Three-dimensional ultrasound image-guided robotic system for accurate microwave coagulation of malignant liver tumours

Background The further application of conventional ultrasound (US) image-guided microwave (MW) ablation of liver cancer is often limited by two-dimensional (2D) imaging, inaccurate needle placement and the resulting skill requirement. The three-dimensional (3D) image-guided robotic-assisted system provides an appealing alternative option, enabling the physician to perform consistent, accurate therapy with improved treatment effectiveness. Methods Our robotic system is constructed by integrating an imaging module, a needle-driven robot, a MW thermal field simulation module, and surgical navigation software in a practical and user-friendly manner. The robot executes precise needle placement based on the 3D model reconstructed from freehand-tracked 2D B-scans. A qualitative slice guidance method for fine registration is introduced to reduce the placement error caused by target motion. By incorporating the 3D MW specific absorption rate (SAR) model into the heat transfer equation, the MW thermal field simulation module determines the MW power level and the coagulation time for improved ablation therapy. Two types of wrists are developed for the robot: a ‘remote centre of motion’ (RCM) wrist and a non-RCM wrist, which is preferred in real applications. Results The needle placement accuracies were < 3 mm for both wrists in the mechanical phantom experiment. The target accuracy for the robot with the RCM wrist was improved to 1.6 ± 1.0 mm when real-time 2D US feedback was used in the artificial-tissue phantom experiment. By using the slice guidance method, the robot with the non-RCM wrist achieved accuracy of 1.8 ± 0.9 mm in the ex vivo experiment; even target motion was introduced. In the thermal field experiment, a 5.6% relative mean error was observed between the experimental coagulated neurosis volume and the simulation result. Conclusion The proposed robotic system holds promise to enhance the clinical performance of percutaneous MW ablation of malignant liver tumours. Copyright © 2010 John Wiley & Sons, Ltd.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/78054/1/313_ftp.pd

Thermal ablation of biological tissues in disease treatment: A review of computational models and future directions

Percutaneous thermal ablation has proved to be an effective modality for treating both benign and malignant tumors in various tissues. Among these modalities, radiofrequency ablation (RFA) is the most promising and widely adopted approach that has been extensively studied in the past decades. Microwave ablation (MWA) is a newly emerging modality that is gaining rapid momentum due to its capability of inducing rapid heating and attaining larger ablation volumes, and its lesser susceptibility to the heat sink effects as compared to RFA. Although the goal of both these therapies is to attain cell death in the target tissue by virtue of heating above 50 oC, their underlying mechanism of action and principles greatly differs. Computational modelling is a powerful tool for studying the effect of electromagnetic interactions within the biological tissues and predicting the treatment outcomes during thermal ablative therapies. Such a priori estimation can assist the clinical practitioners during treatment planning with the goal of attaining successful tumor destruction and preservation of the surrounding healthy tissue and critical structures. This review provides current state-of- the-art developments and associated challenges in the computational modelling of thermal ablative techniques, viz., RFA and MWA, as well as touch upon several promising avenues in the modelling of laser ablation, nanoparticles assisted magnetic hyperthermia and non- invasive RFA. The application of RFA in pain relief has been extensively reviewed from modelling point of view. Additionally, future directions have also been provided to improve these models for their successful translation and integration into the hospital work flow

Termoablazione del polmone:confronto sperimentale in vivo fra ablazione con microonde e ablazione a radiofrequenza

OBIETTIVO:confrontare le procedure di termoablazione con microonde(MW) e radiofrequenza (RF) in termini di praticabilità,sicurezza e efficacia in uno studio sperimentale condotto in vivo su coniglio. METODO:20 conigli divisi in due gruppi da 10 sono stati sottoposti alla ablazione con MW (gruppo A) e a RF(gruppo B).Si è effettuata sotto guida TAC una singola ablazione del tessuto polmonare.Per la procedura sono stati utilizzati un prototipo per la ablazione con MW(viva- wave,Tyco Healthcare)e un sistema di ablazione con RF disponibile commercialmente(cool-tip, Tyco Healthcare).Il sacrificio è stato effettuato dopo 3 giorni (gruppoA=5,gruppo B=5) e dopo 7 giorni (gruppoA=5,gruppoB=5). RISULTATI:l'operazione è stata portata a termine in 9 casi su 10 in entrambi i gruppi.Il fal- limento negli altri due casi è stato a causa di decesso per stress anestesiologico(gr.A) e per pneumotorace(gr.B).Un coniglio del gruppo B è morto 24 ore dopo la procedura per grave emotorace.Le complicazioni nel post-operatorio sono state pneumotorace(gr.A=4,gr.B=4), ascesso(grA=1,gr.B=1)e ustione della parete toracica (gr.A=4).Il diametro maggiore della necrosi è stato di 12,1 mm +/- 3,2mm nel gr. A e di 14,8mm +/- 4,9mm nel gr. B.L'esame anatomopatologico ha evidenziato in entrambi i casi:necrosi focale,edema,emorragia e infiltrato linfocitario periferico.Il diametro perilesionale di trombosi dei piccoli vasi è maggiore per il gruppo A rispetto al gruppo B.Gli altri organi non sono stati danneggiati. CONCLUSIONI:la praticabilità e la sicurezza delle MW e della RF sono simili nel modello animale,come anche l'aspetto anatomopatologico,che ha comunque evidenziato una trombosi dei piccoli vasi circondanti la lesione maggiore negli animali sottoposti alla ablazione con microonde

