Search

Objective Thermal ablation (TA) was implemented in public sector cervical cancer prevention services in Zambia in 2012. Initially introduced as a treatment modality in primary healthcare clinics, it was later included in mobile outreach campaigns and clinical research trials. We report the feasibility, acceptability, safety, and provider uptake of TA in diverse clinical contexts. Methods Screening services based on visual inspection with acetic acid were offered by trained nurses to non-pregnant women aged 25-59 years. Women with a type 1 transformation zone (TZ) were treated with same-visit TA. Those with a type 2 or 3 TZ, or suspicious for cancer, were managed with same-visit electrosurgical excision or punch biopsy, respectively. A provider survey was conducted. Results Between 2012 and 2020, 2123 women were treated with TA: primary healthcare clinics, n = 746; mobile outreach clinics, n = 1127; research clinics, n = 250. Of the 996 women treated in primary healthcare and research clinics, 359 (48%) were HIV positive. Mild cramping during treatment was the most common adverse effect. No treatment interruptions occurred. No major complications were reported in the early (6 weeks) follow-up period. Providers expressed an overwhelming preference for TA over cryotherapy. Conclusion TA was feasible, safe, and acceptable in diverse clinical contexts. It was the preferred ablation method of providers when compared with cryotherapy.

Percutaneous thermal ablation is an important treatment for lung cancer and is widely used in hospitals. Puncture biopsy is generally required for pathological diagnosis before or after thermal ablation. Pathological diagnosis provides both evidence of benign and malignant lesions for ablation therapy and is of important significance for the next step in disease management. Furthermore, the sequence of ablation and biopsy affects the accuracy of pathological diagnosis, the complete ablation rate of thermal ablation, and incidence of surgery‐related complications. Ultimately, it may affect the patient's benefit from local treatment. This article reviews the research progress of traditional asynchronous biopsy followed by ablation, the emerging methods of synchronous biopsy followed by ablation, and synchronous ablation followed by biopsy in the last decade. Key points The sequence of ablation and biopsy affects the accuracy of pathological diagnosis, the complete ablation rate of thermal ablation, and the incidence of surgical‐related complications. This article reviewed the recent 10 years' literature on the surgical sequence of biopsy and ablation for lung tumors, the advantages, disadvantages and indications of different orders were analyzed., This article reviews the research progress of traditional asynchronous biopsy followed by ablation, the emerging methods of synchronous biopsy followed by ablation, and synchronous ablation followed by biopsy in the last decade.

Magnetic resonance imaging (MRI) has become a popular modality in guiding minimally invasive thermal therapies, due to its advanced, nonionizing, imaging capabilities and its ability to record changes in temperature. A variety of MR thermometry techniques have been developed over the years, and proton resonance frequency (PRF) shift thermometry is the current clinical gold standard to treat a variety of cancers. It is used extensively to guide hyperthermic thermal ablation techniques such as high-intensity focused ultrasound (HIFU) and laser-induced thermal therapy (LITT). Essential attributes of PRF shift thermometry include excellent linearity with temperature, good sensitivity, and independence from tissue type. This noninvasive temperature mapping method gives accurate quantitative measures of the temperature evolution inside biological tissues. In this review, the current status and new developments in the fields of MR-guided HIFU and LITT are presented with an emphasis on breast, prostate, bone, uterine, and brain treatments.Level of Evidence 5Technical Efficacy Stage 3 The project was co-financed by the European Regional Development Fund (ERDF) under Ireland’s European Structural, Investment Funds Programme 2014–2020 and Enterprise Ireland; Grant agreement: CF-2017-0826-P, Irish Research Council postgraduate scholarship GOIPG/2018/82 and the NUI Galway College of Science. peer-reviewed 2021-11-20

Purpose Intraoperative T2 -weighted (T2-w) imaging unreliably captures image contrast specific to thermal ablation after transcranial MR-guided focused ultrasound surgery, impeding dynamic imaging feedback. Using a porcine thalamotomy model, we test the unproven hypothesis that intraoperative DWI can improve dynamic feedback by detecting lesioning within 30 minutes of transcranial MR-guided focused ultrasound surgery. Methods Twenty-five thermal lesions were formed in six porcine models using a clinical transcranial MR-guided focused ultrasound surgery system. A novel diffusion-weighted pulse sequence monitored the formation of T2-w and diffusion-weighted lesion contrast after ablation. Using postoperative T2-w contrast to indicate lesioning, apparent intraoperative image contrasts and diffusion coefficients at each lesion site were computed as a function of time after ablation, observed peak temperature, and observed thermal dose. Lesion sizes segmented from imaging and thermometry were compared. Image reviewers estimated the time to emergence of lesion contrast. Intraoperative image contrasts were analyzed using receiver operator curves. Results On average, the apparent diffusion coefficient at lesioned sites decreased within 5 minutes after ablation relative to control sites. In-plane lesion areas on intraoperative DWI varied from postoperative T2-w MRI and MR thermometry by 9.6 ± 9.7 mm2 and - 4.0 ± 7.1 mm2 , respectively. The 0.25, 0.5, and 0.75 quantiles of the earliest times of observed T2-w and diffusion-weighted lesion contrast were 10.7, 21.0, and 27.8 minutes and 3.7, 8.6, and 11.8 minutes, respectively. The T2-w and diffusion-weighted contrasts and apparent diffusion coefficient values produced areas under the receiver operator curve of 0.66, 0.80, and 0.74, respectively. Conclusion Intraoperative DWI can detect MR-guided focused ultrasound surgery lesion formation in the brain within several minutes after treatment.

