Thermal Ablation Treatment Research Articles

Tumor vascular occlusion by calcium-based thermosensitizer provokes continuous cavitation effect and thermal energy transition efficiency of radiofrequency ablation therapy

Radiofrequency ablation (RFA) therapy for hepatocellular carcinoma (HCC) suffers from incomplete ablation with tumor remnants, recurrence, and metastasis. To capture these matters, a calcium-based thermosensitizer (CBT) was constructed, which can swell the thermal ablation treatment. DMXAA was encapsulated within CaCO3 nanoparticles and surface-modified using PEG. DMXAA @CBTNps emanates continuous cavitation to enhance the RFA effect, lower RFA power, and shorten the RFA time by responding to the acidic tumor microenvironment and releasing carbon dioxide bubbles. Ca2+ deposition to form calcification instigates the calcium death of the tumor and strengthens the thermal conductivity, wherein CBT fortifies the immunogenic cell death (ICD) of RFA. The vascular disruptor DMXAA is administered to the tumor site to impair the blood and nutrient supply to the tumor tissue. Calcium carbonate nanoparticles generate persistent carbon dioxide bubbles within the acidic microenvironment, leading to a sustained cavitation effect that enhances magneto-thermal conversion. This synergistic approach facilitates tumor vascular occlusion, thereby improving thermal ablation therapy. This strategy is different from previous thermal ablation treatments in that the CBT-released product Ca2+, the continuous cavitation effect of CO2, and the vascular disrupting agent can accelerate the conversion of energy from electromagnetic energy to thermal energy and reduce the heat loss, which significantly amplifies the effect of thermal ablation treatment of HCC and intensifies ICD. Therefore, this research provides a promising avenue and therapeutic platform for clinical liver cancer treatment.

Development of a murine laser interstitial thermotherapy system.

The objective of this study was to develop a murine system for the delivery of laser interstitial thermotherapy (LITT) with probe-based thermometry as a model for human glioblastoma treatment to investigate thermal diffusion in heterogeneous brain tissue. First, the tissue heating properties were characterized using a diode-pumped solid-state near-infrared laser in a homogeneous tissue model. The laser was adapted for use with a repurposed stereotactic surgery frame utilizing a micro laser probe and Hamilton syringe. The authors designed and manufactured a stereotactic frame attachment to work as a temperature probe stabilizer. Application of this novel design was used as a precise method for real-time thermometry at known distances from the thermal ablative center mass during murine LITT studies. Temperature measurements were achieved during LITT that verified the direct thermometry capability of the system without the need for MR-based thermal monitoring. Application of multiple stereotactic design iterations led to an accurately reproducible surgical laser ablation procedure. Histological staining confirmed precise thermal ablation and controllable lesion size based on time and temperature control. Treatment of a syngeneic intracranial glioma model highly resistant to conventional therapy resulted in a modest survival benefit. The authors have successfully developed a murine model system of LITT with direct in situ thermometry for investigation into the effects of thermal ablation and combinatorial treatments in murine brain tumor models.

Treatment efficacy prediction of focused ultrasound therapies using multi-parametric magnetic resonance imaging.

Magnetic resonance guided focused ultrasound (MRgFUS) is one of the most attractive emerging minimally invasive procedures for breast cancer, which induces localized hyperthermia, resulting in tumor cell death. Accurately assessing the post-ablation viability of all treated tumor tissue and surrounding margins immediately after MRgFUS thermal therapy residual tumor tissue is essential for evaluating treatment efficacy. While both thermal and vascular MRI-derived biomarkers are currently used to assess treatment efficacy, currently, no adequately accurate methods exist for the in vivo determination of tissue viability during treatment. The non-perfused volume (NPV) acquired three or more days following MRgFUS thermal ablation treatment is most correlated with the gold standard of histology. However, its delayed timing impedes real-time guidance for the treating clinician during the procedure. We present a robust deep-learning framework that leverages multiparametric MR imaging acquired during treatment to predict treatment efficacy. The network uses qualtitative T1, T2 weighted images and MR temperature image derived metrics to predict the three day post-ablation NPV. To validate the proposed approach, an ablation study was conducted on a dataset (N=6) of VX2 tumor model rabbits that had undergone MRgFUS ablation. Using a deep learning framework, we evaluated which of the acquired MRI inputs were most predictive of treatment efficacy as compared to the expert radiologist annotated 3 day post-treatment images.

