows prompt diagnosis, identification of important prognostic parameters, and planning of an appropriate therapeutic strategy. Whereas androgen-suppressive therapy is associated with only a temporary benefit, transperineal salvage cryosurgery offers a potentially curative option for patients with localized disease, even those with significant comorbidities. Technological advances, including computerized treatment planning and miniaturized cryoprobes, may provide further therapeutic advantages and lower complication rates. Cryotherapy should be included among the established therapeutic options for recurrence after radiotherapy.

Patient selection, cancer control, and complications after salvage local therapy for postradiation prostate-specific antigen failure

Among men who experience prostate-specific antigen (PSA) failure after external beam radiation or brachytherapy (RT), many will harbor occult micrometastases; however, a significant minority will have a true local-only failure and, thus, potentially may benefit from a salvage local therapy. Those most likely to have a local-only failure initially have low-risk disease (PSA < 10 ng/mL, Gleason score < or =6, clinical T1c or T2a tumor status), pretreatment PSA velocity < 2.0 ng/mL per year at the time of initial presentation, interval to PSA failure > 3 years, PSA doubling time > 12 months, negative bone scan and pelvic imaging, and positive rebiopsy. In addition, men with presalvage PSA levels > 10 ng/mL, presalvage T3/T4 disease, or presalvage Gleason scores > or =7 on a rebiopsy sample without significant RT effects are unlikely to be cured by salvage local therapy. Based on a review of all series of post-RT salvage prostatectomy, cryosurgery, and brachytherapy published in English since 1990, morbidity can be substantial. Although urinary incontinence appeared to be greater after salvage prostatectomy (41%) or cryosurgery (36%) than after brachytherapy (6%), patients who received salvage brachytherapy faced a 17% risk of grade 3 or 4 genitourinary complications and a fistula risk that averaged 3.4% across all series. From this review, the authors concluded that prospective randomized studies are needed to determine the relative efficacy of the 3 major local salvage modalities and that additional research is needed to identify factors associated with an increased risk of significant complications to improve patient selection and to augment the benefit/risk ratio associated with attempts to cure local-only recurrences after radiation 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.

Histological changes in prostate biopsies after salvage cryotherapy: effect of chronology and the method of biopsy

OBJECTIVES

To examine changes in prostate biopsies at different intervals after salvage cryotherapy and the effect of biopsy type (transrectal ultrasonography-guided vs transurethral resection, TUR), as the sequence and extent of histological changes occurring in the prostate after salvage cryotherapy for local failure of prostate cancer treatment are unknown.

PATIENTS AND METHODS

In all, 158 prostate biopsies from 150 patients were examined histologically after salvage cryotherapy for prostate cancer after radiotherapy had failed. Specimens were grouped by time from cryotherapy and biopsy technique.

RESULTS

Biopsies showed hyalinization, necrosis, inflammation and residual cancer. Hyalinization became predominant over time, most notably in biopsies with no residual cancer. Core biopsies showed more hyalinization and regenerating glands, while TUR biopsies showed more necrosis and inflammation.

CONCLUSIONS

Tissue cryo-injury and reactive changes last for >1 year; more extensive cryo-injury suggests more effective cancer ablation. A long-term follow-up is necessary, as prostate cancer might remain indolent for >1 year.

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.

Transperineal Salvage Cryosurgery (SC) for Prostate Adenocarcinoma

Criteria used for the diagnosis and treatment of recurrent prostate adenocarcinoma after radiotherapy are examined according to recently published studies in the literature. The diagnosis of recurrence is confirmed by the histological test of a biopsy performed due to the gradual increase in prostate-specific antigen (PSA). Proper sampling, nomenclature and analysis of prostate biopsies allow an early diagnosis to identify some important prognostic parameters and to plan the most appropriate therapeutic strategy for every single case. Androgen suppressive therapy only induces a temporary benefit in these patients. Transperineal salvage cryosurgery (SC) represents a recognized effective treatment option. Technological advances, including computerized treatment planning and miniaturized cryoprobes, allow further potential therapeutic advantages and reduce complications. Results of SC are promising even in patients with other comorbidities; therefore, it is useful to include it among therapeutic instruments for failures following radiotherapy.

