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# Hyperthermia - Science topic

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My project is hyperthermic treatment of cancer using biomedical antenna, for that I am using a 4x4 patch antenna array design and a spherical homogenous glandular tissue with a tumor inside it. By giving appropriate phase and amplitude input I am able to heat the tumor at a temperature of 41.935'C but the input power is 36 W for a single antenna!!!. I am feeding all antenna's individually so the thing is power input is not at all practical input. I request you to give your suggestion on how to reduce the power input without affecting the temperature distribution.
You are putting in about 500 W of power through 16 antennas.
This is enough to raise 1.2 ml (1.06 cm cube) of water 100 deg per second.
You are raising the target area by about 6 deg.
I expect your problem is that you are heating a lot of other tissue at the same time. It only has to be a 5 cm cube and it only goes up 1 degree per second. If you have included conduction, then heat will travel outwards (mostly) and you will lose the effect of the concentrated heat in the centre if you heat too slowly.
I think you are also heating up tissue directly below the antennas (as well as all the tissue, a little bit). All this requires that you put in more power than you actually need just to heat up the part you want. Work out the power and energy budget. It is fairly simple to do, and you will see where the power is being wasted, and you will find out if there is anything you can do about it.
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My project is hyperthermic treatment of cancer using biomedical antenna. I have successfully managed to show max SAR and max temperature distribution at the tumor location inside the homogeneous breast phantom. Now my professor asked me to solve the pennes bio-heat equation and the power density relation to back prove if i am getting that temperature value. I am finding difficulty doing this can you share Matlab code or doc reference to do so. I have values of thermal conductivity, blood perfusion coefficient etc but these values are digits whereas temperature distribution is a 3-D quantity.
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Electrical circuits for different experiments e.g Brownian motion, Hystesis Law and etc
Yes
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Under the pandemic of COVID-19, screening becomes important to tackle the spread. Fever is one of the screening criteria for many public places screening for access.
However, how is fever defined?
Is the 0.1 degree change makes the significance?
What is the range of standard deviation being acceptable?
What machine is accurate?
Is those hand held infrared measuring machines reliable?
Is there scenarios giving false negative tha may make a huge consequence?
Normal Body Temperature: A Systematic Review.
Open Forum Infect Dis. 2019;6(4):ofz032. Published 2019 Apr 9.
CDC considers a person to have a fever when he or she has a measured temperature of 100.4° F (38° C) or greater, or feels warm to the touch, or gives a history of feeling feverish.
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I have synthesized some Iron oxide nanoparticles (powder sample). I have checked it's response with strong neodymium magnet in lab. Now I want to check its temperature response with time.
So I want to know how much amount of sample (maximum and minimum ) would be needed for this measurement ? In some literature they reported 1mg/ml and in others 5,10, 20...50 mg/ml also ? So I am confused whether I should use low concentrations or high one. ?
The number of nanoparticles in a hyperthermia experiment depends on your biological material. Although there is iron in the blood, iron nanoparticles are toxic. The reference point can be the death concentration of 50% of the biological material. These concentrations are known and tabulated. For the experiment, you need to take the concentration even less. Start with low concentrations.
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Page 7 line 17 In the present experiment, bimetallic alloy nanoparticles produced and a single surface plasmon resonance (SPS) peak of intensity of 409 nm is observed, and probe of identification of Ag/Co alloy, which is very close to the SPR peak at 410 nm of Ag/Co alloy synthesized by chemical reaction process [22].
Line 17. You are speaking about SPS. But because the research is focused on the nanoparticles they have Localise Surface Plasmon Resonance (LSPS).
Why did you used the wavelength 808 nm? Because the absorption caused by LSPR is around 400 nm (Figure 5) and at 808 nm the absorption due to plasmon resonance is negligible!
The possible reason for the higher temperature profiles and rise of nanofluid than water alone is the plasmonic hyperthermia effect of nanoparticles.
Line 57- "The possible reason for the higher temperature profiles and rise of nanofluid than water alone is the plasmonic hyperthermia effect of nanoparticles." The plasmonic behaviour is significant at around 400 nm. At wavelength 808 nm the absorption caused by Localised Surface Plasmon resonance (LSPR) are unneglectable. This discrepancies has to be explain in the text and in the Conclusion.
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dear colleagues,
What is the similarities and differences of these 3 terms in biomedical sciences. if there is more, please add it here to make more complex question with a wholistic idea!
Hyperthermia therapy , Photodynamic therapy and Photothermal therapy
Amir
In Photodynamic therapy (PDT) a certain photosensitizing agent is used, and upon excitation with the proper wavelength, it produces a cytotoxic form of oxygen that kills cancer cells.