Safety and effectiveness of balloon catheter-assisted ultrasound-guided percutaneous microwave ablation in difficult-site liver cancer

BackgroundBalloon catheter isolation is a promising auxiliary method for thermal ablation treatment of liver cancer. We aimed to explore the safety and effectiveness of balloon catheter isolation-assisted ultrasound-guided percutaneous microwave ablation (MWA) in treating liver cancer in difficult anatomical locations. MethodsData of 132 patients with 145 difficult-site liver cancer treated with ultrasound-guided percutaneous MWA were retrospectively analyzed. Participants were classified into the isolation (n = 40) and non-isolation (n = 92) groups based on whether the patients were treated using a balloon catheter prior to ablation. The major complication rates, local tumor residuals (LTR), and tumor follow-up for local tumor progression (LTP) at 6 and 12 months post-ablation were compared between the two groups. ResultsThe rates of major postoperative complications did not significantly differ between the isolation and non-isolation groups (2.5% vs. 4.3%, P = 0.609). The postoperative LTR rates were significantly different between the isolation and non-isolation groups (4.8% vs. 17.5%, P = 0.032). Balloon catheter isolation [odds ratio (OR) = 0.225, 95% confidence interval (CI): 0.085–0.595, P = 0.009] and tumor diameter (OR = 2.808, 95% CI: 1.186–6.647, P = 0.019) were identified as independent factors influencing LTR rate. The cumulative LTP rates at 6 and 12 months after ablation showed no significant differences between the isolation and non-isolation groups (2.6% vs. 7.9%, P = 0.661; 4.9% vs. 9.8%, P = 0.676, respectively). Cox proportional hazards regression analysis showed that tumor diameter was an independent risk factor for cumulative LTP rate (OR = 3.445, 95% CI: 1.406–8.437, P = 0.017). ConclusionsBalloon catheter isolation-assisted MWA was safe and effective in the treatment of difficult-site liver cancer. Additionally, tumor diameter significantly influenced LTR and LTP rates after ablation.

Thermoablation Using Radiofrequency and Microwaves of Autonomous Thyroid Nodules: Our Experience

Significant results have been achieved using ultrasound-guided and ultrasound-assisted ablative techniques, such as Laser Thermal Ablation (LTA), Radiofrequency Ablation (RFA), High-Intensity Focused Ultrasound (HIFU), and Microwave Ablation (MWA). These techniques are ideally suited for the treatment of normally functioning benign thyroid nodes with local compressive symptoms or aesthetic problems. These treatments have been applied to hyperfunctioning “hot” nodes. LTA and RFA are the most commonly used. From January 2021 to July 2023 at our Center, a total of 160 patients with benign thyroid nodules were treated, of which 35 had autonomous nodules [1-4]. Our analysis focused on evaluating the locoregional treatment of the latter. Based on the volume and ultrasound-vascular characteristics, patients were selected for thermoablative treatment with either RFA or MWA (Amica Gen HS - Hospital Service) starting in July 2022. No complications were documented. However, one patient was referred for surgery and 1 patient was re-treated with MWA. In the light of personal experience ultrasound-guided thermal ablation treatment with RFA in patients with a single pretoxic or toxic thyroid nodule with or without associated compressive or aesthetic symptoms has proven to be very effective and satisfactory. The treatment must be preceded by adequate information regarding the advantages and disadvantages of the various procedures and the methods of the treatment session. MWA proved to be more effective than RFA with no functional recovery of the treated nodules even if they were relatively larger in size. We obtained the suspension of thyrostatic therapy with normalization of the TSH level in the third month after treatment.

Locoregional interventional therapy for hepatocellular carcinoma: radiologic and clinical factors predictive of untreatable progression and time to untreatable progression.