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.

Salvage cryosurgery for locally recurrent prostate cancer following radiotherapy

The popularity of radiotherapy as a minimally invasive treatment for prostate cancer is increasing. Despite advancements in radiation delivery, a number of patients will fail treatment. Salvage radical prostatectomy has been the main therapeutic option for locally recurrent radiation failure prostate cancer with curative intent. The operation is technically difficult to perform and associated with significant comorbidities. Salvage cryotherapy has emerged as a minimally invasive alternative option. In this article, we review the role of cryotherapy in recurrent prostate cancer and compare its outcome with salvage radical prostatectomy.

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.

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.

Incomplete glandular ablation after salvage cryotherapy for recurrent prostate cancer after radiotherapy

PURPOSE

To determine the clinical variables associated with inadequate salvage cryotherapy and to correlate the disease-free survival rates associated with biopsy results in prostate cancer (CaP).

METHODS AND MATERIALS

Between July 1992 and January 1995, 150 patients underwent salvage cryotherapy for locally recurrent CaP. Biopsy specimens were examined for the presence of cancer cells and normal or atypical glands, all of which were considered evidence of inadequate cryotherapy. Clinical variables, as predictors of biopsy results, were evaluated with univariate and multivariate analyses. The impact of the biopsy results on disease-free survival was also determined.

RESULTS

The number of cryoprobes and freeze-thaw cycles correlated with inadequate cryotherapy (p = 0.037 and p = 0.0022, respectively). The number of freeze-thaw cycles was an independent predictor of inadequate cryotherapy (p = 0.003). The finding of cancer cells in the biopsy specimens was the only histopathologic variable that affected disease-free survival (p = 0.016).

CONCLUSION

Complete ablation of the prostate gland and tumor is difficult to achieve with salvage cryotherapy. To optimize for complete ablation, salvage cryotherapy should include at least two freeze-thaw cycles and a minimum of five cryoprobes. The finding of atypical or normal epithelial tissue in biopsy specimens after salvage cryotherapy is not predictive of biochemical failure.

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.

PSA progression following radical prostatectomy and radiation therapy: new standards in the new Millennium

Prostate-specific antigen (PSA) progression following radical treatments of clinically localized prostate cancer is a common problem facing both the patient and the urologist. Not all patients with relapsing disease have an equal risk of death due to prostate cancer. After surgery, biochemical failure can be defined as persisting detectable levels of PSA after radical prostatectomy or a PSA rise after a period of normalization. On the other hand, definitions of PSA progression after radiation therapy vary and no clear consensus can be found. This review of the recent international literature updates the knowledge about the diagnostic procedures used in relapsing patients. Predictors of progression are precised leading to a better patient selection, based on currently available tables and nomograms. Indeed, identification of high risk patients may allow a more appropriate treatment decision. After radical treatment, the analysis of time to recurrence, PSA doubling time, PSA kinetics combined to modern imaging techniques such as 111In capromab penditide scan may allow a better identification of the recurrence site. Thus, an optimal treatment strategy may be envisaged such as local irradiation, salvage surgery, hormone therapy or combinations for which indications and results are provided. Alternative options such as cryotherapy still need further investigation. At last, the use of artificial neural networks will certainly enhance the selection of patients submitted to radical treatments as well as the selection of relapsing patients to allow a more appropriate adjuvant therapy.

Photodynamic therapy for prostate cancer recurrence after radiotherapy: a phase I study

PURPOSE

Photodynamic therapy, using a photosensitizing drug activated by red light, can destroy localized areas of cancer with safe healing and without the cumulative toxicity associated with ionizing radiation. We used photodynamic therapy in a phase I-II study to treat patients with locally recurrent prostate cancer after radiotherapy.

