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

Salvage Cryoablation for Recurrent Prostate Cancer Following Radiation-A Comprehensive Review

The treatment options for prostate cancer typically entail active surveillance, surgery, radiation, or a combination of the above. Disease recurrence remains a concern, with a wide range of recurrence rates having been reported in the literature. In the setting of recurrence, the salvage treatment options include salvage prostatectomy, salvage high-intensity focused ultrasound (HIFU), stereotactic body radiotherapy (SBRT), salvage brachytherapy, and salvage cryoablation. In this review, we analyze the currently available data related to salvage cryoablation for recurrent prostate cancer following radiation.

Radiation therapy and IRreversible electroporation for intermediate risk prostate cancer (RTIRE)

INTRODUCTION

Radiation Therapy and IRreversible Electroporation for Intermediate Risk Prostate Cancer (RTIRE) is a phase II clinical trial testing combination of radiation therapy and irreversible electroporation for intermediate risk prostate cancer BACKGROUND: PCa is the most common non-cutaneous cancer in men and the second leading cause of cancer death in men. PCa treatment is associated with long term side effects including urinary, sexual, and bowel dysfunction. Management of PCa is based on risk stratification to prevent its overtreatment and associated treatment-related toxicity. There is increasing interest in novel treatment strategies, such as focal therapy, to minimize treatment associated morbidity. Focal therapy alone has yet to be included in mainstream guidelines, given ongoing concerns with potentially higher risk of recurrence. We hypothesize combining focal therapy with whole gland, reduced dose radiotherapy will provide acceptable oncologic efficacy with minimal treatment associated morbidity. RTIRE is a phase II single institution, investigator-initiated study combining a local ablative technique though local irreversible electroporation (IRE) with MR guided RT (MRgRT) to treat the entire prostate. The goal is to provide excellent oncologic outcomes and minimize treatment related side effects through leveraging benefits of locally ablative therapy with established radiation treatment techniques.

METHODS

A total of 42 men with intermediate risk PCa per NCCN guidelines and focal grade group (GG) 2 or 3, Gleason Score (GS) 3 + 4 or GS 4 + 3, cancer in an MRI target will be enrolled. Patients with MRI visible foci of GG2/GG3 will undergo focal therapy with IRE of this lesion. Following successful focal therapy, patients will then undergo a course of reduced dose, whole gland MRgRT with either 32.5 Gy in 5 Fractions or 22 Gy in 2 fractions. The primary objective of the study is to determine safety. Secondary outcomes include evaluation of oncologic efficacy (as measured by the proportion of patients free of clinically significant cancer as defined as > Grade Group 1 at 1-year follow-up biopsy), imaging characteristics of patients pre and post RTIRE, impact on quality of life (QoL), and PSA kinetics.

DISCUSSION

Combining IRE with a reduced dose radiotherapy may offer a new treatment paradigm for PCa by both reducing treatment effects of full dose radiotherapy and minimizing the risk of recurrence observed with focal therapy.

TRIAL REGISTRATION

Clinicaltrials.gov identifier: NCT05345444. Date of registration: April 25, 2022.

PROTOCOL VERSION

6.0, July 7, 2023.

A novel in vitro model of clinical cryoablation to investigate the transition zone for focal tumor ablation

Cryoablation (CA) of solid tumors is highly effective at reducing tumor burden and eliminating small, early stage tumors. However, complete ablation is difficult to achieve and cancer recurrence is a significant barrier to treatment of larger tumors compared to resection. In this study, we explored the relationship between temperature, ice growth, and cell death using a novel in vitro model of clinical CA with the Visual-ICE (Boston Scientific) system, a clinically approved and widely utilized device. We found that increasing the duration of freezing from 1 to 2 min increased ice radius from 3.44 ± 0.13 mm to 5.29 ± 0.16 mm, and decreased the minimum temperature achieved from -22.8 ± 1.3 °C to -45.5 ± 7.9 °C. Furthermore, an additional minute of freezing increased the amount of cell death within a 5 mm radius from 42.5 ± 8.9% to 84.8 ± 1.1%. Freezing at 100% intensity leads to faster temperature drops and a higher level of cell death in the TRAMP-C2 mouse prostate cancer cell line, while lower intensities are useful for slow freezing, but result in less cell death. The width of transition zone between live and dead cells decreased by 0.4 ± 0.2 mm, increasing from one to two cycles of freeze/thaw cycles at 100% intensity. HMGB-1 levels significantly increased with 3 cycles of freeze/thaw compared to the standard 2 cycles. Overall, a longer freezing duration, higher freezing intensity, and more freeze thaw cycles led to higher levels of cancer cell death and smaller transition zones. These results have the potential to inform future preclinical research and to improve therapeutic combinations with CA.