In this retrospective cohort study, independent risk factors that influence untreatable progression (UP) and time to UP (TTUP) in patients with hepatocellular carcinoma (HCC) after locoregional interventional therapy were examined. The effects of initial response and best response on UP occurrence and TTUP after locoregional interventional therapy were evaluated. Data were collected from HCC patients who were initially treated with the drug-eluting beads-transcatheter arterial chemoembolization (DEB-TACE) procedure at our hospital from January 2017 to December 2022. Modified response evaluation criteria in solid tumors (m-RECIST) was used to evaluate the radiologic response of tumors. Logistic regression analysis was used to analyze the risk factors for UP in patients, and Cox regression analysis was used to discover independent variables that influenced TTUP. A total of 93 patients who initially underwent the DEB-TACE procedure were included. Subsequent to initial treatment, 50 patients continued with DEB-TACE treatment, while 43 received DEB-TACE and sequential thermal ablation treatment. The probability of developing UP was 82.8% (n = 77). Furthermore, 49 (52.7%) patients achieved an initial response, and 70 (75.3%) achieved the best response. Multivariate logistic regression analysis confirmed three independent risk factors of UP, namely, age (odds ratio [OR]: 0.950, p = 0.044); initial response (OR: 0.177, p = 0.020); and treatment regimen (OR: 7.133, p = 0.007). Multivariate Cox regression found that total bilirubin (hazard ratio [HR]: 1.029, p = 0.002), tumor distribution (HR: 1.752, p = 0.034), Subjective Angiographic Chemoembolization Endpoint (SACE) classification (HR: 0.668, p = 0.043), number of tumors (HR: 1.130, p = 0.004), initial response (HR: 0.539, p = 0.019), and treatment regimen (HR: 4.615, p < 0.001) were independent variables that influenced TTUP. Age, initial response, and treatment regimen significantly affected the occurrence of UP in HCC patients. Initial response, SACE classification, treatment regimen, total bilirubin, number of tumors, and tumor distribution were significantly correlated with TTUP. The initial response following locoregional interventional therapy had greater effects on UP occurrence and TTUP than the best response.

Role of Thermal Ablation in Management of Pulmonary Tumours

Abstract Background An effective alternate option for treating primary and metastatic lung cancers that cannot be operated on is image-guided percutaneous thermal ablation. These methods rely on the heating impact of a percutaneous applicator on surrounding tissue to cause coagulative necrosis of the tumor cells. Aims The current study is to assess the role of CT guided thermal ablation in management of lung tumors. Methods Based on radiological and pathological evaluation, our study involved 40 patients who had CT-guided thermal ablation ("MWA &amp; RFA") treatments at Ain Shams University Hospitals and Misr Radiology Center from February 2020 to February 2022.for 1ry and 2ry lung neoplasms. After thermal ablation there is follow up program at 3, 6 &amp; 12 months post ablation. Results Various lung cancers, including primary and secondary metastatic lung deposits, were prospectively treated using CT-guided RF and MW. In our study, there were 64 lung lesions. 38 lesions were ablated in 25 individuals with MWA with overall success about 84.2%, 26 lesions were ablated in 15 individuals with RFA with overall success about 84.6%, there was no statistical significant differences between MW and RF regarding outcome. Regarding complications there was no intraprocedural death and the overall mortality 60 days post ablation was 0%. No major complication encountered during the procedure. All complications were non significantly more common in the MWA group. The MWA group had much larger lesions and more lesions were hilar or para-hilar in comparison to the RFA group. Conclusion Percutaneous thermal ablation is a safe and effective minimally invasive treatment alternative is selected patients.

