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Orthopaedic Surgery Aug 2020Microwave ablation has been used to treat bone tumors in extremities for more than 30 years. With improved recognition, updated microwave equipment, and expanded...
Microwave ablation has been used to treat bone tumors in extremities for more than 30 years. With improved recognition, updated microwave equipment, and expanded clinical application, microwave ablation has recently been widely used to treat bone tumors. To standardize the application of microwave ablation in the clinical treatment of bone tumors in the limbs, research results and clinical experience involving the use of microwave ablation to treat bone tumors in the limbs have been summarized, and a clinical guideline has been designed. This guideline is aimed at providing a reliable clinical basis for indications, preoperative evaluation and decision-making, perioperative treatment, complications, and other issues via evidence-based medicine. Two aspects are considered-percutaneous microwave ablation and intraoperative microwave ablation of bone tumors in extremities. Ultimately, the guideline is intended to standardize treatment and improve the clinical efficacy of microwave ablation of bone tumors in extremities.
Topics: Ablation Techniques; Bone Neoplasms; Clinical Decision-Making; Extremities; Guidelines as Topic; Humans; Microwaves
PubMed: 32776475
DOI: 10.1111/os.12749 -
Skeletal Radiology Dec 2020Osteoid osteomas are benign bone tumors commonly treated using thermal ablation. We compare the technical success, complication rates, and long-term efficacy of the two...
OBJECTIVE
Osteoid osteomas are benign bone tumors commonly treated using thermal ablation. We compare the technical success, complication rates, and long-term efficacy of the two most common ablation types: radiofrequency and microwave.
MATERIALS AND METHODS
A retrospective study was performed of all osteoid osteoma ablation procedures between 2007 and 2017. A ten-point numerical pain scale was used to quantify symptoms before and after the procedures with > 12-month follow-up. Complications were reported using the Society of Interventional Radiology Adverse Events reporting criteria.
RESULTS
Twenty-nine patients successfully underwent 15 radiofrequency ablations and 15 microwave ablations with a technical success rate of 83% for radiofrequency and 100% for microwave (p = 0.23). Long-term recurrence rates (p = 1.0) and complication rates (p = 0.60) were not significantly different for the groups. One patient developed a skin burn following microwave ablation and another developed 12 months of sciatic neuropathy following radiofrequency ablation.
CONCLUSION
Microwave and radiofrequency ablation are safe and effective methods for treating osteoid osteomas with similar long-term efficacies. Although radiofrequency ablation is more commonly reported to result in skin burns, this complication can arise during microwave ablation.
Topics: Bone Neoplasms; Catheter Ablation; Humans; Microwaves; Neoplasm Recurrence, Local; Osteoma, Osteoid; Radiofrequency Ablation; Retrospective Studies; Treatment Outcome
PubMed: 32564104
DOI: 10.1007/s00256-020-03518-5 -
Journal of Cancer Research and... Sep 2022Image-guided local ablation has becoming a promising treatment option for patients unsuitable for surgical resection. Currently, magnetic resonance (MR) imaging has been...
CONTEXT
Image-guided local ablation has becoming a promising treatment option for patients unsuitable for surgical resection. Currently, magnetic resonance (MR) imaging has been used as guidance for ablation due to its good soft-tissue contrast, high image quality and absence of ionizing radiation. However, the limited operating space and interrupted and delayed imaging of the conventional MR equipment increased the difficulty of puncture during operation. Therefore, we utilized an easy-to-use optical navigation system with a 0.4 T 360° open MR system to perform MR-guided microwave ablation (MWA) to treat liver tumor patients in risk areas.
AIM
To evaluate the safety and efficacy of MR-guided MWA in treating liver tumors using a 0.4 T open and navigated MR system.
MATERIALS AND METHODS
A retrospective analysis was performed on 19 liver tumor patients who underwent MR-guided MWA between August 2014 and August 2017. The complications, complete ablation, and long-term outcomes were analyzed and evaluated.
RESULTS
It was found that navigated MRI guidance allowed for precise needle placement in the targeted tumor, and ablation was successfully performed in all patients without serious intraoperative complications and death. Additionally, complete ablation was reached at 94.74% (18/19), with only one patient discovered with residual tumor, and therefore received another MWA session within three months.
