LOCAL TUMOR CONTROL WITH SALVAGE CRYOTHERAPY FOR LOCALLY RECURRENT PROSTATE CANCER AFTER EXTERNAL BEAM RADIOTHERAPY

Current Status of Salvage Cryoablation for Prostate Cancer following Radiation Failure

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

Salvage radical prostatectomy after external beam radiation therapy: a systematic review of current approaches

BACKGROUND

Radical external beam radiotherapy (EBRT) is a standard treatment for prostate cancer patients. Despite this, the rate of intraprostatic relapses after primary EBRT is still not negligible. There is no consensus on the most appropriate management of these patients after EBRT failure. For these patients, local salvage therapy such as radical prostatectomy, cryotherapy, and brachytherapy may be indicated.

OBJECTIVE

The objectives of this review were to analyze the eligibility criteria for careful selection of appropriate patients and to evaluate the oncological results and complications for each method.

METHODS

A review of the literature was performed to identify studies of local salvage therapy for patients who had failed primary EBRT for localized prostate cancer.

RESULTS

Most studies demonstrated that local salvage therapy after EBRT may provide long-term local control in appropriately selected patients, although toxicity is often significant.

CONCLUSIONS

Our results suggest that for localized prostate cancer recurrence after EBRT, the selection of a local treatment modality should be made on a patient-by-patient basis. An improvement in selection criteria and an integrated definition of biochemical failure for all salvage methods are required to determine which provides the best oncological outcome and least comorbidity.

Current status of cryotherapy for prostate and kidney cancer

In terms of treating diseases, minimally invasive treatment has become a key element in reducing perioperative complications. Among the various minimally invasive treatments, cryotherapy is often used in urology to treat various types of cancers, especially prostate cancer and renal cancer. In prostate cancer, the increased incidence of low-risk, localized prostate cancer has made minimally invasive treatment modalities an attractive option. Focal cryotherapy for localized unilateral disease offers the added benefit of minimal morbidities. In renal cancer, owing to the increasing utilization of cross-sectional imaging, nearly 70% of newly detected renal masses are stage T1a, making them more susceptible to minimally invasive nephron-sparing therapies including laparoscopic and robotic partial nephrectomy and ablative therapies. This article reviews the various outcomes of cryotherapy compared with other treatments and the possible uses of cryotherapy in surgery.

Cryotherapy in prostate cancer

Review objectives:

Cryotherapy use has increased due to technological advances. A review of the literature was performed to evaluate the efficacy and outcomes of whole gland, salvage and targeted focal cryotherapy in the management of prostate cancer.

Review findings:

Cryotherapy use has increased significantly over the last 10 years with a trend towards focal ablation. Whole gland cryotherapy, salvage cryotherapy and focal cryotherapy biochemical recurrence rates appear to be comparable to other treatment modalities for low risk disease, however biochemical failure remains difficult to compare across studies due to a lack of consensus regarding appropriate end points for evaluation of cryotherapy. Short-term focal cryotherapy outcomes are encouraging. Side effect profiles for cryotherapy have significantly improved with fourth generation systems while salvage cryotherapy continues to carry a slightly higher risk of incontinence than primary whole gland cryotherapy. The incidence of erectile dysfunction after focal cryotherapy is dramatically lower than that for whole gland ablation.

Conclusions:

Cryotherapy continues to have an active role in the primary and salvage treatment of prostate cancer. Targeted focal cryotherapy is a promising treatment with minimal morbidity. Further long-term data is needed to support targeted therapy in addition to direct comparison with other treatment modalities.

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.

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

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

Cryoablation of the prostate: technical recommendations

The European Association of Urology guidelines on prostate cancer state that cryotherapy is a true therapeutic alternative for patients with clinically localized prostate cancer. The aim of this paper is to establish a uniform practice for performing prostate cryoablation. A collaboration has been set up among five European centres with experience in almost 1000 prostate cancer patients on the use of cryotherapy. The present recommendations were developed through sharing of experience and thorough discussions within the group. This first paper from the group establishes the technical recommendations for use of prostate cryotherapy.

Update on cryotherapy for localized prostate cancer

Stage migration has led to an increased incidence of localized and low-risk prostate cancer. Intermediate-term data are emerging on the efficacy of cryotherapy, but direct comparison to other therapeutic modalities is difficult as the parameters for recurrence are not well defined. Studies using the American Society for Therapeutic Radiation and Oncology and the Phoenix (nadir plus 2) criteria for biochemical recurrence show that primary cryotherapy appears to be comparable for low-risk prostate cancer as other treatment modalities. In addition, health-related quality-of-life measures have improved with the most recent third-generation systems demonstrating low incontinence and urethrorectal fistula rates. Erectile dysfunction is high with whole gland ablation, but focal therapy may reduce these rates while still ablating unilateral cancerous tissue. Prostate cryotherapy for localized prostate cancer is an evolving but viable therapeutic option. Long-term data are still needed to establish a definitive role for cryosurgery in prostate cancer treatment.

