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High-intensity focused ultrasound (HIFU) is a recent, non-ionizing and non-invasive technology of focal destruction. Independence from the heat-sink effect of blood flow makes HIFU an interesting technique for focal ablation of liver tumors. Current available technology is based on extracorporeal treatment that limits use of HIFU for the treatment of liver tumors, as elementary ablations are small and must be juxtaposed to treat tumors, resulting in long-duration treatment. We developed an HIFU probe with toroidal technology, which increases the volume of ablation, for intra-operative use, and we assessed the feasibility and efficacy of this device in patients with colorectal liver metastasis (CLM) measuring less than 30 mm. This study was an ablate-and-resect, prospective, single-center, phase II study. All ablations were performed in the area of liver scheduled for liver resection to avoid loss of chance of recovery. The primary objective was to ablate CLM with safety margins (>5 mm). Between May 2014 and July 2020, 15 patients were enrolled and 24 CLM were targeted. The HIFU ablation time was 370 s. In total, 23 of 24 CLM were successfully treated (95.8%). No damage occurred to extrahepatic tissues. HIFU ablations were oblate shaped with an average long axis of 44.3 ± 6.1 mm and an average shortest axis of 35.9 ± 6.7 mm. On pathological examination, the average diameter of the treated metastasis was 12.2 ± 4.8 mm. Intra-operative HIFU can safely and accurately produce large ablations in 6 min with real-time guidance (ClinicalTrials.gov identifier: NCT01489787). [ABSTRACT FROM AUTHOR]

Simple Summary: Magnetic-resonance-guided high-intensity focused ultrasound (MRgHIFU) is a promising technology for ablation of liver tumors not eligible for surgery. This study aimed to demonstrate the workflow feasibility and the spatial accuracy of a novel concept of MRgHIFU transducer dedicated to deep intrahepatic targets on six in vivo pig livers. Before the MRgHIFU ablation, a histological marker mimicking a metastasis was defined in a region considered as challenging to resect. The pseudo-tumor, visible on pre-operative MR images and post-mortem gross pathology, was the target for validation of the entire workflow and the relevancy of the novel concept of HIFU transducer. The presence of the MRgHIFU ablations on gross pathology at the expected locations confirmed the ability to induce transcostal thermal lesions by MRgHIFU in challenging tumors. No relevant side effects on near-field tissues such as the skin or ribs were evidenced. Background: HIFU ablation of liver malignancies is particularly challenging due to respiratory motion, high tissue perfusion and the presence of the rib cage. Based on our previous development of a super-convergent phased-array transducer, we aimed to further investigate, in vivo, its applicability to deep intrahepatic targets. Methods: In a series of six pigs, a pseudo-tumor model was used as target, visible both on intra-operatory MRI and post-mortem gross pathology. The transcostal MRgHIFU ablation was prescribed coplanar with the pseudo-tumor, either axial or sagittal, but deliberately shifted 7 to 18 mm to the side. No specific means of protection of the ribs were implemented. Post-treatment MRI follow-up was performed at D7, followed by animal necropsy and gross pathology of the liver. Results: The pseudo-tumor was clearly identified on T1w MR imaging and subsequently allowed the MRgHIFU planning. The peak temperature at the focal point ranged from 58–87 °C. Gross pathology confirmed the presence of the pseudo-tumor and the well-delineated MRgHIFU ablation at the expected locations. Conclusions: The specific design of the transducer enabled a reliable workflow. It demonstrated a good safety profile for in vivo transcostal MRgHIFU ablation of deep-liver targets, graded as challenging for standard surgery. [ABSTRACT FROM AUTHOR]

The article presents the results of numerical simulation of an experiment on irradiating ex vivo bovine liver sample by the therapeutic array of the MR-HIFU clinical system (Sonalleve V1 3.0T, Profound Medical Corp., Canada). Continuous quasi-linear and pulsed shock-wave exposures with the same time-averaged power are compared. Volumetric thermal lesions were generated by moving the focus of the array in its focal plane along discrete trajectories consisting of two or four concentric circles with a maximum radius of 4 mm. The effect of using the criteria for controlling the thermal dose during treatment and ending the sonication on the shape, volume, and exposure time of generating thermal lesion were analyzed. The acoustic field in tissue was calculated using the Westervelt equation; the temperature field was simulated with the inhomogeneous heat conduction equation; and the lesion boundary was determined according to the thermal dose threshold. In the quasi-linear mode corresponding to the clinical one, thermal diffusion leads to elongation of the lesion by a factor of 2–3 along the beam axis compared to the transverse dimension of the trajectory. The use of pulsed shock-wave exposures with switching off the inner circles of the trajectory as they reach the threshold value of the thermal dose makes it possible to significantly suppress the thermal diffusion effects in the axial direction of the beam and obtain localized thermal lesion of a given shape with a thermal ablation rate comparable to the clinical case. [ABSTRACT FROM AUTHOR]

Nonsmall cell lung cancer (NSCLC) is treated by various therapies such as surgical intervention, radiotherapy, chemotherapy, molecular targeted therapy, and immunotherapy. Currently, molecular targeted therapy, including epidermal growth factor receptor (EGFR) inhibitors and Anaplastic Lymphoma Kinase (ALK) and Kirsten Rat Sarcoma viral Oncogene (KRAS) inhibitors, has received much attention and improved the prognosis of NSCLC. Nevertheless, the terminal point of molecular targeted drugs is resistance. Drug resistance has been classified into oligoprogression and extensive progression based on the tumor lesion progression after drug resistance. There is extensive research demonstrating that local therapy (surgical resection, radiotherapy, and thermal ablation) can prolong the survival of patients with drug resistance. This review is intended to determine the efficacy of image‐guided thermal ablation in patients with NSCLC with EGFR mutation. [ABSTRACT FROM AUTHOR]