Option recommended by World Health Organization (WHO) includes human papillomavirus (HPV) primary screening followed by visual inspection with acetic acid (VIA) triage. We implemented a program based on a 3T‐approach (Test‐Triage and Treat). Our objective was to verify the effectiveness of the program by defining a set of performance indices. A sensitization campaign was performed in Dschang (Cameroon) and women aged 30‐49 years were invited to participate for screening based on the 3T‐approach. Participants performed HPV self‐sampling (Self‐HPV), analyzed with the point‐of‐care Xpert HPV assay followed by VIA/VILI triage and treatment if required. Key performance indicators (KPIs) for screening, diagnosis, treatment and follow‐up were defined, and achievable targets were described for which the approach is likely to be running optimally. A total of 840 women with a mean age of 39.4±5.9 years participated. The KPIs included (i) the screening rate (8.4% at 7 months, target =20% at 12 months), (ii) HPV positivity rate (19.8%, expected range 18‐25%), (iii) compliance to referral to VIA/VILI and complete test (100%, target >90%), (iv) compliance to referral to thermal ablation (100%, target >90%), (v) VIA/VILI positivity rate (50.6%, expected range 45‐55%), (vi) a single visit from diagnostic to treatment (79.8%, target >80%), (vii) compliance to follow‐up at 1 month (96.4%, target >80%) and (viii) at 6 months (70.6%, target >80%). Program performance based on the single‐visit 3T‐approach corresponded to defined targets and preliminary results support adequateness of KPIs for periodic monitoring., The study shows the performance of screening for cervical cancer in a single visit, using the 3T strategy, for Test‐Triage and Treat in low‐income countries Our results will be of great interest especially those designing and conducting women’s health screening programs in low‐income countries. Improved primary screening, diagnosis, treatment, and follow‐up, such as in the single‐visit 3T approach to screen cervical cancer in Cameroon, will substantially reduce the incidence of preventable or treatable diseases in low‐ and middle‐income countries.

Objectives To develop a clinicopathological‐based nomogram to improve the prediction of the seeding risk of after percutaneous thermal ablation (PTA) in primary liver carcinoma (PLC). Methods A total of 2030 patients with PLC who underwent PTA were included between April 2009 and December 2018. The patients were grouped into a training dataset (n = 1024) and an external validation dataset (n = 1006). Baseline characteristics were collected to identify the risk factors of seeding after PTA. The multivariate Cox proportional hazards model based on the risk factors was used to develop the nomogram, which was used for assessment for its predictive accuracy using mainly the Harrell's C‐index and receiver operating characteristic curve (AUC). Results The median follow‐up time was 30.3 months (range, 3.2‐115.7 months). The seeding risk was 0.89% per tumor and 1.5% per patient in the training set. The nomogram was developed based on tumor size, subcapsular, α‐fetoprotein (AFP), and international normalized ratio (INR). The 1‐, 2‐, and 3‐year cumulative seeding rates were 0.1%, 0.7% and 1.2% in the low‐risk group, and 1.7%, 6.3% and 6.3% in the high‐risk group, respectively, showing significant statistical difference (P, Seeding on the thoracoabdominal wall from primary liver carcinoma is a potential complication after percutaneous thermal ablation. Seeding risk is a liver ablation complication that affects future oncology management. A calibrated and objective model to predict seeding risk after liver ablation may guide patient selection and ablation treatment.

Human papillomavirus (HPV) test, self-sampling and thermal ablation for cervical intraepithelial neoplasia (CIN) have been developed separately to increase screening coverage and treatment compliance of cervical cancer screening programmes. A large-scale study in rural China screened 9,526 women with their combinations to explore the optimal cervical cancer-screening cascade in the real-world. Participants received careHPV and polymerase chain reaction (PCR) HPV tests on self-collected samples. Women positive on either HPV test underwent colposcopy, biopsy and thermal ablation in a single visit. Samples positive on either HPV test were retested for genotyping. Absolute and relative performance of HPV tests, triage strategies, 'colposcopy and thermal ablation' approach were statistically evaluated. PCR HPV test detected 33.3% more CIN grade two or worse (CIN2+) at a cost of 28.1% more colposcopies compared to careHPV. Sensitivities of PCR HPV and careHPV tests to detect CIN2+ were 96.7 and 72.5%. Specificities for the same disease outcome were 82.1 and 86.0%. Triaging HPV-positive women with HPV16/18 genotyping considerably improved the positive predictive value for CIN2+ (4.8-5.0 to 18.2-19.2%). Ninety-six women positive on HPV and having abnormal colposcopy were eligible for thermal ablation and all accepted same-day treatment, contributing to 64.6% being treated appropriately (CIN1+ on histopathology), which reached up to 84.8% among women positive on HPV 16/18 triage. No serious side-effects/complications were reported. The combination of PCR HPV test followed by HPV 16/18 triaging on self-collected samples and colposcopy of triage positive women followed by immediate thermal ablation might be the appropriate screening cascade for rural China.

BACKGROUND AND OBJECTIVES Complete thermocoagulation of tumors is vital to minimize the risk of local tumor recurrence after a thermal ablation. Histological assessments are not real-time and require experienced pathologists to grade the thermal damage (histopathology) [Correction added on 21 January, 2020 after first online publication: After thermal damage in the preceding sentence, (histopathology) was added]. Real-time assessment of thermal tissue damage during an ablation is necessary to achieve optimal tumor ablation. In our previous studies, we found that continuous monitoring of the wavelength-averaged (435-630 nm) tissue absorption coefficient (µa ) and the reduced scattering coefficient ( μs' ) during heating of a porcine liver at 100°C follows a sigmoidal growth curve. Therefore, we concluded that increases in the tissue µa and μs' during thermocoagulation were correlated with true thermal damage. The goal of this study was to determine if increases in the tissue µa and μs' during thermocoagulation are correlated with true thermal damage. STUDY DESIGN/MATERIALS AND METHODS In this paper, continuously measured values of µa and μs' during heating of the porcine liver tissue were compared with the histology-assessed thermal damage scores at four different temperature points (37°C, 55°C, 65°C, and 75°C). RESULTS The damage scores for the tissues in Group 3 (65°C) and Group 4 (75°C) were significantly different from each other and from the other groups. The damage scores were not significantly different between Group 1 (37°C) and Group 2 (55°C). CONCLUSION The results indicate that relative changes in µa and μs' can be used to classify thermal damage (histopathology) scores with an overall accuracy of 72.5% up to 75°C. [Correction added on 21 January, 2020 after first online publication: After thermal damage in the preceding sentence, (histopathology) was added]. Lasers Surg. Med. © 2019 Wiley Periodicals, Inc.

