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Diagnostic and Interventional Radiology... Nov 2023To evaluate the efficacy of combination therapy using transarterial chemoembolization with microwave ablation (MWA) therapy vs. MWA monotherapy for hepatocellular... (Observational Study)
Observational Study
Combination transarterial chemoembolization and microwave ablation vs. microwave ablation monotherapy for hepatocellular carcinomas greater than 3 cm: a comparative study.
PURPOSE
To evaluate the efficacy of combination therapy using transarterial chemoembolization with microwave ablation (MWA) therapy vs. MWA monotherapy for hepatocellular carcinomas (HCCs) >3 cm in size.
METHODS
This two-arm retrospective observational study included patients with HCCs >3 cm who underwent either combination therapy (29 patients) or MWA monotherapy (35 patients) between 2014 and 2020. The treatment outcomes related to primary treatment efficacy, local tumor progression (LTP), tumor control rate, and overall survival were compared between each cohort.
RESULTS
The technical success and primary efficacy were 96.56% and 100.00% in the combination therapy cohort, and 91.42% and 100.00% in the MWA cohort, respectively, over a mean follow-up period of 27.6 months. The 1- and 3-year rates of LTP-free survival were 78.57% and 69.56% in the combination therapy cohort, vs. 72.45% and 35.44% in the MWA cohort, respectively ( = 0.001). The overall progression-free survival was longer in the combination therapy cohort compared with the MWA cohort (median: 56.0 vs. 13.0 months; = 0.017). With the incorporation of additional locoregional therapy, the overall survival rates were not significantly different, with 1- and 3-year overall survival rates of 100.00% and 88.71% in the combination therapy cohort and rates of 90.15% and 82.76% in the MWA cohort, respectively ( = 0.235).
CONCLUSION
The combination therapy provided significantly longer upfront LTP-free survival in HCCs >3 cm when compared with the MWA treatment alone, albeit with similar local tumor control and overall survival rates when accounting for additional locoregional therapies.
Topics: Humans; Carcinoma, Hepatocellular; Liver Neoplasms; Microwaves; Chemoembolization, Therapeutic; Radiofrequency Ablation; Treatment Outcome; Retrospective Studies; Catheter Ablation
PubMed: 37665139
DOI: 10.4274/dir.2023.232159 -
Journal of Magnetic Resonance Imaging :... Feb 2000We compared the findings of magnetic resonance (MR) images and pathological examination to determine whether or not MR images reflect pathological changes following...
We compared the findings of magnetic resonance (MR) images and pathological examination to determine whether or not MR images reflect pathological changes following microwave coagulation therapy (MCT) on liver tissue. We used microwave (generating frequency 2450 Mhz, wave length 12 cm, output 50 W, 60 second duration) to irradiate six canine livers under general anesthesia. After the animals were sacrificed, the livers were resected. The irradiated regions were cut with margins and divided into two pieces, one for MR study, and the other for pathological examination. The findings were compared. From the center to the marginal layer, the irradiated region presented 4/3 laminal patterns on T1/T2-weighted images: low/high, high/low, very high/high, and iso-low/high intensity. On gradient-echo imaging, the irradiated regions presented no decreasing signals using several echo time lengths. With hematoxylin and eosin stain, MR laminar patterns reflected the histopathological changes, as follows: a tissue loss area surrounding the inserted needle, low/high; decreased sinusoidal width with/without necrotic tissue, high/low; sinusoidal width dilation at the periphery, very high/high; and fatty degenerated tissue surrounding the irradiated area at the boundary of the normal hepatocytes, iso-low/high. The MR signal intensity, which reflected the histopathological changes, presented tissue characterization after MCT, and the macromolecular hydration effect influenced the high intensity on T1-weighted images.
Topics: Animals; Dogs; Electrocoagulation; Liver; Magnetic Resonance Imaging; Microwaves
PubMed: 10713950
DOI: 10.1002/(sici)1522-2586(200002)11:2<168::aid-jmri14>3.0.co;2-w -
Sensors (Basel, Switzerland) Aug 2022Due to the clinically proven benefit of hyperthermia treatments if added to standard cancer therapies for various tumor sites and the recent development of non-invasive...