On the other hand, photothermal therapy, also called plasmonic hyperthermia, uses nanostructures that absorb infrared light and release such extra energy as heat transferred to their surroundings. When those nanostructures are placed in the vicinity of cancer cells, such heat can kill the cancer cells, usually by inducing the apoptosis mechanism at temperature about 44 ºC.
It is worth mentioning that the hyperthermia can be magnetic instead of optical, when using magnetic nanostructures that are submitted to a proper alternating magnetic field from outside.
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How does blood perfusion change during hyperthermia and hypothermia? What mathematical expressions exist for these phenomena? I would like indications of research about the subject. Thank you!
Thank you very much! congratulations on the explanation.
Yes. The Hagen-Poiseuuille Classical Equation relates several parameters for laminar flow through a horizontal pipe (analogous to blood vessels).
So, in your opinion, knowing the relationship between blood viscosity and tissue temperature, and using the Hagen-Pouseuuile equation to determine the flow rate, can I later determine the perfusion?
And how to determine the variation in blood vessel diameter during vasoconstriction or vasodilation?
Thank you very much for participating in this discussion!
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What kind of magnetic nanoparticles we can use for hyperthermia study? Can we use Manganese chalcogenide systems (MnS, MnSe) for hyperthermia treatment?
You should use superparamagnetic nanoparticles. There is an alignment of the magnetic moments inside each NP, producing a high magnetic moment for each NP.  At RT, due to the thermal energy, such moment of each NP rotates randomly, but if a magnetic field is applied,  there will be a net statistical alignment of the magnetic moments of the NPs. It is analogous to what happens to paramagnetic materials, but the magnetic moments are now those of the NPs, so giving rise to a signal which can be up to 10,000 times larger than for a paramagnetic material.
I'm not familiar with Manganese Sulfide, but according to this publication, MnS is antiferromagnetic at low T and superparamagnetic at RT, so you could use it:
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hyperthermia is the technique that neglects the use of chemicals or harmful radiations. The elevated body temperature can damage the cancerous cells.
The answers provided by Dr. Engelmann and Dr. Karel are correct and essentially summarizes the situation.
I would like to add the following points.
1) Oscillating magnetic field (at RF) will generate eddy current heating in tissue materials. The amount of heating and the related temperature elevation depends on several factors. But the major external factors are field amplitude, frequency and tissue size (over which integration is performed to calculate volumetric heating). There is a physiological limit on the product of field amplitude and frequency, which is known as Brezovich's limit (see the details provided by Dr. Engelmann). Depending on actual condition, like tissue size, exposure time, the product of field amplitude and frequency can be optimized to reduce undesired tissue heating.
2) However, this heating is common to healthy and cancer tissue (without considering depth variation) and administration of magnetic nanoparticles in tumor location will cause additional heating due to relaxation and/ or hysteresis losses, which is called magnetic fluid hyperthermia. Details of this process is a separate research topic and there are large no. of literature available.
3) In general, a heating in the range of 42 deg. C is considered to be adequate for causing metabolic damage in cancerous cells. However, the actual temperature and the duration over which temperature needs to be maintained over 42 deg. C varies with size, shape, location and type of tumor (and also on chemical aspects, ph range, leaky vasculature around tumor and oxygen availability, etc.).
4) The damage to healthy cells will definitely occur, if they are exposed to higher temperature for a considerable duration and designing target specific magnetic nanoparticles capable of delivering high localized heating is an open research problem.
5) However, it must be noted that cancerous cells are reported to be more susceptible to temperature increase. In this aspect necrosis and apoptosis needs to be understood.
Also the treatment efficiency of chemo or radio-therapy has been reported to enhance, when the cancerous cells are exposed to higher temperature (42 deg. C).
In summary: Yes RF magnetic field heats up healthy tissues. But the temperature rise can be controlled by varying field amplitude and frequency. Use of magnetic nano particle in cancer locations is for generating heat at a much higher rate than the eddy current heating of the tissues. Minimizing thermal dose to healthy tissues is a question of research.
And hyperthermia does not avoid chemo or radio-therapy. There are several studies on multi-modal hyperthermia (hyperthermia + photo dynamic or hyperthermia + chemo therapy), hyperthermia + drug delivery and hyperthermia + brachytherapy or radiotherapy as concomitant treatment protocol.
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I am actually using antenna radiation for hyperthermia treatment for treating the breast cancer. How could one simulate the temperature distribution inside the breast phantom using CST software?
I know the theory behind it by combinning the SAR values and the bioheat equation. However, I do not know until now how to accomplish it by simulation.
You should use transmission objects material using fat, muscle, and blood.
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Hi,
I have not had any luck finding studies related to hyperthermia testing on collagen 3D models. Is there any specific reason why collagen matrices are not being used for hyperthermia testing?
why could they help?