Depending on the local or targeted treatment, independence on tumor type and minimally-invasive and noninvasive feature, various thermal ablation technologies have been established, but they still suffer from the intractable paradox between safety and efficacy. It has been extensively accepted that improving energy utilization efficiency is the primary means of decreasing thermal ablation power and shortening ablation time, which is beneficial for concurrently improving both treatment safety and treatment efficiency. Recent efforts have been made to receive a significant advance in various thermal methods including non-invasive high-intensity focused ultrasound, minimally-invasive radiofrequency and microwave, and non-invasive and minimally-invasive photothermal ablation, and so on. Especially, various nanobiotechnologies and design methodologies were employed to elevate the energy utilization efficiency for acquiring unexpected ablation outcomes accompanied with tremendously reduced power and time. More significantly, some combined technologies, for example, chemotherapy, photodynamic therapy (PDT), gaseous therapy, sonodynamic therapy (SDT), immunotherapy, chemodynamic therapy (CDT), or catalytic nanomedicine, were used to assist these ablation means to repress or completely remove tumors. We discussed and summarized the ablation principles and energy transformation pathways of the four ablation means, and reviewed and commented the progress in this field including newly developed technology or new material types with a highlight on nanobiotechnology-inspired design principles, and provided the deep insights into the existing problems and development direction. This article is categorized under: Therapeutic Approaches and Drug Discovery > Nanomedicine for Oncologic Disease Therapeutic Approaches and Drug Discovery > Emerging Technologies.

To evaluate the acceptability and safety of thermal ablation (TA) for the treatment of precancerous cervical lesions in women in Honduras.Human papillomavirus (HPV) and visual inspection with acetic acid (VIA) screen-positive eligible women received TA. After treatment, women rated the level of pain experienced during treatment using the Wong-Baker FACES® pain-rating scale from 0 to 10. Short-term safety outcomes that could require medical attention were assessed one month after treatment.A total of 319 women received TA treatment. The average pain rating was 2.5 (95% CI: 2.3-2.8), and 85% rated their pain levels as less than 6. No significant differences in low (below 6) or high (6 and above) pain were found by age or number of biopsies performed, but there was a significant difference by the number of TA applications (P 0.01). When asked if they would recommend this treatment, all women said they would. At the one-month follow-up visit, the most common reported discomforts were bleeding (10%) and cramping (8.4%); 11 women reported severe lower abdominal pain, and none required medical attention.TA is safe and acceptable to patients as a treatment option for precancerous cervical lesions in low-resource settings.Evaluer l'acceptabilité et la sécurité de l'ablation thermique (AT) pour le traitement des lésions cervicales précancéreuses chez les femmes au Honduras. MÉTHODES: Les femmes éligibles, portant le virus du papillome humain (VPH) et avec une inspection visuelle positive au test de dépistage à l'acide acétique (IVA) ont reçu une AT. Après le traitement, les femmes ont estimé le niveau de douleur ressenti au cours du traitement à l'aide de l’échelle d'évaluation de la douleur Wong-Baker FACES® de 0 à 10. Les résultats de sécurité à court terme pouvant nécessiter une attention médicale ont été évalués un mois après le traitement. RÉSULTATS: 319 femmes ont reçu un traitement d’AT. L’estimation moyenne de la douleur était de 2,5 (IC95%: 2,3-2,8) et 85% estimaient que leur niveau de douleur était inférieur à 6. Aucune différence significative dans la douleur faible (moins de 6) ou élevée (6 et plus) n’a été constatée en fonction de l’âge ou du nombre de biopsies réalisées, mais il y avait une différence significative selon le nombre d'applications d’AT (P 0,01). Lorsqu'on leur a demandé si elles recommanderaient ce traitement, toutes les femmes ont répondu qu'elles le feraient. Lors de la visite de suivi à un mois, les malaises les plus fréquents signalés étaient les saignements (10%) et les crampes (8,4%). Onze femmes ont rapporté des douleurs sévères dans le bas de l'abdomen et aucune n'a nécessité de soins médicaux.L'AT est sûre et acceptable pour les patientes comme option de traitement pour les lésions cervicales précancéreuses dans les régions à faibles ressources.

To achieve higher coverage and effectiveness in limited-resource settings, World Health Organization (WHO) guidelines for cervical cancer prevention recommend a screen-and-treat strategy with high-risk human papillomavirus (HPV) testing. We piloted a real-word project to examine the feasibility of this approach in rural Cameroon. Nurses from the Women's Health Program (WHP) of the Cameroon Baptist Convention Health Services (CBCHS) educated women in remote villages on cervical cancer prevention. At a follow-up visit, they explained to nonpregnant women aged 30-65 how to self-collect vaginal specimens for HPV testing with the careHPV assay. The cytobrush specimens were transported in coolers to a CBCHS laboratory for analysis. The nurses returned to villages to inform women of their results, examined HPV-positive women in the primary health centers (PHCs) using visual inspection with acetic acid and Lugol's iodine (VIA/VILI) enhanced by digital cervicography (DC) to guide treatment. Of the 1,270 eligible women screened (mean age: 44.7 years), 196 (15.4%) were HPV-positive, of whom 185 (94.4%) were examined, 16 (8.6%) were VIA/VILI-positive, 8 (4.3%) were VIA/VILI-inadequate, one (0.5%) was VIA/VILI-uncertain and 161 (87.0%) were treated with thermal ablation. One woman had LEEP, and another woman with invasive cancer was treated at a referral facility. The cytobrushes broke off in the vaginas of two women (removed in the village) and in the bladder of another (surgically removed). Community-based cervical cancer screening with self-collected specimens for HPV testing is feasible in rural Cameroon. Education on the proper sampling procedure and follow-up of women who are HPV-positive are essential.