The Effectiveness of Radiofrequency Thermal Ablation in the Treatment of Patients with Osteoid Osteomas of the Spine

Osteoid osteoma is a rare benign osteogenic bone tumor without malignant potential causing severe night pain relieved by nonsteroidal anti-inflammatory drugs. Pain associated with osteoid osteoma of the spine cannot be treated conservatively and requires surgical approach. Types of surgical treatment include intralesional curettage, marginal resection, or en bloc tumor resection. However, absence of clear intraoperative visualization of the lesion often leads to excessive resection of vertebral structures requiring additional bone reconstruction and fixation with metal structures. In some cases, due to incorrect choice of resection area and segment level, repeat surgeries are performed causing secondary spinal deformations, worsening patient’s condition, and increasing economic expenditures. Currently, minimally invasive methods of transcutaneous treatment of osteoid osteomas such as interstitial laser ablation, cryotherapy, and radiofrequency thermal ablation are becoming more prominent.Aim. To evaluate the effectiveness of radiofrequency thermal ablation treatment in patients with osteoid osteoma.Materials and methods. The prospective study included 12 patients with osteoid osteoma of the spine. Their quality of life was evaluated using the Short Form-36 (SF-36) questionnaire prior to radiofrequency thermal ablation and 30, 90 and 180 days after. At the first visit and during observation, pain syndrome intensity was measured using the Visual Analog Scale (VAS) and R.G. Watkins scale for objective evaluation of pain syndrome per number of analgesics administrations.Results. Follow-up duration varied between 12 and 36 months. In all clinical cases, general, physical, and psychological health improved 2–3-fold. Pain intensity at day 1 after radiofrequency thermal ablation compared to mean pain intensity during the day prior to the procedure was significantly lower (р = 0.05). At the final examination, none of the patients had pain (pain syndrome intensity 0 per VAS); all patients had subjective satisfaction level of 100 %. Analgesics (nonsteroidal anti-inflammatory drugs and paracetamol) were administered on request for 8 ± 2.34 days after the procedure.Conclusion. Based on literature data and our own experience of diagnosis and surgical treatment of osteoid osteoma of the spine, we conclude that in cases of small lesions (&lt;2 cm) in hard to access locations, computed tomography-controlled radiofrequency thermal ablation allows to perform surgical intervention safely, effectively and with minimal number of complications.

Characterizing Metabolic Heterogeneity of Hepatocellular Carcinoma with Hyperpolarized 13C Pyruvate MRI and Mass Spectrometry.

Purpose To characterize the metabolomic profiles of two hepatocellular carcinoma (HCC) rat models, track evolution of these profiles to a stimulated tumor state, and assess their effect on lactate flux with hyperpolarized (HP) carbon 13 (13C) MRI. Materials and Methods Forty-three female adult Fischer rats were implanted with N1S1 or McA-RH7777 HCC tumors. In vivo lactate-to-pyruvate ratio (LPR) was measured with HP 13C MRI at 9.4 T. Ex vivo mass spectrometry was used to measure intratumoral metabolites, and Ki67 labeling was used to quantify proliferation. Tumors were first compared with three normal liver controls. The tumors were then compared with stimulated variants via off-target hepatic thermal ablation treatment. All comparisons were made using the Mann-Whitney test. Results HP 13C pyruvate MRI showed greater LPR in N1S1 tumors compared with normal liver (mean [SD], 0.564 ± 0.194 vs 0.311 ± 0.057; P < .001 [n = 9]), but not for McA-RH7777 (P = .44 [n = 8]). Mass spectrometry confirmed that the glycolysis pathway was increased in N1S1 tumors and decreased in McA-RH7777 tumors. The pentose phosphate pathway was also decreased only in McA-RH7777 tumors. Increased proliferation in stimulated N1S1 tumors corresponded to a net increase in LPR (six stimulated vs six nonstimulated, 0.269 ± 0.148 vs 0.027 ± 0.08; P = .009), but not in McA-RH7777 (eight stimulated vs six nonstimulated, P = .13), despite increased proliferation and metastases. Mass spectrometry demonstrated relatively increased lactate production with stimulation in N1S1 tumors only. Conclusion Two HCC subtypes showed divergent glycolytic dependency at baseline and during transformation to a high proliferation state. This metabolic heterogeneity in HCC should be considered with use of HP 13C MRI for diagnosis and tracking. Keywords: Molecular Imaging-Probe Development, Liver, Abdomen/GI, Oncology, Hepatocellular Carcinoma © RSNA, 2024 See also commentary by Ohliger in this issue.