Due to the clinically proven benefit of hyperthermia treatments if added to standard cancer therapies for various tumor sites and the recent development of non-invasive temperature measurements using magnetic resonance systems, the hyperthermia community is convinced that it is a time when even patients with brain tumors could benefit from regional microwave hyperthermia, even if they are the subject of a treatment to a vital organ. The purpose of this study was to numerically analyze the ability to achieve a therapeutically relevant constructive superposition of electromagnetic (EM) waves in the treatment of hyperthermia targets within the brain. We evaluated the effect of the target size and position, operating frequency, and the number of antenna elements forming the phased array applicator on the treatment quality. In total, 10 anatomically realistic 2D human head models were considered, in which 10 circular hyperthermia targets with diameters of 20, 25, and 30 mm were examined. Additionally, applicators with 8, 12, 16, and 24 antenna elements and operating frequencies of 434, 650, 915, and 1150 MHz, respectively, were analyzed. For all scenarios considered (4800 combinations), the EM field distributions of individual antenna elements were calculated and treatment planning was performed. Their quality was evaluated using parameters applied in clinical practice, i.e., target coverage (TC) and the target to hot-spot quotient (THQ). The 12-antenna phased array system operating at 434 MHz was the best candidate among all tested systems for HT treatments of glioblastoma tumors. The 12 antenna elements met all the requirements to cover the entire target area; an additional increase in the number of antenna elements did not have a significant effect on the treatment quality.
Topics: Brain Neoplasms; Glioblastoma; Humans; Hyperthermia, Induced; Magnetic Resonance Imaging; Microwaves
PubMed: 36015874
DOI: 10.3390/s22166115 -
Physics in Medicine and Biology Feb 2021Time-reversal (TR) is a known wideband array beam-forming technique that has been suggested as a treatment planning alternative in deep microwave hyperthermia for cancer...
Time-reversal (TR) is a known wideband array beam-forming technique that has been suggested as a treatment planning alternative in deep microwave hyperthermia for cancer treatment. While the aim in classic TR is to focus the energy at a specific point within the target, no assumptions are made on secondary lobes that might arise in the healthy tissues. These secondary lobes, together with tissue heterogeneity, may result in hot-spots (HSs), which are known to limit the efficiency of the thermal dose delivery to the tumor. This paper proposes a novel wideband TR focusing method that iteratively shifts the focus away from HSs and towards cold-spots from an initial TR solution, a procedure that improves tumor coverage and reduces HSs. We verify this method on two different applicator topologies and several target volume configurations. The algorithm is deterministic and runs within seconds, enabling its use for real-time applications. At the same time, it yields results comparable to those obtained with global stochastic optimizers such as Particle Swarm.
Topics: Algorithms; Humans; Hyperthermia, Induced; Microwaves; Neoplasms; Time Factors
PubMed: 33326945
DOI: 10.1088/1361-6560/abd41a -
Urologia Internationalis 1988Twenty-five patients with transitional cell carcinoma of the bladder have been treated with combined therapy consisting of microwave regional coagulation and...
Twenty-five patients with transitional cell carcinoma of the bladder have been treated with combined therapy consisting of microwave regional coagulation and intracavitary irradiation. A remote-controlled after-loading system was utilized for the radiation therapy. The follow-up period ranged from 6 to 19 months with an average of 11.4 months. Tumor stages were Tis (n = 2), Ta or T1 (n = 17), T2 (n = 2), T3 (n = 3) and T4 (n = 1), and grades were G1 (n = 10), G2 (n = 11) and G3 (n = 4). In 23 patients (92%), there was no endoscopic or histologic evidence of tumor after the initial treatment. Heterotopic recurrences were found after 2 or 3 months in 3 patients who received microwave regional coagulation or intracavitary regional irradiation. Additional intracavitary whole bladder mucosal irradiation was performed for 10 patients with multiple tumors and frequent recurrent tumors. Nine patients had no recurrence (average follow-up 11 months). Our preliminary findings indicate that combination therapy of microwave coagulation and intracavitary irradiation is a useful treatment for bladder cancer.
