Contrast-Enhanced Ultrasound Imaging of Prostate Gland in Neutered Dogs.

Stefano Spada,Augusto Carluccio,Gary C W England,Marco Russo,Massimo Vignoli

doi:10.3390/ani11020559

Stefano Spada, Augusto Carluccio + Show 3 more

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https://doi.org/10.3390/ani11020559

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Abstract

Simple SummaryDiagnosis of prostatic neoplasia in dogs remains critical since none of the diagnostic methods routinely performed seem to have sufficient sensitivity or specificity. In recent years, contrast-enhanced ultrasound of the prostate gland has been successfully performed in intact dogs. However, data regarding the performance of the technique in castrated dogs have not been provided, despite the incidence of prostate neoplasia potentially being higher after castration. The purpose of the present study was to evaluate the application of contrast-enhanced ultrasound in castrated dogs and to describe the vascular pattern of the canine prostate. Prior to contrast-enhanced ultrasound evaluation, B-mode ultrasound was performed to assess prostate size and parenchymal features. In all cases, perfusion kinetics of the contrast agent within the prostate was analyzed, with the aim of detecting any areas with increased microvessel density. None of the dogs had any ultrasonographically detected pathology. Contrast ultrasound allowed an improved and enhanced ability to evaluate the prostate compared with B-mode ultrasound. This technique is not yet to become a first-choice diagnostic tool; however, since the results of this study are favorable, it seems likely that contrast ultrasound will have an important role in the future for the detection of prostate pathologies in neutered dogs.Prostatic neoplasia (PN) occurs in 5–7% of dogs with prostatic disease, with castrated dogs having the same or higher prevalence when compared to intact dogs. Considering the promising results achieved by performing contrast-enhanced ultrasound (CEUS) in intact dogs to detect PN, the present study aimed to acquire data on the prostatic perfusion pattern in neutered dogs. CEUS was performed in 64 neutered dogs, using a 5–7.5 MHz linear transducer with coded harmonic capability, dedicated analytical software, and a second-generation contrast agent, SonoVue. After B-mode evaluation was performed to assess mean prostate volume, the CEUS examination was undertaken. The flow of contrast agent was visible 10 s after injection. The subcapsular vessels were highlighted and produced rapid peripheral rim enhancement. Subsequently, the contrast agent reached the prostatic urethra via the parenchymal arterioles and gradually reached the entire prostate. Perfusion peak intensity (PPI) and time to peak (TTP) values were respectively 45.3% and 34.1 s. The measured parameters were compared with those obtained in previous studies on intact dogs with normal and with pathological patterns. In this study, CEUS showed features that may be promising for its use as a diagnostic tool for early detection of PN in neutered dogs.

Highlights

Prostate neoplasia (PN) is a rare disease in both intact and neutered dogs [1], with Shetland Sheepdogs and Scottish Terriers at increased risk [2].The mean age of diagnosis is 10 years
A higher prevalence of PN is seen in neutered dogs; both neutered and intact animals develop it at the same age
B-mode ultrasound revealed that all the prostate glands had an oval shape with clear and smooth margins, as well as homogeneous and hypoechoic parenchyma

Summary

Introduction

Prostate neoplasia (PN) is a rare disease (prevalence of 0.43%) in both intact and neutered dogs [1], with Shetland Sheepdogs and Scottish Terriers at increased risk [2].The mean age of diagnosis is 10 years. A higher prevalence of PN is seen in neutered dogs; both neutered and intact animals develop it at the same age. This aspect suggests that neutering is not an initiator of cancer, but promotes tumor progression [2,6], or at least does not protect against the development of neoplasia. Neutering is a routine surgical procedure in dogs and results in a decrease in testosterone and its active metabolite DHT (dihydrotestosterone) in the general circulation. The reduction of these hormones leads to prostate shrinkage and a decrease in sexual behavior, resulting in infertility [7,8]. A definitive explanation of how the absence of gonadal hormones may influence the development of neoplasia in reproductive or nonreproductive tissues is still pending [11]

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