Whole Gland Primary Prostate Cryoablation: Initial Results From the Cryo On-Line Data Registry

Salvage prostate intensity modulated radiation therapy after cryotherapy failure

Cryotherapy is an ablative therapy that can be used to treat localized prostate cancer. In case of recurrence, treatment options are not well-defined, and their outcomes are unknown. We therefore collected all patients treated with radiotherapy after cryotherapy for prostate cancer recurrence in Nantes (France) between 2012 and 2019. We identified ten patients. After a median follow-up of 5 years, two patients presented late grade 3 toxicities; one patient presented a grade 3 rectal hemorrhage, and one had a grade 3 hematuria. Two patients relapsed at 61 and 62 months, and three patients died of other causes. Radiotherapy to treat local prostate cancer recurrence after cryotherapy seems feasible and effective in local control. These results do not allow us to recommend this technique in current practice but are encouraging for the conduct of prospective trials.

Salvage radiotherapy after initial cryotherapy for localized prostate cancer: A systematic review of the literature

The treatment of local prostate cancer recurrence after cryotherapy is challenging since the optimal management is unknown. We collected the available evidence to date to better define the risk and benefit of salvage radiotherapy (SRT) after cryotherapy failure for localized prostate cancer. This review confirms the feasibility of SRT in terms of biochemical control and late toxicity rate. However, the absence of comparative trials or prospective studies, coupled with the heterogeneity of patients treated and the variations in treatments delivered across the analyzed studies, highlights the need for cautious consideration when opting for salvage radiotherapy. Therefore, we highly recommend the inclusion of patients in dedicated clinical trials to comprehensively assess the efficacy and safety of this approach.

Salvage Cryoablation for Recurrent Prostate Cancer Following Primary External Beam Radiotherapy or Primary Cryotherapy: A Propensity Score Matched Analysis of Mid-term Oncologic and Functional Outcomes

INTRODUCTION

Local prostate cancer recurrence following radiotherapy (XRT) or cryoablation (CRYO) may be addressed with salvage cryotherapy (SCT), although little is known about how the primary treatment modality affects SCT results. Oncologic and functional outcomes of patients who underwent SCT after primary XRT (XRT-SCT) or cryoablation (CRYO-SCT) were studied.

METHODS

Data was collected using the Duke Prostate Cancer database and the Cryo On-Line Data (COLD) registry. The primary outcome was biochemical progression-free survival (BPFS).  Urinary incontinence, rectourethral fistula, and erectile dysfunction were secondary outcomes. The Kaplan-Meier log-rank test and univariable/multivariable Cox proportional hazards (CPH) models were utilized to evaluate BPFS between groups.

RESULTS

419 XRT-SCT and 63 CRYO-SCT patients met inclusion criteria, that was reduced to 63 patients in each cohort after propensity matching. There was no difference in BPFS at 2 and 5 years both before (P = .5 and P = .7) and after matching (P = .6 and P = .3). On multivariable CPH, BPFS was comparable between treatment groups (CRYO-SCT, HR=1.1, [0.2-2.2]).  On the same analysis, BPFS was lower in D'Amico high-risk (HR 3.2, P < .01) and intermediate-risk (HR 1.95, P < .05) categories compared to low-risk. There was no significant difference in functional outcomes between cohorts.

CONCLUSION

Following primary cryotherapy, salvage cryoablation provides comparable intermediate oncological outcomes and functional outcomes compared to primary radiotherapy.

Primary Total Prostate Cryoablation for Localized High-Risk Prostate Cancer: 10-Year Outcomes and Nomograms

The role of prostate cryoablation was still uncertain for patients with high-risk prostate cancer (PC). This study was designed to investigate 10-year disease-free survival and establish a nomogram in localized high-risk PC patients. Between October 2008 and December 2020, 191 patients with high-risk PC who received primary total prostate cryoablation (PTPC) were enrolled. The primary endpoint was biochemical recurrence (BCR), defined using Phoenix criteria. The performance of pre-operative and peri-operative nomograms was determined using the Harrell concordance index (C-index). Among the cohort, the median age and PSA levels at diagnosis were 71 years and 12.3 ng/mL, respectively. Gleason sum 8-10, stage ≥ T3a, and PSA > 20 ng/mL were noted in 27.2%, 74.4%, and 26.2% of patients, respectively. During the median follow-up duration of 120.4 months, BCR-free rates at 1, 3, 5, and 10 years were 92.6%, 76.6%, 66.7%, and 50.8%, respectively. The metastasis-free, cancer-specific, and overall survival rates were 89.5%, 97.4%, and 90.5% at 10 years, respectively. The variables in the pre-operative nomogram for BCR contained PSA at diagnosis, clinical stage, and Gleason score (C-index: 0.73, 95% CI, 0.67-0.79). The variables in the peri-operative nomogram for BCR included PSA at diagnosis, Gleason score, number of cryoprobes used, and PSA nadir (C-index: 0.83, 95% CI, 0.78-0.88). In conclusion, total prostate cryoablation appears to be an effective treatment option for selected men with high-risk PC. A pre-operative nomogram can help select patients suitable for cryoablation. A peri-operative nomogram signifies the importance of the ample use of cryoprobes and helps identify patients who may need early salvage treatment.

Data-driven adaptive needle insertion assist for transperineal prostate interventions

Objective.Clinical outcomes of transperineal prostate interventions, such as biopsy, thermal ablations, and brachytherapy, depend on accurate needle placement for effectiveness. However, the accurate placement of a long needle, typically 150-200 mm in length, is challenging due to needle deviation induced by needle-tissue interaction. While several approaches for needle trajectory correction have been studied, many of them do not translate well to practical applications due to the use of specialized needles not yet approved for clinical use, or to relying on needle-tissue models that need to be tailored to individual patients.Approach.In this paper, we present a robot-assisted collaborative needle insertion method that only requires an actuated passive needle guide and a conventional needle. The method is designed to assist a physician inserting a needle manually through a needle guide. If the needle is deviated from the intended path, actuators shifts the needle radially in order to steer the needle trajectory and compensate for needle deviation adaptively. The needle guide is controlled by a new data-driven algorithm which does not requirea prioriinformation about needle or tissue properties. The method was evaluated in experiments with bothin vitroandex vivophantoms.Main results.The experiments inex vivotissue reported a mean final placement error of 0.36 mm with a reduction of 96.25% of placement error when compared to insertions without the use of assistive correction.Significance.Presented results show that the proposed closed-loop formulation can be successfully used to correct needle deflection during collaborative manual insertion with potential to be easily translated into clinical application.

Oncological and functional outcomes of men undergoing primary whole gland cryoablation of the prostate: A 20-year experience

BACKGROUND

This study reports the oncological and functional outcomes in men with localized prostate cancer (Pca) who were treated with primary whole gland cryoablation (WGC) of the prostate.

