Contrast enhanced ultrasound (CEUS) with MRI image fusion for monitoring focal therapy of prostate cancer with high intensity focused ultrasound (HIFU)¹

Issue title: Special Issue in Honour of the Editor-in-Chief Prof. Dr. Ing. Friedrich Jung on his 70th Birthday

Article type: Research Article

Authors: Apfelbeck, M.^{a; #; *} | Clevert, D.-A.^{b; #} | Ricke, J.^b | Stief, C.^a | Schlenker, B.^a

Affiliations: [a] Department of Urology, University Hospital Grosshadern, Ludwig-Maximilians- University Munich, Munich, Germany | [b] Department of Clinical Radiology, Interdisciplinary Ultrasound-Center, University Hospital Grosshadern, Ludwig-Maximilians-University Munich, Munich, Germany

Correspondence: [*] Corresponding author: Maria Apfelbeck, M.D., Department of Urology, University Hospital Grosshadern, Ludwig-Maximilians-University Munich, Marchioninistr. 15, 81377 Munich, Germany. Tel.: +49 89 44007 2971; Fax: +49 89 44007 8890; E-mail: Maria.Apfelbeck@med.uni-muenchen.de.

Note: [#] These authors contributed equally to this article.

Note: [1] The manuscript is dedicated to Prof. F. Jung on the occasion of his 70th birthday.

Abstract: INTRODUCTION:Reduced acceptance of radical prostatectomy in patients with low risk or intermediate risk prostate cancer has significantly changed treatment strategies in prostate cancer (PCa) during the last years. Focal therapy of the prostate with high intensity focused ultrasound (HIFU) is an organ-preserving treatment for prostate cancer with less impairment of health-related quality of life. Follow-up after HIFU therapy by imaging modalities remains a major problem as eg. MRI performs poorly. Contrast enhanced ultrasound (CEUS) allows to monitor the vascular architecture of organs non-invasively. However, only limited data are available using CEUS to define successful and complete HIFU treatment of the prostate. In this study, we aimed to evaluate short-term image findings using CEUS and image fusion before and after HIFU treatment. MATERIALS AND METHODS:Prospective single arm study in patients with uni- or bilateral, low or intermediate risk prostate cancer or recurrent cancer after radiotherapy treated with HIFU at our institution between October 2016 and November 2017. HIFU hemiablation or whole gland treatment was performed using the Focal One® device. PCa was diagnosed either by multiparametric magnetic resonance imaging (mpMRI) followed by MRI fusion based targeted biopsy combined with 12 core transrectal ultrasound (TRUS) guided biopsy or 12 core random biopsy only. Monitoring of the target region before, immediately and 24 hours after the ablation was done by CEUS in combination with image fusion using an axial T2-weighted MRI sequence. RESULTS:6 consecutive patients with Gleason score (GS) 6, 5 patients with GS 7a prostate cancer and one patient with biochemical recurrence after radiotherapy were included in the study. Three patients underwent whole gland treatment due to histological proven bilateral PCa or recurrent PCa after radiotherapy. Hemiablation was performed in 9 patients with unilateral tumor and no PIRADS 4 or 5 lesion in the contralateral lobe. Median patient age was 69.8 years and median PSA (prostate-specific antigen) level was 8.4 ng/ml. CEUS showed markedly reduced microbubbles in the ablated area, the prostate capsule still showed signs of perfusion. The study is limited by the short follow up and small number of patients. CONCLUSIONS:CEUS examination showed a reduction of microcirculation in the treated area immediately after the treatment and 24 hours later. The combination of CEUS and image fusion seems to be helpful for detecting the PCa target lesion and monitor the success of HIFU ablation treatment. Evidence for image findings after HIFU-therapy are rare. Further studies on this topic are needed.

Keywords: High intensity focused ultrasound therapy, image fusion, prostate, CEUS, contrast enhanced ultrasound

DOI: 10.3233/CH-189123

Journal: Clinical Hemorheology and Microcirculation, vol. 69, no. 1-2, pp. 93-100, 2018