MATERIALS AND METHODS

Patients with an increasing prostate specific antigen (PSA) and biopsy proven local recurrence after radiotherapy were offered photodynamic therapy. Three days after intravenous administration of the photosensitizer meso-tetrahydroxyphenyl chlorin, light was applied using optical fibers inserted percutaneously through perineal needles positioned in the prostate with imaging guidance. Patients were followed with PSA measurements, prostate biopsies, computerized tomography or magnetic resonance imaging and questionnaires on urinary and sexual function.

RESULTS

Photodynamic therapy was given to 14 men using high light doses in 13. Treatment was well tolerated. PSA decreased in 9 patients (to undetectable levels in 2) and 5 had no viable tumor on posttreatment biopsies. After photodynamic therapy, contrast enhanced computerized tomography or magnetic resonance imaging showed necrosis involving up to 91% of the prostate cross section. In 4 men stress incontinence developed (troublesome in 2 and mild in 2) which is slowly improving. Sexual potency was impaired in 4 of the 7 men able to have intercourse before photodynamic therapy, which did not improve. There were no rectal complications directly related to photodynamic therapy, but in 1 patient a urethrorectal fistula developed following an ill-advised rectal biopsy 1 month after therapy.

CONCLUSIONS

Photodynamic therapy is a new option that could be suitable for organ confined prostate cancer recurrence after radiotherapy. With more precise light dosimetry, it may be possible to destroy essentially all glandular tissue within the prostate with few complications. These results suggest that photodynamic therapy merits further investigation.

Prospective trial of cryosurgical ablation of the prostate: five-year results

OBJECTIVES

To determine in a prospective pilot study the safety and efficacy of cryosurgical ablation for localized prostate carcinoma.

METHODS

A total of 87 cryosurgical procedures were performed on 76 consecutive patients between December 1994 and February 1998. All patients had histologically proved adenocarcinoma of the prostate, with prostate-specific antigen (PSA) readings of less than 30 ng/mL. Clinical evaluations, PSA determinations, and patient self-reported quality-of-life questionnaires (functional assessment of cancer treatment-prostate; FACT-P) were used to determine biochemical and clinical disease-free status and complications. Patients had a mean follow-up of 50 months (minimum 36).

RESULTS

Follow-up biopsies were performed in 73 patients, and 72 were negative for malignancy after one or more treatments. Ten patients required two treatments and 1 patient required three treatments. The 5-year overall and cancer-specific survival rate was 89% (95% confidence interval, 83% to 97%) and 98.6% (95% confidence interval, 96% to 100%), respectively. The undetectable PSA rate (less than 0.3 ng/mL) for low-risk patients (n = 13) was 60% at 5 years; for moderate-risk patients (n = 23), it was 77%, and for high-risk patients (n = 40), 48%. The corresponding percentage of patients with a PSA level less than 1.0 ng/mL at 5 years was 75%, 89%, and 76%. Sloughing occurred in 3 patients (3.9%), incontinence in 1 (1.3%), and testicular abscess in 1 (1.3%). At 3 years, 18 (47%) of 38 patients capable of unassisted intercourse at the time of cryosurgery had resumed sexual intercourse, 5 spontaneously and 13 with sildenafil or prostaglandin.

CONCLUSIONS

The results of this prospective evaluation show cryosurgery to be both a safe and an effective option in the treatment of localized prostate cancer.