Salvage Cryoablation of the Prostate: Followup and Analysis of Predictive Factors for Outcome

PURPOSE

We assessed the efficacy of cryoablation of the prostate with an emphasis on finding predictive factors that lead to improved outcome.

MATERIALS AND METHODS

A total of 187 patients with locally recurrent prostate cancer after radiotherapy underwent salvage cryoablation of the prostate, and were studied after a mean followup of 39 months. Survival analysis was performed with the Kaplan-Meier method. Several variables were tested for predictive value using the Cox regression model including serum prostate specific antigen before radiotherapy, serum prostate specific antigen at cryoablation, clinical stage before radiotherapy, Gleason score before radiotherapy, Gleason score at cryoablation, number of positive biopsy cores and use of neoadjuvant hormonal therapy before cryoablation.

RESULTS

Serum prostate specific antigen at cryoablation was a predictive factor for biochemical recurrence on univariate and multivariate analysis (p <0.001). Patients with pre-cryoablation prostate specific antigen less than 4 ng/ml had a 5 and 8-year biochemical recurrence-free survival of 56% and 37%, respectively. In contrast, patients with pre-cryoablation prostate specific antigen 10 ng/ml or greater had a 5 and 8-year biochemical recurrence-free survival of only 1% and 7%, respectively. Patients with pre-cryoablation prostate specific antigen from 4 to 9.99 ng/ml had intermediate survival outcomes. Of the patients 32% were started on hormonal therapy for disease progression at a mean of 31 months postoperatively. Overall 5 and 8-year survival was 97% and 92%, respectively.

CONCLUSIONS

Salvage cryoablation is a viable treatment option for patients with prostate cancer in whom radiation therapy has failed. Salvage cryoablation should be performed when serum prostate specific antigen is still relatively low because in these patients the procedure may potentially be curative. Even when cryoablation fails to eradicate the disease in some patients, it allows hormonal therapy to be deferred for a significant period of time in that cohort.

Dynamic contrast-enhanced magnetic resonance imaging for localization of recurrent prostate cancer after external beam radiotherapy

PURPOSE

To compare the performance of T2-weighted (T2w) imaging and dynamic contrast-enhanced (DCE) magnetic resonance imaging (MRI) of the prostate gland in the localization of recurrent prostate cancer in patients with biochemical failure after external beam radiotherapy (EBRT).

METHODS AND MATERIALS

T2-weighted imaging and DCE MRI were performed in 33 patients with suspected relapse after EBRT. Dynamic contrast-enhanced MRI was performed with a temporal resolution of 95 s. Voxels enhancing at 46 s after injection to a greater degree than the mean signal intensity of the prostate at 618 s were considered malignant. Results from MRI were correlated with biopsies from six regions in the peripheral zone (PZ) (base, mid, and apex). The percentage of biopsy core positive for malignancy from each region was correlated with the maximum diameter of the tumor on DCE MRI with a linear regression model.

RESULTS

On a sextant basis, DCE MRI had significantly better sensitivity (72% [21of 29] vs. 38% [11 of 29]), positive predictive value (46% [21 of 46] vs. 24% [11 of 45]) and negative predictive value (95% [144 of 152] vs. 88% [135 of 153] than T2w imaging. Specificities were high for both DCE MRI and T2w imaging (85% [144 of 169] vs. 80% [135 of 169]). There was a linear relationship between tumor diameters on DCE MRI and the percentage of cancer tissue in the corresponding biopsy core (r = 0.9, p < 0.001), with a slope of 1.2.

CONCLUSIONS

Dynamic contrast-enhanced MRI performs better than T2w imaging in the detection and localization of prostate cancer in the peripheral zone after EBRT. This may be helpful in the planning of salvage therapy.

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

OBJECTIVE

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

METHODS

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

RESULTS

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

CONCLUSION

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

Prostate gland: MR imaging appearance after vascular targeted photodynamic therapy with palladium-bacteriopheophorbide

PURPOSE

To prospectively evaluate the magnetic resonance (MR) imaging appearance of the prostate and periprostatic tissues after vascular targeted photodynamic therapy (VTP) with palladium-bacteriopheophorbide for locally recurrent carcinoma after external beam radiation therapy.

