Dynamic prostatic and laser-ablated lesion volume change after transperineal laser ablation in canine: preliminary observation and its clinical significance

Rui-Qing Liu,Ji-Bin Liu,Shao-Bo Duan,Si-Guo Cheng,Zhi-Yang Chang,Hui-Cun Cao,Guang-Shao Cao,Ya-Qiong Li,Na Li,Lian-Zhong Zhang

doi:10.1080/02656736.2020.1842517

Abstract

Aim The purpose of this study is to observe the volume change of prostate and laser-ablated lesions in the canine and to explore the mechanism and clinical significance through histopathology. Materials and methods Transperineal laser ablation (TPLA) was performed under the guidance of transrectal ultrasound (TRUS) in eight canines. Two canines were sacrificed 1 day and 1 week after TPLA, respectively. The remaining six canines were sacrificed after finishing transrectal contrast-enhanced ultrasound (TR-CEUS) at three phases. Results The prostatic volumes immediately following TPLA and 1 week later were larger than before TPLA (20.1 ± 3.9 vs 17.1 ± 3.8 ml; 21.7 ± 3.6 vs 17.1 ± 3.8 ml, p < 0.05), but 1 month later, returned to the preoperative level (17.4 ± 3.2 ml). At three time points, the mean volumes of laser-ablated lesions at 3 W/600 J were 0.6 ± 0.2, 1.1 ± 0.4, and 1.7 ± 0.5 ml, respectively, while those of laser-ablated lesions at 3 W/1200 J were 1.2 ± 0.2, 1.6 ± 0.3, and 2.2 ± 0.5 ml, respectively. The mean volumes of laser-ablated lesions increased significantly over time after TPLA (p < 0.050). Conclusion The prostate volume transient enlarges after TPLA, which prompts for clinical application that it should prolong appropriately the duration of urinary catheterization to avoid acute urinary retention. Many inflammatory cells were observed in the laser-ablated lesions and adjacent normal prostate parenchyma through histopathology. It is speculated that the inflammatory response is involved in the progression of tissue damage.

Highlights

Prostate cancer (PCa) is the most commonly diagnosed solid cancer among men, and remains a leading cause of cancer death [1]
For the low risk and localized PCa, focal therapy could reduce the complication of radical prostatectomy, including incontinence, impotence, and damage to surrounding organs [2]
Focal therapy of the prostate could be administered by several modalities: high-intensity focused ultrasound (HIFU) [4], cryoablation [5], photodynamic therapy [6], laser ablation [7], radiofrequency ablation (RFA) [8], and microwave ablation (MWA) [9]

Summary

Introduction

Prostate cancer (PCa) is the most commonly diagnosed solid cancer among men, and remains a leading cause of cancer death [1]. For the low risk and localized PCa, focal therapy could reduce the complication of radical prostatectomy, including incontinence, impotence, and damage to surrounding organs [2]. Focal therapy aims to maintain the oncological benefit of active treatment options and reduces the risk of side effects through preserving noncancerous tissues, which possesses advantages of minimally invasiveness, local anesthesia, shorter length of stay in hospital, and fast recovery [3]. Percutaneous laser ablation is performed by delivering the laser light inside the tissue usually via a flexible optical fiber with a small diameter (0.2À0.8 mm). Prostate tissue is well suited for laser ablation due to its optical absorption rate and lack of excessive vascularity [12]. The laser ablation for moderate-risk PCa was found safe and feasible in phases I and II clinical trial [7,13]

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Conclusion