High-temperature Hyperthermia Research Articles

Reconfigurable, zero-energy, and wide-temperature loss-assisted thermal nonreciprocal metamaterials

Thermal nonreciprocity plays a vital role in chip heat dissipation, energy-saving design, and high-temperature hyperthermia, typically realized through the use of advanced metamaterials with nonlinear, advective, spatiotemporal, or gradient properties. However, challenges such as fixed structural designs with limited adjustability, high energy consumption, and a narrow operational temperature range remain prevalent. Here, a systematic framework is introduced to achieve reconfigurable, zero-energy, and wide-temperature thermal nonreciprocity by transforming wasteful heat loss into a valuable regulatory tool. Vertical slabs composed of natural bulk materials enable asymmetric heat loss through natural convection, disrupting the inversion symmetry of thermal conduction. The reconfigurability of this system stems from the ability to modify heat loss by adjusting thermal conductivity, size, placement, and quantity of the slabs. Moreover, this structure allows for precise control of zero-energy thermal nonreciprocity across a broad temperature spectrum, utilizing solely environmental temperature gradients without additional energy consumption. This research presents a different approach to achieving nonreciprocity, broadening the potential for nonreciprocal devices such as thermal diodes and topological edge states, and inspiring further exploration of nonreciprocity in other loss-based systems.

Numerical modelling of the laser high-temperature hyperthermia using the dual-phase lag equation

Numerical modelling of the laser high-temperature hyperthermia using the dual-phase lag equation

Fully tuned RBF neural network controller for ultrasound hyperthermia cancer tumour therapy

ABSTRACTThermal dose is an important clinical efficacy index for hyperthermia cancer treatment. This paper presents a new direct radial basis function (RBF) neural network controller for high-temperature hyperthermia thermal dose during the therapeutic procedure of cancer tumours by short-time pulses of high-intensity focused ultrasound (HIFU). The developed controller is stabilized and automatically tuned based on Lyapunov functions and ant colony optimization (ACO) algorithm, respectively. In addition, this thermal dose control system has been validated using one-dimensional (1-D) biothermal tissue model. Simulation results showed that the fully tuned RBF neural network controller outperforms other controllers in the previous studies by achieving targeted thermal dose with shortest treatment times less than 13.5 min, avoiding the tissue cavitation during the thermal therapy. Moreover, the maximum value of its mean integral time absolute error (MTAE) is 98.64, which is significantly less than the resulted errors for the manual-tuned controller under the same treatment conditions of all tested cases. In this study, integrated ACO method with robust RBF neural network controller provides a successful and improved performance to deliver accurate thermal dose of hyperthermia cancer tumour treatment using the focused ultrasound transducer without external cooling effect.

Gold nanorods together with HSP inhibitor-VER-155008 micelles for colon cancer mild-temperature photothermal therapy

Enhancing the heat-sensitivity of tumor cells provides an alternative solution to maintaining the therapeutic outcome of photothermal therapy (PTT). In this study, we constructed a therapeutic system, which was composed of methoxy-polyethylene-glycol-coated-gold-nanorods (MPEG-AuNR) and VER-155008-micelles, to evaluate the effect of VER-155008 on the sensitivity of tumor cells to heat, and further investigate the therapeutic outcome of MPEG-AuNR mediated PTT combined with VER-155008- micelles. VER-155008- micelles down-regulate the expression of heat shock proteins and attenuate the heat-resistance of tumor cell. The survival of HCT116 cells treated with VER-155008- micelles under 45 °C is equal to that treated with high temperature hyperthermia (55 °C) in vitro. Furthermore, we proved either the MPEG-AuNR or VER-155008- micelles can be accumulate in the tumor site by photoacoustic imaging and fluorescent imaging. In vivo anti-cancer evaluation showed that tumor size remarkably decreased (smaller than 100 mm3 or vanished) when treated with combing 45 °C mild PTT system, which contrasted to the tumor size when treated with individual 45 °C mild PTT (around 500 nm3) or normal saline as control (larger than 2000 nm3). These results proved that the VER-155008- micelles can attenuate the heat-resistance of tumor cells and enhance the therapeutic outcome of mild-temperature photothermal therapy.