METHODS

The authors retrospectively reviewed their prospectively collected cryosurgery database between January 2002 and September 2019 for men who were treated with WGC of the prostate at a tertiary referral center. Primary outcome includes biochemical recurrence-free survival (BRFS). Secondary outcomes include failure-free survival (FFS), metastasis-free survival (MFS) and adverse events.

RESULTS

A total of 260 men were included in the study. Men having had prior treatment for Pca were excluded. Median follow-up was 107 months (interquartile range [IQR], 68.3-132.5 months). BRFS, FFS, and MFS at 10 years were 84%, 66%, and 96%, respectively. High risk D'Amico classification was associated with a lower BRFS and FFS on multivariable analysis. No patient had any Pca-related death during follow-up. American Urological Association symptoms score and bother index were unchanged following cryoablation. Median International Index of Erectile Function score precryoablation and post-cryoablation was 7 (IQR, 3-11) and 1 (IQR, 1-5), respectively. Stress urinary incontinence, defined as requiring any protective pads only occurred in five patients (2%). No patient developed a fistula. Grade > 2 Clavien-Dindo adverse events occurred in six (2.3%) patients.

CONCLUSION

WGC of the prostate can achieve excellent oncological and functional outcomes in men with localized Pca at the 10-year mark. Primary WGC may be a good option for men who desire to preserve urinary continence and have an excellent oncologic outcome.

LAY SUMMARY

Primary whole gland cryoablation is an alternative treatment option to radical prostatectomy and radiotherapy for men with organ-confined prostate cancer. Patients had excellent cancer outcomes 1 years after whole gland cryoablation, and patients with PSA nadir 0.1 ng/ml or lower after treatment were less likely to have disease recurrence.

Tumor location on MRI determines outcomes of patients with prostate cancer after total prostate cryoablation

We investigated the association between tumor location on multiparametric magnetic resonance imaging (mpMRI) and outcomes of prostate cancer patients after primary total prostate cryoablation (PTPC). Between March 2010 and December 2012, consecutive 192 prostate cancer patients receiving PTPC were enrolled. Tumor locations were determined and classified as anterior apex (AA), anterior midgland (AM), anterior base (AB), posterior apex (PA), posterior midgland (PM) and posterior base (PB) using mpMRI. Midline location, central location, seminal vesicle invasion, extraprostatic extension, multiple tumors, and tumor volume were also identified. Prostate local recurrence and biochemical failure were considered as primary and secondary endpoints, respectively. Tumors on mpMRI were identified in 148 (77.1%) patients. Tumor locations were most frequently noted in PM (89, 46.4%), followed by AM (55, 28.6%), PB (53, 27.6%), PA (46, 24%), AA (35, 18.2%) and AB (31, 16.1%). Midline and central tumors were observed in 34 (17.7%) and 14 (7.3%) patients, respectively. During a median follow-up duration of 81 months (range, 2-114 months), 71 (37.0%) and 29 (40.8%) patients experienced biochemical failure and local recurrence, respectively. Multivariable analyses revealed only AA tumors increased the risk of local recurrences (HR = 2.98, 95% CI. 1.36-6.49). None of location-related parameters was associated with biochemical failure. Tumor location on mpMRI has a significant association with local tumor recurrence in patients receiving PTPC. Physicians should be cautious when conducting cryoablation for prostate tumors in AA location.

Long-term biopsy outcomes in prostate cancer patients treated with external beam radiotherapy: a systematic review and meta-analysis

BACKGROUND

Biopsy after external beam radiotherapy (EBRT) for localised prostate cancer (PCa) is an infrequently used but potentially valuable technique to evaluate local recurrence and predict long-term outcomes.

METHODS

We performed a meta-analysis of studies until March 2020 where a post-EBRT biopsy was performed on patients with low-to intermediate risk PCa, according to the Preferred Reporting Items for Systematic Review and Meta-analysis (PRISMA) statement. The primary outcome was the aggregate post-EBRT positive biopsy rate (≥2 years after EBRT) and the associated odds ratio (OR) of a positive biopsy on biochemical failure (BCF), distant metastasis-free survival (DMFS) and prostate cancer-specific mortality (PCSM). A sensitivity analysis was performed which examined biopsy rate as a function of post-EBRT biopsy protocol, PCa risk, ADT usage and radiation dose.

RESULTS

A total of 22 studies were included, of which 10 were randomised controlled trials and 12 were cohort studies. Nine out of the 22 studies used dosing regimens consistent with the 2020 NCCN radiotherapy guidelines. The weighted-average positive biopsy rate across all 22 studies was 32% (95%-CI: 25-39%, n = 3017). In studies where post-treatment biopsy was part of the study protocol, the rate was 35% (95%-CI: 21-38%, n = 2450). In the subgroup of studies that conformed to the 2020 NCCN radiotherapy guidelines, this rate was 22% (95% CI: 19-41%, n = 832). Patients with positive biopsy had a 10-fold higher odds of developing BCF (OR of 10.3, 95%-CI: 3.7-28.7, p < 0.00001), 3-fold higher odds of developing distant metastasis (OR 3.1, 95%-CI: 2.1-4.7, p < 0.00001) and 5-fold higher odds of dying from their PCa (OR 5.1, 95%-CI: 2.6-10, p < 0.00001).

CONCLUSION

A positive biopsy after EBRT is associated with a poor prognosis compared to a negative biopsy. The post-EBRT positive biopsy rate is an important measure which provides additional insight when comparing EBRT to other treatment modalities for PCa.

Primary cryotherapy for localized prostate cancer treatment

INTRODUCTION

Prostate cryotherapy is an available treatment option for localized prostate cancer (PC) included on minimal invasive therapies but still under evaluation. We started our cryotherapy program in 2008 for selected patients with localized PC. Our objective is to evaluate the oncologic and functional outcomes of primary cryotherapy in men with clinically localized PC.

SUBJECTS AND METHODS

We retrospectively evaluated all patients who underwent primary cryotherapy for localized PC treatment at our center between January 2008 and December 2017. In order to downsize prostates between 40 and 60cc neoadjuvant 3-month hormonal therapy was administered. Primary endpoint was biochemical progression-free survival (BPFS) rate as defined by the Phoenix criteria. Secondary endpoints were cancer-specific survival (CSS), overall survival (OS), patient reported functional outcomes and complication rates. Factors influencing de BPFS were evaluated individually using Kaplan-Meyer and Cox regression models and in a multivariate model using Cox regression.