PURPOSE: Early evaluation of tumor response to thermal ablation therapy can help identify untreated tumor cells and then perform repeated treatment as soon as possible. The purpose of this work was to explore the potential of rhein-based necrosis-avid contrast agents (NACAs) for early evaluation of tumor response to microwave ablation (MWA). METHODS: 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyl tetrazolium bromide (MTT) assay was performed to test the cytotoxicity of rhein-based NACAs against HepG2 cells. Rat models of liver MWA were used for investigating the effectiveness of rhein-based NACAs in imaging the MWA lesion, the optimal time period for post-MWA MRI examination, and the metabolic behaviors of 68 Ga-labeled rhein-based NACAs. Rat models of orthotopic liver W256 tumor MWA were used for investigating the time window of rhein-based NACAs for imaging the MWA lesion, the effectiveness of these NACAs in distinguishing the residual tumor and the MWA lesion, and their feasibility in early evaluating the tumor response to MWA. RESULTS: Gadolinium 2,2',2''-(10-(2-((4-(4,5-Dihydroxy-9,10-dioxo-9,10-dihydroanthracene-2-carboxamido)butyl)amino)-2-oxoethyl)-1,4,7,10-tetraazacyclododecane-1,4,7-triyl)triacetic acid (GdL2 ) showed low cytotoxicity and high quality in imaging the MWA region. The optimal time period for post-MWA MRI examination using GdL2 was 2 to 24 h after the treatment. During 2.5 to 3.5 h postinjection, GdL2 can better visualize the MWA lesion in comparison with gadolinium 2-[4,7,10-tris(carboxymethyl)-1,4,7,10-tetraazacyclododec-1-yl]acetic acid (Gd-DOTA), and the residual tumor would not be enhanced. The tumor response to MWA as evaluated by using GdL2 -enhanced MRI was consistent with histological examination. CONCLUSION: GdL2 appears to be a promising NACA for the tumor response assessment after thermal ablation therapies. ispartof: MAGNETIC RESONANCE IN MEDICINE vol:82 issue:6 pages:2212-2224 ispartof: location:United States status: published

The expanding landscape of options for Parkinson's disease (PD) therapeutics calls for novel ways to improve delivery of treatments to counteract neurodegeneration or enhance symptomatic control. This unmet need is particularly relevant for opportunities in gene therapy, which, in recent PD clinical trials, has required invasive neurosurgical approaches into the CNS. One of the promising techniques to bring new therapies into the brain for PD therapeutics involves an evolving technology, focused ultrasound. Focused ultrasound has been used to alleviate tremor by thermal ablation with high-energy sonication. Using similar equipment but much lower sonication energy, focused ultrasound assisted with micro-bubbles can temporarily open the blood-brain barrier at specific brain targets to facilitate real-time magnetic resonance-guided delivery of therapeutic agents. To explore the current status and future of focused ultrasound in transvascular therapeutics for PD, a November 2018 workshop reviewed its accomplishments and challenges. This report summarizes key points of discussion and provides further background to the promising roles focused ultrasound offers. © 2019 International Parkinson and Movement Disorder Society.

AIM To retrospectively compare the treatment effect of intraprocedural computed tomography/magnetic resonance-contrast-enhanced ultrasound (CT/MR-CEUS) fusion imaging (FI) with that of conventional ultrasound (US) in the guidance and assessment of thermal ablation of hepatocellular carcinoma (HCC). METHODS The FI group (112 patients with 129 HCC) was treated between April 2010 and December 2012, whereas the US group (83 patients with 90 HCC) was treated between January 2008 and March 2010. Either CT/MR-CEUS FI or US was used to guide puncture, provide immediate assessment, and guide supplementary ablation. Technical efficacy, cumulative local tumor progression rate (LTP), recurrence-free survival (RFS), and overall survival (OS) were evaluated and compared during follow-up. Technical success rate of CT/MR-CEUS FI was also recorded. RESULTS Technical efficacy was significantly higher in the FI group than in the US group (100% vs. 86.7%, P

Background The study was conducted to assess the safety and efficacy of thermal ablation for the treatment of subpleural lung cancer. Methods Eighty‐nine patients with 101 subpleural lung cancers were identified between January 2012 and July 2018 in our database and included in this study. Tumors were classified as adhering to cervical, costal, diaphragmatic, and mediastinal pleurae. Lesions were categorized based on their relationship to the pleura: close to the pleura, causing pleural indentation, and involving the pleura. The complete ablation rate, local progression‐free survival, complications, and associated factors were analyzed. Results Subpleural lung cancers included lesions located under costal (n = 69), mediastinal (n = 17), cervical (n = 8), and diaphragmatic (n = 7) pleurae. The rate of complete ablation was 87.1% and the local progression‐free survival rates at 3, 6, 12, and 24 months were 86%, 77%, 75%, and 64%, respectively. Tumor size was the most important factor influencing technique efficacy (P 30 mm. There were nine (10.11%) major complications, including one chest abscess, five cases of pneumothorax, and three cases of hemothorax. The occurrence of major complications was associated with increased levels of pain within 48 hours post‐procedure (P

Hepatocellular carcinoma (HCC) is the fifth most common malignant tumor and constitutes a major health threat globally. Intermediate HCC (Barcelona Clinic Liver Cancer Staging, stage B) encompasses a wide range of patients and is characterized by substantial heterogeneity with varying tumor burdens and liver functions. Therefore, it is paramount to evaluate the patient's overall conditions and to select the most appropriate therapy based on available evidence. Transarterial chemoembolization is the recommended first-line therapy for intermediate HCC patients. However, in clinical practice, other treatment options are also used as alternative therapies, such as hepatic resection, percutaneous thermal ablation, radiotherapy (RT), systemic treatment, immunotherapy, and so forth. In this review, we will introduce current treatment strategies for intermediate HCC, discuss their advantages and disadvantages, and propose future directions.

Electrosurgery with argon plasma coagulation is a widespread technique used in various medical fields for applications which range from hemostasis to devitalization processes. Developing tools which provide feedback concerning tissue condition during these surgeries is fundamental for improving the safety and success of this treatment. We present here a method based on diffuse reflectance spectroscopy to monitor gastric mucosal devitalization treatments. The analysis of the diffusely reflected spectra of the tissue allows us to differentiate between ablation states by using linear discriminant analysis (LDA) as a classification algorithm. An ex vivo pilot study on several swine stomachs showed promising results, with 97.8% of correctly classified ablation states on a new unseen stomach, encouraging further tests with human tissue., Electrosurgery with argon plasma coagulation is a widespread technique used in various medical fields for applications which range from hemostasis to devitalization processes. Here, we present a method based on diffuse reflectance spectroscopy to monitor gastric mucosal devitalization treatments. The analysis of the diffusely reflected spectra of the tissue allows us to differentiate between ablation states by using linear discriminant analysis as a classification algorithm.

