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

The history of cryosurgery in Canada: A tale of two cities

Although not commonly available in Canada, cryosurgery (cryoablation) for prostate cancer has been practiced in many countries. The field of cryoablation has evolved significantly over the past 30 years. Two prostate cryoablation programs were started in Canada in the early 1990s, in London, ON and Calgary, AB, focusing, respectively, on salvage therapy following radiation failure and primary local treatment. This article chronicles the development of the two programs and outlines the scientific and clinical contributions by investigators at the two centers.

Salvage Therapy Options for Local Prostate Cancer Recurrence After Primary Radiotherapy: a Literature Review

PURPOSE OF REVIEW

While recurrence after primary treatment of prostate cancer (PCa) is not uncommon, there is currently no consensus on the most appropriate management after radiation treatment failure. This article seeks to explore the currently utilized modalities for salvage treatment for radiorecurrent PCa. We focused our review on the oncologic outcomes and reported toxicity rates in the latest studies examining salvage radical prostatectomy (SRP), salvage cryotherapy (SCT), salvage high-intensity focused ultrasound (HIFU) and re-irradiation.

RECENT FINDINGS

There does not appear to be any significant difference in overall survival for more invasive salvage radical prostatectomy compared to the minimally invasive salvage approaches. Additionally, there seems to be a trend towards lower morbidity rates associated with minimally invasive and focal salvage treatment. We are encouraged by the results presented in this review and find that there is clearly a role for emerging minimally invasive and focal therapies as durable options for salvage treatment in patients with radiorecurrent PCa.

Comparative Oncologic and Toxicity Outcomes of Salvage Radical Prostatectomy Versus Nonsurgical Therapies for Radiorecurrent Prostate Cancer: A Meta-Regression Analysis

CONTEXT

In the absence of randomised controlled trials comparing the oncologic, toxicity, and functional outcomes of salvage radical prostatectomy (SRP), salvage high-intensity focused ultrasound (SHIFU), salvage brachytherapy (SBT), and salvage cryotherapy (SCT), controversy exists as to the optimal salvage modality in radiorecurrent prostate cancer.

OBJECTIVE

We carried out a meta-regression analysis to determine whether there is a difference in oncologic, toxicity, and functional outcomes using data from original publications of salvage modalities in the postradiation setting.

EVIDENCE ACQUISITION

We performed a systematic review of PubMed/Medline citations according to the Preferred Reporting Items for Systematic Review and Meta-analysis (PRISMA) statement. We included 63 articles in the analysis (25 on SRP, 8 on SHIFU, 16 on SCT, 14 on SBT).

EVIDENCE SYNTHESIS

Median values of the following variables were extracted from each study: patient age, length of follow-up, prostate-specific antigen (PSA) before radiotherapy (RT), PSA before salvage therapy, Gleason score before RT, and time interval between RT and salvage therapy. Functional, toxicity, and oncologic outcomes were measured according to rates of impotence, incontinence, fistula formation, urethral strictures, and biochemical recurrence. Meta-regression adjusting for confounders found no significant difference in oncologic outcomes between SRP and nonsurgical salvage modalities. SBT, SCT, and SHIFU appeared to have better continence outcomes than SRP. No significant difference in toxicity outcomes between modalities was found, although limitations such as reporting, selection, and publication bias and between-study heterogeneity must also be considered with these conclusions.

CONCLUSIONS

Oncologic outcomes are comparable for SRP and all three nonsurgical salvage modalities. We found no significant differences in toxicity outcomes among modalities; however, SRP appears to be associated with worse rates of urinary incontinence than SBT, SCT, and SHIFU.

PATIENT SUMMARY

We performed a meta-regression analysis to compare oncologic, functional, and toxicity outcomes between salvage radical prostatectomy and nonsurgical salvage modalities. Oncologic and toxicity outcomes appear to be similar; however, all nonsurgical salvage modalities may be associated with better continence outcomes.

Targeted radiotherapy with gold nanoparticles: current status and future perspectives

Radiation therapy (RT) is the treatment of cancer and other diseases with ionizing radiation. The ultimate goal of RT is to destroy all the disease cells while sparing healthy tissue. Towards this goal, RT has advanced significantly over the past few decades in part due to new technologies including: multileaf collimator-assisted modulation of radiation beams, improved computer-assisted inverse treatment planning, image guidance, robotics with more precision, better motion management strategies, stereotactic treatments and hypofractionation. With recent advances in nanotechnology, targeted RT with gold nanoparticles (GNPs) is actively being investigated as a means to further increase the RT therapeutic ratio. In this review, we summarize the current status of research and development towards the use of GNPs to enhance RT. We highlight the promising emerging modalities for targeted RT with GNPs and the corresponding preclinical evidence supporting such promise towards potential clinical translation. Future prospects and perspectives are discussed.

Review of the efficacy and safety of cryoablation for the treatment of small renal masses

PURPOSE

Small renal masses are increasingly being discovered incidentally on imaging for another reason. The standard of care of these masses involves excision by open or laparoscopic techniques. Recently, ablative techniques, such as radiofrequency ablation (RFA) and cryoablation, have taken a more prominent role in the treatment algorithm of these masses. We evaluate the effectiveness and safety of cryoablation to treat renal tumours.

METHODS

A review of the literature was conducted. There was no language restriction. Studies were obtained from the following sources: the Cochrane Library, PUBMED, EMBASE and LILACS.

RESULTS

There was no clinical trial identified in the literature. Thus, we described the results from 23 case series and retrospective studies with a reasonable sample size (number of reported patients in each study ≥30), with a total of 2104 analyzed tumours from 2038 patients. There was wide variability in the outcomes reported, but success rates were generally good. Follow-up was generally short, but some series reported outcomes at 5 years. The most common complications reported were hemorrhage (some of the patients requiring transfusion), perinephric hematoma and urine leaks.

CONCLUSION

Cryoablation presents a feasible treatment for patients with small renal masses. Only short-term data are available and, as such, meaningful conclusions regarding long-term cancer control cannot be made. More rigorous studies are needed.