RESULTS

During the mentioned period, a total of 177 men were treated with cryotherapy. With a mean follow-up of 60 months (SD 32.9), the Kaplan-Meier analysis shows an overall BPFS rate was 67%. BPFS by risk group was 70.2%, 70.3% and 50.0% for the low, intermediate and high risk groups, respectively (p = 0.925). Overall time to BR was 93.67 months (SD 2.84, IC95%: 88.10-99.24): 95.91 (SD 3,44), 93.23 (SD 4.81) and 89.77 (SD 6.67) months for the low, intermediate and high risk groups, respectively. In both univariate and multivariate analysis, the only predictor of biochemical progression was de PSA nadir (HR 1.56 IC95%: 1.50-1.63). Continence was fully maintained in 95% of patients after the procedure. Postoperative complications included UTI (17.5%), hematuria (9.6%), perineal hematoma (11%) and postoperative pain (4.5%). No fistulas were reported. 8.5% of patients had acute urinary retention solved conservatively.

CONCLUSION

Cryotherapy is a safe option for selected patients with localized prostate cancer that provides competitive oncologic outcomes and a low morbidity profile.

MRI guided procedure planning and 3D simulation for partial gland cryoablation of the prostate: a pilot study

PURPOSE

This study reports on the development of a novel 3D procedure planning technique to provide pre-ablation treatment planning for partial gland prostate cryoablation (cPGA).

METHODS

Twenty men scheduled for partial gland cryoablation (cPGA) underwent pre-operative image segmentation and 3D modeling of the prostatic capsule, index lesion, urethra, rectum, and neurovascular bundles based upon multi-parametric MRI data. Pre-treatment 3D planning models were designed including virtual 3D cryotherapy probes to predict and plan cryotherapy probe configuration needed to achieve confluent treatment volume. Treatment efficacy was measured with 6 month post-operative MRI, serum prostate specific antigen (PSA) at 3 and 6 months, and treatment zone biopsy results at 6 months. Outcomes from 3D planning were compared to outcomes from a series of 20 patients undergoing cPGA using traditional 2D planning techniques.

RESULTS

Forty men underwent cPGA. The median age of the cohort undergoing 3D treatment planning was 64.8 years with a median pretreatment PSA of 6.97 ng/mL. The Gleason grade group (GGG) of treated index lesions in this cohort included 1 (5%) GGG1, 11 (55%) GGG2, 7 (35%) GGG3, and 1 (5%) GGG4. Two (10%) of these treatments were post-radiation salvage therapies. The 2D treatment cohort included 20 men with a median age of 68.5 yrs., median pretreatment PSA of 6.76 ng/mL. The Gleason grade group (GGG) of treated index lesions in this cohort included 3 (15%) GGG1, 8 (40%) GGG2, 8 (40%) GGG3, 1 (5%) GGG4. Two (10%) of these treatments were post-radiation salvage therapies. 3D planning predicted the same number of cryoprobes for each group, however a greater number of cryoprobes was used in the procedure for the prospective 3D group as compared to that with 2D planning (4.10 ± 1.37 and 3.25 ± 0.44 respectively, p = 0.01). At 6 months post cPGA, the median PSA was 1.68 ng/mL and 2.38 ng/mL in the 3D and 2D cohorts respectively, with a larger decrease noted in the 3D cohort (75.9% reduction noted in 3D cohort and 64.8% reduction 2D cohort, p 0.48). In-field disease detection was 1/14 (7.1%) on surveillance biopsy in the 3D cohort and 3/14 (21.4%) in the 2D cohort, p = 0.056) In the 3D cohort, 6 month biopsy was not performed in 4 patients (20%) due to undetectable PSA, negative MRI, and negative MRI Axumin PET. For the group with traditional 2D planning, treatment zone biopsy was positive in 3/14 (21.4%) of the patients, p = 0.056.

CONCLUSIONS

3D prostate cancer models derived from mpMRI data provide novel guidance for planning confluent treatment volumes for cPGA and predicted a greater number of treatment probes than traditional 2D planning methods. This study prompts further investigation into the use of 3D treatment planning techniques as the increase of partial gland ablation treatment protocols develop.

[Percutaneous MR-guided prostate cancer cryoablation: Predictive factors and oncologic outcomes]

OBJECTIVE

To determine the pejorative predictive factors on oncologic outcomes of percutaneous MR-guided whole gland prostate cancer cryoablation (CA).

METHODS

Medical records of patients treated from 2009 to 2012, to assess medium-term oncologic outcomes, were reviewed. Prostate biopsies were performed in local recurrence suspicion (biochemical failure, MR follow-up failure).

RESULTS

Among 18 patients, mean age of 72.6 (61-78), 2 (11 %) and 7 (38.9 %) biological and reported biopsy-proven local recurrence respectively with our initial technic of CA. Mean follow-up and recurrence were 56.3 (±21.7) and 20.7 (±13.9) months respectively. A previous treatment of prostate cancer (P=0.5), pre-treatment PSA (P=0.2), pre-treatment Gleason/ISUP score (P=0.4), nadir PSA post-CA (P=0.22) were not associated with recurrence. Bilateral positive cores appears as a pejorative predictive factor (P=0.04). However mean pre-treatment positive cores percentage, 25 (±16.5) in responding patients versus 40.7 (±25.2) in case of recurrence, and maximum percentage of cancer extent in each positive core, 10.6 (±9.3) in responding patients versus 18.7 (±16.5) in case of recurrence, seemed associated with local recurrence after prostate CA but our analysis wasn't able to find a difference (P=0.09 and P=0.3 respectively) due to a lack of power.

CONCLUSION

Bilateral positive cores appears as a pejorative predictive factor. In our experience, important tumor volume seem to be a pejorative predictive factor for oncologic outcomes after PCA whereas treatment, PSA, Gleason/ISUP score, nadir PSA are not.

LEVEL OF EVIDENCE

4.