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The amount of heat generated by SPIONs under external magnetic field  is denoted as the specific absorption rate (SAR). SAR is the radio frequency electromagnetic field absorbed per unit of mass of biological tissue and is expressed in watts per kilogram (W/kg).
SAR is described in 2 ways in different literatures:
1) SAR(w/g)=(c/m).(dT/dt)
2) SAR (w/g)= c. ΔT/Δt
Which one of these equations are the right one for SAR measuermetnts? how we can have 2 equation for a single  physical parameter ??
All the best
SAR (W/kg)= Cv*ΔT/Δt , where Cv is the volumetric specfic heat. SAR can be derived from Penne's bioheat equation for the case when assuming no thermal conduction ΔT/Δr = 0, where r is the spatial vector incorporating x.y and z.
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I want to simulate temperature distribution and acoustic wave propagation during High-Intensity Focused Ultrasound Hyperthermia in a 3-Dimensional model by using Comsol Software.
I did the simulation based on examples I saw in the Comsol but the results were not correct.
In fact, Acoustic Pressure Field is occured in Transducer surface that is not true.
If anyone can help me, I will appreciate him/her so much.
Dear Sahba,
if you like, you can send me your model (without solution calculation and without meshing) and I will have a look on it in COMSOL. E-mail your model to michael.hader@uni-bayreuth.de with a short description of your problem and calculation model, i.e. what do you expect or want to find out?
Kind regards,
Michael
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I am Dr. P. Prameela from Veltech University, Chennai, India. We have been developing nanoferrite materials for core applications. Recently we have extended our research area into materials for magetic hyperthermia.
In this regard, after going through your paper, I am requesting you to help us in taking the frequency dispersion of permeability of our samples using network analyzer. Let me also know how we can measure the real & imaginary parts of the permeability & how the sample holder will be at higher frequency (2 -18 GHz).
Thanking you
Dr.P.Prameela
Dear Dr Prameela, there are may ways to measure the dielectric and magnetic properties of your samples the best way in your case depends on the requirements in precision and also on the sample shape available. For broadband measurements the method described by Walter Barry can be useful (coax or stripline) lets have further discussions by normal e-mail (Fritz.Caspers@cern.ch)
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Nanomaterials for Magnetic and Optical Hyperthermia Applications
No, I haven't
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How to calculate the unavoidable exergy destruction of demethanizer and deethanizer in the attached figure? Some paper said using minimun reflux ratio to calculate unvoidable exergy destruction of columns, but I find it impossible used it in complex demethanizer and deethanizer because infinite stages cannot be achieved in simulation. So I think wether it is right that I just increase the theoretical stages to a certain value and I define it as unavoidable condition.
Refer to my paper, demethanizer energy targeting.
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Hello,
I would like to know how it is possible to heat at 42ºC during one hour the brain of mice (thermal therapy) in an easy way.
Maxime.
Dear Mohamed Azab,
I want to simulate an hyperthermia pre-treatment used for glioma, before drug treatment. It seems that 42ºC or no more than 45ºC is the temperature for that, but Ido not have easy access to LASER or ultrasound.
Thank you
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I am reviewing Fluoride Death Data including the excess deaths attributable to Fluoride Toxicity, including but not limited to: Alzheimer’s, Anaesthetic Hyperthermia, Aortic Rupture, Asthma, Cancer, Cataract, Chronic Kidney Disease (including Pyelonephritis), Chronic Obstructive Pulmonary Disease, Crime (including Fluoride enhanced Plumbosolvency leading to elevated Blood Lead Levels), Diabetes, Fluoridation overdosing, Eclampsia, Foetal and Perinatal mortality, Gels, Rinses and Toothpastes, Hip Fracture, Liver Failure (including Fat Burner and Tea products), Stroke, Sudden Infant Death Syndrome, Suicide. I have already found many references but would like assistance in building a comprehensive bibliography.
Fluoride is known to increase the incidence of bone fracture. Older adults have a 5- to 8-fold increased risk for all-cause mortality during the
first 3 months after hip fracture. We can therefore safely say Fluoride causes excess deaths via this mechanism.
See this interesting article with references.
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heat acclimatization can increase performance of athlete and occupational for physical activity in heat condition.
for this purpose we have to train for adaptation in heat condition regularly. but I have some question about chronic heat stress.
does living in heat climate can lead to chronic fatigue?
does hyperthermia and heat illness occur without any symptom chronically?
