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Mak NL, Ng WH, Ooi EH, Lau EV, Pamidi N, Foo JJ, Ooi ET, Ali AFM. Enlarging the thermal coagulation volume during thermochemical ablation with alternating acid-base injection by shortening the injection interval: A computational study. COMPUTER METHODS AND PROGRAMS IN BIOMEDICINE 2024; 243:107866. [PMID: 37865059 DOI: 10.1016/j.cmpb.2023.107866] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/26/2023] [Revised: 10/12/2023] [Accepted: 10/13/2023] [Indexed: 10/23/2023]
Abstract
BACKGROUND AND OBJECTIVES Thermochemical ablation (TCA) is a cancer treatment that utilises the heat released from the neutralisation of acid and base to raise tissue temperature to levels sufficient to induce thermal coagulation. Computational studies have demonstrated that the coagulation volume produced by sequential injection is smaller than that with simultaneous injection. By injecting the reagents in an ensuing manner, the region of contact between acid and base is limited to a thin contact layer sandwiched between the distribution of acid and base. It is hypothesised that increasing the frequency of acid-base injections into the tissue by shortening the injection interval for each reagent can increase the effective area of contact between acid and base, thereby intensifying neutralisation and the exothermic heat released into the tissue. METHODS To verify this hypothesis, a computational model was developed to simulate the thermochemical processes involved during TCA with sequential injection. Four major processes that take place during TCA were considered, i.e., the flow of acid and base, their neutralisation, the release of exothermic heat and the formation of thermal damage inside the tissue. Equimolar acid and base at 7.5 M was injected into the tissue intermittently. Six injection intervals, namely 3, 6, 15, 20, 30 and 60 s were investigated. RESULTS Shortening of the injection interval led to the enlargement of coagulation volume. If one considers only the coagulation volume as the determining factor, then a 15 s injection interval was found to be optimum. Conversely, if one places priority on safety, then a 3 s injection interval would result in the lowest amount of reagent residue inside the tissue after treatment. With a 3 s injection interval, the coagulation volume was found to be larger than that of simultaneous injection with the same treatment parameters. Not only that, the volume also surpassed that of radiofrequency ablation (RFA); a conventional thermal ablation technique commonly used for liver cancer treatment. CONCLUSION The numerical results verified the hypothesis that shortening the injection interval will lead to the formation of larger thermal coagulation zone during TCA with sequential injection. More importantly, a 3 s injection interval was found to be optimum for both efficacy (large coagulation volume) and safety (least amount of reagent residue).
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Affiliation(s)
- Nguoy L Mak
- Department of Mechanical Engineering, School of Engineering, Monash University Malaysia, Jalan Lagoon Selatan, 47500 Bandar Sunway, Selangor, Malaysia
| | - Wen H Ng
- Department of Mechanical Engineering, School of Engineering, Monash University Malaysia, Jalan Lagoon Selatan, 47500 Bandar Sunway, Selangor, Malaysia
| | - Ean H Ooi
- Department of Mechanical Engineering, School of Engineering, Monash University Malaysia, Jalan Lagoon Selatan, 47500 Bandar Sunway, Selangor, Malaysia.
| | - Ee V Lau
- Department of Mechanical Engineering, School of Engineering, Monash University Malaysia, Jalan Lagoon Selatan, 47500 Bandar Sunway, Selangor, Malaysia
| | - N Pamidi
- Jeffrey Cheah School of Medicine and Health Sciences, Monash University Malaysia, Jalan Lagoon Selatan, 47500 Bandar Sunway, Selangor, Malaysia
| | - Ji J Foo
- Department of Mechanical Engineering, School of Engineering, Monash University Malaysia, Jalan Lagoon Selatan, 47500 Bandar Sunway, Selangor, Malaysia
| | - Ean T Ooi
- School of Engineering and Information Technology, Faculty of Science and Technology, Federation University, VIC 3350, Australia
| | - Ahmad F Mohd Ali
- MSU Medical Centre, Management and Science University, University Drive, Off Persiaran Olahraga, 40100 Shah Alam, Selangor, Malaysia
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Remlova E, Feig VR, Kang Z, Patel A, Ballinger I, Ginzburg A, Kuosmanen J, Fabian N, Ishida K, Jenkins J, Hayward A, Traverso G. Activated Metals to Generate Heat for Biomedical Applications. ACS MATERIALS LETTERS 2023; 5:2508-2517. [PMID: 37680546 PMCID: PMC10481395 DOI: 10.1021/acsmaterialslett.3c00581] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/31/2023] [Accepted: 08/10/2023] [Indexed: 09/09/2023]
Abstract
Delivering heat in vivo could enhance a wide range of biomedical therapeutic and diagnostic technologies, including long-term drug delivery devices and cancer treatments. To date, providing thermal energy is highly power-intensive, rendering it oftentimes inaccessible outside of clinical settings. We developed an in vivo heating method based on the exothermic reaction between liquid-metal-activated aluminum and water. After establishing a method for consistent activation, we characterized the heat generation capabilities with thermal imaging and heat flux measurements. We then demonstrated one application of this reaction: to thermally actuate a gastric resident device made from a shape-memory alloy called Nitinol. Finally, we highlight the advantages and future directions for leveraging this novel in situ heat generation method beyond the showcased example.