An injectable ionic hydrogel inducing high temperature hyperthermia for microwave tumor ablation.

Microwave tumor ablation is of clinical significance and has been considered as a promising cancer minimally invasive therapy. One of the challenges in this field is the optimization of the susceptible agent. Herein, a novel chitosan-based ionic hydrogel which can induce rather high temperature hyperthermia as a susceptible agent for microwave ablation is reported. Owning to the high porosity of the hydrogel, a strong ion confinement effect can be realized, therefore, strong polarization under microwave exposure is ensured for rapid heat generation. In addition, the as-synthesized hydrogel has negligible bio-toxicity and excellent spatial stability in vivo which can guarantee a reproducible therapeutic effect for repeated treatment. In vivo anti-tumor investigation has demonstrated that excellent therapeutic efficiency can be achieved after repeated microwave thermal therapy with a rather low power density (2.0 W, 2.45 GHz). Further, computer simulation was conducted to elucidate the microwave heating mechanism. Our investigation provides a biocompatible and stable agent for microwave tumor ablation and demonstrates its great significance for potential clinical application.

Fast and high temperature hyperthermia coupled with radiotherapy as a possible new treatment for glioblastoma.

BackgroundA new transcranial focused ultrasound device has been developed that can induce hyperthermia in a large tissue volume. The purpose of this work is to investigate theoretically how glioblastoma multiforme (GBM) can be effectively treated by combining the fast hyperthermia generated by this focused ultrasound device with external beam radiotherapy.Methods/DesignTo investigate the effect of tumor growth, we have developed a mathematical description of GBM proliferation and diffusion in the context of reaction–diffusion theory. In addition, we have formulated equations describing the impact of radiotherapy and heat on GBM in the reaction–diffusion equation, including tumor regrowth by stem cells. This formulation has been used to predict the effectiveness of the combination treatment for a realistic focused ultrasound heating scenario.Our results show that patient survival could be significantly improved by this combined treatment modality.DiscussionHigh priority should be given to experiments to validate the therapeutic benefit predicted by our model.Electronic supplementary materialThe online version of this article (doi:10.1186/s40349-016-0078-3) contains supplementary material, which is available to authorized users.

High temperature hyperthermia treatment for canines exhibiting superficial tumors: A report of three cases.

High temperature hyperthermia (HTH) treatment has previously been demonstrated to suppress tumor growth in a tumor-bearing rat model. In the present study, the effects of HTH therapy for the treatment of spontaneous tumors in canines was evaluated. In case 1, an 18-year-old female Papillon presented with a right forelimb rhabdomyosarcoma. Case 2 was a 13-year-old male English Cocker Spaniel with a right external auditory canal ceruminous adenocarcinoma and case 3 was a 14-year-old male Golden Retriever that exhibited a perianal gland adenocarcinoma, which surrounded the anus. HTH treatment was performed in all three cases for 10 min at 45–65°C with or without the inhalation of isoflurane. In case 1, the tumor disappeared four weeks following HTH treatment. In case 2, the tumor volume had decreased by day 21, and in case 3, HTH was performed three times and the tumor disappeared following the third procedure. HTH is considered to be a simple procedure with no severe side effects. Consequently, this treatment modality is hypothesized to become a useful alternative therapy for superficial tumors in companion animals.

Non-surgical treatment of canine oral malignant melanoma: A case study of the application of complementary alternative medicine.

This report describes a dog with a clinical stage III oral malignant melanoma that was treated with complementary alternative medicine (CAM). The CAM included high temperature hyperthermia, dendritic cell therapy and lupeol injections. Surgery, radiation and chemotherapy were not performed. Two months after the start of treatment, the tumor disappeared and after six months, the follow-up examinations revealed no recurrence or metastasis of the tumor. Quality of life (QOL) of the dog was maintained; therefore, the application of CAM may be an effective treatment for canine oral malignant melanoma. The effective application of CAM has the potential to prolong life and maintain an excellent QOL for pets.