Topics: Brachytherapy; Carcinoma, Transitional Cell; Combined Modality Therapy; Follow-Up Studies; Humans; Microwaves; Neoplasm Invasiveness; Neoplasm Recurrence, Local; Urinary Bladder Neoplasms
PubMed: 3176200
DOI: 10.1159/000281330 -
International Journal of Hyperthermia :... Mar 2005Treatment of tumours greater than 2 cm by radiofrequency (RF) or microwave ablation typically use multiple sequential applications, since most currently available... (Comparative Study)
Comparative Study Review
Treatment of tumours greater than 2 cm by radiofrequency (RF) or microwave ablation typically use multiple sequential applications, since most currently available ablation devices are limited to use of a single applicator at a time. A major focus of current ablation research is on methodologies that allow increasing the coagulation zone to more rapidly treat large tumours. The ability to use multiple applicators simultaneously would satisfy this need. It would significantly reduce treatment time and may lead to a reduction in local tumour progression, especially in perivascular locations. Several methods have been suggested that potentially allow simultaneous use of multiple applicators, both with radiofrequency (RF) and microwave (MW) ablation. This review compares the different methods of multiple applicator use, investigating advantages and disadvantages of each modality.
Topics: Catheter Ablation; Humans; Microwaves; Neoplasms; Treatment Outcome
PubMed: 15764353
DOI: 10.1080/02656730412331286894 -
Current Drug Metabolism 2018Hyperthermia has been proposed as a promising treatment modality for its advantageous profiles such as mini/non-invasiveness, good tolerability and cost-effectiveness.... (Review)
Review
BACKGROUND
Hyperthermia has been proposed as a promising treatment modality for its advantageous profiles such as mini/non-invasiveness, good tolerability and cost-effectiveness. Quick development of nanotechnology in recent years has greatly broadened the application area of hyperthermia and endowed it with attractive new functions. This review aims to present an overview of different nanostructures mediated hyperthermia in terms of external stimuli source.
METHODS
We performed to review for the development and current status of nanostructure-mediated hyperthermia, by searching MEDLINE, EMBASE, and Cochrane Library database for identification of relevant articles.
RESULTS
In the present study, the systemic results of hyperthermia mediated by nanostructures were researched, and five different kinds of external sources were found and listed in this review. The brief mechanism and commonly explored nanostructures were introduced and then combined therapies of nanostructure-mediated hyperthermia stimulated by different external sources were investigated. Finally, challenges with current nanostructures mediated hyperthermia were discussed in order to give advice to the future development of nanostructure-mediated hyperthermia.
CONCLUSIONS
Despite all the achievements the new technology of nanostructure-mediated hyperthermia have made in pre-clinical animal experiments, there are still much to be pursued in the further development to be biocompatible, effective and precise.
Topics: Animals; Humans; Hyperthermia, Induced; Magnetic Phenomena; Microwaves; Nanostructures; Neoplasms
PubMed: 29380691
DOI: 10.2174/1389200219666180129141757 -
Critical Reviews in Biomedical... 2010Microwave ablation is an emerging treatment option for many cancers, cardiac arrhythmias, and other medical conditions. During treatment, microwaves are applied directly... (Review)
Review
Microwave ablation is an emerging treatment option for many cancers, cardiac arrhythmias, and other medical conditions. During treatment, microwaves are applied directly to tissues to produce rapid temperature elevations sufficient to produce immediate coagulative necrosis. The engineering design criteria for each application differ, with individual consideration for factors such as desired ablation zone size, treatment duration, and procedural invasiveness. Recent technological developments in applicator cooling, power control, and system optimization for specific applications promise to increase the utilization of microwave ablation in the future. This article reviews the basic biophysics of microwave tissue heating, provides an overview of the design and operation of current equipment, and outlines areas for future research.