Despite the rapid elaboration of multiple, novel systemic agents introduced for metastatic renal cell carcinoma (mRCC) in recent years, a durable complete response remains elusive with systemic therapy alone. Definitive treatment of the metastatic deposit remains the sole potentially curative option and is a cornerstone of mRCC therapy, offering potential for both local control and palliation of tumor-related symptoms. In this review, the evidence supporting the definitive treatment of mRCC is examined and summarized, including the use of surgical metastasectomy, thermal ablation, radiotherapy, and other minimally invasive options. Multimodal approaches, including the combination of metastasectomy with novel systemic agents, are discussed. Finally, the authors review considerations for patient selection for this type of therapy and summarize available risk-stratification tools that may help guide shared decision making.

Image-guided ablation of thyroid disease is increasingly being commonly reported. Techniques including ethanol injection and thermal ablation using radio-frequency, laser, and microwave devices have been described. Minimally invasive approaches to the management of benign cystic, solid, and functional thyroid nodules as well as both primary and recurrent thyroid malignancy have been reported. The purpose of this article is to review the current evidence relating to image-guided ablation of thyroid disease with a focus on clinical outcomes and complication rates for patients treated with this minimally invasive approach.

Purpose Catheter-based ultrasound applicators can generate thermal ablation of tissues adjacent to body lumens, but have limited focusing and penetration capabilities due to the small profile of integrated transducers required for the applicator to traverse anatomical passages. This study investigates a design for an endoluminal or laparoscopic ultrasound applicator with deployable acoustic reflector and fluid lens components, which can be expanded after device delivery to increase the effective acoustic aperture and allow for deeper and dynamically adjustable target depths. Acoustic and biothermal theoretical studies, along with benchtop proof-of-concept measurements, were performed to investigate the proposed design. Methods The design schema consists of an array of tubular transducer(s) situated at the end of a catheter assembly, surrounded by an expandable water-filled conical balloon with a secondary reflective compartment that redirects acoustic energy distally through a plano-convex fluid lens. By controlling the lens fluid volume, the convex surface can be altered to adjust the focal length or collapsed for device insertion or removal. Acoustic output of the expanded applicator assembly was modeled using the rectangular radiator method and secondary sources, accounting for reflection and refraction at interfaces. Parametric studies of transducer radius (1-5 mm), height (3-25 mm), frequency (1.5-3 MHz), expanded balloon diameter (10-50 mm), lens focal length (10-100 mm), lens fluid (silicone oil, perfluorocarbon), and tissue attenuation (0-10 Np/m/MHz) on beam distributions and focal gain were performed. A proof-of-concept applicator assembly was fabricated and characterized using hydrophone-based intensity profile measurements. Biothermal simulations of endoluminal ablation in liver and pancreatic tissue were performed for target depths between 2-10 cm. Results Simulations indicate that focal gain and penetration depth scale with the expanded reflector-lens balloon diameter, with greater achievable performance using perfluorocarbon lens fluid. Simulations of a 50 mm balloon OD, 10 mm transducer outer diameter (OD), 1.5 MHz assembly in water resulted in maximum intensity gain of ~170 (focal dimensions: ~12 mm length x 1.4 mm width) at ~5 cm focal depth and focal gains above 100 between 24-84 mm depths. A smaller (10 mm balloon OD, 4 mm transducer OD, 1.5 MHz) configuration produced a maximum gain of 6 at 9 mm depth. Compared to a conventional applicator with a fixed spherically-focused transducer of 12 mm diameter, focal gain was enhanced at depths beyond 20 mm for assembly configurations with balloon diameters ≥ 20 mm. Hydrophone characterizations of the experimental assembly (31 mm reflector/lens diameter, 4.75 mm transducer radius, 1.7 MHz) illustrated focusing at variable depths between 10-70 mm with a maximum gain of ~60 and demonstrated agreement with theoretical simulations. Biothermal simulations (30 s sonication, 75°C maximum) indicate that investigated applicator assembly configurations, at 30 mm and 50 mm balloon diameters, could create localized ellipsoidal thermal lesions increasing in size from 10-55 mm length x 3-6 mm width in liver tissue as target depth increased from 2-10 cm. Conclusions Preliminary theoretical and experimental analysis demonstrates that combining endoluminal ultrasound with an expandable acoustic reflector and fluid lens assembly can significantly enhance acoustic focal gain and penetration from inherently smaller diameter catheter-based applicators. This article is protected by copyright. All rights reserved.

Chronic venous disease is a common disorder associated with a variety of symptoms in later disease stages but also with complications such as venous leg ulcer. This, in turn, has substantial socioeconomic effects and significantly impacts patients' quality of life. While there are a number of diagnostic procedures available, color-flow duplex ultrasound has become the gold standard. As regards therapeutic options, major advances have been made in recent decades. Today, there are alternatives to saphenofemoral ligation and stripping of the great saphenous vein, including endovenous thermal ablation techniques. However, treatment selection continues to depend on many factors such as individual anatomical circumstances and disease stage. The following article provides an overview of the anatomy and pathophysiology as well as current diagnostic and therapeutic standards.

BACKGROUND Irreversible electroporation (IRE) has emerged as a novel, safe ablative therapy for peri-vascular lesions. However, there remains a paucity of data on long-term outcomes. METHODS We identified patients who underwent open IRE (1/2011-6/2015) for primary and secondary hepatic malignancies. Local ablation-zone recurrence (LR) was determined by cross-sectional imaging. Cumulative incidence (CumI) of LR was calculated and a competing risks regression assessed factors associated with LR. RESULTS Forty patients had 77 lesions treated. The majority of lesions were of colorectal origin (74%). Median tumor size was 1.3 cm (range 0.5-6). Most patients (86%) had prior systemic therapy and 29% received systemic therapy following IRE. With a median follow-up of 25.7 months (range 4.5-58.8 months), 10 lesions in 9 patients recurred locally (CumI: 13.4%, 95%CI: 7.8-22.2%). Median estimated time to LR was not reached and no LR occurred after 19 months. Factors significantly associated with LR included ablation zone size (HR 1.58; 95%CI 1.12-2.23; P = 0.0093) and body mass index (HR 1.21 95%CI 1.10-1.34; P = 0.0001). CONCLUSION IRE LR rates were low after the treatment of well selected, small tumors. This technique is useful for lesions in anatomic locations precluding resection or thermal ablation.