Prostate cryoablation: a scientific rationale for future modifications

This investigation was designed to identify potential directions for future modification of the percutaneous prostate cryoablation procedure. An analysis of prostate cancer location and volume in radical prostatectomy specimens was performed to evaluate the potential clinical consequences of these proposed modifications. A list of recommendations for improvements in the prostate cryoablation procedure was compiled from informal discussions held with participants in 9 training courses and conferences on prostate cryoablation over 18 months. Subsequently, a population of 112 consecutive, sagittally sectioned whole-mount radical prostatectomy samples was evaluated for prostate cancer volume, number of individual foci, and location to examine the disease-specific outcomes of these proposed modifications. The most common areas for potential alterations in the current cryoablation technique include modifications that would further simplify the procedure, continue to reduce real and perceived toxicity, and augment efficacy. Importantly, modifications designed to reduce treatment side effects could conflict with efforts designed to improve eradication of prostate cancer. Pathologic analysis revealed multifocal cancer in 79.5% of the samples, with 66% of cases exhibiting cancer within 5 mm of the urethra. The median volume of the index cancer was 1.6 cm3, whereas the median volume of the smaller ancillary lesions was 0.3 cm3. Prostate parenchymal-sparing alterations, proposed to reduce incontinence and erectile dysfunction by targeting the index cancer, would likely eradicate clinically significant cancer in 79% of men. The recent enthusiasm for prostate cryoablation as a reasonable minimally invasive treatment option for men with clinically localized cancer is likely to result in modifications of the established surgical technique. Knowledge of the anatomic location and cancer volume within the prostate gland is an important adjunct to planning such alterations. It is possible that parenchymal-sparing modifications to total gland prostate cryoablation can eradicate clinically significant cancer in most men, with a reduction in toxicity and cost.

Salvage cryotherapy for recurrent prostate cancer after radiotherapy: variables affecting patient outcome

PURPOSE

To determine the long-term disease-specific survival (DSS) and disease-free survival (DFS) rates after salvage cryotherapy for locally recurrent adenocarcinoma of the prostate and to identify pretreatment factors that have an impact on DSS and DFS.

PATIENTS AND METHODS

Between July 1992 and January 1995, 131 patients who had received definitive radiation therapy (XRT) underwent salvage cryotherapy for locally recurrent adenocarcinoma of the prostate. Cryotherapy failure was defined as an increasing postcryotherapy prostate-specific antigen (PSA) level of > or = 2 ng/mL above the postcryotherapy nadir, a positive prostate biopsy, or radiographic evidence of metastatic disease. Clinical variables were studied to determine whether there was an association with the DSS and DFS.

RESULTS

The median follow-up was 4.8 years. The 5-year DSS rates were 87% for patients with a precryotherapy Gleason score < or = 8 and 63% for those with Gleason scores of 9 and 10 (P =.012). The 5-year DFS rates were 57% for patients with a precryotherapy PSA level of < or = 10 ng/mL and 23% for those with a PSA level greater than 10 ng/mL (P =.0004). The 5-year DSS rates for patients with a pre-XRT clinical stage of T1 to T2 and those with a clinical stage of T3 to T4 were 94% and 72%, respectively (P =.0041). The 5-year DFS rates for these groups were 90% and 69%, respectively (P =.0057).

CONCLUSION

Androgen-independent local recurrences, Gleason score, and pre-XRT clinical stage were important factors that had an impact on DSS and DFS. The subset of patients cured by salvage cryotherapy seems to be small, and patient selection is important.

Interstitial microwave thermal therapy for prostate cancer: method of treatment and results of a phase I/II trial

PURPOSE

Interstitial microwave thermal therapy is experimental treatment for prostate cancer with the goal of curing disease, while causing fewer complications than standard treatment options. We present a method for delivering interstitial microwave thermal therapy using microwave radiating helical antennae inserted percutaneously under transrectal ultrasound guidance. We report the results of a trial of this method in 25 patients in whom primary external beam radiation therapy had previously failed. This patient group currently has limited curative options that are associated with a high complication rate. However, these recurrent tumors often remain localized to the prostate, and so they may be amenable to localized therapy.

MATERIALS AND METHODS

Patients with proved prostatic adenocarcinoma were candidates for treatment when prostate specific antigen (PSA) was 15 ng./ml. or less and prostate volume was 50 cc. or less. Followup included PSA measurement, digital rectal examination, urinalysis, and documentation of adverse events at 4, 8, 12 and 24 weeks. Sextant biopsy was performed at week 24. The procedure involved the insertion of 5 antennae percutaneously through a modified brachytherapy template. The antenna arrangement was determined based on computer simulated predictions of temperature throughout the prostate. The prostate was dissected away from the rectum by an injection of sterile saline to provide a thermal barrier that protected the rectum from thermal damage. Temperatures were monitored using interstitial mapping thermistor probes that were also inserted through the template. A minimum peripheral target temperature of 55C but less than 70C was maintained for 15 to 20 minutes, while the urethra, rectum and hydrodissection space remained below 42C. The urethra and rectum were actively cooled in addition to hydrodissection.