Background: Although microwave ablation (MWA) has a low complication rate and good efficacy for small-size (≤ 3 cm) colorectal liver metastases (CRLM), local control decreases with increasing size. Stereotactic body radiotherapy (SBRT) is gaining interest as a potential means to treat intermediate-size CRLM and might be less susceptible to increasing volume. The objective of this study is to compare the efficacy of MWA to SBRT in patients with unresectable, intermediate-size (3–5 cm) CRLM. Methods: In this two-arm, multicentre phase II/ III randomized controlled trial, 68 patients with 1–3 unresectable, intermediate-size CRLM suitable for both MWA and SBRT, will be included. Patients will be treated with MWA or SBRT as randomised. The Primary endpoint is local tumour progression-free survival (LTPFS) at 1 year (intention-to-treat analysis). Main secondary endpoints are overall survival, overall and distant progression-free survival (DPFS), local control (LC) and procedural morbidity and mortality and assessment of pain and quality of life. Discussion: Current guidelines lack clear recommendations for the local treatment of liver only intermediate-size, unresectable CRLM and studies comparing curative intent SBRT and thermal ablation are scarce. Although safety and feasibility to eradicate tumours ≤ 5 cm have been established, both techniques suffer from lower LTPFS and LC rates for larger-size tumours. For the treatment of unresectable intermediate-size CRLM clinical equipoise has been reached. We have designed a two-armed phase II/ III randomized controlled trial directly comparing SBRT to MWA for unresectable CRLM 3–5 cm. Level of Evidence: Level 1, phase II/ III Randomized controlled trial. Trial Registration: NCT04081168, September 9th 2019. [ABSTRACT FROM AUTHOR]

The 5-year recurrence rate of thermal ablation for hepatocellular carcinoma (HCC) is high, and whether this treatment strategy induces systemic immune response remains elusive. This study aimed to investigate the effects of thermal ablation on HCC patients' cytokine profiles and to explore the correlation of cytokine profiles with tumor recurrence after ablation. A total of 22 HCC patients were included in this prospective study. The levels of 27 cytokines in the peripheral blood of HCC patients were measured before ablation (baseline), week 1, and week 4 after ablation using a Bio-Plex Pro Human Cytokine 27-plex Assay kit. Cytokines showed different dynamic changing trends after ablation treatment. It was found that the level of IL-6 was significantly elevated at week 1 and returned to the baseline level at week 4 after ablation. The level of IL-10 was slightly reduced at week 1 and significantly decreased at week 4. The levels of MCP-1, macrophage inflammatory protein-1β (MIP-1β), and TNF-α were similarly reduced at week 1 and increased at week 4. The levels of IL-17, platelet-derived growth factor-BB (PDGF-BB), and regulated upon activation, normal T cell expressed and secreted (RANTES) showed little to no change at week 1 while an observable increase at week 4. Patients with a high IL-10 level (2.99 pg/ml) at baseline and low levels of TNF-α (20.4 pg/ml), PDGF-BB (107.78 pg/ml), and RANTES (2303.94 pg/ml) at week 4 were at risk of tumor recurrence during 1-year follow-up. The results suggested that thermal ablation activated systemic immune responses by changing the levels of cytokines. The results also demonstrated that measurement of IL-10 at baseline, TNF-α, PDGF-BB, and RANTES at week 4 after ablation might predict the risk of tumor recurrence. [ABSTRACT FROM AUTHOR]

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Aim: To evaluate the mid-term clinical efficacy of microwave in situ inactivation combined with bone grafting or polymethyl methacrylate (PMMA) filling in the treatment of giant cell tumor of bone (GCTB). Methods: This is a retrospective, descriptive, and analytical study. A total of 30 GCTB patients received microwave in situ inactivation from January 2012 to January 2020, whose clinical recurrence rate was evaluated at the last follow-up after microwave in situ inactivation surgery. The Musculoskeletal Tumor Society (MSTS) function score was used to evaluate the postoperative clinical panoramic results. Results: All patients were followed up for 21 to 110 months, with an average of 63.79 months. Distal femur (40%) and proximal tibia (28%) had a higher rate of GCTB incidence. Seventeen percent of tumor patients suffered from associated pathologic fracture. The rate of Campanacci classification stage III was 60%. The average MSTS score was evaluated as 27.53 points overall at the last follow-up. In terms of complications, three, two, two and one cases developed fat liquefaction, controllable tissue rejection reaction, incision infection and degenerative changes around lesion joint, respectively, without in situ recurrences and reoperation as well as distant lung metastasis. Conclusions: The method of microwave in situ inactivation combined with bone grafting or PMMA filling is prudently recommended as one of the options for the limb salvage treatment of giant cell tumor of long and periarticular bone. Level of evidence: IV: case series. [ABSTRACT FROM AUTHOR]

Purpose: The objectives were to investigate the safety and efficacy of thermal ablation as an alternative to liver transplantation for hepatocellular carcinoma patients with clinically significant portal hypertension (CSPH). Materials and Methods: From July 2016 to September 2019, hepatocellular carcinoma patients with CSPH treated by liver transplantation (N=37) or thermal ablation (N=114) were enrolled. Cumulative intrahepatic recurrence, overall survival and major complications were compared by propensity score matching. Results: In the two matched groups, the 1-, 2-, and 3-year intrahepatic recurrence rates for the ablation group (22.3%, 50.0%, and 50.0%, respectively) were significantly higher than those for the transplantation group (4.5%, 4.5%, and 4.5%, respectively) (P=0.016). The 1-, 2-, and 3-year overall survival rates were comparable between the two groups [96.1%, 88.7%, and 88.7%, respectively (ablation group) vs. 84.6%, 76.2%, and 76.2%, respectively (transplantation group)] (P=0.07). The major complication rate for the ablation group [4.8% (3/62)] was significantly lower than that for the transplantation group [36.0% (9/25)] (P<0.001). Conclusions: Thermal ablation is a safe and effective alternative for hepatocellular carcinoma patients with CSPH. [ABSTRACT FROM AUTHOR]

Tumor-induced osteomalacia (TIO) is a rare paraneoplastic syndrome associated with tumors secreting fibroblast growth factor 23 that can be cured with complete surgical resection of the tumor. However, when these tumors are at difficult locations, less invasive modalities such as thermal ablation (TA) might be a good alternative. A 40-year-old woman was seen for a second opinion because of severe hypophosphatemia with complaints of fatigue, myalgia, and muscle weakness for which she needed IV phosphate for 15 to 18 hours per day in addition to oral alfacalcidol and phosphate. Initial laboratory results revealed hypophosphatemia (0.59 mmol/L [1.83 mg/dL]; reference range, 0.90-1.50 mmol/L [8.40-10.2 mg/dL]), increased fibroblast growth factor 23 levels (137 RU/mL; reference range, <125 RU/mL), and a reduced TmP-GFR (0.47 mmol/L; reference range, 0.8-1.4 mmol/L). Gallium-positron emission tomography/computed tomography (CT) showed moderately increased uptake at thoracic vertebra (Th) 8 and mildly increased uptake at Th7, suggestive of TIO. Complete tumor removal would have required resection of at least 1 vertebral body. Therefore, CT-guided TA was performed at Th8. No complications were observed, and in the months after, treatment with IV phosphate could be discontinued, indicating a satisfying result from the procedure. This extreme TIO case demonstrates that CT-guided TA can be an alternative to extensive or risky classical surgery. [ABSTRACT FROM AUTHOR]