BACKGROUND: The feasibility and outcome of endoscopic resection in ampullary tumors with intraductal growth remains unclear. OBJECTIVE: To assess the safety, feasibility and outcomes of these patients treated by thermal ablation. METHODS: Retrospective observational study. All consecutive patients who underwent an endoscopic snare papillectomy with a 6-month minimum follow-up were included. Ablation was performed with cystotomes and soft/forced coagulation. Successful endoscopic treatment was defined as no adenomatous residual tissue or recurrence observed at follow-up. RESULTS: Of 86 patients presenting with an ampullary tumor, 73 (58 ± 14 years old, 49% men, 34% familial adenomatous polyposis) (median tumor size: 20 mm, range: 8–80) were included. En bloc and curative resection rates were achieved in 46.6% and 83.6%, respectively. Intraductal ingrowth was seen in 18 (24.7%) patients and histologically confirmed in 12 (16.4%). Intraductal ablation achieved a 100% success rate, with a 20-month median follow-up. Most of these patients had malignant forms (n = 8, 66.7%), with a higher adenocarcinoma rate (33.3% versus 3.3%, p = 0.001) compared to extraductal tumors. Overall, there was a 20.5% complication rate with no significant differences between both groups (p = 0.676). CONCLUSIONS: Intraductal ablation achieves a high therapeutic success rate in ampullary tumors with ≤20 mm ductal extension, even in malignant forms or biliary and pancreatic involvement. The technique is feasible, cheap and safe and may avoid major surgery.

Image-guided thermal ablation is a well-established locoregional technique for the treatment of hepatocellular carcinoma (HCC). HCC surveillance programs have led to an increase in the number of patients diagnosed at an early stage of the disease who are eligible for thermal ablation. Tumor response is assessed on imaging and requires extensive follow-up; thus, radiologists play a key role in defining the technical success and efficacy of treatment as well as identifying progressive disease. Although they are rare, complications, such as secondary infections, must also be identified. Several contrast-enhanced imaging techniques can be used at different postprocedural timepoints but magnetic resonance imaging (MRI) and computed tomography (CT), which allow both liver-centered and whole-body imaging are the cornerstones of follow-up. This review describes the imaging features of HCC following thermal ablation. After describing the basic technical elements of follow-up imaging, imaging findings are divided into three groups: normal and expected features (the good), abnormal features, uncontrolled disease, and complications (the bad), and atypical or rare presentations (the ugly). J. Magn. Reson. Imaging 2016;44:1070-1090.

Purpose: Endoluminal ultrasound may serve as a minimally invasive option for delivering thermal ablation to pancreatic tumors adjacent to the stomach or duodenum. The objective of this study was to explore the basic feasibility of this treatment strategy through the design, characterization, and evaluation of proof-of-concept endoluminal ultrasound applicators capable of placement in the gastrointestinal (GI) lumen for volumetric pancreas ablation under MR guidance. Methods: Two variants of the endoluminal applicator, each containing a distinct array of two independently powered transducers (10 × 10 mm 3.2 MHz planar; or 8 × 10 × 20 mm radius of curvature 3.3 MHz curvilinear geometries) at the distal end of a meter long flexible catheter assembly, were designed and fabricated. Transducers and circulatory water flow for acoustic coupling and luminal cooling were contained by a low-profile polyester balloon covering the transducer assembly fixture. Each applicator incorporated miniature spiral MR coils and mechanical features (guiding tips and hinges) to facilitate tracking and insertion through the GI tract under MRI guidance. Acoustic characterization of each device was performed using radiation force balance and hydrophone measurements. Device delivery into the upper GI tract, adjacent to the pancreas, and heating characteristics for treatment of pancreatic tissue were evaluated in MR-guided ex vivo and in vivo porcine experiments. MR guidance was utilized for anatomical target identification, tracking/positioning of the applicator, and MR temperature imaging (MRTI) for PRF-based multislice thermometry, implemented in the real-time RTHawk software environment. Results: Force balance and hydrophone measurements indicated efficiencies of 48.8% and 47.8% and −3 dB intensity beam-widths of 3.2 and 1.2 mm for the planar and curvilinear transducers, respectively. Ex vivo studies on whole-porcine carcasses revealed capabilities of producing ablative temperature rise (ΔT > 15 °C) contours in pancreatic tissue 4–40 mm long and 4–28 mm wide for the planar transducer applicator (1–13 min sonication duration, ∼4 W/cm2 applied acoustic intensity). Curvilinear transducers produced more selective heating, with a narrower ΔT > 15 °C contour length and width of up to 1–24 mm and 2–7 mm, respectively (1–7 min sonication duration, ∼4 W/cm2 applied acoustic intensity). Active tracking of the miniature spiral coils was achieved using a Hadamard encoding tracking sequence, enabling real-time determination of each coil's coordinates and automated prescription of imaging planes for thermometry. In vivo MRTI-guided heating trials in three pigs demonstrated capability of ∼20 °C temperature elevation in pancreatic tissue at 2 cm depths from the applicator, with 5–7 W/cm2 applied intensity and 6–16 min sonication duration. Dimensions of thermal lesions in the pancreas ranged from 12 to 28 mm, 3 to 10 mm, and 5 to 10 mm in length, width, and depth, respectively, as verified through histological analysis of tissue sections. Multiple-baseline reconstruction and respiratory-gated acquisition were demonstrated to be effective strategies in suppressing motion artifacts for clear evolution of temperature profiles during MRTI in the in vivo studies. Conclusions: This study demonstrates the technical feasibility of generating volumetric ablation in pancreatic tissue using endoluminal ultrasound applicators positioned in the stomach lumen. MR guidance facilitates target identification, device tracking/positioning, and treatment monitoring through real-time multislice PRF-based thermometry.