Dear Seyyed,
Qian S, Li M, Li G, Liu K, Li B, Jiang Q, Li L, Yang Z, Sun G. Environmental heat stress enhances mental fatigue during sustained attention task performing: evidence from an ASL perfusion study. Behav Brain Res 2015;280:6-15. https://www.sciencedirect.com/science/article/pii/S0166432814007724?via%3Dihub
PUSPITA N, KURNIAWIDJAJA M, HIKMAT RAMDHAN D. Health Effect Symptoms Due to Heat Stress Among Gong Factory Workers in Bogor, Indonesia. In The 2nd International Meeting of Public Health 2016 with theme “Public Health Perspective of Sustainable Development Goals: The Challenges and Opportunities in Asia-Pacific Region”. KnE Life Sciences 2018;469-475. https://www.knepublishing.com/index.php/Kne-Life/article/view/2308/5104
Vargas N, Marino F. Heat stress, gastrointestinal permeability and interleukin-6 signaling - Implications for exercise performance and fatigue. Temperature (Austin) 2016;3(2):240-251. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4964994/pdf/ktmp-03-02-1179380.pdf
Otani H, Kaya M, Tamaki A, Watson P. Separate and combined effects of exposure to heat stress and mental fatigue on endurance exercise capacity in the heat. Eur J Appl Physiol 2017;117(1):119-129. https://link.springer.com/article/10.1007%2Fs00421-016-3504-x
Robertson CV, Marino FE. Cerebral responses to exercise and the influence of heat stress in human fatigue. J Therm Biol 2017;63:10-15. https://www.sciencedirect.com/science/article/pii/S0306456516301668?via%3Dihub
Best wishes from Germany,
Martin
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I am a physician specialized in Clinical Environmental Medicine using Mild Whole Body Hypertermia to treat people suffering from chronic complex environment associated multisystem illnesses.
Peter Ohnsorge
In a recent review of sauna, there are some studies - albeit small - that support what you've just stated - hyperthermia, via infrared sauna, but with milder temperature settings for chronic complex illnesses like CFE/ME, Fibromyalgia, chronic pain, etc. See attached.
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As in modern age, magnetic nano-particles (particularly iron oxides) are under extensive research for their possible applications in hyperthermia, Drug Delivery, etc .
I will be thankful for your comments/suggestions to clear my understanding about the effect of size variation of Magnetic nanoparticles on the amount of heat generated. If we use Np's e.g Fe3O4 of spherical shape and apply same AC magnetic field, but just vary the size of NP's used in different experiments.
How much will it effect the amount of heat generated ?
Thanks
Dear Irfan,
Let me try to summarize some magnetic properties related with the size of the nanoparticles.
The size is very important in magnetism because the anisotropy energy depends of it. On the other hand the magnetic domains have a finite size and the monodomain nanoparticles presents superparamagnetism, i,e, hysteresis cycles without area and therefore without losses (i.e. without heat within a DC field the AC allows to produce it in very subtle form). This means that the spins rotate coherently as if you had an only superspin for the whole nanoparticle. On the other hand, this produces a Neel relaxation time exponentially dependent of the size of the nanoparticles. That is to say, the size directly tells you how the magnetizacion of the samples can relax from a kind of "macroscopic ferromagnetism" to a "paramagnetism".
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Note that i work on microwave hyperthermia
Hi Maha,
Bit late answering this, but in case you are still having troubles.
There could be three reasons for not getting the results:
1) You need to give the input signal a pulse. I tend to use a rectangular signal.
2) You need to change the simulation duration in the solver setup window.
3) Make sure that your units are set to (s) I usually have mine on (ns) and this has caught me out a few times.
If you have tried both of these and are sill having issues please don't hesitate to get in touch
Hope this helps.
Shaun
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Co-precipitation or thermal decomposition, etc.?
The paper might be of interest to you:
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My study state is hyperthermia and i make a field monitor 3000 sec but when i changed it to 9000 sec,the temperature still the same.what is my fault??
Firstly, thanks for reply.But all these answers explain transient thermal, i work with stationary case and when i changed the time at field monitor the temperature still the same.I want to know the wrong in my boundary condition or exposure time i defined.
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I synthesised magnetic nanoparticles. I donot have proper idea about hyperthermia application.
Dear Mohana,
check out the Radiomag project page here on Researchgate, lots of useful information there that should help.
regards,
Carl
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I have seen some articles about tumor cell's high temperature and lower PH, I am wondering that if tumor cell has better resistance which means that tumor cell has lower temperature when heated by laser or microwave, or not? I cannot find any papers about this, what i can find are all about Hyperthermia. my email is: liwanhe12358@gmail.com for better communication. Thanks.
It is well known that tumor tissue has higher metabolic rate and energy expenditure than surrounding healthy tissue, so that more energy (heat) is produced which could identified via thermodiagnostic methods which are used crrrently -though - less commonly for diagnosis of solid tumors when comparing pattern of heat in normal vs tumor tissue.