Primary aldosteronism (PA) is the most prevalent form of secondary hypertension and is most commonly caused by an adrenal adenoma or bilateral adrenal hyperplasia. Minimally invasive adrenalectomy is the treatment of choice for unilateral disease. Here, we report the case of a 57-year-old man with previous bladder cancer who was referred for evaluation of resistant hypertension and hypokalemia. Diagnostic workup indicated PA with computed tomography imaging revealing a left adrenal adenoma and adrenal venous sampling lateralizing to the left adrenal. He was therefore referred for a left adrenalectomy using a retroperitoneoscopic approach. However, surgery was complicated by significant perinephritis related to previous bladder cancer immunotherapy and, in view of an identifiable adrenal adenoma, a partial adrenalectomy was performed. Despite histology confirming removal of an adrenal adenoma, he remained hypertensive and hypokalemic with persistent PA. He underwent a computed tomography-guided percutaneous thermal (microwave) ablation of the residual adrenal nodule with immediate biochemical reversal of PA. Six years postprocedure, he remains biochemically and clinically cured from PA. This article presents the details of the case and reviews the literature on long-term outcomes for patients undergoing thermal ablation and adrenalectomy, suggesting that thermal ablation may be a viable alternative for selected patients. [ABSTRACT FROM AUTHOR]

Small renal masses (SRM) are defined as contrast-enhancing solid masses detected on diagnostic imaging, with a size of less than or equal to 4cm, corresponding to renal cell carcinoma stage T1a. These tumours are mainly benign, with an indolent nature and rare metastatic potential. Given the size and nature of these tumours, there has been a significant evolution and in management modalities of these tumours. These range from conventional radical approaches such as radical nephrectomy, partial nephrectomy, to more conservative approaches such as active surveillance, and some novel emerging management strategies such as various thermal ablation techniques. The treatment decision depends on patient factors such as age and co-morbidity, and tumour factor on radiological imaging, such as tumour size, location, growth rate and biopsy result. In this review, we aim to provide the latest updates on approaching SRM and various management modalities. [ABSTRACT FROM AUTHOR]

To compare long term outcomes after great saphenous vein (GSV) treatment with three radiofrequency (RF) thermal devices: Venefit (Closurefast), Radiofrequency Induced Thermal Therapy (RFITT), and Endovenous Radiofrequency (EVRF). A 72 month follow up of patients who were treated in the randomised 3RF study. A total of 172 participants from the 3RF study were invited to take part in a single visit, long term, follow up study. Failure of GSV closure was assessed with duplex ultrasound (DUS) and constituted the primary outcome. Patients completed questionnaires for secondary outcomes: Aberdeen Varicose Vein Questionnaire (AVVQ), Euroqol 5D (EQ-5D), and patient reported varicose veins measured by counting vein occupying boxes in AVVQ question 1. Twenty-two patients (12%) had already been re-treated. Of the remainder, 13 (7%) could not be contacted, 20 (11%) declined invitation, and one did not consent. Therefore, 116 (64%) and 95 (53%) participants completed questionnaires and DUS, respectively. Failure of GSV closure on 72 month DUS was 16%, 21%, and 37% for Venefit, RFITT, and EVRF, respectively (p =.14), whilst outcomes for all failures were 14%, 17%, and 44% (p <.001) (Venefit vs. EVRF: p <.001; RFITT vs. EVRF: p <.001; and Venefit vs. RFITT: p =.63). There were no between group differences in AVVQ or EQ-5D scores. Rates of patient reported presence of any varicose veins were high for all groups (97%, 92%, and 97% after Venefit, RFITT, and EVRF, respectively; p =.48). The EVRF treated participants reported more extensive recurrence than the Venefit and RFITT participants (p =.008). Long term technical outcomes after RF ablation for GSV varicose veins were significantly better after Venefit and RFITT compared with EVRF treatment. However, quality of life scores showed no differences after 72 months. Rates of patient reporting any varicose veins were high for all treatments. ClinicalTrials.gov Identifier: NCT04720027. [ABSTRACT FROM AUTHOR]

PURPOSE To evaluate the technical feasibility and outcomes of thermal ablation following selective intra-arterial lipiodol injection (SIALI) for targeting primary and secondary liver tumors invisible on ultrasound (US) and non-contrast computed tomography (CT). METHODS This retrospective study included 18 patients with 20 tumors (67% male, mean age 60.8 ± 12.1 years). The 20 tumors included 15 liver metastases and 5 hepatocellular carcinomas. All patients underwent single-session SIALI and subsequent CT-guided thermal ablation. The primary outcome was a technical success, defined as visualization of the tumor after SIALI and successful thermal ablation. Secondary outcomes were local recurrence rate and procedure-related complications. RESULTS The median tumor size was 1.5 (1-2.5) cm. In addition, SIALI was performed with a median volume of 3 (1-10) mL of lipiodol resulting in intra-tumoral iodized oil accumulation in 19 tumors and negative imprint with iodized oil accumulation of the surrounding liver parenchyma in 1 tumor. The technical success rate was 100%. No local occurrence was observed at a mean follow-up time of 3 ± 2.5 years. CONCLUSION SIALI to tag liver tumors not visible with US and non-contrast CT before percutaneous ablation is highly feasible and has a high success rate for the treatment of both primary and secondary liver tumors. [ABSTRACT FROM AUTHOR]

Graphical abstract The microwave ablation (MWA) of large hepatic gland tumour using multiple trocars operated at 2.45/6 GHz frequencies has been analysed. The ablation region (in vitro) obtained using parallel and non-parallel insertion of multiple trocars into the tissue has been analysed and compared with the numerical studies. The present study has considered a typical triangular-shaped hepatic gland model for experimental and numerical analysis. COMSOL Multiphysics software with inbuilt bioheat transfer, electromagnetic waves, heat transfer in solids and fluids and laminar flow physics has been used to obtain the numerical results. Experimental analysis has been conducted on egg white using a market-available microwave ablation device. It has been found from the present study that MWA operated at 2.45/6 GHz with the non-parallel position of multiple trocars into the tissue leads to a considerable increase in the ablation region as compared to the parallel insertion of trocars. Hence, non-parallel insertion of trocars is suitable to treat irregular-shaped large cancerous tumours (>3 cm). The non-parallel simultaneous insertion of trocars can overcome the healthy tissue ablation issue as well as the problem associated with indentation. Further, reasonable accuracy (with the difference being nearly ±0.1 cm in ablation diameter) has been achieved in comparing the ablation region and temperature variation between experimental and numerical studies. The present study may create a new path in the ablation of large size tumours (>3 cm) with multiple trocars of all shapes by sparing the healthy tissue. [ABSTRACT FROM AUTHOR]

