Active hydrodissection might optimize cryosurgical ablation of the prostate

Rectal mesenteric metastasis from prostate cancer treated with adjunctive hydrodissection during cryoablation

ABSTRACT

Cryoablation is a safe and promising technique for patients with solid tumors. However, when adjacent to vulnerable structures, appropriate protective measures are necessary while carrying out this procedure. Herein, we present a case of a prostate cancer patient with rectal mesenteric metastasis who underwent cryoablation. The lesion was separated from the rectum by hydrodissection. No grade II-IV adverse events were encountered intraoperatively, and dramatic improvements in the stool were observed. These findings indicate that cryoablation combined with hydrodissection is a safe and reliable treatment method for lesions adjacent to the rectum.

Clinical value of normal saline injection for expansion of the anterior perirectal space during prostate cryoablation

BACKGROUND

The objective of this study is to describe the technique and evaluate the clinical value of normal saline (NS) injection for expanding the anterior perirectal space during prostate cryoablation for prostate cancer (PCa) patients.

METHODS

PCa patients who received cryoablation between August 2014 and December 2019 were enrolled, and the technique of NS injection was adopted. The complications were evaluated. The prostate-specific antigen (PSA) nadir and biochemical progression-free survival (bPFS) were measured in localized PCa patients who received cryoablation as the primary treatment.

RESULTS

A total of 159 PCa patients were included. Among 147 patients with the data of anterior perirectal space, the median (interquartile range [IQR]) distance of estimated iceball edge beyond the prostatic capsule was 8.3 (7.0-10.0) mm. No cases of urethrorectal fistula were reported; 29 patients developed urinary retention and 25 patients presented scrotal edema. All complications below Clavien-Dindo grade IIIb disappeared within 7 weeks after surgery. Urinary incontinence was reported in 6 patients. Among localized PCa patients, the median (IQR) follow-up time was 56.5 (36.0-73.5) months. The estimated 5-year bPFS was 82.3% overall, 82.8% for low-to intermediate-risk PCa patients, and 82.1% for high-risk PCa patients. For 52 patients received cryoablation alone, the median (IQR) PSA nadir was 0.147 (0.027-0.381) ng/mL.

CONCLUSIONS

The technique of NS injection for expanding the anterior perirectal space during cryoablation surgery could avoid urethrorectal fistula and might benefit localized PCa patients with lower PSA nadir and longer bPFS.

Rationale for Utilization of Hydrogel Rectal Spacers in Dose Escalated SBRT for the Treatment of Unfavorable Risk Prostate Cancer

In this review we outline the current evidence for the use of hydrogel rectal spacers in the treatment paradigm for prostate cancer with external beam radiation therapy. We review their development, summarize clinical evidence, risk of adverse events, best practices for placement, treatment planning considerations and finally we outline a framework and rationale for the utilization of rectal spacers when treating unfavorable risk prostate cancer with dose escalated Stereotactic Body Radiation Therapy (SBRT).

Trans-rectal Ultrasound-Guided Autologous Blood Injection in the Interprostatorectal Space Prior to Percutaneous MRI-Guided Cryoablation of the Prostate

OBJECTIVE

To report a novel technique of ultrasound-guided injection of autologous blood in the interprostatorectal space, in an attempt to facilitate ablative prostatic procedures by widening durably the space between the rectum and the prostate.

MATERIALS AND METHODS

Between April and November 2016, four consecutive patients underwent the haemoprotection injection technique. For each patient, we recorded the time to perform the technique, the amount of injected blood, the achieved distances between the rectum and the prostate post-injection at fixed defined points (apex, middle, and base of prostate at the midline, left, and right sides of the gland), the extension of the ice ball outside the prostate capsule at those fixed points, and whether any residual blood was present on 1-month follow-up MRI.

RESULTS

Mean time to perform haemoprotection injection was 54 min, with an average blood volume of 103 cc. Mean distance achieved at the apex, middle, and base of the prostate, respectively, was 12, 13, and 16 mm in the midline; 8, 10, and 13 mm on the left side; and 9, 10, and 13 mm on the right side. The mean extension distance of the ice ball beyond the capsule was 4, 6, and 6 mm in the midline; 4, 5, and 6 mm on the left side; and 1, 3, and 3 mm on the right side. No residual blood was present on 1-month follow-up MRI in all patients. No rectal fistula occurred.

CONCLUSION

Haemoprotection may create a safe and effective virtual space between the prostate and rectum.

Standardization of definitions in focal therapy of prostate cancer: report from a Delphi consensus project

PURPOSE

To reach standardized terminology in focal therapy (FT) for prostate cancer (PCa).

METHODS

A four-stage modified Delphi consensus project was undertaken among a panel of international experts in the field of FT for PCa. Data on terminology in FT was collected from the panel by three rounds of online questionnaires. During a face-to-face meeting on June 21, 2015, attended by 38 experts, all data from the online rounds were reviewed and recommendations for definitions were formulated.

RESULTS

Consensus was attained on 23 of 27 topics; Targeted FT was defined as a lesion-based treatment strategy, treating all identified significant cancer foci; FT was generically defined as an anatomy-based (zonal) treatment strategy. Treatment failure due to the ablative energy inadequately destroying treated tissue is defined as ablation failure. In targeting failure the energy is not adequately applied to the tumor spatially and selection failure occurs when a patient was wrongfully selected for FT. No definition of biochemical recurrence can be recommended based on the current data. Important definitions for outcome measures are potency (minimum IIEF-5 score of 21), incontinence (new need for pads or leakage) and deterioration in urinary function (increase in IPSS >5 points). No agreement on the best quality of life tool was established, but UCLA-EPIC and EORTC-QLQ-30 were most commonly supported by the experts. A complete overview of statements is presented in the text.

CONCLUSION

Focal therapy is an emerging field of PCa therapeutics. Standardization of definitions helps to create comparable research results and facilitate clear communication in clinical practice.

Denonvilliers' space expansion by transperineal injection of hydrogel: implications for focal therapy of prostate cancer

We developed and assessed a technique of: (i) expanding Denonvilliers' space by hydrogel (polyethylene glycol) during focal cryoabation; and (ii) temperature mapping to ensure protection of the rectal wall. In a fresh cadaver, 20 cc of hydrogel was injected transperineally into Denonvilliers' space under transrectal ultrasound guidance. Successful expansion of Denonvilliers' space was achieved with a range of 9-11 mm thickness covering the entire posterior prostate surface. Two freeze-thaw cycles were used to expand the iceball reaching the rectal wall as an end-point. Intraoperative transrectal ultrasound monitoring and temperature mapping in Denonvilliers' space by multiple thermocouples documented real-time iceball expansion up to 10 mm beyond the prostate, and safety in protecting the rectal wall from thermal injury. The lowest temperatures of the thermocouples with a distance of 0 mm, 5 mm and 10 mm from the prostate were: -35°C, -18°C and 0°C (P < 0.001), respectively. In gross and microscopic examination, the hydrogel mass measured 11 × 40 × 34 mm, which was identical to the intraoperative transrectal ultrasound measurements, there was no infiltration of the hydrogel into the rectal wall or prostate and no injury to the pelvic organs. In conclusion, the expansion of Denonvilliers' space by transperineal injection of hydrogel is feasible and a promising technique to facilitate energy-based focal therapy of prostate cancer.