Modelling and Analysis of a new Integrated Radiofrequency Ablation and Division Device

Master'sMASTER OF ENGINEERIN

นวัตกรรมใหม่ในการรักษามะเร็งตับด้วยคลื่นความถี่ไมโครเวฟ

บทคัดย่อการผ่าตัดศัลยกรรมเนื้องอกตับหรือมะเร็งที่ตับ (Hepatocellular Cancer: HCC) ได้รับการพิสูจน์ว่าเพิ่มโอกาสในการรอดชีวิตโดยรวมของผู้ป่วย แต่อย่างไรก็ตามผู้ป่วยส่วนใหญ่ไม่สามารถผ่าตัดได้ จึงต้องมีการพัฒนาวิธีการทางความร้อน และวิธีการทางเคมี วิธีการทางความร้อนจากคลื่นไมโครเวฟ (Microwave Coagulation Therapy: MCT) ก็จะเป็นหนึ่งในวิธีทางกายภาพบำบัดด้วยทฤษฎีการถ่ายโอนความร้อน วัตถุประสงค์ของบทความนี้จึงเป็นการวิเคราะห์ ทบทวนบทความ ประเมินข้อมูลงานวิจัยที่เกี่ยวข้องกับการรักษาเนื้องอกตับหรือมะเร็งที่ตับด้วยวิธีการทางความร้อนจากคลื่นไมโครเวฟที่มีอยู่ในปัจจุบัน เพื่อเป็นหลักฐาน และแนวทางสำหรับการพัฒนาทางวิศวกรรมและสนับสนุนการใช้งานทางการแพทย์บทความนี้จะศึกษารวมรวมบทความที่ถูกตีพิมพ์หรือนำเสนอการพัฒนาสายอากาศ และวิธีการทางความร้อนจากคลื่นไมโครเวฟเพื่อรักษาเนื้องอก เซลล์ตับที่ผิดปกติหรือมะเร็งตับ งานวิจัยนี้ได้ทบทวนและนำเสนอบทความที่ศึกษา พัฒนาออกแบบสายอากาศ และวิธีการทางความร้อนจากคลื่นไมโครเวฟสำหรับรักษาเนื้องอกตับ หรือมะเร็งตับ ซึ่งวิธีการ MCT นั้นนักวิจัยคาดหวังว่าสามารถรองรับการรักษามะเร็งตับและทำลายโซนเนื้อร้ายขนาดใหญ่(ขนาดเส้นผ่านศูนย์กลางของมะเร็งโตกว่า 3 cm) ได้สำเร็จคำสำคัญ: มะเร็งตับ คลื่นความถี่ไมโครเวฟ วิธีการทางความร้อนจากคลื่นไมโครเวฟAbstractBackground: Surgical resection of malignant hepatic tumors has been demonstrated to increase the chance of survival; however, it is not always feasible in patients with hepatocellular carcinoma. For patients with unrespectable tumors, various chemical and thermal ablation modalities have been developed. Microwave Coagulation Therapy (MCT) has been used as an alternative to resection, and its efficacy has been evaluated in order to be a guideline for engineering development and to support its clinical use. Published articles on antenna development and Microwave Coagulation Therapy (MCT) for hepatocellular carcinoma or cancer are studied. The reviews of antennas development and Microwave Coagulation Therapy (MCT) suggest the efficacy of microwave coagulation therapy (MCT) for larger necrosis zones (&gt;3 cm in diameter) and/or ablation of multiple lesions.Keywords: Hepatocellular Carcinoma: HCC, Radio Frequency, Microwave Frequency, Microwave Coagulation Therapy: MC

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IMAGING DI FUSIONE E NUOVE TECNOLOGIE ABLATIVE IN ONCOLOGIA INTERVENTISTICA

Le terapie oncologiche interventistiche stanno entrando sempre più nella pratica clinica quali efficaci terapie alternative o complementari per molte malattie tumorali. Tali terapie, per definizione mini-invasive, sono effettuate sotto la guida delle metodiche per immagine. L’imaging di fusione consente di allineare e sovrapporre in tempo reale le immagini ottenute mediante metodiche diverse, allo scopo di sfruttare al meglio le caratteristiche di ognuna, superandone i rispettivi limiti. La prima fase del progetto ha dimostrato la fattibilità e la accuratezza della guida di procedure interventistiche mediante un sistema di fusione di immagini di tomografia computerizzata e ultrasuoni in un modello ex-vivo. Nella seconda e terza fase del progetto sono state valutate fattibilità e sicurezza di nuove procedure ablative per il trattamento di neoplasie polmonari, in un modello animale in-vivo. Nella seconda fase sono stati trattati con successo e senza complicanze 10 conigli New Zealand White, mediante agoelettrodo ad uncini per fusi. Nella terza fase è stata dimostrata la fattibilità e sicurezza della termoablazione polmonare mediante micro-onde in 10 conigli New Zealand White , paragonando i risultati con quelli ottenuti in un gruppo di 10 animali trattati con la termoablazione a radiofrequenza