Antitumor effects of high-temperature hyperthermia on a glioma rat model.

High-temperature hyperthermia (HTH) is an established treatment option for cancer. The aim of the present study was to reveal the exact correlation between HTH at temperatures of 50–70°C and the resulting antitumor effects, using a glioma rat model. In the 60°C (T-60) and 70°C (T-70) HTH groups, tumor growth rates were significantly suppressed compared with those in the nontreatment (NT) group. In the 50°C (T-50) HTH group, tumor growth rates were not suppressed compared with those in the NT group. The numbers of terminal dUTP nick-end labeling-positive cells in tumor tissue were significantly higher in the T-50, T-60 and T-70 groups than those in the NT group. The Ki-67-positive areas were significantly decreased in the T-70 group compared with those in the NT and T-60 groups. Our data indicate that HTH at 60 and 70°C suppresses tumor growth in a glioma rat model. In particular, cell proliferation was significantly suppressed by HTH at 70°C. However, differences in the mechanism of action of HTH at 60 and 70°C were observed.

Antitumor effect and immune response induced by local hyperthermia in B16 murine melanoma: Effect of thermal dose

This study aimed at investigating the antitumor effect and immune response induced by local high-temperature hyperthermia at different thermal doses in B16 murine melanoma. The screened optimal thermal dose (50°C, 15 min) which was demonstrated to be the most effective in immune response activation was applied to the treatment of lung metastasis. The optimal thermal dose was determined by evaluating the tumor volume change, survival period of tumor-bearing mice, and immune indices including interleukin (IL)-2, interferon (IFN)-γ and TNF-α mRNA expression in the spleen of mice subjected to local hyperthermia at various thermal doses. The activation of the immune response was further investigated by rechallenging the cured mice 60 days after hyperthermia treatment. The screened optimal thermal dose combined with immunoadjuvant compound 48/80 was applied for melanoma lung metastasis. While local hyperthermia effectively inhibited B16 melanoma tumor growth and prolonged the survival period of tumor-bearing mice, the antitumor immunity was significantly enhanced and the effect was thermal dose-dependent. Higher temperatures (≥50°C) induced a significant effect even with a short treatment time (≤15 min). No tumor regrowth was observed for rechallenged B16 melanoma in mice following treatment with local hyperthermia at a higher temperature. Local hyperthermia by optimal thermal dose in combination with immunoadjuvant compound 48/80 is an effective approach for the treatment of B16 melanoma lung metastasis. This study indicated that the use of a local high-temperature hyperthermia protocol inhibits tumor growth and stimulates a favorable antitumor immune response against malignant melanoma. The results of these experiments may have clinical significance for the treatment of melanoma.

Coaxial Slot Antenna Design for Microwave Hyperthermia using Finite- Difference Time-Domain and Finite Element Method

Hyperthermia also called thermal therapy or thermotherapy is a type of cancer treatment in which body tissue is exposed to high temperatures. Research has shown that high temperatures can damage and kill cancer cells, usually with minimal injury to normal tissues. Otherwise, ablation or high temperature hyperthermia, including lasers and the use of radiofrequency, microwaves, and high-intensity focused ultrasound, are gaining attention as an alternative to standard sur- gical therapies. The electromagnetic microwave irradiation applied to the tumor tissue causes water molecules to vibrate and rotate, resulting in tissue heating and subsequently cell death via thermal-induced protein denaturation. The effective- ness of this technique is related to the temperature achieved during the therapy, as well as the length time of treatment and cell and tissue characteristics. Numerical electromagnetic and thermal simulations are used to optimize the antenna design and predict heating patterns. A computer modeling of a double slot antenna for interstitial hyperthermia was designed us- ing two different numerical methods, the Finite Element Method and a Finite-Difference Time-Domain. The aim of this work is to analyze both numerical methods and finally experiments results are compared to the simulated results generated by a thermal model. Our results show that normalized SAR patterns using FEM and FDTD look broadly similar. Further- more, the computed 60 °C isotherm using FEM and the measured lesion diameter in ex vivo tissue results agree very well.