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Affiliation(s)
- Eva Remlova
- Division
of Gastroenterology, Department of Medicine, Brigham and Women’s Hospital, Harvard Medical School, Boston, Massachusetts 02115, United States
- Department
of Health Sciences and Technology, Eidgenössische
Technische Hochschule Zürich, Universitätstrasse 2, 8092 Zürich, Switzerland
| | - Vivian Rachel Feig
- Division
of Gastroenterology, Department of Medicine, Brigham and Women’s Hospital, Harvard Medical School, Boston, Massachusetts 02115, United States
- The
David H. Koch Institute for Integrative Cancer Research, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, United States
| | - Ziliang Kang
- Division
of Gastroenterology, Department of Medicine, Brigham and Women’s Hospital, Harvard Medical School, Boston, Massachusetts 02115, United States
- Department
of Mechanical Engineering, Massachusetts
Institute of Technology, Cambridge, Massachusetts 02139, United States
| | - Ashka Patel
- Division
of Gastroenterology, Department of Medicine, Brigham and Women’s Hospital, Harvard Medical School, Boston, Massachusetts 02115, United States
- Department
of Bioengineering, Northeastern University, Boston, Massachusetts 02115, United States
| | - Ian Ballinger
- Division
of Gastroenterology, Department of Medicine, Brigham and Women’s Hospital, Harvard Medical School, Boston, Massachusetts 02115, United States
| | - Anna Ginzburg
- Division
of Gastroenterology, Department of Medicine, Brigham and Women’s Hospital, Harvard Medical School, Boston, Massachusetts 02115, United States
- Department
of Cell/Cellular and Molecular Biology, Northeastern University, Boston, Massachusetts 02115, United States
| | - Johannes Kuosmanen
- Department
of Mechanical Engineering, Massachusetts
Institute of Technology, Cambridge, Massachusetts 02139, United States
| | - Niora Fabian
- Department
of Mechanical Engineering, Massachusetts
Institute of Technology, Cambridge, Massachusetts 02139, United States
- Division
of Comparative Medicine, Massachusetts Institute
of Technology, Cambridge, Massachusetts 02139, United States
| | - Keiko Ishida
- Division
of Gastroenterology, Department of Medicine, Brigham and Women’s Hospital, Harvard Medical School, Boston, Massachusetts 02115, United States
- The
David H. Koch Institute for Integrative Cancer Research, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, United States
| | - Joshua Jenkins
- Division
of Gastroenterology, Department of Medicine, Brigham and Women’s Hospital, Harvard Medical School, Boston, Massachusetts 02115, United States
- Department
of Mechanical Engineering, Massachusetts
Institute of Technology, Cambridge, Massachusetts 02139, United States
| | - Alison Hayward
- Division
of Gastroenterology, Department of Medicine, Brigham and Women’s Hospital, Harvard Medical School, Boston, Massachusetts 02115, United States
- Department
of Mechanical Engineering, Massachusetts
Institute of Technology, Cambridge, Massachusetts 02139, United States
- Division
of Comparative Medicine, Massachusetts Institute
of Technology, Cambridge, Massachusetts 02139, United States
| | - Giovanni Traverso
- Division
of Gastroenterology, Department of Medicine, Brigham and Women’s Hospital, Harvard Medical School, Boston, Massachusetts 02115, United States
- The
David H. Koch Institute for Integrative Cancer Research, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, United States
- Department
of Mechanical Engineering, Massachusetts
Institute of Technology, Cambridge, Massachusetts 02139, United States
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Thompson EA, Fowlkes NW, Jacobsen MC, Layman RR, Cressman ENK. Quantitative Dual-Energy CT Image Guidance for Thermochemical Ablation: In Vivo Results in the Rabbit VX2 Model. J Vasc Interv Radiol 2023; 34:782-789. [PMID: 36539151 PMCID: PMC10542852 DOI: 10.1016/j.jvir.2022.12.026] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2022] [Revised: 12/07/2022] [Accepted: 12/10/2022] [Indexed: 12/23/2022] Open
Abstract
