Advanced CT techniques for hepatic microwave ablation zone monitoring and follow-up

2021 ◽  
Author(s):  
Meghan G. Lubner ◽  
Timothy J. Ziemlewicz ◽  
Shane A. Wells ◽  
Ke Li ◽  
Po-Hung Wu ◽  
...  
Keyword(s):  
Microwave Ablation ◽  
Ablation Zone

scholarly journals Ablation Zone Involution of Liver Tumors Is Faster in Patients Treated with Irreversible Electroporation Than Microwave Ablation

Medicina ◽  
2021 ◽  
Vol 57 (9) ◽  
pp. 877
Author(s):  
Fourat Ridouani ◽  
Mario Ghosn ◽  
Francois Cornelis ◽  
Elena N Petre ◽  
Meier Hsu ◽  
...  
Keyword(s):  
Microwave Ablation ◽  
Total Bilirubin ◽  
Liver Enzymes ◽  
Liver Tumors ◽  
Irreversible Electroporation ◽  
Ratio Test ◽  
Ablation Zone ◽  
Time Interaction ◽  
Over Time

Background and Objectives: To compare ablation zone involution following microwave ablation (MWA) or irreversible electroporation (IRE) of liver tumors. Materials and Methods: MWA or IRE performed for colorectal cancer liver metastasis (CRLM) or hepatocellular carcinoma (HCC) during January 2011 to December 2015 were analyzed. Patients with a tumoral response on 1-year follow-up computed tomography (CT) were included. Generalized estimating equations were used to evaluate the differences between the two modalities on ablation zone involution observed on CT at 6 (M6) and 12 months (M12), and on laboratory values (total bilirubin, alanine transaminase, aspartate transaminase, alkaline phosphatase, albumin, and platelets count). The likelihood ratio test was used to assess whether the association between ablation modalities and these outcomes differed over time. Results: Seventeen (17/44, 39%) women and 27 (27/44, 61%) men were included, with 25 HCC (25/44, 57%) and 19 CRLM (19/44, 43%) patients. IRE was used in 9 (9/19, 47%) CRLM and 5 (5/25, 20%) HCC patients, respectively. All other patients had MWA. Ablation zone size and involution between IRE and MWA differed significantly over time (interaction p < 0.01), with a mean of 241.04 vs. 771.08 mm2 (ratio 0.313; 95% CI, 0.165–0.592; p < 0.01) at M6 and 60.47 vs. 589.43 mm2 (ratio 0.103; 95% CI, 0.029–0.365; p < 0.01) at M12. Changes in liver enzymes did not differ significantly between IRE and MWA at both timepoints. Conclusions: Liver tumors treated with IRE underwent faster involution when compared to tumors treated with MWA, but liver enzymes levels were comparable.

scholarly journals Finite Element Analysis of the Microwave Ablation Method for Enhanced Lung Cancer Treatment

Cancers ◽  
2021 ◽  
Vol 13 (14) ◽  
pp. 3500
Author(s):  
Marija Radmilović-Radjenović ◽  
Martin Sabo ◽  
Marta Prnova ◽  
Lukaš Šoltes ◽  
Branislav Radjenović
Keyword(s):  
Dielectric Properties ◽  
Cancer Cells ◽  
Microwave Ablation ◽  
Absorption Rate ◽  
Specific Absorption Rate ◽  
Surrounding Tissue ◽  
Physical Parameters ◽  
Medical Procedure ◽  
Ablation Zone ◽  
Specific Absorption