Focal Minimally Invasive Treatment in Localized Prostate Cancer: Comprehensive Review of Different Possible Strategies

BACKGROUND

Focal therapy is a promising, minimally invasive method for the treatment of patients with localized prostate cancer. According to the existing literature, there is growing evidence for positive functional outcomes and oncological effectiveness. The aim of this review is to evaluate the technical efficacy of three minimally invasive techniques (cryoablation, electroporation, and microwave ablation) and their impact on quality of life in patients with prostate cancer.

METHODS

Studies between January 2020 and July 2023 were selected using PubMed, Embase, and The Cochrane Library and analyzed following PRISMA guidelines; they have not been registered.

RESULTS

Twenty-three studies investigating three different sources of energy to deliver focal therapy were found. Thirteen studies evaluated the performance of the cryoablation therapy, seven studies of the irreversible electroporation, and three studies of microwave ablation option. The majority of studies were retrospective cohort studies. Cryoablation showed excellent oncological outcomes for low-grade prostate cancer, whether performed on the lesion, on the hemigland, or on the entire gland, with the best results obtained for patients with intermediate risk. Irreversible electroporation showed promising oncological outcomes with no significant changes in functional outcomes. Microwave ablation showed great early functional outcomes.

CONCLUSIONS

The oncological effectiveness of minimally invasive treatment in comparison to standard of care is still under investigation, despite encouraging results in terms of functional outcomes improvement and adverse events reduction. More comprehensive research is needed to fully understand the function of minimally invasive treatment in patients with localized PCa.

Performance of 18F-DCFPyL PET/CT in Primary Prostate Cancer Diagnosis, Gleason Grading and D'Amico Classification: A Radiomics-Based Study

This study aimed to investigate the performance of 18F-DCFPyL positron emission tomography/computerized tomography (PET/CT) models for predicting benign-vs-malignancy, high pathological grade (Gleason score > 7), and clinical D'Amico classification with machine learning. The study included 138 patients with treatment-naïve prostate cancer presenting positive 18F-DCFPyL scans. The primary lesions were delineated on PET images, followed by the extraction of tumor-to-background-based general and higher-order textural features by applying five different binning approaches. Three layer-machine learning approaches were used to identify relevant in vivo features and patient characteristics and their relative weights for predicting high-risk malignant disease. The weighted features were integrated and implemented to establish individual predictive models for malignancy (Mm), high path-risk lesions (by Gleason score) (Mgs), and high clinical risk disease (by amico) (Mamico). The established models were validated in a Monte Carlo cross-validation scheme. In patients with all primary prostate cancer, the highest areas under the curve for our models were calculated. The performance of established models as revealed by the Monte Carlo cross-validation presenting as the area under the receiver operator characteristic curve (AUC): 0.97 for Mm, AUC: 0.73 for Mgs, AUC: 0.82 for Mamico. Our study demonstrated the clinical potential of 18F-DCFPyL PET/CT radiomics in distinguishing malignant from benign prostate tumors, and high-risk tumors, without biopsy sampling. And in vivo 18F-DCFPyL PET/CT can be considered a noninvasive tool for virtual biopsy for personalized treatment management.

Supplementary Information

The online version contains supplementary material available at 10.1007/s43657-023-00108-y.

Intermediate-term oncological and functional outcomes of salvage cryotherapy for the management of prostate cancer recurrence after primary brachytherapy versus primary cryotherapy: A propensity score-matched analysis

BACKGROUND

Salvage cryotherapy (SCT) is widely used to treat prostate cancer (PCa) recurrence after radiotherapy (RT). We studied the intermediate oncological and functional outcomes of patients who underwent SCT following cryotherapy (CRYO-SCT) recurrence and compare it to recurrence after brachytherapy (BT-SCT).

METHODS

An IRB-approved retrospective cohort study utilizing patient data from the Cryo On-Line Data Registry and the Duke PCa database between 1992 and 2016. Biochemical recurrence (BCR) using Phoenix criteria was the primary endpoint assessed at 2- and 5-years post-SCT. Secondary endpoints assessed functional outcomes including urinary continence, erectile function, and recto-urethral fistula. Association between treatment and biochemical progression-free survival was assessed using inverse probability weighted (IPTW) Cox proportional hazards regression. The differences in the secondary functional outcomes were assessed by Pearson's χ2 test or Fisher's exact test, corrected for IPTW.