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Hyperthermia
thanks pappu sir
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I'm just looking for hyperthermia measurements facility in India so that I can characterise it
Dear Vijay, so far as I know there is no good facility for testing particles developed for MFH. I hope in near future it may be developed.
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i want to check any synergistic or additive effect but my two indicators are not two drugs rather drug is applied with hyperthermia to enhance the apoptosis. so in this case can i apply isobolograph to check the synergistic effects or not? please guide me in this respect..
First of all, you have to be sure your factors really increase apoptosis. I suggest you do  flow cytometer with annexin V with different concentrations or conditions.
For checking apoptosis also means checking cytotoxicity. You have to decide a cytotoxicity assay to find the factors' cytotoxic effect in a concentration range of 0%-100% cytotoxicity. So, you have to conduct a cytotoxicity assay like SRB or MTT with the factors (hyperthermia and the drug). First of all, you have to find the concentrations of the factors to induce 0 to 100% growth inhibition. So when you find this concentrations you have to plan another experiment of cytotoxicity with each factor and combination. For example if a certain concentration of the drug inhibits 40% of growth, and hypothermia inhibits 40% of growth individually. In these certain conditions, if you combine them, they should give 80% if they are additive, if more than 80%, like 100% they are synergitic, if the result is less than 80%, so they are antagonistic. You can just transform this percent numbers to 0-1, like 80% = 0.8
Good luck
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Dear Colleagues
I have many difficulties in finding electro-thermal parameters of styrofoam (polystyrene) and laboratory glass (polypropylene)? In literature the authors rather have not mentioned which parameters they used in numerical simulations. I am especially interested in such parameters:
Relative Permittivity
Electrical Conductivity [S/m]
MassDensity [kg/m3]
Specific Heat [J/(kg K)]
Thermal Conductivity [W/(m K)]
for frequencies in the range of 100 kHz - 1000 kHz.
Maybe do you know the publications with such parameters?
I will be grateful for your help!
Best Wishes,
Piotr
Vitalii, you help me a lot!
Best Wishes,
Piotr
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I am considering possibilities of hyperthermia like scenario to destroy cancerous tissues inside a human body using a swallowed pill. I am conserving solid-state devices like Gunn diodes or RTDs to generate local RF heating to achieve my goals. Your comments and guidance to existing technologies would be valuable. Thank you.
Is your approach similar to HIFU? which was approved for early stage prostate cancer patients.
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.
Dear Margarethus,
In order to try to bring you a simple (but in fact too simplistic) response facing a more than complex situation, I would recommend:
1) to use "easy" s.c. models (in syngeneic mice) if you want to study any relationships between a treatment and an immune response in a very large sense of the term,
2) idem is you just want to confirm in vivo data that you obtained in vitro,
3) to avoid s.c. xenografts because these types of models are of very poor clinical relevance,
3) moving on orthotopic models to study any potential treatment against metastases, knowing that i) a primary tumor that has not yet metastasize is cured by surgery or surgery + radiotherapy, and ii) 90% of cancer patients die from their metastases:
3.a. thus moving in orthopic AND metastasizing SYNGENEIC models
OR
3.b. idem with xenografts, with my personal opinion that 3.a. is as good as 3.b. and that 3.b. can be performed once you have positive data in 3.a..
Best regards
Robert
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Dear Colleagues
In the literature, I have found two different formulas for Neel relaxation time, namely:
tal_N = tal0*exp (K*VM/(kB*T))                                             (1)
and
tal_N = tal0/2*sqrt ((pi*kB*T)/(K*VM))*exp(K*VM/(kB*T))       (2)
For the same parameters I received about 3.6 times larger times for model (1)
Do You know which model is proper for magnetic fluid hyperthermia and when they are used?
I will be grateful for your help!
Best Wishes,
Piotr
Dear Piotr,
(1) is correct for magnetic relaxation without external magnetic field. (2) I think is not correct.
In case of high external magnetic field (magnetic anisotropy axis parallel to the external magnetic field) I think is OK Neel-Brown model.
In low amd medium external magnetic field  is most suitable Coffey model.
Several works:
All the best, Mihaela
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Cancer therapy
Laser and radiofrequency-induced hyperthermia for nanocomposites with SPION (Super Paramagnetic Iron-oxide Nanoparticle) and other magnetic materials (with supposedly hysteresis based heating effects), hydrogel and NPs (nanoparticles) info are plentiful on the net, go and google!
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In both conditions, we know that duration and core body temperature affects the mortality. I am trying to understand/ find papers that have estimated the amount of time a patient can survive the low or high body temperature. For example, in children locked in vehicles an average of 4.6 hours results in death of the child. Does anyone know the limits of survival in both conditions? Is there any Paper/Book I could refer? Thanks
Some hypothermia info on small children:
in 1994, a 2-year old survived 6 hours at minus 22 degrees C, but had to have one leg amputated. The body was almost frozen. Her temperature was 14 degrees C, probably the lowest ever recorded.