Knowledge of the frequency dependence of the dielectric properties of the lung tissues and temperature profiles are essential characteristics associated with the effective performance of microwave ablation. In microwave ablation, the electromagnetic wave propagates into the biological tissue, resulting in energy absorption and providing the destruction of cancer cells without damaging the healthy tissue. As a consequence of the respiratory movement of the lungs, however, the accurate prediction of the microwave ablation zone has become an exceptionally demanding task. For that purpose, numerical modeling remains a primordial tool for carrying out a parametric study, evaluating the importance of the inherent phenomena, and leading to better optimization of the medical procedure. This paper reports on simulation studies on the effect of the breathing process on power dissipation, temperature distribution, the fraction of damage, and the specific absorption rate during microwave ablation. The simulation results obtained from the relative permittivity and conductivity for inflated and deflated lungs are compared with those obtained regardless of respiration. It is shown that differences in the dielectric properties of inflated and deflated lungs significantly affect the time evolution of the temperature and its maximum value, the time, the fraction of damage, and the specific absorption rate. The fraction of damage determined from the degree of tissue injury reveals that the microwave ablation zone is significantly larger under dynamic physical parameters. At the end of expiration, the ablation lesion area is more concentrated around the tip and slot of the antenna, and the backward heating effect is smaller. The diffuse increase in temperature should reach a certain level to destroy cancer cells without damaging the surrounding tissue. The obtained results can be used as a guideline for determining the optimal conditions to improve the overall success of microwave ablation.

Microwave ablation of benign thyroid nodules: 3‐year follow‐up outcomes

Head & Neck ◽  
2021 ◽  
Author(s):  
Fangqiong Luo ◽  
Lei Huang ◽  
Xiuqun Gong ◽  
Zhiyu Han ◽  
Fangyi Liu ◽  
...  
Keyword(s):  
Microwave Ablation ◽  
Thyroid Nodules ◽  
Benign Thyroid Nodules ◽  
Benign Thyroid

scholarly journals Clinical Application of CT-Guided Percutaneous Microwave Ablation for the Treatment of Lung Metastasis from Colorectal Cancer

2017 ◽  
Vol 2017 ◽  
pp. 1-9
Author(s):  
Lin Li ◽  
Ketong Wu ◽  
Haiyang Lai ◽  
Bo Zhang
Keyword(s):  
Colorectal Cancer ◽  
Lung Metastasis ◽  
Microwave Ablation ◽  
Progression Free Survival ◽  
Ct Guided ◽  
Metastatic Lesions ◽  
Local Progression ◽  
Invasive Method ◽  
Percutaneous Microwave Ablation

Objective. The aim of our research is to explore the clinical efficacy and safety of CT-guided percutaneous microwave ablation (MWA) for the treatment of lung metastasis from colorectal cancer. Materials and Methods. CT-guided percutaneous MWA was performed in 22 patients (male 14, female 8, mean age: 56.05 ± 12.32 years) with a total of 36 lung metastatic lesions from colorectal cancer between February 2014 and May 2017. Clinical data were retrospectively analyzed with respect to the efficacy, safety, and outcome. Results. Of the 36 lesions, 34 lesions (94.4%) reduced obviously with small cavitations or fibrous stripes formed and had no evidence of recurrence during follow-up. The volume of the other 2 lesions demonstrated local progression after 6 months by follow-up CT. The primary complications included pneumothorax (28%), chest pain (21%), and fever (5%). These symptoms and signs were obviously relieved or disappeared after several-day conservative treatment. The mean follow-up of the patients was 25.54 ± 12.58 months (range 2–41 months). The estimated progression-free survival rate was 94.4%. Conclusion. Our results demonstrate that CT-guided percutaneous MWA appears to be an effective, reliable, and minimally invasive method for the treatment of lung metastasis from colorectal cancer. This trial is registered with ChiCTR-ORC-17012904.

Hepatic Microwave Ablation Zone Size: Correlation with Total Energy, Net Energy, and Manufacturer-Provided Chart Predictions

2016 ◽  
Vol 27 (9) ◽  
pp. 1389-1396 ◽  
Author(s):  
Paul B. Shyn ◽  
Jeffery R. Bird ◽  
R. Marie Koch ◽  
Servet Tatli ◽  
Vincent M. Levesque ◽  
...  
Keyword(s):  
Total Energy ◽  
Microwave Ablation ◽  
Net Energy ◽  
Ablation Zone ◽  
Zone Size

US-guided Microwave Ablation of Low-Risk Papillary Thyroid Microcarcinoma: Longer-Term Results of a Prospective Study