Primary Whole-gland Cryoablation for Prostate Cancer: Biochemical Failure and Clinical Recurrence at 5.6 Years of Follow-up

We retrospectively evaluated complications and functional and oncologic outcomes of 94 consecutive men who underwent primary whole-gland cryoablation for localized prostate cancer (PCa) from 2002 to 2012. Kaplan-Meier and multivariable Cox regression analyses were performed using a landmark starting at 6 mo of follow-up. In total, 75% patients had D'Amico intermediate- (48%) or high- (27%) risk PCa. Median follow-up was 5.6 yr. Median time to prostate-specific antigen (PSA) nadir was 3.3 mo, and 70 patients reached PSA <0.2ng/ml postcryoablation. The 90-d high-grade (Clavien Grade IIIa) complication rate was 3%, with no rectal fistulas reported. Continence and potency rates were 96% and 11%, respectively. The 5-yr biochemical failure-free survival (PSA nadir+2ng/ml) was 81% overall and 89% for low-, 78% for intermediate-, and 80% for high-risk PCa (p=0.46). The median follow-up was 5.6 and 5.1 yr for patients without biochemical failure and with biochemical failure, respectively. The 5-yr clinical recurrence-free survival was 83% overall and 94% for low-, 84% for intermediate-, and 69% for high-risk PCa (p=0.046). Failure to reach PSA nadir <0.2ng/ml within 6 mo postcryoablation was an independent predictor for biochemical failure (p=0.006) and clinical recurrence (p=0.03). The 5-yr metastases-free survival was 95%. Main limitation is retrospective evaluation. Primary whole-gland cryoablation for PCa provides acceptable medium-term oncologic outcomes and could be an alternative for radiation therapy or radical prostatectomy. PATIENT SUMMARY: Cryoablation is a safe, minimally-invasive procedure that uses cold temperatures delivered via probes through the skin to kill prostate cancer (PCa) cells. Whole-gland cryoablation may offer an alternative treatment option to surgery and radiotherapy. We found that patients had good cancer outcomes 5 yr after whole-gland cryoablation, and those with a prostate-specific antigen value ≥0.2ng/ml within 6 mo after treatment were more likely to have PCa recurrence.

Impact on genitourinary function and quality of life following focal irreversible electroporation of different prostate segments

PURPOSE

We aimed to evaluate the genitourinary function and quality of life (QoL) following the ablation of different prostate segments with irreversible electroporation (IRE) for localized prostate cancer (PCa).

METHODS

Sixty patients who received primary focal IRE for organ-confined PCa were recruited for this study. Patients were evaluated for genitourinary function and QoL per prostate segment treated (anterior vs. posterior, apex vs. base vs. apex-to-base, unilateral vs. bilateral). IRE system settings and patient characteristics were compared between patients with preserved vs. those with impaired erectile function and urinary continence. Data were prospectively collected at baseline, 3, 6, and 12 months using the expanded prostate cancer index composite, American Urological Association symptom score, SF-12 physical and mental component summary surveys. Difference over time within segments per questionnaire was evaluated using the Wilcoxon's signed rank test. Outcome differences between segments were assessed using covariance models. Baseline measurements included questionnaire scores, age, and prostate volume.

RESULTS

There were no statistically significant changes over time for overall urinary (P = 0.07-0.89), bowel (P = 0.06-0.79), physical (P = 0.18-0.71) and mental (P = 0.45-0.94) QoL scores within each segment. Deterioration of sexual function scores was observed at 6 months within each segment (P = 0.001-0.16). There were no statistically significant differences in QoL scores between prostate segments (P = 0.08-0.97). Older patients or those with poor baseline sexual function at time of treatment were associated with a greater risk of developing erectile dysfunction.

CONCLUSION

IRE is a feasible modality for all prostate segments without any significantly different effect on the QoL outcomes. Older patients and those with poor sexual function need to be counseled regarding the risk of erectile dysfunction.

Predictors of Rectourethral Fistula Formation After Primary Whole-Gland Cryoablation for Prostate Cancer: Results from the Cryo On-Line Database Registry

PURPOSE

To define the incidence and risk factors associated with rectourethral fistula (RUF) formation following primary whole-gland cryosurgery using a multicenter centralized registry.

PATIENTS AND METHODS

The Cryo On-Line Data (COLD) registry was queried for men undergoing primary whole-gland cryotherapy between 1990 and 2014 who developed a RUF. Patient factors and disease parameters were correlated with RUF using chi-square and the t-test. Variables with p < 0.25 were entered into a binary logistic regression with stepwise backward elimination to determine the factors associated with RUF formation.

RESULTS

A total of 4102 men underwent primary whole-gland cryotherapy in the COLD registry at the time of analysis. Postoperative RUF was documented in 50 out of 4102 cases (1.2%). Patients with RUF had similar demographic data, prostate volume, preoperative prostate-specific antigen level, and clinical stage in comparison to those without fistula. On both univariate and multivariate analyses, postoperative urinary retention (odds ratio [OR]: 6.30; confidence interval [95% CI] 3.43-11.58, p < 0.001), preoperative Gleason score of ≥7 (OR: 1.92; 95% CI 1.08-3.43, p = 0.027), and preoperative incontinence (OR: 2.95; 95% CI 1.12-7.76, p = 0.028) were the most significant risk factors associated with RUF formation.

CONCLUSION

Primary whole-gland cryotherapy for prostate cancer is associated with a historically low rate (1.2%) of postoperative RUF formation. The rate decreased further to 0.55% over the last several years, suggesting better patient selection and technical improvement. Postoperative urinary retention, Gleason score ≥7, and preoperative urinary incontinence were the key demographic, clinical, and pathologic features associated with RUF formation in this study.

Adjuvant androgen-deprivation therapy following prostate total cryoablation in high-risk localized prostate cancer patients - Open-labeled randomized clinical trial

PURPOSE

To investigate the efficacy and safety profile of 12-month adjuvant androgen-deprivation therapy (ADT) following total-gland cryoablation (TGC) in patients with high-risk localized prostate cancer (HRLPC).

MATERIALS AND METHODS

This open-label randomized trial included 38 HRLPC patients who received TGC between July 2011 and March 2013. Within 4 weeks after TGC, subjects were randomly assigned (1:1) to either the 12-month adjuvant ADT or non-adjuvant ADT group. The primary outcome was biochemical failure measured by the Phoenix definition. Adverse events were measured at month 1, 2, 3, 6, 9 and 12. In addition, a cohort of 145 HRLPC patients was selected retrospectively for outcome validation.

RESULTS

The adjuvant ADT and non-adjuvant ADT groups did't differ in peri-operative characters, such as age, preoperative PSA, tumor stages, Gleason score, prostate size and cryoprobe number. Four patients with adjuvant ADT withdrew from this trial for personal reasons (N = 2), elevated liver function (N = 1) and poorly controlled hyperglycemia (N = 1). In contrast, none in non-adjuvant ADT group experienced adverse events. Biochemical failures were identified in 5 (26%) patients in each group during a median follow-up duration of 45 months. The median times to biochemical failure were 25 and 5.5 months for adjuvant ADT and non-adjuvant ADT groups, respectively. Biochemical-failure survival curves converged 24 months after TGC. Univariable and multivariable analyses revealed adjuvant ADT was not associated with biochemical recurrences in the validation cohort.

CONCLUSIONS

Adjuvant ADT does not reduce biochemical failure for HRPLC patients undergoing TGC. It should be further confirmed by a larger cohort.