Ultrasound-guided ablation procedures have been growing in popularity and offer many advantages compared with traditional surgery for thyroid nodules. Many technologies are available, with thermal ablative techniques being the most popular currently though other nonthermal techniques, such as cryoablation and electroporation, are gaining interest. The objective of the present review is to provide an overview of each of the currently available ablative therapies and their applications in various clinical indications. [ABSTRACT FROM AUTHOR]

Background: An important cervical cancer prevention strategy in low- and middle-income countries (LMICs) has been single-visit screen-and-treat (SV-SAT) approach, using visual inspection with acetic acid (VIA) and ablative treatment with cryotherapy to manage precancerous lesions. While SV-SAT with VIA and cryotherapy have established efficacy, its population level coverage and impact on reducing cervical cancer burden remains low. In Kenya, the estimated cervical cancer screening uptake among women aged 30–49 is 16% and up to 70% of screen-positive women do not receive treatment. Thermal ablation for treatment of precancerous lesions of the cervix is recommended by the World Health Organization and has the potential to overcome logistical challenges associated with cryotherapy and facilitate implementation of SV-SAT approach and increase treatment rates of screen-positive women. In this 5-year prospective, stepped-wedge randomized trial, we plan to implement and evaluate the SV-SAT approach using VIA and thermal ablation in ten reproductive health clinics in central Kenya. Methods: The study aims to develop and evaluate implementation strategies to inform the national scale-up of SV-SAT approach with VIA and thermal ablation through three aims: (1) develop locally tailored implementation strategies using multi-level participatory method with key stakeholders (patient, provider, system-level), (2) implement SV-SAT approach with VIA and thermal ablation and evaluate clinical and implementation outcomes, and (3) assess the budget impact of SV-SAT approach with VIA and thermal ablation compared to single-visit, screen-and-treat method using cryotherapy. Discussion: Our findings will inform national scale-up of the SV-SAT approach with VIA and thermal ablation. We anticipate that this intervention, along with tailored implementation strategies will enhance the adoption and sustainability of cervical cancer screening and treatment compared to the standard of care using cryotherapy. Trial registration: NCT05472311. [ABSTRACT FROM AUTHOR]

Simple Summary: The aim of this study was to collate the achievements to date in the field of the treatment and prevention of complications during thyroidectomy, with a particular focus on the latest findings. The points of interest were modern surgical techniques, the prevention of damage to the parathyroid glands and the recurrent laryngeal nerves during surgery and perioperative bleeding. Thyroid cancer is the most common cancer of the endocrine system, and, in recent years, there has been a phenomenon of overdiagnosis followed by subsequent overtreatment. This results in an increasing number of thyroidectomy complications being faced in clinical practice. In this paper, we present the current state of knowledge and the latest findings in the fields of modern surgical techniques, thermal ablation, the identification and assessment of parathyroid function, recurrent laryngeal nerve monitoring and treatment and perioperative bleeding. We reviewed 485 papers, from which we selected 125 papers that are the most relevant. The main merit of this article is its comprehensive view of the subject under discussion—both general, concerning the selection of the appropriate method of surgery, and particular, concerning the selection of the appropriate method of prevention or treatment of selected perioperative complications. [ABSTRACT FROM AUTHOR]

Argon plasma coagulation (APC) is an electrosurgical procedure used, among other indications, for treatment of dysplastic Barrett's mucosa. Homogeneous and safe application can be compromised by varying distances and suboptimal angle of the probe to the tissue. In this study, we present ArgoCap, a novel endoscopic device developed to facilitate endoluminal APC treatment. Objectives of this preclinical study were to assess feasibility and safety and to determine suitable APC settings. One-hundred and thirty-two APC treatments of predefined areas using various APC settings were performed ex vivo in the opened porcine esophagus. Depth of thermal injury was assessed histologically. Feasibility of APC treatment in different locations was examined in 20 explanted porcine esophagi and in first in vivo porcine applications. APC treatment in all quadrants of the esophagus was feasible. Histologically, thermal effects involving the whole thickness of the mucosa were visible with all settings. APC with pulsed mode resulted in deep thermal damage with all power settings. No lesions of the muscular layer occurred using precise (E8, E9) and forced (10 W, 20 W) mode. Esophageal APC using ArgoCap is feasible and safe. The device has the potential to improve APC treatment of larger mucosal areas. [ABSTRACT FROM AUTHOR]

Brain temperature, regulated by the balance between blood circulation and metabolic heat generation, is an important parameter related to neural activity, cerebral hemodynamics, and neuroinflammation. A key challenge for integrating brain temperature into clinical practice is the lack of reliable and non-invasive brain thermometry. The recognized importance of brain temperature and thermoregulation in both health and disease, combined with limited availability of experimental methods, has motivated the development of computational thermal models using bioheat equations to predict brain temperature. In this mini-review, we describe progress and the current state-of-the-art in brain thermal modeling in humans and discuss potential avenues for clinical applications. [ABSTRACT FROM AUTHOR]

This work proposes the characterization of the temperature dependence of the thermal properties of heart and lung tissues from room temperature up to > 90 °C. The thermal diffusivity (α), thermal conductivity (k), and volumetric heat capacity (Cv) of ex vivo porcine hearts and deflated lungs were measured with a dual-needle sensor technique. α and k associated with heart tissue remained almost constant until ~ 70 and ~ 80 °C, accordingly. Above ~ 80 °C, a more substantial variation in these thermal properties was registered: at 94 °C, α and k respectively experienced a 2.3- and 1.5- fold increase compared to their nominal values, showing average values of 0.346 mm2/s and 0.828 W/(m·K), accordingly. Conversely, Cv was almost constant until 55 °C and decreased afterward (e.g., Cv = 2.42 MJ/(m3·K) at 94 °C). Concerning the lung tissue, both its α and k were characterized by an exponential increase with temperature, showing a marked increment at supraphysiological and ablative temperatures (at 91 °C, α and k were equal to 2.120 mm2/s and 2.721 W/(m·K), respectively, i.e., 13.7- and 13.1-fold higher compared to their baseline values). Regression analysis was performed to attain the best-fit curves interpolating the measured data, thus providing models of the temperature dependence of the investigated properties. These models can be useful for increasing the accuracy of simulation-based preplanning frameworks of interventional thermal procedures, and the realization of tissue-mimicking materials. [ABSTRACT FROM AUTHOR]