PURPOSE To evaluate the feasibility of using dual-energy computed tomography (CT) and theranostic cesium hydroxide (CsOH) for image guidance of thermochemical ablation (TCA) in a rabbit VX2 tumor model. MATERIALS AND METHODS In vivo experiments were performed on New Zealand white rabbits, where VX2 tumor fragments (0.3 mL) were inoculated into the right and left flanks (n = 16 rabbits, 32 tumors). Catheters were placed in the approximate center of 1- to 2-cm diameter tumors under ultrasound guidance. TCA was delivered in 1 of 3 treatment groups: untreated control, 5-M TCA, or 10-M TCA. The TCA base reagent was doped with 250-mM CsOH. Dual-energy CT was performed before and after TCA. Cesium (CS)-specific images were postprocessed on the basis of previous phantom calibrations to determine Cs concentration. Line profiles were drawn through the ablation center. Twenty-four hours after TCA, subjects were euthanized, and the resulting damage was evaluated with histopathology. RESULTS Cs was detected in 100% of treated tumors (n = 21). Line profiles indicated highest concentrations at the injection site and decreased concentrations at the tumor margins, with no Cs detected beyond the ablation zone. The maximum detected Cs concentration ranged from 14.39 to 137.33 mM. A dose-dependent trend in tissue necrosis was demonstrated between the 10-M TCA and 5-M TCA treatment groups (P = .0005) and untreated controls (P = .0089). CONCLUSIONS Dual-energy CT provided image guidance for delivery, localization, and quantification of TCA in the rabbit VX2 model.
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Affiliation(s)
- Emily A Thompson
- Department of Imaging Physics, the University of Texas MD Anderson Cancer Center, Houston, Texas
| | - Natalie W Fowlkes
- Department of Veterinary Medicine and Surgery, the University of Texas MD Anderson Cancer Center, Houston, Texas
| | - Megan C Jacobsen
- Department of Imaging Physics, the University of Texas MD Anderson Cancer Center, Houston, Texas
| | - Rick R Layman
- Department of Imaging Physics, the University of Texas MD Anderson Cancer Center, Houston, Texas
| | - Erik N K Cressman
- Department of Interventional Radiology, the University of Texas MD Anderson Cancer Center, Houston, Texas.
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Mak NL, Ooi EH, Lau EV, Ooi ET, Pamidi N, Foo JJ, Mohd Ali AF. An in silico derived dosage and administration guide for effective thermochemical ablation of biological tissues with simultaneous injection of acid and base. COMPUTER METHODS AND PROGRAMS IN BIOMEDICINE 2022; 227:107195. [PMID: 36323179 DOI: 10.1016/j.cmpb.2022.107195] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/22/2022] [Revised: 10/05/2022] [Accepted: 10/18/2022] [Indexed: 06/16/2023]
Abstract
BACKGROUND AND OBJECTIVES Thermochemical ablation (TCA) is a thermal ablation technique involving the injection of acid and base, either sequentially or simultaneously, into the target tissue. TCA remains at the conceptual stage with existing studies unable to provide recommendations on the optimum injection rate, and reagent concentration and volume. Limitations in current experimental methodology have prevented proper elucidation of the thermochemical processes inside the tissue during TCA. Nevertheless, the computational TCA framework developed recently by Mak et al. [Mak et al., Computers in Biology and Medicine, 2022, 145:105494] has opened new avenues in the development of TCA. Specifically, a recommended safe dosage is imperative in driving TCA research beyond the conceptual stage. METHODS The aforesaid computational TCA framework for sequential injection was applied and adapted to simulate TCA with simultaneous injection of acid and base at equimolar and equivolume. The developed framework, which describes the flow of acid and base, their neutralisation, the rise in tissue temperature and the formation of thermal damage, was solved numerically using the finite element method. The framework will be used to investigate the effects of injection rate, reagent concentration, volume and type (weak/strong acid-base combination) on temperature rise and thermal coagulation formation. RESULTS A higher injection rate resulted in higher temperature rise and larger thermal coagulation. Reagent concentration of 7500 mol/m3 was found to be optimum in producing considerable thermal coagulation without the risk of tissue overheating. Thermal coagulation volume was found to be consistently larger than the total volume of acid and base injected into the tissue, which is beneficial as it reduces the risk of chemical burn injury. Three multivariate second-order polynomials that express the targeted coagulation volume as functions of injection rate and reagent volume, for the weak-weak, weak-strong and strong-strong acid-base combinations were also derived based on the simulated data. CONCLUSIONS A guideline for a safe and effective implementation of TCA with simultaneous injection of acid and base was recommended based on the numerical results of the computational model developed. The guideline correlates the coagulation volume with the reagent volume and injection rate, and may be used by clinicians in determining the safe dosage of reagents and optimum injection rate to achieve a desired thermal coagulation volume during TCA.