Spatiotemporal modeling of nano-delivered chemotherapeutics for synergistic microwave ablation cancer therapy

Background and objectiveThe effectiveness of current microwave ablation (MWA) therapies is limited. Administration of thermosensitive liposomes (TSLs) which release drugs in response to heat has presented a significant potential for enhancing the efficacy of thermal ablation treatment, and the benefits of targeted drug delivery. However, a complete knowledge of the mechanobiological processes underlying the drug release process, especially the intravascular drug release mechanism and its distribution in response to MWA needs to be improved. Multiscale computational-based modeling frameworks, integrating different biophysical phenomena, have recently emerged as promising tools to decipher the mechanobiological events in combo therapies. The present study aims to develop a novel multiscale computational model of TSLs delivery following MWA implantation. MethodsDue to the complex interplay between the heating procedure and the drug concentration maps, a computational model is developed to determine the intravascular release of doxorubicin from TSL, its transvascular transport into the interstitium, transport in the interstitium, and cell uptake. Computational models can estimate the interplays among liposome and drug properties, tumor perfusion, and heating regimen to examine the impact of essential parameters and to optimize a targeted drug delivery platform. ResultsResults indicated that the synergy of TSLs with MWA allows more localized drug delivery with lower side effects. The drug release rate and tumor permeability play crucial roles in the efficacy of TSLs during MWA treatment. The computational model predicted an unencapsulated drug lime around the ablated zone, which can destroy more cancer cells compared to MWA alone by 40%. Administration of TSLs with a high release rate capacity can improve the percentage of killed cancer cells by 24%. Since the heating duration in MWA is less than 15 min, the presented combination therapy showed better performance for highly permeable tumors. ConclusionThis study highlights the potential of the proposed computational framework to address complex and realistic scenarios in cancer treatment, which can serve as the future research foundation, including advancements in nanomedicine and optimizing the pair of TSL and MWA for both preclinical and clinical studies. The present model could be as a valuable tool for patient-specific calibration of essential parameters.

Experiences of women participating in a human papillomavirus-based screen-triage-and treat strategy for cervical cancer prevention in Malawi.

To explore the experiences of Malawian women who underwent a human papillomavirus (HPV)-based screen-triage-treat algorithm for cervical cancer (CxCa) prevention. This algorithm included GeneXpert® HPV testing of self-collected vaginal samples, visual inspection with acetic acid (VIA) and colposcopy for HPV-positive women, and thermal ablation of ablation-eligible women. In-depth interviews were conducted with participants of a trial that evaluated the feasibility of a HPV-based screen-triage-treat algorithm among women living with HIV and HIV negative women in Lilongwe, Malawi. Participants were recruited from 3 groups: 1) HPV-negative; 2) HPV-positive/VIA-negative; 3) HPV-positive/VIA-positive and received thermal ablation. Interviews explored baseline knowledge of CxCa and screening, attitudes towards self-collection, and understanding of test results. Content analysis was conducted using NVIVO v12. Thematic saturation was reached at 25 interviews. Advantages of HPV self-collection to participants were convenience of sampling, same-day HPV results and availability of same-day treatment. There was confusion surrounding HPV-positive/VIA-negative results, as some participants still felt treatment was needed. Counseling, and in particular anticipatory guidance, was key in helping participants understand complex screening procedures and results. Overall, participants expressed confidence in the HPV screen-triage-treat strategy. HPV testing through self-collected samples is a promising tool to increase CxCa screening coverage. A multi-step screening algorithm utilizing HPV self-testing, VIA triage and thermal ablation treatment requires proper counseling and anticipatory guidance to improve patient understanding. Incorporating thorough counseling in CxCa screening programs can change women's perspectives about screening, build trust in healthcare systems, and influence healthcare seeking behavior towards routine screening and prevention.