The purpose of this study is to investigate the feasibility and performance of a stationary, non-focused dual-sectored tubular transurethral ultrasound applicator for thermal exposure of tissue regions adjacent to the urethra for treatment of stress urinary incontinence (SUI) through acoustic and biothermal simulations on 3D anatomical models. Parametric studies in a generalized tissue model over dual-sectored ultrasound applicator configurations (acoustic surface intensities, lateral active acoustic output sector angles, and durations) were performed. Selected configurations and delivery strategies were applied on 3D pelvic anatomical models. Temperature and thermal dose distributions on the target region and surrounding tissues were calculated. Endovaginal cooling was explored as a strategy to mitigate vaginal heating. The 75-90° dual-sectored transurethral tubular transducer (3.5 mm outer diameter (OD), 14 mm length, 6.5 MHz, 8.8-10.2 W/cm2) and 2-3-min sonication duration were selected from the parametric study for acoustic and biothermal simulations on anatomical models. The transurethral applicator with two opposing 75-90° active lateral tubular sectors can create two heated volumes for a total of up to 1.8 cm3 over 60 EM43 °C, with at least 10 mm radial penetration depth, 1.2 mm urethral sparing, and no lethal damage to the vagina and adjacent bone (

Small renal masses (SRM) are defined as contrast-enhancing solid masses detected on diagnostic imaging, with a size of less than or equal to 4cm, corresponding to renal cell carcinoma stage T1a. These tumours are mainly benign, with an indolent nature and rare metastatic potential. Given the size and nature of these tumours, there has been a significant evolution and in management modalities of these tumours. These range from conventional radical approaches such as radical nephrectomy, partial nephrectomy, to more conservative approaches such as active surveillance, and some novel emerging management strategies such as various thermal ablation techniques. The treatment decision depends on patient factors such as age and co-morbidity, and tumour factor on radiological imaging, such as tumour size, location, growth rate and biopsy result. In this review, we aim to provide the latest updates on approaching SRM and various management modalities.

Abstract Background Thermal ablation has been increasingly used in the treatment of lung cancer in recent years. This meta-analysis aims to investigate the therapeutic effect and safety of thermal ablation plus chemotherapy as compared with chemotherapy alone in treating patients with lung malignancy in China based on current evidence. Methods Databases including PubMed, Web of Science, Embase and the Cochrane Library were searched for clinical reports. Additional literature search was also performed by searching the reference list of included studies and latest reviews. Raw data including objective response rate, disease control rate, progression-free survival, overall survival and the incidence of major complication were extracted and pooled. Results A total of 12 studies in China including 1282 patients with lung malignancy were included in this meta-analysis. The number of studies that reported data of objective response rate, disease control rate, progression-free survival, overall survival and major complication was 8, 7, 7, 6 and 7, respectively. The combination therapy of thermal ablation plus chemotherapy showed a significantly better efficacy in improving objective response rate (odds ratio = 2.73; P

Purpose To characterize the coagulation zones created by two radiofrequency (RF)-based hemostatic devices: one comprised an internally cooled monopolar electrode and the other comprised externally irrigated bipolar electrodes (saline-linked).Materials and methods RF-induced coagulation zones were created on ex vivo and in vivo porcine models. Computer modeling was used to determine the RF power distribution in the saline-linked device.Results Both external (irrigation) and internal cooling effectively prevented tissue sticking. Under ex vivo conditions in ‘painting’ application mode, coagulation depth increased with the applied power: 2.8 − 5.6 mm with the 3-mm monopolar electrode, 1.6 − 6.0 mm with the 5-mm monopolar electrode and 0.6 − 3.2 mm with the saline-linked bipolar electrodes. Under in vivo conditions and using spot applications, the 3-mm monopolar electrode created coagulation zones of similar depth to the saline-linked bipolar electrodes (around 3 mm), while the 5-mm monopolar electrode created deeper coagulations (4.5 − 6 mm) with less incidence of popping. The presence of saline around the saline-linked bipolar electrodes meant that a significant percentage of RF power (50 − 80%) was dissipated by heating in the saline layer. Coagulation zones were histologically similar for all the tested devices.Conclusions Both external (irrigation) and internal cooling in hemostatic RF devices effectively prevent tissue sticking and create similar coagulation zones from a histological point of view. Overall, saline-linked bipolar electrodes tend to create shallower coagulations than those created with an internally cooled monopolar electrode.

Key points 125I brachytherapy is a treatment for locally recurrent HCC after ablation. 125I brachytherapy combined with ablation may improve tumor control. Vascular invasion, multiple lesions, and AFP are prognostic risk factors. 125I brachytherapy is a safe method with a curative effect.

Objective To evaluate the biliary complication rates and efficacy of peribiliary tumor ablation using irreversible electroporation (IRE) or radiofrequency ablation (RFA).Material and methods This is a retrospective study of 42 consecutive patients with 44 peribiliary tumors (≤5 mm distance between the tumor margin and the primary or secondary bile duct). Data were collected between January 2014 and September 2020 from patients who underwent percutaneous liver ablation using IRE (n = 13) or RFA (n = 31).Results The median length of follow-up was 23.1 months. The mean tumor size was 17.2 ± 5.2 mm in IRE vs. 18.4 ± 7.0 mm in RFA (p= .56). Complete tumor ablation was achieved in 100% with a significantly larger ablation zone in the IRE group (3.8 ± 0.3 cm vs. 2.6 ± 0.6 cm, p

Purpose To evaluate the overall survival (OS), local progression-free survival (PFS) and prognostic factors of patients with colorectal cancer liver metastases (CRLM) undergoing microwave ablation (MWA).Method A total of 132 patients were retrospectively enrolled who had been treated between 2010 and 2018. For the evaluation of survival rates, all patients were divided according to their indications (curative n = 57 and debulking (patients with additional non-target extrahepatic metastases) n = 75). In total, 257 ablations were evaluated for prognostic factors: number of liver metastases, primary tumor origin (PTO), diameter and volume of metastases, duration and energy of ablation.Results The OS was 32.1 months with 93.2% of patients free from recurrence at 28.3 months (median follow-up time). The one- year and three-year OS were 82.72% and 41.66%, respectively. The OS and recurrence-free survival of the curative group were statistically significantly higher than the debulking group (p .05).Conclusions Satisfactory OS and local tumor PFS can be achieved in patients with CRLM using MWA with the number of metastases and the location of the primary tumor influencing the outcome of patients. The metastasis’s size and the duration and energy used for ablation were not of significant prognostic value.