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Affiliation(s)
- Nguoy L Mak
- Mechanical Engineering Discipline, School of Engineering, Monash University Malaysia, Jalan Lagoon Selatan, Bandar Sunway 47500, Selangor, Malaysia
| | - Ean H Ooi
- Mechanical Engineering Discipline, School of Engineering, Monash University Malaysia, Jalan Lagoon Selatan, Bandar Sunway 47500, Selangor, Malaysia; Advanced Engineering Platform, Monash University Malaysia, Jalan Lagoon Selatan, Bandar Sunway 47500, Selangor, Malaysia.
| | - Ee V Lau
- Mechanical Engineering Discipline, School of Engineering, Monash University Malaysia, Jalan Lagoon Selatan, Bandar Sunway 47500, Selangor, Malaysia
| | - Ean T Ooi
- School of Engineering and Information Technology, Faculty of Science and Technology, Federation University, VIC 3350, Australia
| | - Narendra Pamidi
- Jeffrey Cheah School of Medicine and Health Sciences, Monash University Malaysia, Jalan Lagoon Selatan, Bandar Sunway 47500, Selangor, Malaysia
| | - Ji J Foo
- Mechanical Engineering Discipline, School of Engineering, Monash University Malaysia, Jalan Lagoon Selatan, Bandar Sunway 47500, Selangor, Malaysia
| | - Ahmad F Mohd Ali
- MSU Medical Centre, Management and Science University, University Drive, Off Persiaran Olahraga, Shah Alam 40100, Selangor, Malaysia
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Mak NL, Ooi EH, Lau EV, Ooi ET, Pamidi N, Foo JJ, Mohd Ali AF. A computational framework to simulate the thermochemical process during thermochemical ablation of biological tissues. Comput Biol Med 2022; 145:105494. [PMID: 35421791 DOI: 10.1016/j.compbiomed.2022.105494] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2022] [Revised: 03/20/2022] [Accepted: 04/03/2022] [Indexed: 11/03/2022]
Abstract
Thermochemical ablation (TCA) is a thermal ablation therapy that utilises heat released from acid-base neutralisation reaction to destroy tumours. This procedure is a promising low-cost solution to existing thermal ablation treatments such as radiofrequency ablation (RFA) and microwave ablation (MWA). Studies have demonstrated that TCA can produce thermal damage that is on par with RFA and MWA when employed properly. Nevertheless, TCA remains a concept that is tested only in a few animal trials due to the risks involved as the result of uncontrolled infusion and incomplete acid-base reaction. In this study, a computational framework that simulates the thermochemical process of TCA is developed. The proposed framework consists of three physics, namely chemical flow, neutralisation reaction and heat transfer. An important parameter in the TCA framework is the neutralisation reaction rate constant, which has values in the order of 108 m3/(mol⋅s). The present study will demonstrate that since the rate constant impacts only the rate and direction of the reaction but has little influence on the extent of reaction, it is possible to replicate the thermochemical process of TCA by employing significantly smaller values of rate constant that are numerically tractable. Comparisons of the numerical results against experimental studies from the literature supports this. The aim of this framework is for researchers to advance and develop TCA to gain an in-depth understanding of the fundamental mechanisms of TCA and to develop a safe treatment protocol of TCA in the hope of advancing TCA into clinical trials.