RESULTS

Peripheral target temperatures of 55C were achieved. The urethra and rectum remained at a safe temperature. The procedure, including setup and treatment, required approximately 2.5 hours of operating room time. At 24 weeks the PSA nadir was 0.5 ng./ml. or less in 52% of patients and 0.51 to 4 ng./ml. was achieved in an additional 40%. The negative biopsy rate at 24 weeks was 64%, assuming that 3 patients lost to followup would have had positive results. No major complications were observed and in most cases minor complications resolved within 3 months.

CONCLUSIONS

Interstitial microwave thermal therapy for prostate cancer was developed to heat the prostate safely to a cytotoxic temperature. Experience with 25 patients in whom external beam radiation therapy for prostate cancer had failed indicates that the treatment is safe. Although our series indicates that this therapy may be effective, further studies and longer followup are required in larger patient groups to confirm the potential role of this therapy as an option for recurrent and primary prostate cancer.

Salvage external beam radiotherapy for clinical failure after cryosurgery for prostate cancer

PURPOSE

To investigate the role of external beam radiotherapy (EBRT) as salvage treatment of prostate cancer after cryosurgery failure.

METHODS AND MATERIALS

Between 1993 and 1998, 6 patients underwent EBRT with curative intent for local recurrence of prostate cancer after cryosurgery. All 6 patients had biopsy-proven recurrence and palpable disease on digital rectal examination at the time of EBRT. The median follow-up was 34 months (range 8-46). The median prostate-specific antigen level was 2.3 ng/mL (range 0.8-4.1). No patient had evidence of metastatic disease. Two patients received hormonal therapy before beginning EBRT. No patient received hormonal therapy after EBRT completion. The median elapsed time between cryosurgery and EBRT was 3 years (range 1.5-4). The median delivered dose was 66 Gy (range 62-70.2) using a 10-MeV photon beam. An in-house-developed three-dimensional treatment planning system was used to plan delivery of the prescribed dose with conformal radiotherapy techniques.

RESULTS

After EBRT, all patients had complete resolution of palpable disease. Four patients (66%) were disease free at the time of the last follow-up. Two patients developed biochemical failure as defined by the American Society for Therapeutic Radiology and Oncology consensus definition. One of these patients had a prostate-specific antigen level of 97 ng/mL before cryosurgery. No patient developed distant metastasis during follow-up. Two patients (33%) developed proctitis; 1 case resolved with Rowasa suppositories and 1 required blood transfusion.

CONCLUSIONS

Our preliminary results suggest that EBRT can render a significant number of patients biochemically free of disease and can cause complete resolution of clinically palpable disease after initial cryosurgery. The results also showed that EBRT can be given without excessive morbidity. EBRT should be considered as a treatment option in these potentially curable cases.

Image-guided prostate cryosurgery: state of the art

BACKGROUND

Cryosurgery was first used to treat prostate cancer in the early 1970s but it was not until 1993, when the results from percutaneous ultrasound-guided cryosurgery were published, that the potential advantages of this treatment became apparent. Changes in equipment and techniques have improved the results of cryosurgery, in both tumor control and lower morbidity.

METHODS

The author has reviewed data of his own and those of others concerning the changes in techniques employed and outcomes from prostate cryosurgery.

RESULTS

Ultrasound-guided percutaneous transperineal placement of the cryoprobes allows monitoring of freezing in real time. Monitoring temperature at critical locations, separating the rectum and prostate by saline injection, and using argon gas rather than liquid nitrogen-based equipment have improved results and lowered complication rates. The technique produces outcomes similar to those obtained with brachytherapy and three-dimensional conformal radiation therapy.

CONCLUSIONS

Advantages of cryosurgery include the ability to re-treat patients without added morbidity and to treat salvage postradiation patients with acceptable results and morbidity. The recent demonstration that "nerve-sparing" cryosurgery is possible suggests that cryosurgery may be used more often.