Novel nanoparticle CS-C60-Fe3O4 magnetically induces tissue-specific aggregation and enhances thermal ablation of hepatocellular carcinoma

Metallofullerenes are an important type of metallic nanomaterial with promising applications in several medical fields. Thermal ablation, including radiofrequency ablation (RFA) and microwave ablation (MWA), is an important treatment strategy for advanced hepatocellular carcinoma (HCC). The thermal expansion of fullerenes makes them good adjuncts to thermal ablation treatment of HCC. In this study, we used an innovative method of emulsification and cross-linking to produce CS-C60-Fe3O4 (Chitosan-C60-Fe3O4) nanoparticles, which have the advantages of uniform particle size and high bioavailability, as a kind of novel nano-pharmaceutical. The CS-C60-Fe3O4 nanoparticles were prepared by the cross-linking reaction from chitosan–acetic acid solution, Fe3O4 nanoparticles by Fe2SO4·7H2O and FeCl3·6H2O, and C60. The average particle size of CS-C60-Fe3O4 was 194.3 nm. Because CS-C60-Fe3O4 is magnetic, it can achieve specific and tissue aggregation in HCC tumor tissues. Moreover, compared with normal soluble C60 (EL35-C60), CS-C60-Fe3O4 prolonged the retention time of C60 in the blood of mice. CS-C60-Fe3O4 alone is not cytotoxic to cultured cells or tumor tissues, but when combined with thermal ablation strategies (RFA and MWA), it significantly upregulates the antitumor effects of thermal ablation on HCC tissues, that is, it acts as a sensitiser to thermal ablation. In the presence of thermal ablation, CS-C60-Fe3O4 interfered with iron metabolism in HCC cells and induced ferroptosis of HCC cells in the tumor tissues. These results not only expand our understanding of metallofullerenes but also provide additional options for the treatment of advanced HCC.

Novel indocyanine green-loaded photothermal nanoparticles targeting TRPV1 for thermal ablation treatment of severe murine asthma induced by ovalbumin and lipopolysaccharide

To identify a replacement strategy for bronchial thermoplasty (BT) with non-invasive and free-of-severe side effect is urgently needed in the clinic for severe asthma treatment. In this study, PLGA-PEG@ICG@TRPV1 pAb (PIT) photothermal nanoparticles targeting bronchial TRPV1 were designed for photothermal therapy (PTT) against severe murine asthma induced by ovalbumin and lipopolysaccharide. PIT was formulated with a polyethylene glycol (PEG)-grafted poly (lactic-co-glycolic) acid (PLGA) coating as a skeleton structure to encapsulate indocyanine green (ICG) and was conjugated to the polyclonal antibody against transient receptor potential vanilloid 1 (TRPV1 pAb). The results revealed that PIT held good druggability due to its electronegativity and small diameter. PIT demonstrated great photothermal effects both in vivo and in vitro and exhibited good ability to target TRPV1 in vitro because of its selective cell uptake and specific cell toxicity toward TRPV1-overexpressing cells. The PIT treatment effectively reduced asthma symptoms in mice. This is evident from improvements in expiratory airflow limitation, significant decreases in inflammatory cell infiltration in the airways, and increases in goblet cell and columnar epithelial cell proliferation. In conclusion, PIT alleviates severe murine asthma symptoms through a combination of TRPV1 targeting and photothermal effects.

Pulsed-field ablation versus standard thermal ablation in treatment of paroxysmal atrial fibrillation: a systematic review and meta-analysis

Pulsed field ablation (PFA) is a novel modality for atrial fibrillation (AF). This analysis compared the safety and efficacy of PFA vs. Standard thermal ablation (STA) in subjects with paroxysmal AF. A comprehensive exploration of electronic databases was adopted to identify trials in English, of human studies, from inception to 10th October 2024, and compared PFA to STA for paroxysmal AF. Pooled analyses were performed to assess treatment success, AF recurrence, adverse events, procedural time, and other secondary outcomes. Three studies (n = 1733) were included in the analysis. PFA demonstrated a significantly higher success rate than STA (OR = 1.29, 95% CI = [1.05-1.58], p = 0.02). There was no potential difference in AF recurrence, procedural time, or secondary outcomes. Pericardial complications and vascular access consequences were more common in the PFA subjects. PFA is an alternative to STA for paroxysmal AF treatment, offering a higher initial success rate and comparable long-term efficacy. However, the increased risk of pericardial complications and vascular access complications should be carefully considered. Further research is required to support such outcomes and to better understand the long-term outcomes of PFA.