Thermal Therapy, Part 1: An Introduction to Thermal Therapy

Thermal therapy is widely known and electromagnetic (EM) energy, ultrasonic waves, and other thermal-conduction-based devices have been used as heating sources. In particular, advances in EM technology have paved the way for promising trends in thermotherapeutical applications such as oncology, physiotherapy, urology, cardiology, ophthalmology, and in other areas of medicine as well. This series of articles is generally written for oncologists, cancer researchers, medical students, biomedical researchers, clinicians, and others who have an interest in this topic. This article reviews key processes and developments in thermal therapy with emphasis on two techniques, namely, hyperthermia [including long-term low-temperature hyperthermia (40-41 degrees C for 6-72 hr), moderate-temperature hyperthermia (42-45 degrees C for 15-60 min), and thermal ablation, or high-temperature hyperthermia (> 50 degrees C for > 4-6 min)]. The article will also provide an overview of a wide range of possible mechanisms and biological effects of heat. This information will be discussed in light of what is known about the degree of temperature rise that is expected from various sources of energy. The review concludes with an evaluation of human exposure risk to EM energy or the corresponding heat, trends in equipment development, and future research directions.

Thermal ablation and high-temperature thermal therapy: Overview of technology and clinical implementation

High-temperature hyperthermia or thermal therapy is being applied for destruction of canceroustissue, eradication or reduction of benign tumours and targeted tissue modification and remodelling.Many of these high-temperature technologies provide a minimally-invasive alternative with lowermorbidities compared to the traditional surgical procedures. The effects of high-temperature thermalexposure on tissues, examples of heating technology and procedures of clinical practice related tohigh-temperature thermal therapy are reviewed. This brief review encompasses interstitial, endocavity,intraluminal and external applications of RF, microwave, ultrasound, laser and thermal conductionenergy sources. The technology is prevalent and in various levels of advancement, with themove toward more spatially-accurate and controllable heating systems combined with image-guidanceand treatment verification warranted, especially for the treatment of cancer.

Examination of the exciting condition for the high-temperature magnetic hyperthermia

The soft-heating method is one of the hyperthermia. The heater that consists of thermosensitive ferrite is implanted into the body, and heated by a high-frequency magnetic field. This paper applies the "advanced" soft-heating method. A complex type of heater, composed of thermosensitive ferrite wound on a metallic ring, is created. This complex type of heater produces heat due to losses of hysteresis and inductive current. The effect of the exciting frequency on the heating value of a complex type of heater is examined. As a result, the area of 12/spl times/7 mm is heated over 60/spl deg/C in phantom, in the condition of 6 mT-100 kHz. The heated area in vitro is confirmed, so a test in vivo is examined. The tumors of mice were heated to the point at which the tumor is necrotized.

Heat Characteristics of Micro Magnetic Heat Elements for Advanced Hyperthermia

Hyperthermia is one of the therapeutic techniques that attempt to mainly induce necrosis in cancer cells by heating. To cause necrosis in tumors under hyperthermia with certainty, the authors proposed high-temperature hyperthermia. For this study, the authors examined the heat characteristics of the heat element composed of a thermosensitive magnetic material and a metal ring with various volumes. Our results showed that heat characteristics have a tendency to saturate with an increase in element volume.