In 2001 a 1-year old was left outside for  3-4 hours in freezing conditions. It took doctors 1 1/2 hours to get the heart beating again.
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A lot many reports have emerged in the recent past investigating non-invasive RF hyperthermia using nanoparticles for cancer treatment. What are the presumed advantages of capacitive RF hyperthermia over inductive RF hyperthermia or vice versa? Since capacitive RF hyperthermia can cause heating up of ions, would its use on the body produce undesirable heating effects unlike inductive hyperthermia?
Dear Sajid Fazal,
The biggest difference is whether the technology requires invasive procedures yes or no.
In general non-invasive RF electromagnetic heating can be delivered using:
RF-capacitive coupling: two electrodes are placed on either side of the body and RF-current is flowing between both electrodes. The advantages are relative simple technology (so cheap systems). Disadvantages in most clinical applications is that the E-field is directed perpendicular on tissue transitions, more specifically those between fatty and muscle tissue. In this situation flux is constant resulting in preferential fat heating over muscle heating. Skin cooling with cold water is used to prevent over heating of fatty tissue. This works for patients with fat layers of less than 2 cm thickness. Western patients have in general fat thicknesses of more than 2 cm RF. A second disadvantage is that RF-capacitive heating does not provide a mean for focusing of RF-energy to the treatment volume. Frequencies used in clinical practice vary from 8 to 27 MHz.
RF-inductive coupling: RF-energy is transferred using inductive fields. The applicator consists often of an helical coil or pancake coil. In the early days of hyperthermia large single and multiple turn helical coils have been placed around the patient. RF-currents will be induced in the peripheral layers  of the body causing heating. Deep heating is poor as in the center of the coil no currents flow. Advantages: energy coupling through air, avoiding direct contact of the heating system with the patient. Disadvantage: poor deep heating and no ability to focus heating at the target volume. Frequencies used in clinical practice vary from 8 to 27 MHz.
RF-radiative coupling: multiple radiative antennas are used to couple energy to the patient. Water is used as a coupling medium between the antenna and the human body to preferentially transfer the energy to the patient. Further the water provides also a possibility to cool the superficial tissue, reduces the antenna size (high relative permittivity) and reduce reflection of RF-energy from the skin (in comparison a tissue contrast of air-skin has 60% reflections versus nearly zero for water-skin).
The main advantage of RF-radiative energy transfer is the ability to focus RF-energy at the target volume by optimizing the phase and amplitude settings per antenna. Using hyperthermia treatment planning phase and amplitude settings can be optimized based on the feedback of measured temperatures and patient information.
All the above is explained and demonstrated in the attached papers.
Besides the non-invasive technologies one can use more invasive procedures.
The most recent technology with promising potential for selective tumor heating is nano-particle inductive heating. Multiple papers have been published on this topic. A special issue of the Int. J. of Hyperthermia was devoted to this technology. Please check this literature.
Although the ultimate idea is to coat the nano-particles with proteins that connect to receptors at the tumors cell, the current practice is that the nano-particles still must be injected directly into the tumor in order to obtain a sufficient high concentration of nano-particles to allow sufficient energy delivery to increase tumor temperature to 43°C.
Regards,
Gerard van Rhoon
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I would like to demonstrate a non-specific, general immune-system activation of mild hyperthermia treatment on normal, healthy mouse.
Can anybody suggest me a very simple method to measure this effect? I am open for any idea... (For example change of the leukocyte population in peripheral blood, appearance of some cytokine, etc.)
Phagocytosis assay.  NK cell killing assay LPS or ComA. PHA stimulated. Proliferation assay.   Using. Circulated blood or splenocyte
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The setup is isoflurane with passive scavenging through an activated charcoal filter. These mice are Parvalbumin Cre (+) and (-). Mice are placed on a heating pad throughout surgery. There also is a lamp about a foot and a half above the surgery table that can get pretty hot. I'm not sure if this is the problem though. The mice have no problem going down. Their breathing is normal up until about an hour to an hour and a half. Their breathing becomes labored, they start pooping, and their muscles become rigid. Although their breathing gets lighter, they do not respond to a tail or toe pinch reflex. After about 5-10 minutes of this labored breathing, they die. The isoflurane level is between 0.5 and 2 during surgery.
Do you think it is a problem with the isoflurane chamber, hyperthermia, buildup up isoflurane waste, or something else? Any help would be greatly appreciated. I have attached a video of the labored breathing with the mouse not responding to a touch pinch.