Purpose To develop and evaluate susceptibility corrected 2D proton resonance frequency (PRF)-based magnetic resonance (MR)-thermometry for the accurate assessment of the ablation zone of hepatic microwave ablation (MWA).Methods and materials Twelve hepatic MWA were performed in five LEWE minipigs with human-like fissure-free liver. Temperature maps during ablation of PRF-based MR-thermometry were corrected by modeling heat induced susceptibility changes. Ablation zones were determined using cumulative equivalent minutes at 43 °C (CEM43) as tissue damage model. T1 weighted (w) post-ablation contrast-enhanced (CE) MR-imaging and manually segmented postmortem histology were used for validation. The agreement of uncorrected (raw) and susceptibility corrected (corr) MR-thermometry with T1w post-ablation CE MR-imaging and histology was evaluated. The Wilcoxon-signed rank test and Bland–Altman analysis were applied.Results With the susceptibility corrected MR-thermometry a significantly increased dice coefficient (raw: 77% vs. corr: 83%, p

Objective With the aim of standardizing and improving the use of ultrasound-guided PLA on PTMC, a panel of experts from China and Italy, jointly issued this expert consensus on the clinical use of PLA for low-risk PTMC.Methods This expert consensus was developed by Chinese and Italian experts who have specific competence and expertise in this area. An evidence-based approach combining the knowledge and practical experience of the panelists was utilized.Results Twenty-six expert consensus recommendations were developed, spanning topics including the indications and contraindications of PLA for PTMC, physician training, preoperative preparation of patients, intraoperative technical procedures, possible complications, efficacy assessment, follow-up strategy, the approach to new PTMC and metastatic lymph nodes after treatment, thyroid-stimulating hormone inhibition therapy, and quality control of the entire procedure.Conclusion We summarized practical recommendations about standardized and improved PLA treatment for PTMC.

Interventional oncologists provide several effective treatment options for patients with metastatic colorectal cancer (mCRC), including embolization and ablation-based techniques. Molecular imaging methods such as positron emission tomography (PET) can play an important role in managing mCRC patients. In this review, we aim to highlight the role of molecular imaging in mCRC management by interventional oncologists including: initial staging and pretreatment planning; predicting molecular subtypes, prognosis, and treatment outcomes; intraprocedural guidance; and assessing treatment response and post-procedural monitoring.

Microwave ablation (MWA) is becoming an increasingly important minimally invasive treatment option for localized tumors in many organ systems due to recent advancements in microwave technology that have conferred many advantages over other tumor ablation modalities. Despite these improvements in technology and development of applicators for site-specific tumor applications, the vast majority of commercially available MWA applicators are generally designed to create large-volume, symmetric, ellipsoid or spherically-shaped treatment zones and often lack the consistency, predictability, and spatial control needed to treat tumor targets near critical structures that are vulnerable to inadvertent thermal injury. The relatively new development and ongoing translation of directional microwave ablation (DMWA) technology, however, has the potential to confer an added level of control over the treatment zone shape relative to applicator position, and shows great promise to expand MWA’s clinical applicability in treating tumors in challenging locations. This paper presents a review of the industry-standard commercially available MWA technology, its clinical applications, and its limitations when used for minimally-invasive tumor treatment in medical practice followed by discussion of new advancements in experimental directional microwave ablation (DMWA) technology, various techniques and approaches to its use, and examples of how this technology may be used to treat tumors in challenging locations that may otherwise preclude safe treatment by conventional omni-directional MWA devices.

Aims To evaluate the long-term survival benefits of high intensity focused ultrasound (HIFU) ablation in patients with hepatocellular carcinoma (HCC) combined with portal vein tumor thrombus (PVTT).Methods The data of patients with HCC-PVTT treated with HIFU from January 2014 to December 2019 were retrospectively analyzed. All patients received HIFU ablation for both PVTT and liver tumor in one session. Perioperative adverse events (AEs) were recorded, and follow-up was performed postoperatively. The Kaplan–Meier method was used for survival analysis.Results Median follow-up was 13.75 ± 1.31 months. A total of 144 patients (male/female: 122/22, age: 54.15 ± 11.84 years old) were included in the study. A total of 267 liver tumors (tumor number: 1.87 ± 1.65, range 1–10) were treated with HIFU. The mean ± SD diameter of viable liver tumors was 100.98 ± 61.65 mm. The reported postoperative AEs of HIFU were skin edema (93.75%), local pain (69.44%) and fever (7.64%). There was no liver failure, gastrointestinal bleeding or perioperative death. The median overall survival (OS) time was 14 months, while the cumulative survival rates of 0.5, 1, 2 and 3 years were 79.0%, 58.6%, 33.3% and 5.9%, respectively. The median OS of PVTT types I, II and III was 22, 13 and 14 months, respectively, and the difference was not statistically significant (p > 0.05).Conclusion HIFU is a minimally invasive method for HCC-PVTT with fewer complications, which could prolong the OS. Patients with PVTT type III could benefit more from HIFU, compared to types I and II.

Purpose The catheter-based ultrasound (CBUS) can reach the target tissue directly and achieve rapid treatment. The frequency shift keying (FSK) signal is proposed to regulate and evaluate tumor ablation by a miniaturized dual-frequency transducer.Methods A dual-frequency transducer prototype (3 × 7 × 0.4 mm) was designed and fabricated for the CBUS applicator (OD: 3.8 mm) based on the fundamental frequency of 5.21 MHz and the third harmonic frequency of 16.88 MHz. Then, the acoustic fields and temperature field distributions using the FSK signals (with 0, 25, 50, 75, and 100% third harmonic frequency duty ratios) were simulated by finite element analysis. Finally, tissue ablation and temperature monitoring were performed in phantom and ex vivo tissue, respectively.Results At the same input electrical power (20 W), the output acoustic power of the fundamental frequency of the transducer was 10.03 W (electroacoustic efficiencies: 50.1%), and that of the third harmonic frequency was 6.19 W (30.6%). As the third harmonic frequency duty ratios increased, the shape of thermal lesions varied from strip to droplet in simulated and phantom experimental results. The same trend was observed in ex vivo tests.Conclusion Dual-frequency transducers excited by the FSK signal can control the morphology of lesions.Significance The acoustic power deposition of CBUS was optimized to achieve precise ablation.