Optimal power deposition patterns for ideal high temperature therapy/hyperthermia treatments

If it were possible to achieve, an ideal high temperature therapy or hyperthermia treatment would involve a single heating session and yield a desired thermal dose distribution in the tumour that would be attained in the shortest possible treatment time without heating critical normal tissues excessively. Simultaneously achieving all of these goals is impossible in practice, thus requiring trade-offs that allow clinicians to approach more closely some of these ideal goals at the expense of others. To study the basic nature of a subset of these trade-offs, the present simulation study looked at a simple, ideal case in which the tumour is heated by a single, optimized (with respect to space) power pulse, with no power deposition in the normal tissue. Results were obtained for two different clinical strategies (i.e. trade-off approaches), including: (1) an ‘aggressive’ approach, wherein the desired, uniform thermal dose is completely delivered to the tumour during the power-on period. This approach gives the clinician the satisfaction of knowing that the tumour was treated completely while power was being delivered, and yields the shortest attainable tumour dose delivery time. However, that benefit is attained at the cost of both ‘overdosing’ the tumour during the subsequent cool down period and, paradoxically, requiring a longer, overall treatment time. Here, the treatment time is considered as that time interval from the initiation of the heating pulse to the time at which the entire tumour has decayed to a specified ‘safe’ temperature — below 43°C for our calculations. And, (2) a ‘conservative’ approach is considered, wherein the desired uniform dose is attained at the post-heating time at which the complete tumour cools back down to ‘basal’ conditions, taken as 4 h in this study. This conservative approach requires less applied power and energy and avoids the ‘overdosing’ problem, but at the cost of having a tumour dose delivery time that can be significantly longer than the heating pulse duration. This approach can require that clinicians wait a significant time after the power has been turned off before being able to confirm that the desired tumour thermal dose was reached. The present findings show that: (1) for both clinical strategies, an optimal power deposition shape (with respect to position in the tumour) can always be found that provides the desired uniform thermal dose in the tumour, regardless of the heating pulse duration chosen or the tumour perfusion pattern; and (2) shorter heating pulses are preferable to longer ones in that they require less total energy, take less total time to treat the patients, and have optimal power deposition patterns less influenced by perfusion. On the other hand, shorter pulses always require higher temperatures, and for the ‘aggressive’ clinical approach, they give significantly larger excess thermal doses in the tumour. The aggressive approach always requires longer treatment times than comparable conservative treatments. The optimal power patterns for both strategies involve a high-power density at the tumour boundary, which frequently creates a ‘thermal wave’ that contributes significantly to the final thermal dose distribution attained.

複数の発熱体を用いたハイパーサーミアの加温領域に関する基礎的考察

Hyperthermia is a well-known treatment for cancer. When the tumor volume is somewhat large, a temperature difference occurs between the tumor core and the near edge. High-temperature hyperthermia is proposed to keep the temperature of the heaters high. The soft-heating method used excites a thermosensitive magnetic heater in a high-frequency magnetic field. The temperature distribution when two or more heaters were used was measured for a hybrid heater composed of thermosensitive magnetic material and a metal ring, and the effective area for hyperthermia was examined.

高温ハイパーサーミア用複合発熱体に関する一考察

Hyperthermia is a therapeutic technique against cancer. It necrotizes cancer cells by applying heat at about 43°C, at which the survival rate of cancer cells drastically drops. However, in case of a substantially large tumor, there is a possibility that cancer cells may survive when there is a difference in the temperature between the central part and marginal region. For this condition, high-temperature hyperthermia is proposed as a way to ensure that the malignant tumor is necrotized. In this study, using the soft heating method, which is a kind of inductive heating method, with hybrid heaters, we examined the temperature distributions of hybrid heaters that varies with the configuration of metal rings for the thermosensitive magnetic material.

Consideration of handy excitation apparatus for the inductive hyperthermia

Hyperthermia is one of the therapeutic techniques for cancer that attempts to necrotize cancer cells by heating. In this study, we examine a device based on handy circular excitation coils and hybrid heaters for high-temperature hyperthermia using the soft heating method.

ハイパーサーミア用感温磁性体に関する一考察

High-temperature hyperthermia is proposed as a means of reliably necrotizing malignant tumors in cancer therapy. Consideration of the temperature distributions of two kinds of hybrid heaters showed that a hybrid heater with two metal rings attached is superior to a hybrid heater with one metal ring attached.