Dear Sam,
We've been doing quite a lot of stereotaxic surgery usually administering AAV's into the hypothalamus and amygdala and it is always very important to determine that both your skills and set-up are appropriate. Can I ask if there are other users that successfully use your set-up? If so what do they do differently? Are your surgeries longer than others performing a similar protocol? If you are just learning the procedure nothing beats watching someone skilled in the procedure to pick-up any necessary tips from them.
In the past, we had a few problems with our initial anesthetic set-up using Isoflurane, it just needed some slight modifications. This was largely due to either providing too much isoflurane or having the scavenger set at too high a level. You can tell if the mouse is getting too much anesthetic - their breathing will get quite labored and they'll start to gasp. If they are getting too little then they'll start to squirm as they gain consciousness. Remember that the scavenger canister needs to be changed regularly and if you have a new canister it will scavenger much more than one that is near-full. Isoflurane is a good choice of anesthetic but needs careful monitoring throughout the surgery. It really shouldn't need to be adjusted throughout. We normally have it set around 1.5. I'd think that if you are using less than 1 then something is not set-up correctly. If the animals have slow steady breathing then you know that the anaesthetic set-up is appropriate.
In regards to temperature, if you are using a homeothermic blanket then the temperature should not be an issue as the blanket will regulate it appropriately. If you don't have a homeothermic blanket I'd suggest that you get one. Heating pads/blankets are alright for post-surgery recovery but shouldn't be used during the surgery itself.
Can I also ask if you are using any analgesic? If so, is the dose appropriate? If the animals are dying after about an hour, it might be an overdose from the analgesic.
I agree that you should perform a test to determine if the surgery is killing the animal. This could be done just placing a mouse in the frame as usual and monitoring it as you would during a surgery for the same amount of time. If the mouse survives than you know it's the surgery and not the set-up and can seek some expertise on the surgery itself.
Hope this helps.
J
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Interested in heat-labile linkers or thermo-responsive biocompatible polymers for hyperthermia cancer treatment application.
Great, cant wait to read the paper.
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Hello, I'm currently working in magnetic hyperthermia related topic. Is it possible to achieve temperature rise if I put iron oxide magnetic particles in a RF coil of 1.5 T MRI (64 MHz) for 5 minutes? Will the particles vibrate and heat up? The particle has superparamagnetic properties (15 emu/gr). Thanks.
The magnetic coupling for inductive heating in single domain particles occurs at kHz range. MRI frequency is too high for heating.Nevertheless You could measure some heating butit Should be of the Same order than the tissue alone.
Hope this helps.
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Common non invasive methods use blankets or ice, cold water immersion would be probably faster, but current guidelines for therapeutic hypothermia do not consider it.
Could cold water immersion be useful for other than heat stroke and hyperthermia treatment?
I'll preface this with the disclosure that I do have a conflict of interest with the company involved in this, but an alternative method for cooling, followed by maintenance and then rewarming, is described in these articles:
[1] Markota A, Kit B, Fluher J, Sinkovic A. Use of an oesophageal heat transfer device in therapeutic hypothermia. Resuscitation. 2015;89:e1-2.
[2] Hegazy A, Lapierre D, Althenayan E. Targeted temperature management after cardiac arrest and fever control with an esophageal cooling device. Critical Care. 2015;19:P424.
There's also a company, Life Recovery Systems (no conflict of interest) that sells an immersion device along the lines of what you asked originally.  They've published some data showing safety in defibrillation, but I'm not sure about overall ease of use.
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I want to work on targeted delivery of magnetic nanosystem on cancer cell for hyperthermia application. From prior art search, I found that surface receptor and antibody targeted delivery are the ways to deliver nanoparticles to the cancerous cell. Can we identify cancer cells from normal cells with the help of plasma membrane pore size? Can you suggest any new way for targeted delivery of nanoparticles to cancerous cells?
Hi,
There are number of papers relating to changes in the property of plasma membrane in cancerous cells when compared to normal cell. This includes change in the lipid composition, membrane proteins and saccharides on the protein. I don't think the porosity of the plasma membrane changes. By the way pores are not formed just like that. Pores are formed only when channel proteins (membrane proteins) open.
Enhanced permeability and retention (EPR) effect in the tumor vasculature of cancer cells might help you to target the nanoparticles. There are number of reviews related to EPR effect and drug delivery.
Nanoparticle uptake depends on number of factors like the size, charge, cell type and ligands molecules bound to it. So it is better take a closer look on the type of cancer cell you are going to target and characterize the nanoparticles before using it. Targeting the cancer cells through surface receptors (like folic acid receptor) and antibody works better. Hope this helps you
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I am performing magnetic hyperthermia experiments with iron oxide nanoparticles. I am facing a strange problem. Though my system is capable of producing higher coil current (we can calculate the magnetic field for a typical coil of known dimension from current), I am not being able to increase the current beyond certain value. If I place a solid metal piece inside the coil, I am able to increase the current, but for nanoparticle specimens in typical glass vials, power is just not getting transferred to the system from tank circuit. I am able to reach a maximum magnetic field of 0.8 kAmp/meter, whereas, in literature I often see magnetic field values in the order of 10-20 kAmp/meter for such nanoparticle systems of comparable weight percentage. My question is how to increase the coil current?