Purpose: Test objects for High Intensity Focused Ultrasound (HIFU) are required for the standardization and definition of treatment, Quality Assurance (QA), comparison of results between centers and calibration of devices. This study describes a HIFU test object which provides temperature measurement as a function of time, in a reference material compatible with Magnetic Resonance (MR) and ultrasound. Materials and methods: T-Type fine wire thermocouples were used as sensors and 5 correction methods for viscous heating artifacts were assessed. The phantom was tested in a MR-HIFU Philips Sonalleve device over a period of 12 months, demonstrating stability and validity to evaluate the performance of the device. Results: The study furnished useful information regarding the MR-HIFU sessions and highlighted potential limitations of the existing QA and monitoring methods. The importance of temperature monitoring along the whole acoustic path was demonstrated as MR Thermometry readings differed in the three MR plane views (coronal, sagittal, transverse), in particular when the focus was near a soft-tissue/bone interface, where there can be an MR signal loss with significant temperature and thermal dose underestimation (138% variation between the three plane views). Conclusions: The test object was easy to use and has potential as a valid tool for training, QA, research and development for MR guided HIFU and potentially ultrasound guided devices.

Purpose Transarterial chemoembolization (TACE) was obtained acceptable benefit for advanced hepatocellular carcinoma (HCC). Here in this study, we compared the benefit of TACE combined palliative thermal ablation with TACE alone for HCC with portal vein tumor thrombus (PVTT). Methods Patients with HCC and PVTT were retrospectively analyzed from January 2012 to December 2017, who accepted treatment of TACE alone (TACE group) or TACE plus palliative thermal ablation (TACE + P-ablation group). Propensity score matching (PSM) was applied to balance differences between the two groups. Overall survival (OS) and progression-free survival (PFS) rates were compared between groups. Results Median follow-up time was 7.4 (3.0–60.0) months. In the cohort, 142 patients were enrolled in TACE group and 86 patients were enrolled in TACE + P-ablation group. The pre-PSM estimated 6-, 12-, and 18-month OS rates for the TACE + P-ablation group were 70.9, 46.5, and 31%, respectively, whereas rates for the TACE group were 57, 23.1, and 10%, respectively. After PSM, OS and PFS rates remained coincident with the pre-PSM. Risk factors for poor OS included PVTT type III and type II relative to type I (HR = 1.76; 95% CI, 1.13–2.74; p = .01) and (HR = 1.86; 95% CI, 1.2–2.88; p = .006), TACE alone (HR = 1.40; 95% CI, 1.01–1.96; p = .04), a single TACE treatment (HR = 2.69; 95% CI, 1.79–4.03; p

Purpose: Micron-sized perfluorocarbon droplet adjuvants to focused ultrasound therapies allow lower applied power, circumvent unwanted prefocal heating, and enhance thermal dose in highly perfused tissues. The heat enhancement has been shown to saturate at increasing concentrations. Experiments were performed to empirically model the saturating heating effects during focused ultrasound. Materials and methods: The measurements were made at varying concentrations using magnetic resonance thermometry and focused ultrasound by circulating droplets of mean diameter 1.9 to 2.3 µm through a perfused phantom. A simulation was performed to estimate the interaction radius size, empirically. Results: The interaction radius, representing the radius of a sphere encompassing 90% of the probability for the transformation of acoustic energy into heat deposition around a single droplet, was determined experimentally from ultrasonic absorption coefficient measurements The simulations suggest the interaction radius was approximately 12.5-fold larger than the geometrical radius of droplets, corresponding to an interaction volume on the order of 2000 larger than the geometrical volume. Conclusions: The results provide information regarding the dose–response relationship from the droplets, a measure with 15% precision of their interaction radii with focused ultrasound, and subsequent insights into the underlying physical heating mechanism.

Objective To investigate the survival benefit of thermal ablation (TA) plus chemotherapy for Stage-IV nonsmall cell lung cancer (NSCLC). Methods From the Surveillance, Epidemiology and End Results (SEER) database, data of Stage-IV NSCLC patients receiving different treatment modalities (TA plus chemotherapy vs. chemotherapy) from 2004 to 2016 were retrospectively analyzed using propensity-score matching (PSM) for covariates. Kaplan–Meier curves and the log-rank test for intergroup comparison of overall survival (OS) and lung cancer-specific survival (LCSS) and subgroup analyses in the PSM cohort evaluated possible survival benefits. Cox proportional risk models evaluated independent prognostic factors. Results Among 52,574 patients, 152 received TA plus chemotherapy. After PSM, the TA plus chemotherapy and chemotherapy groups included 150 and 445 patients, respectively. Compared to the chemotherapy group, the TA plus chemotherapy group had better OS (p = 0.042) and LCSS (p = 0.031), especially in patients aged 70 and older in age-stratified subgroup analysis; no statistically significant beneficial trend was noted for patients younger than 70 years. Subgroup analysis by tumor size showed superior OS and LCSS with TA plus chemotherapy than chemotherapy for tumors ≤3.0 cm; however, no significant difference was found in subgroups with larger tumors. Multivariate analysis showed that TA plus chemotherapy was an independent prognostic factor for OS and LCSS (hazard ratio 0.70 [95% confidence interval 0.59–0.84] and 0.70 [0.58–0.84], respectively; p

Purpose Thermal ablation (TA) is a minimally invasive treatment method for symptomatic benign thyroid nodules (BTNs). This study aimed to evaluate the value of TA by comparing the efficacy, safety, and patient satisfaction with conventional/open thyroidectomy (ConT) and endoscopic thyroidectomy (ET) for symptomatic BTNs. Methods Patients with symptomatic BTNs who underwent ConT, ET, or TA therapy between January 2018 and January 2020 were included. Pre-operation data of the two comparisons (TA vs. ConT and TA vs. ET) was balanced using propensity score matching. The technique efficacy (volume reduction ratio ≥50%), nodule disappearance, and regrowth rate were calculated after ablation. The operation and hospitalization time, medical cost, complications, post-operative symptoms, and cosmetic scores were recorded and compared. Patient satisfaction was evaluated using a telephone survey. Results After a median 19-month follow-up (range, 12–36 months), the technique efficacy rate, nodule disappearance, and regrowth rate were 93.2% (119/129), 6.8% (10/129), and 0.8% (1/129), respectively. Operation time, hospitalization time, and medical costs were less for patients in the TA group than for patients in the ConT and ET groups (all p 0.05). Post-operative hypothyroidism was less frequent in the TA group than in the ConT and ET groups (all p