RESULTS

A total of 194 patients met inclusion criteria. The BCR rate for BT-SCT and CRYO-SCT was 23 (20.4%) and 17 (21%) at 2 years and 30 (26.5%) and 22 (27.2%) at 5 years according to Phoenix criteria. There was no statistical difference in 2 years (hazard ratio [HR] 0.9; 95% confidence interval [CI], 0.5-1.7, p = 0.7) or 5-year BCR (HR: 0.86; 95% CI, 0.5-1.5, p = 0.6) between the groups. The functional outcomes like urinary continence (p = 0.4), erectile function (p = 0.1), and recto-urethral fistula (p = 0.3) were not statistically different.

CONCLUSION

CRYO-SCT appears to be well tolerated, with comparable oncological and functional outcomes to patients failing primary BT. The findings also demonstrated that SCT can render a significant number of patients biochemically free of disease after initial CRYO with minimal morbidity. SCT is a viable treatment option to salvage local PCa recurrence following either BT or cryoablation failure.

Oncological and Functional Outcomes for Men Undergoing Salvage Whole-gland Cryoablation for Radiation-resistant Prostate Cancer

BACKGROUND

There is no consensus on the optimal approach for salvage local therapy in radiation-resistant/recurrent prostate cancer (RRPC).

OBJECTIVE

To investigate oncological and functional outcomes for men treated with salvage whole-gland cryoablation (SWGC) of the prostate for RRPC.

DESIGN, SETTING, AND PARTICIPANTS

We retrospectively reviewed our prospectively collected cryosurgery database between January 2002 and September 2019 for men who were treated with SWGC of the prostate at a tertiary referral center.

INTERVENTION

SWGC of the prostate.

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

The primary outcome was biochemical recurrence-free survival (BRFS) according to the Phoenix criterion. Secondary outcomes included metastasis-free survival, cancer-specific survival, and adverse events.

RESULTS AND LIMITATIONS

A total of 110 men with biopsy-proven RRPC were included in the study. Median follow-up for patients without biochemical recurrence (BCR) after SWGC was 71 mo (interquartile range [IQR] 42.3-116). BRFS was 81% at 2 yr and 71% at 5 yr. A higher prostate-specific antigen (PSA) nadir after SWGC was associated with worse BRFS. The median International Index of Erectile Function-5 score was 5 (IQR 1-15.5) before SWGC and 1 (IQR 1-4) after SWGC. Stress urinary incontinence, strictly defined as the use of any pads after treatment, was 5% at 3 mo and 9% at 12 mo. Clavien-Dindo grade ≥3 adverse events occurred in three patients (2.7%).

CONCLUSIONS

In patients with localized RPPC, SWGC achieved excellent oncological outcomes with a low rate of urinary incontinence, and represents an alternative to salvage radical prostatectomy. Patients with fewer positive cores and lower PSA tended to have better oncological outcomes following SWGC.

PATIENT SUMMARY

For men with prostate cancer that persists after radiotherapy, a freezing treatment applied to the whole prostate gland can achieve excellent cancer control. Patients who did not have elevated prostate-specific antigen (PSA) at 6 years after this treatment appeared to be cured.

Suitable T stage for cryosurgery to spare the anus in patients with low rectal cancer

Sphincter preserving therapy is a key research focus for treating low rectal cancer; however, the role of cryotherapy in this process has seldom been reported in the literature. Therefore, we conducted a comprehensive report on the role of cryoablation in sphincter preservation and explored its effect in rectal cancers. An observational study used longitudinal observation and follow-up. Participants were screened from patients whose medical records showed cryotherapy intervention for low rectal cancers from January 2016 to December 2020, with more than 2 years of follow-up. The primary endpoint was progress-free survival, and the secondary outcomes were mainly related to sphincter preservation rate and complications. Thirty-five patients were enrolled in this study, all of whom had their sphincters preserved. Until June 2022, 35 cases achieved long-term progression-free survival (41.77 ± 15.58), with no recurrence observed in 88.57% (31/35) of all patients at follow-up. Cryotherapy showed no significant differences in progress-free survival between sexes (p > 0.05). Cox regression was used to analyze the factors affecting local recurrence, with sex, T stage, size, and cryo-time taken as covariates. The results showed that T stage was a risk factor for local recurrence (p = 0.01, odds ratio: 16.27, 95% confidence interval: 8.20,145.75). Analysis of the T stage according to different subgroups showed that T3 stage was an independent risk factor (p = 0.002). We observed seven cases of complications, which were classified into grades I-II. In patients with low rectal cancers, cryotherapy can safely and effectively preserve the anus and avoid low anterior resection syndrome. Cryoablation has a better curative effect on radical treatment, especially for tumors in the T₀-₂ N₀M₀ stage.