CONCLUSION
360° open MR system combined with navigation systems conveniently enhanced the operation of MR-guided ablation, producing effective outcomes. Therefore, this option may be a safe and effective therapy for liver tumors in patients, especially for those situated in risk areas and those not visible to identify by ultrasound or computerized tomography.
Topics: Catheter Ablation; Humans; Liver Neoplasms; Magnetic Resonance Imaging; Magnetic Resonance Spectroscopy; Microwaves; Retrospective Studies; Treatment Outcome
PubMed: 36204874
DOI: 10.4103/jcrt.jcrt_367_21 -
Advances in Experimental Medicine and... 2016The ideal cancer therapy not only induces the death of all localized tumor cells with less damage to surrounding normal tissue, but also activates a systemic antitumor... (Review)
Review
The ideal cancer therapy not only induces the death of all localized tumor cells with less damage to surrounding normal tissue, but also activates a systemic antitumor immunity. Heat-based tumor ablation has the potential to be such a treatment as it can minimal-invasively ablate a targeted tumor below the skin surface, and may subsequently augment host antitumor immunity. This chapter primarily introduces increasing pre-clinical and clinical evidence linking antitumor immune response to thermal tumor ablation, and then discusses the potential mechanisms involved in ablation-enhanced host antitumor immunity. The seminal studies performed so far indicate that although it is not possible to make definite conclusions on the connection between thermal ablation and antitumor immune response, it is nonetheless important to conduct extensive studies on the subject in order to elucidate the processes involved.
Topics: Ablation Techniques; Catheter Ablation; Cryosurgery; High-Intensity Focused Ultrasound Ablation; Humans; Laser Therapy; Microwaves; Neoplasms
PubMed: 26486336
DOI: 10.1007/978-3-319-22536-4_8 -
Digestive Surgery 2016With the advent of novel and somewhat effective chemotherapy against pancreas cancer, several groups developed a new interest on locally advanced pancreatic cancer... (Review)
Review
With the advent of novel and somewhat effective chemotherapy against pancreas cancer, several groups developed a new interest on locally advanced pancreatic cancer (LAPC). Unresectable tumors constitute up to 80% of pancreatic cancer (PC) at the time of diagnosis and are associated with a 5-year overall survival of less than 5%. To control those tumors locally, with perhaps improved patients survival, significant advances were made over the last 2 decades in the development of ablation methods including cryoablation, radiofrequency ablation, microwave ablation, high intensity focused ultrasound and irreversible electroporation (IRE). Many suggested a call for caution for possible severe or lethal complications in using such techniques on the pancreas. Most fears were on the heating or freezing of the pancreas, while non-thermal ablation (IRE) could offer safer approaches. The multimodal therapies along with high-resolution imaging guidance have created some enthusiasm toward ablation for LAPC. The impact of ablation techniques on primarily non-resectable PC remains, however, unclear.
Topics: Catheter Ablation; Chemoradiotherapy, Adjuvant; Cryosurgery; Electroporation; Humans; Microwaves; Pancreatic Neoplasms
PubMed: 27216160
DOI: 10.1159/000445021 -
Journal of the American Heart... May 2024Transcatheter renal denervation (RDN) has had inconsistent efficacy and concerns for durability of denervation. We aimed to investigate long-term safety and efficacy of... (Comparative Study)
Comparative Study
BACKGROUND
Transcatheter renal denervation (RDN) has had inconsistent efficacy and concerns for durability of denervation. We aimed to investigate long-term safety and efficacy of transcatheter microwave RDN in vivo in normotensive sheep in comparison to conventional radiofrequency ablation.
METHODS AND RESULTS
Sheep underwent bilateral RDN, receiving 1 to 2 microwave ablations (maximum power of 80-120 W for 240 s-480 s) and 12 to 16 radiofrequency ablations (180 s-240 s) in the main renal artery in a paired fashion, alternating the side of treatment, euthanized at 2 weeks (acute N=15) or 5.5 months (chronic N=15), and compared with undenervated controls (N=4). Microwave RDN produced substantial circumferential perivascular injury compared with radiofrequency at both 2 weeks [area 239.8 (interquartile range [IQR] 152.0-343.4) mm versus 50.1 (IQR, 32.0-74.6) mm, <0.001; depth 16.4 (IQR, 13.9-18.9) mm versus 7.5 (IQR, 6.0-8.9) mm <0.001] and 5.5 months [area 20.0 (IQR, 3.4-31.8) mm versus 5.0 (IQR, 1.4-7.3) mm, =0.025; depth 5.9 (IQR, 1.9-8.8) mm versus 3.1 (IQR, 1.2-4.1) mm, =0.005] using mixed models. Renal denervation resulted in significant long-term reductions in viability of renal sympathetic nerves [58.9% reduction with microwave (=0.01) and 45% reduction with radiofrequency (=0.017)] and median cortical norepinephrine levels [71% reduction with microwave ( <0.001) and 72.9% reduction with radiofrequency ( <0.001)] at 5.5 months compared with undenervated controls.