Measuring temperature in cells and tissues remotely, with sufficient sensitivity, and in real time presents a new paradigm in engineering, chemistry and biology. Traditional sensors, such as contact thermometers, thermocouples, and electrodes, are too large to measure the temperature with subcellular resolution and are too invasive to measure the temperature in deep tissue. The new challenge requires novel approaches in designing biocompatible temperature sensors—nanothermometers—and innovative techniques for their measurements. In the last two decades, a variety of nanothermometers whose response reflected the thermal environment within a physiological temperature range have been identified as potential sensors. This review covers the principles and aspects of nanothermometer design driven by two emerging areas: single-cell thermogenesis and image guided thermal treatments. The review highlights the current trends in nanothermometry illustrated with recent representative examples.

For the clinical application of high intensity focused ultrasound (HIFU) for thermal ablation of malignant tumors, accurate treatment evaluation is of key importance. In this study, we have employed a multiparametric MRI protocol, consisting of quantitative T1, T2, ADC, amide proton transfer (APT), T1ρ and DCE-MRI measurements, to evaluate MR-guided HIFU treatment of subcutaneous tumors in rats. K-means clustering using all different combinations of the endogenous contrast MRI parameters (feature vectors) was performed to segment the multiparametric data into tissue populations with similar MR parameter values. The optimal feature vector for identification of the extent of non-viable tumor tissue after HIFU treatment was determined by quantitative comparison between clustering-derived and histology-derived non-viable tumor fractions. The highest one-to-one correspondence between these clustering-based and histology-based non-viable tumor fractions was observed for the feature vector {ADC, APT-weighted signal} (R(2) to line of identity (R(2)y=x) = 0.92) and the strongest agreement was seen 3 days after HIFU (R(2)y=x = 0.97). To compare the multiparametric MRI analysis results with conventional HIFU monitoring and evaluation methods, the histology-derived non-viable tumor fractions were also quantitatively compared with non-perfused tumor fractions (derived from the level of contrast enhancement in the DCE-MRI measurements) and 240 CEM tumor fractions (i.e. thermal dose > 240 cumulative equivalent minutes at 43 °C). The correlation between histology-derived non-viable tumor fractions directly after HIFU and the 240 CEM fractions was high, but not significant. The non-perfused fractions overestimated the extent of non-viable tumor tissue directly after HIFU, whereas an underestimation was observed 3 days after HIFU. In conclusion, we have shown that a multiparametric MR analysis, especially based on the ADC and the APT-weighted signal, can potentially be used to determine the extent of non-viable tumor tissue 3 days after HIFU treatment. We expect that this method can be incorporated in the current clinical workflow of MR-HIFU ablation therapies.

Thermal ablation with high intensity focused ultrasound (HIFU) is an emerging noninvasive technique for the treatment of solid tumors. HIFU treatment of malignant tumors requires accurate treatment planning, monitoring and evaluation, which can be facilitated by performing the procedure in an MR-guided HIFU system. The MR-based evaluation of HIFU treatment is most often restricted to contrast-enhanced T1 -weighted imaging, while it has been shown that the non-perfused volume may not reflect the extent of nonviable tumor tissue after HIFU treatment. There are multiple studies in which more advanced MRI methods were assessed for their suitability for the evaluation of HIFU treatment. While several of these methods seem promising regarding their sensitivity to HIFU-induced tissue changes, there is still ample room for improvement of MRI protocols for HIFU treatment evaluation. In this review article, we describe the major acute and delayed effects of HIFU treatment. For each effect, the MRI methods that have been-or could be-used to detect the associated tissue changes are described. In addition, the potential value of multiparametric MRI for the evaluation of HIFU treatment is discussed. The review ends with a discussion on future directions for the MRI-based evaluation of HIFU treatment.

Purpose: In the ongoing endeavor of fine-tuning, the clinical application of transcranial MR-guided focused ultrasound (tcMRgFUS), ex-vivo studies wlkiith whole human skulls are of great use in improving the underlying technology guiding the accurate and precise thermal ablation of clinically relevant targets in the human skull. Described here are the designs, methods for fabrication, and notes on utility of three different ultrasound phantoms to be used for brain focused ultrasound research. Methods: Three different models of phantoms are developed and tested to be accurate, repeatable experimental options to provide means to further this research. The three models are a cadaver, a gel-filled skull, and a head mold containing a skull and filled with gel that mimics the brain and the skin. Each was positioned in a clinical tcMRgFUS system and sonicated at 1100 W (acoustic) for 12 s at different locations. Maximum temperature rise as measured by MR thermometry was recorded and compared against clinical data for a similar neurosurgical target. Results are presented as heating efficiency in units (°C/kW/s) for direct comparison to available clinical data. The procedure for casting thermal phantom material is presented. The utility of each phantom model is discussed in the context of various tcMRgFUS research areas. Results: The cadaveric phantom model, gel-filled skull model, and full head phantom model had heating efficiencies of 5.3, 4.0, and 3.9 °C/(kW/s), respectively, compared to a sample clinical heating efficiency of 2.6 °C/(kW/s). In the seven research categories considered, the cadaveric phantom model was the most versatile, though less practical compared to the ex-vivo skull-based phantoms. Conclusions: Casting thermal phantom material was shown to be an effective way to prepare tissue-mimicking material for the phantoms presented. The phantom models presented are all useful in tcMRgFUS research, though some are better suited to a limited subset of applications depending on the researchers needs.

Background and Aim In patients with cirrhosis and small hepatocellular carcinoma (HCC), thermal ablation is currently recognized as an effective local treatment. Among thermal procedures, radiofrequency ablation (RFA) is the most diffusely used and is the standard against which any new treatment should be compared. In retrospective studies, laser ablation (LA) resulted as safe and effective as RFA. Therefore, we performed a non-inferiority randomized trial comparing RFA with LA in patients with cirrhosis and HCC within Milan criteria. Methods Overall, 140 patients with 157 HCC nodules were randomly assigned to receive RFA or LA. The primary end-point was the proportion of complete tumor ablation (CTA). Secondary end-points were time to local progression (TTLP) and overall survival (OS). Results Per patient CTA rates after RFA and LA were 97.4% (95% CI, 91.0–99.3) and 95.7% (88.1–98.5), respectively (difference = 1.4%, 95% CI from −6.0% to + 9.0%). Per nodule CTA rates for RFA and LA were 97.4% (91.0–99.3) and 96.3% (89.6–98.7), respectively (difference = 1.1%, from −5.7% to + 8.1%). The mean TTLP was comparable between RFA group (42.0 months; 95% CI, 36.83–47.3) and LA group (46.7 months; 95% CI, 41.5–51.9) (P = .591). The mean OS was 42 months in both groups and survival probability at 1 and 3 years was 94% and 89% in RFA group, and 94% and 80% in LA group. Conclusion LA resulted not inferior to RFA in inducing the CTA of HCC nodules and therefore it should be considered as an evaluable alternative for thermal ablation of small HCC in cirrhotic patients.