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Affiliation(s)
- Nguoy L Mak
- Mechanical Engineering Discipline, School of Engineering, Monash University Malaysia, Jalan Lagoon Selatan, 47500, Bandar Sunway, Selangor, Malaysia
| | - Ean H Ooi
- Mechanical Engineering Discipline, School of Engineering, Monash University Malaysia, Jalan Lagoon Selatan, 47500, Bandar Sunway, Selangor, Malaysia; Advanced Engineering Platform, Monash University Malaysia, Jalan Lagoon Selatan, 47500, Bandar Sunway, Selangor, Malaysia.
| | - Ee V Lau
- Mechanical Engineering Discipline, School of Engineering, Monash University Malaysia, Jalan Lagoon Selatan, 47500, Bandar Sunway, Selangor, Malaysia
| | - Ean T Ooi
- School of Engineering and Information Technology, Faculty of Science and Technology, Federation University, VIC, 3350, Australia
| | - N Pamidi
- Jeffrey Cheah School of Medicine and Health Sciences, Monash University Malaysia, Jalan Lagoon Selatan, 47500, Bandar Sunway, Selangor, Malaysia
| | - Ji J Foo
- Mechanical Engineering Discipline, School of Engineering, Monash University Malaysia, Jalan Lagoon Selatan, 47500, Bandar Sunway, Selangor, Malaysia
| | - Ahmad F Mohd Ali
- MSU Medical Centre, Management and Science University, University Drive, Off Persiaran Olahraga, 40100, Shah Alam, Selangor, Malaysia
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Ex Vivo Liver Experiment of Hydrochloric Acid-Infused and Saline-Infused Monopolar Radiofrequency Ablation: Better Outcomes in Temperature, Energy, and Coagulation. Cardiovasc Intervent Radiol 2015; 39:600-5. [PMID: 26486153 DOI: 10.1007/s00270-015-1218-9] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/25/2015] [Accepted: 09/19/2015] [Indexed: 01/01/2023]
Abstract
OBJECTIVE To compare temperature, energy, and coagulation between hydrochloric acid-infused radiofrequency ablation (HAIRFA) and normal saline-infused radiofrequency ablation (NSIRFA) in ex vivo porcine liver model. MATERIALS AND METHODS 30 fresh porcine livers were excised in 60 lesions, 30 with HAIRFA and the other 30 with NSIRFA. Both modalities used monopolar perfusion electrode connected to a RF generator set at 103 °C and 30 W. In each group, ablation time was set at 10, 20, or 30 min (10 lesions from each group at each time). We compared tissue temperatures (at 0.5, 1.0, 1.5, 2.0, 2.5, and 3.0 cm away from the electrode tip), average power, deposited energy, deposited energy per coagulation volume (DEV), coagulation diameters, coagulative volume, and spherical ratio between the two groups. RESULTS Temperature-time curves showed that HAIRFA provided progressively greater heating than that of NSIRFA. At 30 min, mean average power, deposited energy, coagulation volumes (113.67 vs. 12.28 cm(3)) and diameters, and increasing in tissue temperature were much greater with HAIRFA (P < 0.001 for all), except DEV was lower (456 vs. 1396 J/cm(3), P < 0.001). The spherical ratio was closer to 1 with HAIRFA (1.23 vs. 1.46). Coagulation diameters, volume, and average power of HAIRFA increased significantly with longer ablation times. While with NSIRFA, these characteristics were stable till later 20 min, except the power decreased with longer ablation times. CONCLUSIONS HAIRFA creates much larger and more spherical lesions by increasing overall energy deposition, modulating thermal conductivity, and transferring heat during ablation.
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Cressman ENK, Zbacnik AP. Development of a Simple Miniature Thermochemical Ablation Device Suitable for Tumor Ablation Research in Rodent Models. J Med Device 2013. [DOI: 10.1115/1.4025187] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022] Open
Abstract
Thermochemical ablation is a recently developed minimally invasive method with potential for solid tumor treatment such as in liver cancer. A recently described prototype device, however, is too large for use in the more common rodent models of cancer. In this report we describe a simple, low-cost variant of the device that is easy to assemble, small enough to be readily applicable to small animal models, and then demonstrate its use in an ex vivo model for ablation. It should therefore enable study of the method without requiring specialized equipment or access to a machine shop for device manufacture.
