Magnetic Resonance-Guided High-Intensity Focused Ultrasound (MR-HIFU): Technical Background and Overview of Current Clinical Applications (Part 1)

Abstract

ZUSAMMENFASSUNG Hintergrund Der extrakorporale hochintensive fokussierte Ultraschall (HIFU) ist ein vielversprechendes Verfahren zur nichtinvasiven Thermoablation gutartigen und bösartigen Gewebes. Derzeitige HIFU-Therapien nutzen Ultraschall (US-HIFU) oder MRT (MR-HIFU) zur Bildsteuerung mit der Möglichkeit zur integrierten Therapieplanung, Echtzeit-Therapiekontrolle (räumliche Orientierung und Temperatursteuerung) und Therapieevaluation. Methode Dieser Übersichtsartikel basiert auf Publikationen aus Fachzeitschriften, die die thermale Ablation mittels HIFU thematisieren, und beinhaltet zudem eigene klinische Ergebnisse. Es wird ein kurzer Überblick über die häufigsten CEzertifizierten klinischen Applikationen für MR-HIFU gegeben. Ergebnisse Im Laufe des letzten Jahrzehnts erhielten zahlreiche HIFU-basierte Applikationen die Zulassung in diversen Ländern. Im Speziellen ist MR-HIFU nun zugelassen für die Therapie von Uterusmyomen, Linderung von Knochenschmerzen, der Ablation der Prostata und die Therapie des essenziellen Tremors als erste neurologische Applikationsform. Schlussfolgerung MR-HIFU ist eine patientenfreundliche, nichtinvasive Methode zur Thermoablation, welche mittlerweile für mehrere klinische Applikationen zugelassen wurde. Insgesamt bestätigen die bisherigen klinischen Daten die Wirksamkeit und Sicherheit der Therapie sowie die Kosteneffizienz der Methode.Kernaussagen: ▪ HIFU stellt eine vielversprechende Technik zur nichtinvasiven Thermoablation von Gewebe dar. ▪ HIFU wird üblicherweise unter Bildkontrolle mittels Ultraschall (US-HIFU) oder MRT (MR-HIFU) durchgeführt. ▪ Die bevorzugte Bildkontrolle (US-HIFU vs. MR-HIFU) hängt von der geplanten Applikation ab. ▪ MRT bietet einen höheren Weichteilkontrast zur Therapieplanung, eine nahezu in Echtzeit und nichtinvasiv erfolgende Temperaturkontrolle und eine postinterventionelle Therapieevaluation. ▪ MR-HIFU ist CE-zertifiziert für die Therapie von Uterusmyomen, Linderung von Knochenschmerzen, Ablation der Prostata und Therapie des essenziellen Tremors. ABSTR AC TBackground Extracorporeal high-intensity focused ultrasound (HIFU) is a promising method for the noninvasive thermal ablation of benign and malignant tissue. Current HIFU treatments are performed under ultrasound (US-HIFU) or magnetic resonance (MR-HIFU) image guidance offering integrated therapy planning, real-time control (spatial and temperature guidance) and evaluation.Methods This review is based on publications in peer-reviewed journals addressing thermal ablation using HIFU and includes our own clinical results as well. The technical background of HIFU is explained with an emphasis on MR-HIFU applications. A brief overview of the most commonly performed CE-approved clinical applications for MR-HIFU is given.Results Over the last decade, several HIFU-based applications have received clinical approval in various countries. In particular, MR-HIFU is now approved for the clinical treatment of uterine fibroids, palliation of bone pain, ablation of the prostate and treatment of essential tre...

Prediction of pelvic tumour coverage by magnetic resonance-guided high-intensity focused ultrasound (MRgHIFU) from referral imaging

“…Magnetic resonance guided high-intensity focused ultrasound (MRgHIFU) is a noninvasive, non-ionizing treatment modality which has a number of established clinical applications including the ablation of uterine fibroids and bone nerves (for pain palliation) [1], and the treatment of essential tremor [2]. In addition, MRgHIFU is being trialed in the UK for the thermal ablation of recurrent gynaecological tumors (NCT02714621) [3].…”

Improved Treatment Response Following Magnetic Resonance Imaging–Guided Focused Ultrasound for Lumbar Facet Joint Pain

“…11,12 The summation of ultrasound waves causes local heating and induces rapid coagulative necrosis. [11][12][13] This technique allows for extremely precise ablation of targeted tissue with sparing of surrounding structures. [11][12][13] The technique requires no needles or incisions because ultrasound waves are generated by a transducer outside the body.…”

“…[11][12][13] This technique allows for extremely precise ablation of targeted tissue with sparing of surrounding structures. [11][12][13] The technique requires no needles or incisions because ultrasound waves are generated by a transducer outside the body. 11 Magnetic resonance imaging allows for treatment planning and guidance with direct visualization of the target, real-time thermal monitoring of the ablation zone, and postprocedural imaging.…”

“…11 Magnetic resonance imaging allows for treatment planning and guidance with direct visualization of the target, real-time thermal monitoring of the ablation zone, and postprocedural imaging. 13 Numerous applications of MRgFUS are currently in use, largely focused on the treatment of both benign and malignant soft tissue and osseous tumors. 11,13 It has also been utilized for the treatment of other painful conditions such as facet and large joint osteoarthritis.…”

“…13 Numerous applications of MRgFUS are currently in use, largely focused on the treatment of both benign and malignant soft tissue and osseous tumors. 11,13 It has also been utilized for the treatment of other painful conditions such as facet and large joint osteoarthritis. 7,12,14 Magnetic resonance imagingeguided focused ultrasound for the treatment of facet joint osteoarthritis has been reported in a few small human series and swine models, with promising early results.…”