In vivo optoacoustic temperature imaging for image-guided cryotherapy of prostate cancer

The objective of this study is to demonstrate in vivo the feasibility of optoacoustic temperature imaging during cryotherapy of prostate cancer. We developed a preclinical prototype optoacoustic temperature imager that included pulsed optical excitation at a wavelength of 805 nm, a modified clinical transrectal ultrasound probe, a parallel data acquisition system, image processing and visualization software. Cryotherapy of a canine prostate was performed in vivo using a commercial clinical system, Cryocare^® CS, with an integrated ultrasound imaging. The universal temperature-dependent optoacoustic response of blood was employed to convert reconstructed optoacoustic images to temperature maps. Optoacoustic imaging of temperature during prostate cryotherapy was performed in the longitudinal view over a region of 30 mm (long)  ×  10 mm (deep) that covered the rectum, the Denonvilliers fascia, and the posterior portion of the treated gland. The transrectal optoacoustic images showed high-contrast vascularized regions, which were used for quantitative estimation of local temperature profiles. The constructed temperature maps and their temporal dynamics were consistent with the arrangement of the cryoprobe and readouts of the thermal needle sensors. The temporal profiles of the readouts from the thermal needle sensors and the temporal profile estimated from the normalized optoacoustic intensity of the selected vascularized region showed significant resemblance, except for the initial overshoot, that may be explained as a result of the physiological thermoregulatory compensation. The temperature was mapped with errors not exceeding  ±2 °C (standard deviation) consistent with the clinical requirements for monitoring cryotherapy of the prostate. In vivo results showed that the optoacoustic temperature imaging is a promising non-invasive technique for real-time imaging of tissue temperature during cryotherapy of prostate cancer, which can be combined with transrectal ultrasound-the current standard for guiding clinical cryotherapy procedure.

Patient-reported quality of life progression in men with prostate cancer following primary cryotherapy, cyberknife, or active holistic surveillance

BACKGROUND

Technological advancements have led to the success of minimally invasive treatment modalities for prostate cancer such as CyberKnife and Cryotherapy. Here, we investigate patient-reported urinary function, bowel habits, and sexual function in patients following CyberKnife (CK) or Cryotherapy treatment, and compare them with active holistic surveillance (AHS) patients.

METHODS

An IRB-approved institutional database was retrospectively reviewed for patients who underwent CK, Cryotherapy, or AHS. Quality of life (QoL) survey responses were collected every three months and the mean function scores were analyzed in yearly intervals over the 4 years post-treatment.

RESULTS

279 patients (767 survey sets) were included in the study. There was no difference among groups in urinary function scores. The CyberKnife group had significantly lower bowel habit scores in the early years following treatment (year 2 mean difference: -5.4, P < 0.01) but returned to AHS level scores by year 4. Cryotherapy patients exhibited initially lower, but not statistically significant, bowel function scores, which then improved and approached those of AHS. Both CyberKnife (year 1 mean difference: -26.7, P < 0.001) and Cryotherapy groups (-35.4, P < 0.001) had early lower sexual function scores relative to AHS, but then gradually improved and were not significantly different from AHS by the third year post-treatment. A history of hormonal therapy was associated with a lower sexual function scores relative to those patients who did not receive hormones in both CyberKnife (-18.45, P < 0.01) and Cryotherapy patients (-14.6, P < 0.05).

CONCLUSIONS

After initial lower bowel habits and sexual function scores, CyberKnife or Cryotherapy-treated patients had no significant difference in QoL relative to AHS patients. These results highlight the benefit of CyberKnife and Cryotherapy in the management of organ-confined prostate cancer.

Avoidance of androgen deprivation therapy in radiorecurrent prostate cancer as a clinically meaningful endpoint for salvage cryoablation

BACKGROUND

To investigate the ability of salvage cryoablation of the prostate (SCAP) to delay the need for androgen deprivation therapy (ADT) in local recurrence after radiation therapy to the prostate using the Cryo-On-Line Database (COLD) registry.

METHODS

The COLD registry is comprised of a combination of retrospectively and prospectively collected data on patients undergoing primary and SCAP. Patients with local recurrence after radiation therapy were identified. Kaplan-Meier analysis was used to calculate ADT-free survival.

RESULTS

We identified 898 patients that have undergone SCAP in the COLD registry. Overall, the calculated 5-year ADT-free survival probability was 0.713. When stratified by D'Amico risk group, 264 high-risk patients (71.9%), 234 intermediate-risk (86.7%),and 228 low-risk (87.7%) were free of ADT post-SCAP. This correlates with a 5-year ADT-free survival of 60.7, 73.9, and 82.4%, respectively. Patients with post-SCAP PSA nadir of <0.2 ng/mL had a 5 year ADT-free survival of 87.1% compared to 48.7% with a PSA nadir ≥0.2 ng/mL. Pre-operative ADT use or full versus partial gland SCAP did not have an effect on ADT use post-operatively. In 118 (55.4%) of patients with post-operative biochemical recurrence, ADT was not used.

CONCLUSION

For patients with local recurrence after radiation, SCAP is an option that provides a high chance of avoiding or delaying ADT. The potential to delay ADT and its associated side effects should be a part of counseling sessions with the patient when discussing treatment options for locally recurrent prostate cancer after radiation. Avoidance of ADT is more clinically relevant than PSA elevation.

[Evaluation and results of ablative therapies in prostate cancer]

OBJECTIVE

To perform a state of the art about methods of evaluation and present results in ablative therapies for localized prostate cancer.

METHODS

A review of the scientific literature was performed in Medline database (http://www.ncbi.nlm.nih.gov) and Embase (http://www.embase.com) using different associations of keywords. Publications obtained were selected based on methodology, language and relevance. After selection, 102 articles were analysed.

RESULTS

Analyse the results of ablative therapies is presently difficult considering the heterogeneity of indications, techniques and follow-up. However, results from the most recent and homogeneous studies are encouraging. Oncologically, postoperative biopsies (the most important criteria) are negative (without any tumor cells in the treated area) in 75 to 95%. Functionally, urinary and sexual pre-operative status is spared (or recovered early) in more than 90% of the patients treated. More and more studies underline also the correlation between the results and the technique used considering the volume of the gland and, moreover, the "index lesion" localization.

CONCLUSION

The post-treatment pathological evaluation by biopsies (targeted with MRI or, perhaps in a near future, with innovative ultrasonography) is the corner stone of oncological evaluation of ablative therapies. Ongoing trials will allow to standardize the follow-up and determine the best indication and the best techniques in order to optimize oncological and functional results for each patient treated.