Although surgical resection is the primary means of curing both primary and metastatic lung cancers, about 80% of lung cancers cannot be removed by surgery. As most patients with unresectable lung cancer receive only limited benefits from traditional radiotherapy and chemotherapy, many new local treatment methods have emerged, including local ablation therapy. The Minimally Invasive and Comprehensive Treatment of Lung Cancer Branch, Professional Committee of Minimally Invasive Treatment of Cancer of the Chinese Anti-Cancer Association has organized multidisciplinary experts to develop guidelines for this treatment modality. These guidelines aim at standardizing thermal ablation procedures and criteria for selecting treatment candidates and assessing outcomes; and for preventing and managing post-ablation complications.

MRI-guided thermal ablation is a relatively new technique utilising heat to ablate both tumours and epileptogenic lesions. Its use against epilepsy offers some patients a new and relatively safe way of reducing or aborting seizures. Most cases of MRI-guided thermal ablation have been performed in patients with isolated lesions. Placement of depth electrodes prior to laser ablation has been rarely performed. We present a case with bilateral independent lesions traversing eloquent cortex, which, after sampling for seizures and successful ablation, retained normal function. The patient is, to date, seizure-free.

Rationale, aims and objectives Numerous scientific publications have confirmed that percutaneous laser thermal ablation (LTA) represents a possible therapeutic option in selected patients with benign thyroid nodules. A study was carried out to evaluate the feasibility of adopting the LTA technique to treat benign thyroid nodules in a teaching and research hospital in northern Italy. Methods A cost analysis from a company's perspective determined the impact of adoption of the new technique on the overall Hospital budget, considering currently available equipment, infrastructure and personnel, equipment costs and treatment tariffs. Results The cost analysis shows that, strictly from an economic point of view, any provision of the LTA technique will result as a loss on the Hospital's balance sheet. However, it does not estimate the extent of the impact on the overall budget because it did not evaluate the savings that such a technique would make with respect to alternative therapeutic treatments. Therefore, the Hospital policy management decided to extend the current agreement with a private authorized health care structure that already carries out LTA. Also, although difficult to express in economic terms, this new technique would undoubtedly raise the profile and enhance the reputation of the Hospital. Conclusions Using the new technique in these patients could cut costs for the entire regional health care system, widen the experience of the Hospital's endocrinology team and offer the potential for the procedure also to be provided by operators on a freelance basis within the Hospital.

Purpose To present a three-dimensional (3D) segmented echoplanar imaging (EPI) pulse sequence implementation that provides simultaneously the proton resonance frequency shift temperature of aqueous tissue and the longitudinal relaxation time (T1) of fat during thermal ablation. Methods The hybrid sequence was implemented by combining a 3D segmented flyback EPI sequence, the extended two-point Dixon fat and water separation, and the double flip angle T1 mapping techniques. High-intensity focused ultrasound (HIFU) heating experiments were performed at three different acoustic powers on excised human breast fat embedded in ex vivo porcine muscle. Furthermore, T1 calibrations with temperature in four different excised breast fat samples were performed, yielding an estimate of the average and variation of dT1/dT across subjects. Results The water only images were used to mask the complex original data before computing the proton resonance frequency shift. T1 values were calculated from the fat-only images. The relative temperature coefficients were found in five fat tissue samples from different patients and ranged from 1.2% to 2.6%/°C. Conclusion The results demonstrate the capability of real-time simultaneous temperature mapping in aqueous tissue and T1 mapping in fat during HIFU ablation, providing a potential tool for treatment monitoring in organs with large fat content, such as the breast. Magn Reson Med 72:178–187, 2014. © 2013 Wiley Periodicals, Inc.

To confirm the results of an earlier study assessing the safety and efficacy of a laparoscopic radiofrequency volumetric thermal ablation (RFVTA) system among women with symptomatic myomas.In a prospective study at the Hospital of Francisco Marroquin University, Guatemala City, consecutive premenopausal women with symptomatic myomas seeking uterine-sparing treatment were enrolled between August 2008 and July 2011. The women were treated by RFVTA. Uterine fibroid symptom and health-related quality-of-life (UFS-QOL) questionnaires were completed at 0, 3, 6, and 12 months.Among 114 women screened, 36 were enrolled (ages 33-51 years), and 35 were followed for 12 months. Symptom severity scores reduced significantly (P0.05): baseline (63.3), 3 months (23.1), 6 months (15.4), 12 months (9.6). Health-related quality-of-life scores improved significantly (P0.05): baseline (37.3), 3 months (79.9), 6 months (85.1), 12 months (87.7). The mean ± SD difference in uterine volume from baseline (215.2 ± 117.9 cm(3)) to 12 months (167.0 ± 120.8 cm(3)) was 48.2 cm(3) (95% CI: -22.8 to 119.2; P=0.192). Nine adverse events among 8 individuals were minor and unrelated to the procedure.RFVTA of fibroids resulted in significantly improved symptom severity and quality-of-life scores and provides an outpatient uterine-sparing option for treatment of myomas.

A large number of adrenal tumors are now identified either incidentally or associated with a metastatic workup for cancer. While the vast majority of these lesions are benign, those that prove to be primary or secondary cancers are traditionally treated with surgical resection. A wide variety of alternative, less invasive therapies exist. One of these, thermal ablation, is examined herein. J. Surg. Oncol. 2012; 106:626–631. © 2012 Wiley Periodicals, Inc.