CONCLUSIONS
Transcatheter microwave RDN produces deep circumferential perivascular ablations without significant arterial injury to provide effective and durable RDN at 5.5 months compared with radiofrequency RDN.
Topics: Animals; Microwaves; Sympathectomy; Renal Artery; Kidney; Sheep; Catheter Ablation; Time Factors; Disease Models, Animal; Blood Pressure; Female; Radiofrequency Ablation
PubMed: 38664237
DOI: 10.1161/JAHA.123.031795 -
Surgical Endoscopy Dec 2023Primary hepatocellular carcinoma (HCC) and colorectal liver metastases (CRLM) represent the liver's two most common malignant neoplasms. Liver-directed therapies such as...
SAGES/AHPBA guidelines for the use of microwave and radiofrequency liver ablation for the surgical treatment of hepatocellular carcinoma or colorectal liver metastases less than 5 cm.
BACKGROUND
Primary hepatocellular carcinoma (HCC) and colorectal liver metastases (CRLM) represent the liver's two most common malignant neoplasms. Liver-directed therapies such as ablation have become part of multidisciplinary therapies despite a paucity of data. Therefore, an expert panel was convened to develop evidence-based recommendations regarding the use of microwave ablation (MWA) and radiofrequency ablation (RFA) for HCC or CRLM less than 5 cm in diameter in patients ineligible for other therapies.
METHODS
A systematic review was conducted for six key questions (KQ) regarding MWA or RFA for solitary liver tumors in patients deemed poor candidates for first-line therapy. Subject experts used the GRADE methodology to formulate evidence-based recommendations and future research recommendations.
RESULTS
The panel addressed six KQs pertaining to MWA vs. RFA outcomes and laparoscopic vs. percutaneous MWA. The available evidence was poor quality and individual studies included both HCC and CRLM. Therefore, the six KQs were condensed into two, recognizing that these were two disparate tumor groups and this grouping was somewhat arbitrary. With this significant limitation, the panel suggested that in appropriately selected patients, either MWA or RFA can be safe and feasible. However, this recommendation must be implemented cautiously when simultaneously considering patients with two disparate tumor biologies. The limited data suggested that laparoscopic MWA of anatomically more difficult tumors has a compensatory higher morbidity profile compared to percutaneous MWA, while achieving similar overall 1-year survival. Thus, either approach can be appropriate depending on patient-specific factors (very low certainty of evidence).
CONCLUSION
Given the weak evidence, these guidelines provide modest guidance regarding liver ablative therapies for HCC and CRLM. Liver ablation is just one component of a multimodal approach and its use is currently limited to a highly selected population. The quality of the existing data is very low and therefore limits the strength of the guidelines.
Topics: Humans; Liver Neoplasms; Carcinoma, Hepatocellular; Microwaves; Catheter Ablation; Treatment Outcome; Radiofrequency Ablation; Colorectal Neoplasms; Retrospective Studies
PubMed: 37957297
DOI: 10.1007/s00464-023-10468-1 -
International Journal of Hyperthermia :... 2021To study the differences between continuous and short-pulse mode microwave ablation (MWA).
PURPOSE
To study the differences between continuous and short-pulse mode microwave ablation (MWA).
METHODS
We built a computational model for MWA including a 200 mm long and 14 G antenna from Amica-Gen and solved an electromagnetic-thermal coupled problem using COMSOL Multiphysics. We compared the coagulation zone (CZ) sizes created with pulsed and continuous modes under and conditions. The model was used to compare long vs. short pulses, and 1000 W high-powered short pulses. experiments were conducted to validate the model.