Configuring thermal ablation volumes for treatment of distinct tumor shapes: a repeatability study using a robotic approach.

In the current clinical practice of thermal ablation treatment for liver tumors, achieving consistent and effective clinical outcomes across tumors of varying shapes, sizes and locations remains challenging. The aim of this study was to evaluate the repeatability of a novel robotic approach for configurable ablation of distinct tumor shapes and compare it to the standard ablation technique for creating ellipsoidal ablation volumes. The repeatability was evaluated in terms of width variability in created ablation volumes. Using a robotic navigation platform, custom ablation profiles configured with power, time, and distance parameters were designed to create four distinct ablation shapes. The profiles were applied for microwave ablation in a tissue-mimicking liver model. For comparison of ablation shape variability, six standard ellipsoidal shapes were created using the standard ablation technique by configuring power and time parameters. For each sample, the resulting ablation area was segmented, and the resulting shape width and length were calculated at the measurement points. Width variability was calculated as the median of the absolute pairwise differences in width at each measurement point, and configurable versus standard ablation shapes were compared using the Mann-Whitney U test. All tissue-mimicking samples were successfully ablated using both configurable (n = 48) and standard ablation technique (n = 35). Study findings revealed noninferiority regarding repeatability of created ablation shapes using the robotic platform for configurable ablation, compared to created standard ellipsoidal ablation shapes (p < 0.001, 95% CI ≤ -0.05mm, Δ = -0.22mm). Median repeatability of created configurable shapes was 1.00mm, and for standard shapes 1.22mm. Maximal repeatability for both groups was below 3mm. The repeatability of configurable ablation shapes was observed to be noninferior to the standard ablation shapes. Achieving configurable ablation volumes underscores the potential to advance personalization of thermal ablation treatment and broaden its applicability to distinct tumor cases. In-vivo validation is needed for evaluation of the clinical implications of this novel treatment technique.

Thermal ablation of hepatocellular carcinoma.

Percutaneous treatment of hepatocellular carcinoma (HCC) by means of thermal ablation (TA) has been introduced in clinical guidelines as a potentially curative treatment for the early stages of the disease since the early 2000s. Due to its safety profile and cost-effectiveness, TA can be offered as a first-line treatment for patients with HCC smaller than 3 cm. Thermal ablative techniques are in fact widely available at many centres worldwide and include radiofrequency (RF) and microwave (MW) ablation, with the latter increasingly applied in clinical practice in the last decade. Pre-clinical studies highlighted, as potential advantages of MW-based ablation, the ability to achieve higher temperatures (>100°C) and larger ablation zones in shorter times, with less susceptibility to blood flow-induced heat sink effects. Despite these advantages, there is no evidence of superior overall survival in patients treated with MW as compared to those treated with RF ablation. Local control has been proven to be superior to MW ablation with a similar complication rate. It is expected that further improvement of TA results in the treatment of HCC will result from the refinement of guidance and monitoring tools and the careful assessment of ablation margins. Thermal ablative treatments may also be performed on nodules larger than 3 cm by applying multiple devices or combining percutaneous and intra-arterial approaches. The role of novel immunotherapy regimens in combination with ablation is also currently under evaluation in clinical trials, with several potential benefits. In this review, indications, technical principles, results, and future prospects of TA for the treatment of HCC will be examined.

Full thermal ablation versus partial thermal ablation for secondary hyperparathyroidism: A meta-analysis.