Assessment of Cryosurgical Device Performance Using a 3D Tissue-Engineered Cancer Model

As the clinical use of cryoablation for the treatment of cancer has increased, so too has the need for knowledge on the dynamic environment within the frozen mass created by a cryoprobe. While a number of factors exist, an understanding of the iceball size, critical isotherm distribution/penetration, and the resultant lethal zone created by a cryoprobe are critical for clinical application. To this end, cryoprobe performance is typically characterized based on the iceball size and temperature penetration in phantom gel models. Although informative, these models do not provide information as to the impact of heat input from surrounding tissue nor give any information on the ablative zone created. As such, we evaluated the use of a tissue-engineered tumor model (TEM) to assess cryoprobe performance including iceball size, real-time thermal profile distribution, and resultant ablative zone. Studies were conducted using an Endocare V-probe cryoprobe, with a 10/5/10 double freeze–thaw protocol using prostate and renal cancer TEMs. The data demonstrate the generation of a 33- to 38-cm3 frozen mass with the V-Probe cryoprobe following the double freeze of which ∼12.7 and 6.5 cm3 was at or below −20°C and −40°C, respectively. Analysis of ablation zone using fluorescence microscopy 24 hours postthaw demonstrated that the internal ∼40% of the frozen mass was completely ablated, whereas in the periphery of the iceball (outer 1 cm region), a gradient of partial to minimal destruction was observed. These findings correlated well with clinical reports on renal and prostate cancer cryoablation. Overall, this study demonstrates that TEMs provide an effective model for a more complete characterization of cryoablation device performance. The data demonstrate that while the overall iceball size generated in the TEM was consistent with published reports from phantom models, the integration of an external heat load, circulation, and cellular components more closely reflect an in vivo setting and the impact of penetration of the critical (−20°C and −40°C) isotherms into the tissue. This is important as it is well appreciated in clinical practice that the heat load of a tissue, cryoprobe proximity to vasculature, and so on, can impact outcome. The TEM model provides a means of characterizing the impact on ablative dose delivery allowing for a better understanding of probe performance and potential impact on ablative outcome.

Magnetic resonance imaging-transrectal ultrasound fusion focal cryotherapy of the prostate: A prospective development study

OBJECTIVES

The use of software-based magnetic resonance-transrectal ultrasound fusion to deliver focal therapy may increase the precision of treatment. This is a prospective development study assessing the feasibility of Magnetic resonance imaging-transrectal ultrasound (MRI-TRUS) fusion focal cryotherapy.

METHODS AND MATERIALS

Consecutive patients undergoing focal cryotherapy were included in an academic registry (December 2013-June 2014). MRI-TRUS fusion focal cryotherapy was offered to men with visible clinically significant prostate cancer (Galil SeedNet system). Eligibility was determined by multiparametric MRI (mpMRI), and transperineal template mapping or targeted biopsies. A rigid fusion platform (Biojet) was used with the operator ensuring the ice ball covered at least the lesion. Adverse events were scored using the NCICTC V4. Genitourinary toxicity was assessed using patient-reported outcome measures (IPSS, IIEF-15, and UCLA-EPIC). Early contrast-enhanced MRI and mpMRI at 6 to 12 months were used to assess extent of lesion ablation.

RESULTS

Of 23 patients scheduled, 5 did not have image fusion owing to surgeon preference. Overall, 18 patients undergoing image-fusion cryotherapy had median age of 68 (interquartile range [IQR]: 65-73) years and median preoperative prostate-specific antigen = 9.54 (5.65-16)ng/ml. In all, 13 (72.2%) and 5 (27.8%) patients had intermediate and high-risk cancer, respectively. In total, 10 adverse events were reported with one of these as serious (grade 3) because of admission for hematuria requiring wash out only. There was no difference in the IIEF-15 between baseline and study end (P = 0.24). The IPSS remained stable (P = 0.12), whereas the UCLA-EPIC tended to improve (P = 0.065). The prostate-specific antigen level significantly decreased at 1.8 (1.04-2.93) ng/ml (P<0.001). Both early and late mpMRI showed no residual disease in the treated area. In 2 men, radiological progression of known contralateral disease was observed; both underwent focal high intensity focused ultrasound.

CONCLUSION

MRI-TRUS fusion focal cryotherapy is feasible in most patients and seems to accurately guide ablation demonstrated by posttreatment imaging. Additional studies are needed to determine efficacy using postcryotherapy biopsy.

Percutaneous image-guided cryoablation: current applications and results in the oncologic field

Percutaneous imaging-guided cryoablation (PICA) is a recently developed technique, which applies extreme hypothermia to destroy tumours under close imaging surveillance. It is minimally invasive, safe, repeatable, and does not interrupt or compromise other oncologic therapies. It presents several advantages over more established heat-based thermal ablation techniques (e.g. radiofrequency ablation; RFA) including intrinsic analgesic properties, superior monitoring capability on multi-modal imaging, ability to treat larger tumours, and preservation of tissue collagenous architecture. There has been a recent large increase in reports evaluating the utility of PICA in a wide range of patients and tumours, but systematic analysis of the literature is challenging due to the rapid pace of change and predominance of extensively heterogeneous level III studies. The precise onco-therapeutic role of PICA has not been established. This narrative review outlines the available evidence for PICA in a range of tumours. Current indications include curative therapy of small T1a renal tumours; curative/palliative therapy of small primary/secondary lung tumours where RFA is unsuitable; palliation of painful bone metastases; and urologic treatment of organ-confined prostate cancer. There is growing evidence to support its use for small hepatic tumours, and encouraging results have been obtained for breast tumours, extra-abdominal desmoid tumours, and management of higher-stage tumours and oligometastatic disease. However, the overall evidence base is weak, effectively restricting PICA to cases where standard therapy and RFA are unsuitable. As the technique and evidence continue to mature, the benefits of this emerging technique will hopefully become more widely available to cancer patients in the future.

MRI-guided focal therapy of prostate cancer

With the advent of focal therapy as a recognized treatment option for men with prostate cancer, there are a host of emerging interventions that take advantage of MRI for image guidance. Focal therapy affords a middleground option for patients with low- to intermediate-grade prostate cancer by providing a means of keeping their cancer at bay while avoiding the negative consequences of radical therapies. However, the practice of focal treatment is far from straightforward, with some believing focal treatment errs on the side of overtreatment among patients with low-grade cancer; others worry it is undertreatment in potentially significant multifocal disease. Further research is necessary, both relating to focal therapy in general and to the utility of each MRI-guided focal treatment discussed.

Factors Affecting Lethal Isotherms During Cryoablation Procedures

Background:

Creating appropriately-sized, lethal isotherms during cryoablation of renal tumors is critical in order to achieve sufficiently-sized zones of cell death. To ensure adequate cell death in target treatment locations, surgeons must carefully select the type, size, location, and number of probes to be used, as well as various probe operating parameters.

Objective:

The current study investigates the effects of probe type, operating pressure, and clinical method on the resulting sizes of isotherms in an in vitro gelatin model.