2020 ◽  
Vol 105 (6) ◽  
pp. 1791-1800 ◽  
Author(s):  
Wen-Wen Yue ◽  
Lu Qi ◽  
Dan-Dan Wang ◽  
Shou-Jun Yu ◽  
Xi-Ju Wang ◽  
...  
Keyword(s):  
Prospective Study ◽  
Distant Metastasis ◽  
Microwave Ablation ◽  
Large Population ◽  
Low Risk ◽  
Papillary Thyroid Microcarcinoma ◽  
Function Evaluation ◽  
Papillary Thyroid ◽  
Thyroid Microcarcinoma

Abstract Background Papillary thyroid microcarcinoma (PTMC) has become a main cause of the extremely high incidence of thyroid carcinoma. This study aimed to evaluate the longer-term effectiveness of ultrasound (US)-guided microwave ablation (MWA) for treatment of low-risk PTMC with a large population. Methods This prospective study was approved by ethics committee of our institution. MWA was performed under US-guidance for 119 unifocal PTMC patients without clinically cervical or distant metastasis. The target ablation zone exceeded the tumor edge judged by contrast-enhanced US to avoid marginal residue and recurrence. US and thyroid function evaluation were followed at 1, 3, 6, and 12 months after treatment and every 6 to 12 months thereafter. Any adverse event associated with MWA was evaluated. Results The follow-up duration after MWA was 37.2 ± 20.9 months (range 12-101 months). Tumor volume decreased significantly from 1.87 ± 1.03 mL immediately after MWA to 0.01 ± 0.04 mL at the final evaluation (P &lt; 0.001), with a mean volume reduction ratio of 99.4 ± 2.2% and 107 cases (93.9%) got complete remission. A patient was detected with cervical lymph node metastasis at 26-month follow-up and underwent 1 additional MWA treatment successfully. No distant metastasis was observed. All the acquired histological pathology results confirmed the absence of residual or recurrent tumor cells after MWA. No delayed complications associated with MWA were encountered for all patients. Conclusions Percutaneous MWA is technically feasible for complete PTMC destruction and showed well longer-term effectiveness; thus, it seems to be an effective nonsurgical therapy to complement the current recommendation for selected low-risk PTMC patients.

scholarly journals TDOA-based microwave imaging algorithm for real-time microwave ablation monitoring

2017 ◽  
Vol 10 (2) ◽  
pp. 169-178 ◽  
Author(s):  
Shouhei Kidera ◽  
Luz Maria Neira ◽  
Barry D. Van Veen ◽  
Susan C. Hagness
Keyword(s):  
Real Time ◽  
Microwave Ablation ◽  
Microwave Imaging ◽  
Ablation Zone ◽  
Real Time Monitoring ◽  
Imaging Algorithm ◽  
Array Measurements ◽  
Time Operation ◽  
Real Time Operation ◽  
Propagation Media

Microwave ablation is widely recognized as a promising minimally invasive tool for treating cancer. Real-time monitoring of the dimensions of the ablation zone is indispensable for ensuring an effective and safe treatment. In this paper, we propose a microwave imaging algorithm for monitoring the evolution of the ablation zone. Our proposed algorithm determines the boundary of the ablation zone by exploiting the time difference of arrival (TDOA) between signals received before and during the ablation at external antennas surrounding the tissue, using the interstitial ablation antenna as the transmitter. A significant advantage of this method is that it requires few assumptions about the dielectric properties of the propagation media. Also the simplicity of the signal processing, wherein the TDOA is determined from a cross-correlation calculation, allows real-time monitoring and provides robust performance in the presence of noise. We investigate the performance of this approach for the application of breast tumor ablation. We use simulated array measurements obtained from finite-difference time-domain simulations of magnetic resonance imaging-derived numerical breast phantoms. The results demonstrate that our proposed method offers the potential to achieve millimeter-order accuracy and real-time operation in estimating the boundary of the ablation zone in heterogeneous and dispersive breast tissue.

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