Regarding the thermal ablation treatment of refractory secondary hyperparathyroidism (SHPT), there is no consensus on the ablation range of the hyperplastic parathyroid gland. Therefore, this meta-analysis was conducted to evaluate the efficacy and complications between full and partial thermal ablation in patients with refractory SHPT. Databases including PubMed, EMbase, the Cochrane Library, CNKI (China National Knowledge Infrastructure), and Wanfang databases were searched from inception to July 1, 2023. Eligible studies comparing full thermal ablation and partial thermal ablation for SHPT were included. Data were analyzed using Review Manager Version 5.3. Four studies were included in the meta-analysis. Three cohort studies and one randomized controlled trial involving 62 patients in the full thermal ablation group and 63 patients in the partial thermal ablation group were included. The serum parathyroid hormone (PTH), calcium, and phosphorus levels after full ablation were all lower than those after partial ablation (P < .05). There was no significant difference between the partial and full ablation groups concerning the incidence rate of severe hypocalcemia (P = .09). There was no significant difference between the partial and full ablation groups concerning symptom improvement, including bone joint pain, itching, and myasthenia (P < .05). Full ablation was superior to partial ablation in terms of reducing PTH, calcium and phosphorus levels. Full ablation might not significantly increase the incidence of severe hypocalcemia. Larger multicentre randomized controlled trials are necessary to confirm the conclusion.

Retracted: Meta-Analysis of the Application Effect of Different Modalities of Thermal Ablation and Surgical Treatment in Papillary Thyroid Microcarcinoma

Retracted: Meta-Analysis of the Application Effect of Different Modalities of Thermal Ablation and Surgical Treatment in Papillary Thyroid Microcarcinoma

New Surgical Approach to Treat Fibroids and Solid Tumors - Thermal and Nonthermal Ablation.

There is a trend toward more minimally invasive treatment for symptomatic uterine fibroids. They are image-guided ablation surgery with focused ultrasound, microwave, and radiofrequency ablations that are becoming tested and used in some medical centers or hospitals. Nevertheless, these image-guided ablation surgeries involve thermal ablation to the fibroids, which might lead to thermal injury to the surrounding tissues, for example, nerve injury, vessel injury, and skin burn due to heat diffusion. A new technology - irreversible electroporation (IRE) - is a new paradigm for treating solid tumors. This nonthermal ablation process does not induce high temperatures when treating cancers or solid tumors. The IRE treatment may soon be used for treating fibroids or other solid tumors. In a few clinical trials, IRE is currently used in experimental studies for treating gynecological cancers. This paper will present the minimally invasive thermal ablation treatments for fibroids, introduce this new nonthermal IRE ablation in treating gynecological cancer, and propose its future uses in uterine fibroids.

3D modeling of vector/edge finite element method for multi-ablation technique for large tumor-computational approach.

Microwave ablation (MWA) is a cancer thermal ablation treatment that uses electromagnetic waves to generate heat within the tissue. The goal of this treatment is to eliminate tumor cells while leaving healthy cells unharmed. During MWA, excess heat generation can kill healthy cells. Hence, mathematical models and numerical techniques are required to analyze the heat distribution in the tissue before the treatment. The aim of this research is to explain the implementation of the 3D vector finite element method in a wave propagation model that simulates the specific absorption rate in the liver. The 3D Nedelec elements from H(curl; Ω) space are used to discretize the wave propagation model, and this implementation is helpful in solving many real-world problems that involve electromagnetic propagation with perfect conducting and absorbing boundary conditions. One of the difficulties in ablation treatment is creating a large ablation zone for a large tumor (diameter greater than 3 cm) in a short period of time with minimum damage to the surrounding tissue. This article addresses the aforementioned issue by introducing four antennas into the different places of the tumor sequentially and producing heat uniformly over the tumor. The results demonstrated that 95.5% of the tumor cells were killed with minimal damage to the healthy cells when the heating time was increased to 4 minutes at each position. Subsequently, we studied the temperature distribution and localised tissue contraction in the tissue using the three-dimensional bio-heat equation and temperature-time dependent model, respectively. The local tissue contraction is measured at arbitrary points in the domain and is more noticeable at temperatures higher than 102°C. The thermal damage in the liver during MWA treatment is investigated using the three-state cell death model. The system of partial differential equations is solved numerically due to the complex geometry of the domain, and the results are compared with experimental data to validate the models and parameters.