Method:

Using a total of four cryoprobes from two manufacturers, freeze procedures were conducted in gelatin in order to compare resulting sizes of constant temperature zones (isotherms). The effects of certain procedural parameters which are clinically adjustable were studied.

Results:

Test results show that the sizes of 0 °C,-20 °C and -40 °C isotherms created by similarly-sized probes from two different manufacturers were significantly different for nearly all comparisons made, and that size differences resulting from changing the operating pressure were not as prevalent. Furthermore, isotherm sizes created using a multiple freeze procedure (a ten minute freeze, followed by a five minute passive thaw, followed by another ten minute freeze) did not result in statistically-significant differences when compared to those created using a single freeze procedure in all cases.

Conclusion:

These results indicate that selection of the probe manufacturer and probe size may be more important for dictating the size of kill zones during cryoablation than procedural adjustments to operating pressures or freeze times.

Contemporary Management of Prostate Cancer

Prostate cancer represents a spectrum ranging from low-grade, localized tumors to devastating metastatic disease. We discuss the general options for treatment and recent developments in the field.

Dosimetric benefits of hemigland stereotactic body radiotherapy for prostate cancer: implications for focal therapy

OBJECTIVE

Compared with standard, whole-gland (WG) therapies for prostate cancer, focal approaches may provide equivalent oncologic outcomes with fewer adverse effects. The purpose of this study was to compare organ-at-risk (OAR) dosimetry between hemigland (HG) and WG stereotactic body radiotherapy (SBRT) plans.

METHODS

Volumetric-modulated arc radiotherapy-based SBRT plans were designed to treat the left HG, right HG and WG in eight patients, using five fractions of 8 Gy. OARs of interest included the contralateral HG, rectum, urinary bladder, urethra, penile bulb and contralateral neurovascular bundle.

RESULTS

Rectal V80% (the percentage of a normal structure receiving a dose of 80%) and V90% were significantly lower with HG plans than with WG plans (median values of 4.4 vs 2.5 cm(3) and 2.1 vs 1.1 cm(3), respectively, p < 0.05 by Student's t-test). Bladder V50% was also reduced significantly in HG plans (32.3 vs 17.4 cm(3), p < 0.05), with a trend towards reduction of V100% (3.4 vs 1.3 cm(3), p = 0.09). Urethral maximum dose and mean doses to the penile bulb and contralateral neurovascular bundle were also reduced significantly (42.0 vs 39.7 Gy, p < 0.00001; 13.3 vs 9.2 Gy, p < 0.05; and 40.2 vs 19.3 Gy, p < 0.00001, respectively).

CONCLUSION

Targeting an HG volume rather than a WG volume when delivering SBRT can offer statistically significant reductions for all OARs. Given the large magnitude of the reduction in dose to these OARs, it is anticipated that HG SBRT could offer a superior toxicity profile when compared with WG SBRT. This is likely to be most relevant in the context of salvaging a local failure after radiation therapy.

ADVANCES IN KNOWLEDGE

The dosimetric feasibility of HG SBRT is demonstrated. When compared with WG SBRT plans, the HG plans demonstrate statistically significant and large magnitude reduction in doses to the rectum, bladder, urethra, penile bulb and contralateral neurovascular bundle, suggesting the possibility of improved toxicity outcomes with HG SBRT. This is likely to be most relevant in the context of salvaging a local failure after radiation therapy.

A pretreatment nomogram for prediction of biochemical failure after primary cryoablation of the prostate

BACKGROUND

To create a predictive nomogram for biochemical failure following primary whole-gland cryoablation of the prostate for localized prostate cancer (LPCa).

METHODS

We retrospectively analyzed 2,242 patients from the Cryo On-Line Database (COLD) who were treatment naive and had undergone primary whole gland cryoablation of the prostate for biopsy-confirmed LPCa. Kaplan-Meier (KM) curves estimating 5 year biochemical progression-free survival (bPFS) were generated. Multivariable Cox proportional hazards analysis (CoxPH) was performed in order to construct the nomogram. The nomogram was internally validated using the bootstrap technique.

RESULTS

Overall, the KM estimated 5 year bPFS was 72.8%. Stratified by D'Amico risk, The KM estimated 5 year bPFS was 82.6%, 71.1%, and 57.8% for low-, intermediate-, and high-risk groups, respectively. Statistically significant predictors of biochemical outcomes from CoxPH analysis were pre-treatment prostate specific antigen (PTPSA) (P < 0.001), total prostate volume (P = 0.004), clinical stage (P = 0.034), and Gleason score (0.004). A nomogram for predicted 5 year biochemical progression free probability was constructed with a concordance index of 0.652. An online risk calculator was also generated.

CONCLUSIONS

To the best of our knowledge, this is the first predictive nomogram for biochemical outcomes after primary whole gland cryoablation of the prostate using socio-demographic, pretreatment, clinical, and prostate biopsy data. Our nomogram and online risk calculator can guide both patients and urologists for shared decision making regarding definitive treatment options.

Comparison of Outcomes Between Preoperatively Potent Men Treated with Focal Versus Whole Gland Cryotherapy in a Matched Population

BACKGROUND AND PURPOSE

The refinement in the localization of prostate cancer tumor foci through transperineal template-mapping biopsies and MRI has led to an increased interest in lesion-directed focal prostatic cryoablation. Data are lacking, however, that compare the outcomes of whole-gland (WG) to focal ablation therapy (FT). The aim of our study was to assess both oncologic and functional outcomes between WG and FT cryoablation of the prostate after having matched patients for preoperative characteristics.

PATIENTS AND METHODS

We matched with a 1:1 ratio 317 men who underwent FT with 317 who underwent WG treatment in the Cryo Online Data (COLD) registry between 2007 and 2013. All patients were low-risk according to the D'Amico risk groups and were matched according to age at surgery. We only included preoperatively potent men. Oncologic outcomes were biochemical recurrence (BCR) free-survival defined according to the American Society for Radiation Oncology (ASTRO) and Phoenix criteria and assessed by Kaplan-Meier curves. Only patients with prostate-specific antigen (PSA) nadir data were included in oncologic outcome analysis. Functional outcomes were assessed at 6, 12, and 24 months after the procedure for erectile function (defined as ability to have intercourse with or without erectile aids), urinary continence, urinary retention, and rates of fistula formation.