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Affiliation(s)
| | - Anthony P. Zbacnik
- Department of Radiology, University of Minnesota, 424 Delaware Street, SE MMC 292, Minneapolis, MN 55455
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Deng ZS, Liu J. Chemothermal therapy for localized heating and ablation of tumor. JOURNAL OF HEALTHCARE ENGINEERING 2013; 4:409-26. [PMID: 23965596 DOI: 10.1260/2040-2295.4.3.409] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
Chemothermal therapy is a new hyperthermia treatment on tumor using heat released from exothermic chemical reaction between the injected reactants and the diseased tissues. With the highly minimally invasive feature and localized heating performance, this method is expected to overcome the ubiquitous shortcomings encountered by many existing hyperthermia approaches in ablating irregular tumor. This review provides a relatively comprehensive review on the latest advancements and state of the art in chemothermal therapy. The basic principles and features of two typical chemothermal ablation strategies (acid-base neutralization-reaction-enabled thermal ablation and alkali-metal-enabled thermal/chemical ablation) are illustrated. The prospects and possible challenges facing chemothermal ablation are analyzed. The chemothermal therapy is expected to open many clinical possibilities for precise tumor treatment in a minimally invasive way.
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Affiliation(s)
- Zhong-Shan Deng
- Technical Institute of Physics and Chemistry, Chinese Academy of Sciences, Beijing, China.
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Cressman ENK, Jahangir DA. Dual mode single agent thermochemical ablation by simultaneous release of heat energy and acid: hydrolysis of electrophiles. Int J Hyperthermia 2013; 29:71-8. [PMID: 23311380 DOI: 10.3109/02656736.2012.756124] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
PURPOSE This study aimed to investigate two readily available electrophilic reagents, acetyl chloride (AcCl), and acetic anhydride (Ac(2)O), for their potential in tissue ablation. MATERIALS AND METHODS Reagents were diluted in diglyme as solutions up to 8 mol/L and tested in a gel phantom with NaOH solutions and ex vivo in porcine liver. Temperature, pH, and volume measurements were obtained. Infrared and gross pathological images were obtained in bisected specimens immediately after injection. RESULTS AcCl was much more reactive than Ac(2)O and AcCl was therefore used in the tissue studies. Temperature increases of up to 37°C were noted in vitro and 30°C in ex vivo tissues using 4 mol/L AcCl solutions. Experiments at 8 mol/L were abandoned due to the extreme reactivity at this higher concentration. A change in pH of up to 4 log units was noted with 4 mol/L solutions of AcCl with slight recovery over time. Ablated volumes were consistently higher than injected volumes. CONCLUSIONS Reaction of electrophiles in tissues shows promise as a new thermochemical ablation technique by means of only a single reagent. Further studies in this area are warranted.
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Affiliation(s)
- Erik N K Cressman
- Department of Radiology, University of Minnesota Medical Center, Minneapolis, Minnesota, USA.
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Cressman ENK, Shenoi MM, Edelman TL, Geeslin MG, Hennings LJ, Zhang Y, Iaizzo PA, Bischof JC. In vivo comparison of simultaneous versus sequential injection technique for thermochemical ablation in a porcine model. Int J Hyperthermia 2012; 28:105-12. [PMID: 22335224 DOI: 10.3109/02656736.2011.644620] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
PURPOSE To investigate simultaneous and sequential injection thermochemical ablation in a porcine model, and compare them to sham and acid-only ablation. MATERIALS AND METHODS This IACUC-approved study involved 11 pigs in an acute setting. Ultrasound was used to guide placement of a thermocouple probe and coaxial device designed for thermochemical ablation. Solutions of 10 M acetic acid and NaOH were used in the study. Four injections per pig were performed in identical order at a total rate of 4 mL/min: saline sham, simultaneous, sequential, and acid only. Volume and sphericity of zones of coagulation were measured. Fixed specimens were examined by H&E stain. RESULTS Average coagulation volumes were 11.2 mL (simultaneous), 19.0 mL (sequential) and 4.4 mL (acid). The highest temperature, 81.3°C, was obtained with simultaneous injection. Average temperatures were 61.1°C (simultaneous), 47.7°C (sequential) and 39.5°C (acid only). Sphericity coefficients (0.83-0.89) had no statistically significant difference among conditions. CONCLUSIONS Thermochemical ablation produced substantial volumes of coagulated tissues relative to the amounts of reagents injected, considerably greater than acid alone in either technique employed. The largest volumes were obtained with sequential injection, yet this came at a price in one case of cardiac arrest. Simultaneous injection yielded the highest recorded temperatures and may be tolerated as well as or better than acid injection alone. Although this pilot study did not show a clear advantage for either sequential or simultaneous methods, the results indicate that thermochemical ablation is attractive for further investigation with regard to both safety and efficacy.