Topics: Animals; Biotechnology; Electrocoagulation; Humans; Microwaves; Models, Biological
PubMed: 21175404
DOI: 10.1615/critrevbiomedeng.v38.i1.60 -
Annual International Conference of the... Nov 2021Cancer therapies are constantly evolving. Currently, heating tumor tissue is becoming more accessible as a stand-alone method or in combination with other therapies. Due...
Cancer therapies are constantly evolving. Currently, heating tumor tissue is becoming more accessible as a stand-alone method or in combination with other therapies. Due to its multiple advantages over other heating mechanisms, microwave hyperthermia has recently gained a lot of traction. In this work, we present a complementary split-ring resonator that is simultaneously excited in two independent frequency bands. With a high-power signal, the applicator is excited and heats the tissue-under-test up to 50°C with an average heating rate of 0.72°C per second. Furthermore, we present a dielectric temperature control system using the same applicator for microwave hyperthermia applications, which currently still requires an additional thermometry system. By exciting the applicator with a low-power signal, we can constantly monitor its resonant frequency. This resonant frequency depends on the tissue properties, which in turn are temperature-dependent. In the temperature range from 20-50°C, a positive correlation between the temperature and resonant frequency was established.Clinical relevance - Exploiting the dual-band behavior of the complementary split-ring resonator to heat the tissue-under-test while dielectrically monitoring its temperature, creates new possibilities towards a theranostic, non-invasive microwave hyperthermia applicator.
Topics: Hyperthermia, Induced; Microwaves; Precision Medicine; Temperature; Thermometry
PubMed: 34891527
DOI: 10.1109/EMBC46164.2021.9629592 -
Endocrine Nov 2018To evaluate the effectiveness and safety of microwave ablation (MWA), including cooled MWA (cMWA) and uncooled MWA (uMWA), for the treatment of benign thyroid nodules... (Meta-Analysis)
Meta-Analysis Review
PURPOSE
To evaluate the effectiveness and safety of microwave ablation (MWA), including cooled MWA (cMWA) and uncooled MWA (uMWA), for the treatment of benign thyroid nodules (BTNs).
METHODS
The databases of MEDLINE, EMBASE and Cochrane library were searched up to 3 Jun, 2018. In this meta-analysis, data of volume reduction rates (VRRs) at the 3-, 6- and 12-month follow-up, and complications are obtained to evaluate the effectiveness and safety of cMWA and uMWA for the treatment of BTNs.
RESULTS
Nine studies involving 1461 patients with 1845 BTNs were included. The pooled VRR at the 3-month follow-up after MWA therapy reached 54.3% (95% CI: 45.3-63.3%, I = 97.6%), 73.5% (95% CI: 66.7-80.3%, I = 94.9%) at the 6-month follow-up, and 88.6% (95% CI: 84.9-92.4%, I = 92.7%) at the 12-month follow-up. The pooled proportions of overall, major and minor complications were 52.4% (95% CI: 29.8-74.9%; I = 99.5%), 4.8% (95% CI: 2.7-7.0%; I = 55.9%) and 48.3% (95% CI: 31.2-65.4%; I = 99.7%). Both cMWA and uMWA achieved similar pooled VRR at the 3-month follow-up (58.4 vs 45.3%, P = 0.07) and pooled proportion of major complications (4.9 vs 5.0%, P = 0.49), while uMWA had higher pooled proportions of overall and minor complications than cMWA (97.8 vs 29.7%, P < 0.01; 97.8 vs 21.0%, P < 0.01), with more patients suffering pain and skin burn after uMWA (100 vs 5.5%, P < 0.01; 47.2 vs 0.2%, P < 0.01).
CONCLUSION
MWA is an effective treatment modality for BTNs. When considering the patient's comfort, cMWA would be a more preferable procedure with less complications.
Topics: Combined Modality Therapy; Humans; Hypothermia, Induced; Microwaves; Radiofrequency Ablation; Thyroid Nodule; Treatment Outcome
PubMed: 30073455
DOI: 10.1007/s12020-018-1693-2