RESULTS

Median age at the time of the procedure was 66.5 years (standard deviation [SD] 6.6 y), and median follow-up time was 58.3 months. After surgery, 30% (n=95) and 17% (n=55) of the men who received WG and FT, respectively, underwent biopsy, with positive biopsy rates of 11.6% and 14.5%, respectively. BCR-free survival rates at 60 months according to the Phoenix definition were 80.1% and 71.3% in the WG and FT cohorts, respectively, with a hazard ratio of 0.827; according to the ASTRO definition, they were 82.1% and 73%, respectively (all P ≥ 0.1). Erectile function data at 24 months was available for 172 WG and 160 FT treated men. Recovery of erection was achieved in 46.8% and 68.8% of patients in the WG and FT cohorts, respectively (P=0.001). Urinary function data at 24 months was available for 307 WG and 313 FT patients. Continence rates were 98.7% and 100% for WG and FT groups, respectively (P=0.02). Urinary retention at 6, 12, and 24 months was reported in 7.3%, 1.9%, and 0.6%, respectively, in the WG arm, and in 5%, 1.3%, and 0.9%, respectively, in the FT arm. Finally, only one fistula was reported in each group.

CONCLUSIONS

Men with low-risk prostate cancer who underwent FT cryoablation had comparable BCR-survival rates at 60 months to patients treated with WG. However, FT patients had higher erectile function preservation rates at 24 months post-procedure. Urinary continence, retention and fistula rates were similar between the two treatment groups.

Re-purposing cryoablation: a combinatorial 'therapy' for the destruction of tissue

It is now recognized that the tumor microenvironment creates a protective neo-tissue that isolates the tumor from the various defense strategies of the body. Evidence demonstrates that, with successive therapeutic attempts, cancer cells acquire resistance to individual treatment modalities. For example, exposure to cytotoxic drugs results in the survival of approximately 20-30% of the cancer cells as only dividing cells succumb to each toxic exposure. With follow-up treatments, each additional dose results in tumor-associated fibroblasts secreting surface-protective proteins, which enhance cancer cell resistance. Similar outcomes are reported following radiotherapy. These defensive strategies are indicative of evolved capabilities of cancer to assure successful tumor growth through well-established anti-tumor-protective adaptations. As such, successful cancer management requires the activation of multiple cellular 'kill switches' to prevent initiation of diverse protective adaptations. Thermal therapies are unique treatment modalities typically applied as monotherapies (without repetition) thereby denying cancer cells the opportunity to express defensive mutations. Further, the destructive mechanisms of action involved with cryoablation (CA) include both physical and molecular insults resulting in the disruption of multiple defensive strategies that are not cell cycle dependent and adds a damaging structural (physical) element. This review discusses the application and clinical outcomes of CA with an emphasis on the mechanisms of cell death induced by structural, metabolic, vascular and immune processes. The induction of diverse cell death cascades, resulting in the activation of apoptosis and necrosis, allows CA to be characterized as a combinatorial treatment modality. Our understanding of these mechanisms now supports adjunctive therapies that can augment cell death pathways.

Algorithm-based multidisciplinary treatment approach for rectourethral fistula

PURPOSE

The purpose of this study is to report the outcomes of an algorithm-based multidisciplinary treatment approach to rectourethral fistula.

METHODS

This study is a retrospective review of a prospectively collected database at a tertiary center of all consecutive patients treated between 2003 and 2013.

RESULTS

Thirty males (mean age 63 years) were reviewed. Prostate cancer treatment was the most common fistula etiology (97%). Urinary drainage consisted of urethral catheter in all patients and suprapubic catheter in 14 (47%). The rate of fecal diversion was 67%. During a mean follow-up of 72 months, healing rate was 90% and recurrence rate 0%. Spontaneous healing was achieved in 14 patients (47%): 8 (27%) without fecal diversion and 6 (20%) following fecal diversion. Thirteen patients (43%) required definitive intervention. The majority of operated patients underwent transanal or transperineal flap (endorectal, dartos, or gracilis) successfully. Only 2 patients (7%) required an abdominal approach (positive oncologic margins or non-functioning bladder). Fifteen out of the 20 patients (75%) who underwent fecal diversion had stoma closure with an overall permanent stoma rate of 17%. Long-term urinary incontinence was noted in 11 patients (37%). Six patients (20%) required permanent urinary diversion or drainage catheters.

CONCLUSIONS

Algorithm-based treatment approach for rectourethral fistula is useful in the management of this rare condition. Selective fecal diversion is possible, and majority of patients who require definitive intervention can be treated with a transanal or transperineal approach. The rate of permanent stoma is low, but long-term urinary dysfunction is frequent.

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.

Predictors of prostate-specific antigen biochemical recurrence in patients undergoing primary whole-gland prostate cryoablation

PURPOSE

Cryoablation has been proven as a less invasive, safe, and effective treatment for localized prostate cancer. We attempted to identify the predictors of biochemical recurrence after prostate cryoablation for localized prostate cancer in this study.

METHODS

We reviewed 114 patients who underwent primary whole-gland prostate cryoablation for localized prostate cancer from October 2008 to March 2013. The perioperative parameters included age >70 years, initial prostate-specific antigen (PSA), preoperative prostate volume, Gleason score, T stage, D'Amico risk group, postoperative PSA nadir, time to PSA nadir, and PSA biochemical recurrence, defined by Phoenix definition (nadir plus 2 ng/mL). Receiver operating characteristic (ROC) analysis was used for the best cutoff value of PSA nadir for PSA biochemical recurrence. The parameters were analyzed in binary logistic regression and Kaplan-Meier analysis for PSA biochemical recurrence.

RESULTS

A total of 31.6 % (N = 36) patients had PSA biochemical recurrence during the median follow-up of 34.87 ± 16.49 months. ROC analysis revealed that the best cutoff value for biochemical recurrence prediction was when the PSA nadir = 0.3 ng/mL. On multivariate analysis and Kaplan-Meier analysis, the D'Amico high-risk group [hazard ratio (HR) 6.552; p = 0.014], PSA nadir >0.3 ng/mL (HR 34.062; p < 0.001), and time to PSA nadir <3 months (HR 4.144; p = 0.021) were statistically significant for PSA biochemical recurrence.

CONCLUSIONS

The D'Amico high-risk group, postoperative PSA nadir >0.3 ng/mL, and time to PSA nadir <3 months predict biochemical recurrence in primary whole-gland prostate cryoablation.

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.

Cancer immunotherapy using tumor cryoablation

Cryoablation is increasingly being used as a primary treatment for localized cancers and as a salvage therapy for metastatic cancers. Anecdotal clinical reports and animal experiments have confirmed an induction of systemic antitumor immune response by tumor cryoablation. To capitalize on the stimulatory effects of cryoablation for cancer immunotherapy, this response must be intensified using other immunomodulatory agents. This article reviews the preclinical and clinical evidence and discusses the mechanism of the antitumor immune response generated by cryoablation. The rationale and evidence behind several immunotherapy approaches that can be combined with cryoablation to devise a cryoimmunotherapeutic strategy with a potential to impact the progression of metastatic disease are described.