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Affiliation(s)
- Erik N K Cressman
- Department of Radiology, University of Minnesota Medical Center, Minneapolis, Minnesota 55455, USA.
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Geeslin MG, Cressman EN. Thermochemical Ablation: A Device for a Novel Interventional Concept. J Med Device 2012; 6. [PMCID: PMC3707189 DOI: 10.1115/1.4005785] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2011] [Revised: 11/07/2011] [Indexed: 10/23/2023] Open
Abstract
Solid focal and oligometastatic malignancies are appropriate targets for minimally invasive ablative procedures. Thermochemical ablation is an experimental minimally invasive procedure, which exploits certain features of current thermal and chemical tumor ablation therapies. Engineering principles have been used to design a device, which has been research-proven-capable of coagulating tissue through the combination of a thermal and chemical insult. This interventional device completes this assignment by separately guiding the flow of chemical reagents, drawn from auxiliary systems, to a point at the distal tip of an assembled apparatus. At this position, the respective flow-streams converge and undergo an exothermic reaction to produce a heated, hyperosmolar solute, which serves to ablate the targeted tissue. Ex and in vivo studies have confirmed the utility of this device and the physiologic toleration of this interventional concept.
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Affiliation(s)
- Matthew G. Geeslin
- University of Minnesota Medical School,University of Minnesota,Minneapolis, MN 55455e-mail:
| | - Erik N. Cressman
- Department of Radiology,University of Minnesota,Minneapolis, MN 55455
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12
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Cressman ENK, Geeslin MG, Shenoi MM, Hennings LJ, Zhang Y, Iaizzo PA, Bischof JC. Concentration and volume effects in thermochemical ablation in vivo: Results in a porcine model. Int J Hyperthermia 2012; 28:113-21. [DOI: 10.3109/02656736.2011.644621] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023] Open
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13
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Farnam JL, Smith BC, Johnson BR, Estrada R, Edelman TL, Farah R, Cressman ENK. Thermochemical ablation in an ex-vivo porcine liver model using acetic acid and sodium hydroxide: proof of concept. J Vasc Interv Radiol 2011; 21:1573-8. [PMID: 20801679 DOI: 10.1016/j.jvir.2010.06.012] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2009] [Revised: 05/19/2010] [Accepted: 06/03/2010] [Indexed: 12/18/2022] Open
Abstract
PURPOSE To establish proof of concept in tissue, using the exothermic neutralization reaction of acetic acid and sodium hydroxide in ex vivo porcine liver and to conduct an initial probe into the relationships of volume and concentration of reagents to temperatures and the areas affected. MATERIALS AND METHODS A total of 0.5 mL or 2 mL of either 5 mole/L or 10 mole/L acid and base solutions was injected simultaneously into the periphery of ex vivo porcine liver using a prototype injection device. Tissue temperature was recorded at the injection site for 5 minutes using a type T thermocouple temperature probe inserted parallel to and near the tip of the injection device. The injections were repeated for infrared thermography, and ablated tissues were sectioned quickly and imaged. A gross photograph was captured in each case to provide correlation. RESULTS Maximum temperatures (17°C baseline) ranged from 42.1° ± α3.34°C to 61.7° ± α10°C (P<.05) when injecting 0.5 mL of 5 mole/L reactants and 2 mL of 10 mole/L reactants, respectively. The maximum temperature measured by infrared imaging ranged from 31°-47°C. Using an infrared viewing scale from 19°-40°C, the cross-sectional area of tissue heating above baseline measured from 1.07 cm(2)± 0.45 to 4.95 cm(2)± 0.28 (P <05). CONCLUSIONS The reaction of acetic acid and sodium hydroxide releases significant heat energy at the site of injection, and histologic changes are consistent with coagulation necrosis. Increased reagent concentration and volume were associated with larger temperature changes and larger areas of hyperthermia at gross pathology and infrared imaging.
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Affiliation(s)
- Joseph L Farnam
- Department of Radiology, University of Minnesota Medical Center MMC 292, 420 Delaware Street SE, Minneapolis, MN 55455, USA
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