RESULTS
The computational models predicted the axial diameter of the CZ with an error of 2-3% and overestimated the transverse diameter by 9-11%. For short pulses, the computer modeling results showed a trend toward larger CZ when duty cycles decreases. In general, short pulsed mode yielded higher CZ diameters and volumes than continuous mode, but the differences were not significant (<5%), as in terms of CZ sphericity. The same trends were observed in the simulations mimicking conditions. Both CZ diameter and sphericity were similar with short and long pulses. Short 1000 W pulses produced smaller sphericity and similar CZ sizes under and conditions.
CONCLUSIONS
The characteristics of the CZ created by continuous and pulsed MWA show no significant differences from experiments and computer simulations. The proposed idea of enlarging coagulation zones and improving their sphericity in pulsed mode was not evident in this study.
Topics: Ablation Techniques; Catheter Ablation; Computer Simulation; Computers; Liver; Microwaves; Radiofrequency Ablation
PubMed: 33719808
DOI: 10.1080/02656736.2021.1894358 -
International Journal of Hyperthermia :... Feb 2017The use of microwaves (MW) for thermal cancer treatment began in the late 1970s. At first, hyperthermia was induced by using single antennas applied interstitially. This... (Review)
Review
The use of microwaves (MW) for thermal cancer treatment began in the late 1970s. At first, hyperthermia was induced by using single antennas applied interstitially. This was followed by arrays of multiple interstitial antennas driven synchronously at 915 or 2450 MHz. This early work focused on hyperthermia as an adjuvant therapy, but more recently has evolved into a thermally ablative monotherapy. Increased power required to thermally ablate tissues required additional developments such as internally cooled antennas. Larger tumours have also been ablated with MW antenna arrays activated synchronously or non-synchronously. Numerical modelling has provided clinical treatment planning guidance and device design insight throughout this history. MW thermal therapy systems, treatment planning, navigation and image guidance continue to evolve to provide better tools and options for clinicians and patients in order to provide targeting optimisation with the goal of improved treatment for the patient and durable cancer eradication. This paper reviews the history and related technological developments, including antenna design, of MW heating for both hyperthermia and ablation.
Topics: Ablation Techniques; Animals; Equipment Design; Humans; Hyperthermia, Induced; Microwaves; Neoplasms
PubMed: 27492859
DOI: 10.1080/02656736.2016.1214884 -
Turkish Journal of Medical Sciences Aug 2022The aim of the study was to evaluate the relationship between primary tumor type and the effectiveness of microwave ablation (MWA) therapy by comparing the technical and...
BACKGROUND
The aim of the study was to evaluate the relationship between primary tumor type and the effectiveness of microwave ablation (MWA) therapy by comparing the technical and clinical outcomes of MWA in the treatment of colorectal liver metastases (CLM) and noncolorectal liver metastases (NCLM).
METHODS
Between January 2019 and March 2021, 47 consecutive patients (25 male, 22 female) with a total of 63 unresectable hepatic metastases underwent MWA under ultrasound guidance. The patients were divided into CLM (n = 29) and NCLM (n = 18) groups. Patient demographics, procedural details, and complications were noted. The overall survival (OS) and disease-free survival (DFS) rates were also analyzed.
RESULTS
Technical success was 100% in both groups. No major complication was observed. Three minor complications [fatigue (n = 2) and subcutaneous hematoma (n = 1)] were encountered. DFS rates were 88.9%, 71.9%, 64.9%, and 44.0% at 3, 6, 12, and 24-months, respectively, with a mean DFS of 17.4 months (95% CI: 15.1, 19.7). Also, OS rates were 93.7%, 90.0%, 76.8%, and 64.3%, at 3, 6, 12, and 24-months, respectively, with a mean OS of 18.5 months (95% CI: 16.2, 20.7). There was no significant difference in recurrence between the CLM and NCLM groups (p = 0.452). The recurrence rate in liver metastases > 3 cm in size was significantly higher than in metastases ≤ 3 cm in size (p < 0.001).
DISCUSSION
MWA therapy is as effective in the NCLM group as in the CLM group, regardless of histologic type. Metastasis size (>3 cm) was correlated with the recurrence rate in the CLM and NCLM groups.
Topics: Humans; Male; Female; Microwaves; Catheter Ablation; Colorectal Neoplasms; Liver Neoplasms; Radiofrequency Ablation; Treatment Outcome; Retrospective Studies
PubMed: 36326409
DOI: 10.55730/1300-0144.5440