Background Enediynes are anti-cancer agents that are highly cytotoxic due to their propensity for low thermal activation of radical generation. The diradical intermediate produced from Bergman cyclization of the enediyne moiety may induce DNA damage and cell lethality. The cytotoxicity of enediynes and difficulties in controlling their thermal cyclization has limited their clinical use. We recently showed that enediyne toxicity at 37 °C can be mitigated by metallation, but cytotoxic effects of ‘metalloenediynes’ on cultured tumor cells are potentiated by hyperthermia. Reduction of cytotoxicity at normothermia suggests metalloenediynes will have a large therapeutic margin, with cell death occurring primarily in the heated tumor. Based on our previous in vitro findings, FeSO4-PyED, an Fe co-factor complex of (Z)-N,N′-bis[1-pyridin-2-yl-meth-(E)-ylidene]oct-4-ene-2,6-diyne-1,8-diamine, was prioritized for further in vitro and in vivo testing in normal human melanocytes and melanoma cells.Methods Clonogenic survival, apopotosis and DNA binding assays were used to determine mechanisms of enhancement of FeSO4-PyED cytotoxicity by hyperthermia. A murine human melanoma xenograft model was used to assess in vivo efficacy of FeSO4-PyED at 37 or 42.5 °C.Results FeSO4-PyED is a DNA-binding compound. Enhancement of FeSO4-PyED cytotoxicity by hyperthermia in melanoma cells was due to Bergman cyclization, diradical formation, and increased apoptosis. Thermal enhancement, however, was not observed in melanocytes. FeSO4-PyED inhibited tumor growth when melanomas were heated during drug treatment, without inducing normal tissue damage.Conclusion By leveraging the unique thermal activation properties of metalloenediynes, we propose that localized moderate hyperthermia can be used to confine the cytotoxicity of these compounds to tumors, while sparing normal tissue.

Aim This study aimed to develop a novel tumor-bearing tissue phantom model that can be used for US/CT/MR-guided tumor puncture and thermal ablation.Methods The phantom model comprised two parts: a normal tissue-mimicking phantom and a tumor-mimicking phantom. A normal tissue phantom was prepared based on a polyacrylamide gel mixed with thermochromic ink. Moreover, a spherical phantom containing contrast agents was constructed and embedded in the tissue phantom to mimic a tumor lesion. US/CT/MR imaging features and thermochromic property of the phantom model were characterized. Finally, the utility of the phantom model for imaging-guided microwave ablation training was examined.Results The tumor phantom containing contrast agents showed hyper-echogenicity, higher CT numbers, and lower T2 signal intensity compared with the normal tissue phantom in US/CT/MR images. Consequently, we could locate the position of the tumor in US/CT/MR imaging and perform an imaging-guided tumor puncture. When the temperature reached the threshold of 60 °C, the phantom exhibited a permanent color change from cream white to magenta. Based on this obvious color change, our phantom model could clearly map the thermal ablation region after thermotherapy.Conclusions We developed a novel US/CT/MR-imageable tumor-bearing tissue model that can be used for imaging-guided tumor puncture and thermal ablation. Furthermore, it allows visual assessment of the ablation region by analyzing the obvious color change. Overall, this phantom model could be a good training tool in the field of thermal ablation.

Purpose To investigate the value of three-dimensional ultrasound fusion imaging (3DUS-FI) in real-time guiding needle placement by phantom models and in vivo simulations.Materials and methods Two radiologists (beginner and expert) performed needle placement using two-dimensional ultrasound (2DUS) and 3DUS-FI, respectively. In the phantom study, single-needle placement was performed by puncturing the center point of each ball and assessed based on the specimen length. Multiple-needles placement was performed by placing three needles in each ball, and their locations were confirmed by computed tomography, and assessed based on the distance deviation between needles. In the in vivo simulation study, simulated-needle placement was performed by placing a virtual ablation needle in each liver tumor and assessed by the simulated ablative cover rate and margin.Results Specimen length was significantly longer with 3DUS-FI in the beginner, whereas no significant difference was observed in the expert (2DUS vs. 3DUS-FI: beginner, 14.60 ± 2.60 mm vs. 16.25 ± 1.38 mm, p = .017; expert, 16.78 ± 1.40 mm vs. 16.95 ± 1.15 mm, p = .668). Distance deviation between needles was significantly smaller with 3DUS-FI (2DUS vs. 3DUS-FI: beginner, 25.06 ± 16.07 mm vs. 3.72 ± 1.99 mm, p

Purpose To investigate the safety, feasibility, and outcomes of High-Intensity Focused Ultrasound (HIFU) for the treatment of solid tumors in a spontaneous canine cancer model.Methods Dogs diagnosed with subcutaneous solid tumors were recruited, staged and pretreatment biopsies were obtained. A single HIFU treatment was delivered to result in partial tumor ablation using a commercially available HIFU unit. Tumors were resected 3–6 days post HIFU and samples obtained for histopathology and immunohistochemistry. Total RNA was isolated from paired pre and post treated FFPE tumor samples, and quantitative gene expression analysis was performed using the nCounter Canine IO Panel.Results A total of 20 dogs diagnosed with solid tumors were recruited and treated in the study. Tumors treated included Soft Tissue Sarcoma (n = 15), Mast Cell Tumor (n = 3), Osteosarcoma (n = 1), and Thyroid Carcinoma (n = 1). HIFU was well tolerated with only 1 dog experiencing a clinically significant adverse event. Pathology confirmed the presence of complete tissue ablation at the HIFU targeted site and immunohistochemistry indicated immune cell infiltration at the treated/untreated tumor border. Quantitative gene expression analysis indicated that 28 genes associated with T-cell activation were differentially expressed post-HIFU.Conclusions HIFU appears to be safe and feasible for the treatment of subcutaneous canine solid tumors, resulting in ablation of the targeted tissue. HIFU induced immunostimulatory changes, highlighting the canine cancer patient as an attractive model for studying the effects of focal ablation therapies on the tumor microenvironment.

Objective To determine the feasibility and prognostic value of 3D measuring of the ablation margins using a dedicated image registration software.Methods This retrospective study included 104 colorectal liver metastases in 68 consecutive patients that underwent microwave ablation between 08/2012 and 08/2019. The minimal ablation margin (MM) was measured in 2D using anatomic landmarks on contrast enhanced CT(CECT) 4–8 weeks post-ablation, and in 3D using an image registration software and immediate post-ablation CECT. Local tumor progression (LTP) was assessed by imaging up to 24 months after ablation. A blinded interventional radiologist provided feedback on the possibility of additional ablation after examining the 3D-margin measurements.Results The 3D-margin assessment was completed in 79/104 (76%) tumors without the need for target manipulation. In 25/104 (24%) tumors, manipulation was required due to image misregistration. LTP was observed in 40/104 (38.5%) tumors: 92.5% vs 7.5% for those with margin