MATERIALS AND METHODS

Informed consent was obtained from all patients, and approval was obtained from the ethics review boards of all participating institutions. Nonenhanced T2-weighted and dynamic gadolinium-enhanced T1-weighted MR imaging examinations were performed at baseline and 1 week, 4 weeks, and 6 months after VTP in 25 men (age range, 58-83 years; mean age, 73 years) as part of a prospective phase I/II trial. Percentage of MR-depicted necrosis was defined as the volume of nonenhancing prostatic tissue 1 week after VTP divided by the volume of the prostate. Patterns of intra- and extraprostatic necrosis were recorded. Pearson correlation coefficients were used to test correlations between necrosis and prostate-specific antigen level.

RESULTS

Contrast material-enhanced T1-weighted MR images obtained 1 week after therapy showed necrosis in all patients. Treatment margins were irregular in 21 of 25 patients. T2-weighted images showed no clear treatment boundaries in any patient. Extraprostatic necrosis involved the puborectalis or levator ani muscles in 22, obturator internus muscle in 12, periprostatic veins in three, pubic bone marrow in four, and anterior rectal wall in nine of the 25 patients. The neurovascular bundle appeared to be spared in all patients. Percentage of MR-depicted intraprostatic necrosis was correlated with percentage decrease in prostate-specific antigen level (from baseline) at 4 weeks (r=0.41, P=.04) and 12 weeks (r=0.45, P=.02).

CONCLUSION

Contrast-enhanced MR imaging depicts irregular margins of intraprostatic treatment effect. This finding suggests varied tissue sensitivities to VTP with palladium-bacteriopheophorbide.

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

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

Local and systemic therapy for patients with metastatic prostate cancer: should the primary tumor be treated?

Data from well-designed, prospective clinical trials are lacking to support treatment of primary tumor in men diagnosed with metastatic prostate cancer. However, a growing body of evidence suggests that treatment of the primary tumor may enhance cancer control and survival in some men. This evidence is examined and recommendations are made for identifying patients with metastatic prostate cancer who may benefit from definitive treatment of the prostate tumor.

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 therapy for locally recurrent prostate cancer after external beam radiotherapy

The greatest obstacle in the cure of patients with locally recurrent prostate cancer after radiation therapy is the lack of early detection markers. The majority of patients who are candidates for local salvage therapy have locally advanced disease, precluding successful salvage therapy. A low pretreatment prostate specific antigen (PSA) has shown to be a favorable prognostic variable for disease progression, regardless of the specific local salvage therapy used. Of all the local salvage treatment options for these patients, we believe that salvage radical prostatectomy (RP) offers patients the greatest likelihood of a cure. The salvage RP results approach those achieved with standard RP for patients of similar pathologic stage. When patients are treated early in the course of recurrent disease (preoperative PSA < 10 ng/mL), an estimated two-thirds of patients will be disease-free 5 years after salvage RP alone. With better patient selection and continued technical modifications, the morbidity associated with salvage RP has substantially improved. Perioperative complications approach those observed with standard RP and approximately two-thirds of patients will recover urinary continence. Select patients may also recover functional erections when nerve-sparing techniques are used. Salvage cryotherapy and brachytherapy are minimally invasive alternatives to salvage RP. The cancer control results of these procedures appear to be inferior to results achieved with salvage RP. Each of these procedures is associated with significant morbidity and do not appear to provide a clear advantage over salvage RP in terms of posttreatment complications, urinary continence, and erectile function. A long-term cure is possible for patients with locally recurrent prostate cancer after radiation therapy. Local salvage therapy must be instituted early to be successful in the course of progressive disease.

Cryosurgery for prostate cancer

Choice of management for patients with prostate cancer is influenced by patient and disease characteristics and life expectancy. Management options include expectance (watchful waiting), radical prostatectomy, external beam radiotherapy, brachytherapy, and cryosurgical ablation of the prostate (CSAP). The role of cryotherapy in the management of prostate cancer is still evolving. Continued research has allowed the introduction of efficient and safe cryosurgical equipment exemplified by the current third-generation cryosurgical machines. CSAP can be performed in an ambulatory surgery setting or as inpatient surgery with overnight stay. The procedure is performed under continuous ultrasonic monitoring. Mature data from the use of second-generation cryosurgical equipment indicate that CSAP is an effective therapeutic modality for managing patients with prostate cancer. Current data with the third-generation cryosurgical equipment are not mature. However, the favorable side effect profile and the good early responses seem to indicate that this modality will have a prominent role in the management of patients with 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.

Selecting a secondary treatment

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

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.