Contrast‐Enhanced Transrectal Ultrasound for Follow‐up After Focal HIFU Ablation for Prostate Cancer

Abstract

The optimal strategy for imaging after focal therapy for prostate cancer is evolving. This series is an initial report on the use of contrast-enhanced transrectal ultrasound (TRUS) in follow-up of patients after high-intensity focused ultrasound (HIFU) hemiablation for prostate cancer. In 7 patients who underwent HIFU hemiablation, contrast-enhanced TRUS findings were as follows: (1) contrast-enhanced TRUS clearly showed the HIFU ablation defect as a sharply marginated nonenhancing zone in all patients; (2) contrast-enhanced TRUS identified suspicious foci of recurrent enhancement within the ablation zone in 2 patients, facilitating image-guided prostate biopsy, which showed prostate cancer; and (3) contrast-enhanced TRUS findings correlated with multiparametric magnetic resonance imaging and biopsy histologic findings.

Effect of High-Intensity Focused Ultrasound Versus Plasma Radiofrequency Ablation on Recurrent Allergic Rhinitis

“…The instantaneous high temperature generated by HIFU denatures the tissue, leading to coagulative necrosis, and the free radicals generated also promote the decomposition of cells at the same time. In addition, high-amplitude mechanical waves inactivate cells, and chemical reactions of chemical components in the membrane structure under the action of high-energy ultrasound also promote cell death [21–23]. When energy is concentrated in the submucosa of the nasal cavity, the death of immune cells reduces the release of cytokines and inflammatory mediators.…”

Multiparametric ultrasound of prostate: role in prostate cancer diagnosis

“…53 CEUS brings several potential advantages in the management of PCa including diagnosis, facilitating targeted PBx, real-time evaluation and confirmation of adequate tissue ablation after focal therapy (FT), and identification of post-treatment recurrence during post-ablation surveillance by achieving better vascular imaging resolution. 52 Doppler ultrasound can accurately assess macrovessels but not vessels less than 200 μm as those typically seen with angiogenesis. Ultrasound contrast containing microbubbles measuring 2-6 μm are pure intravascular as they do not cross into the interstitial space, they are small enough to pass through the pulmonary circulation and enter the systemic circulation, but large enough not to escape the endothelium, and excellent to see microvasculature typical of prostate adenocarcinoma.…”

“…64,65 Ablated tissue by highintensity focused ultrasound (HIFU) can be confirmed as a flat curve with minimal slope on TIC (Figure 2). 52 Elastography. Ultrasound elastography, an imaging technique that detects and quantifies tissue stiffness, is helpful in diagnosing PCa as malignant tissue has greater stiffness than benign tissue.…”

“…CEUS consists of the imaging technique involving the administration of intravenous ultrasound contrast agents to improve the visualization of structures of interest. 52 Specifically, for PCa, this strategy aids in the detection, diagnosis, and follow-up of suspicious lesions while performing targeted PBx with TRUS.…”

“… 53 CEUS brings several potential advantages in the management of PCa including diagnosis, facilitating targeted PBx, real-time evaluation and confirmation of adequate tissue ablation after focal therapy (FT), and identification of post-treatment recurrence during post-ablation surveillance by achieving better vascular imaging resolution. 52 …”