Am I missing something? I would like to get some help in this regard. I am open for comments and suggestions.
I am agree with Mr. Rasbindu. You need to change the power supply. And use a  generator with higher current value but be careful, high currents can damage your device.
I am looking for some one who has such instruments and is interested to have collaboration with me on this field!
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Hyperthermic Isolated Lung Perfusion (HILP) can be performed using moderate or true hyperthermia (39 and 41 degrees C, respectively). Under these conditions, does it occurs a significant effusion from the sane parenchima? Is this effusion exudative or transudative in nature?
Does HILP also increases the rate of transudative effusion in the metastases-affected lung parenchima?
Check these papers out:
Treatment of pleural effusion caused by lung carcinoma with circular intrapleural hyperthermic perfusion and its mechanism. Kang M,
Zhou L,Lin P. Zhonghua yi xue za zhi [2001, 81(19):1176-1179]
CONCLUSION: (1) Circular intrapleural hyperthermic perfusion is a new, safe, and effective treatment for MPE. (2) Apoptosis-mediated cytocidal function, improvement of body immunity after hyperthermic perfusion and continuous wash of the perfusion fluid are important mechanisms of intrapleural hyperthermic perfusion in treatment of MPE caused by lung carcinoma.
Anaesthetic management of cytoreductive surgery followed by hyperthermic intrathoracic chemotherapy perfusion. christoph.kerscher@gmx.net  et al. Journal of Cardiothoracic Surgery 2014, 9:125
Future Perspectives of Interstitial and Perfusional Hyperthermia
Gian Franco Baronzio et al.      http://www.ncbi.nlm.nih.gov/books/NBK6232/
Diagnosis and Treatment of Pleural Effusion        Victoria Villena Garrido et al.        Arch Bronconeumol. 2006;42:349-72. - Vol. 42 Num.07
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Hi, everybody. I am trying to design a hyperthermia induced drug release nano-system, containing a thermal-sensitive chemical linker which would be cleavage and release conjugated drugs after thermal treatment. It's best that this linker owns -NH2 ending.
However, i haven't found out an appropreate thermo-induced cleavaged linker between drugs and other polymers.
It seems azo linker is a candidate, which would release nirogen gas by cleavage in high temperature.
Please reccommand some text books or papers in terms of stimulus-induced cleavage of chemical bond, e.g. cleavage of disulfide linker in high inracellular glutathione (GSH) concentraion
Thank you every big man
thermo-sensitive polymeric micells are not i am looking for, but thank you a lot all the time.
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I am starting a new work related to " magnetite nanoparticles for hyperthermia applications". Therefore I kindly request experts in this field to guide me to few important and fundamental papers on hyperthermia applications of magnetic nanoparticles, which can be useful for any beginners in this subbject.
Rosensweig, R. E., Heating magnetic fluid with alternating magnetic field. J. Mag. Mag. Mater. 2002, 252, 370-374.
Rudolf, H.; Silvio, D.; Michael, R., Effects of size distribution on hysteresis losses of magnetic nanoparticles for hyperthermia. J. Phys.: Condens. Matter. 2008, 20, 385214.
Hugounenq, P.; Levy, M.; Alloyeau, D.; Lartigue, L.; Dubois, E.; Cabuil, V.; Ricolleau, C.; Roux, S.; Wilhelm, C.; Gazeau, F.; Bazzi, R., Iron Oxide Monocrystalline Nanoflowers for Highly Efficient Magnetic Hyperthermia. J. Phys. Chem. C 2012, 116, 15702-15712.
Lee, J.-H.; Jang, J.-t.; Choi, J.-s.; Moon, S. H.; Noh, S.-h.; Kim, J.-w.; Kim, J.-G.; Kim, I.-S.; Park, K. I.; Cheon, J., Exchange-coupled magnetic nanoparticles for efficient heat induction. Nat. Nano. 2011, 6, 418-422.
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From practical point of view (keeping aside research aspirations), what are the basic requirements of a candidate specimen for being a good system for magnetic hyperthermia applications? As per my understanding we need the followings.
1) System must be stable overa a large period of time. (I mean no settlement).
2) System must be capable of attaining hyperthermia temperature window (43-45 deg-cels).
3) System must be bio-compatible.
Any other most essential properties are required? Kindly comment.
There are two possibilities to heat magnetic particles by subjecting them to AC magnetic field (1) FM particles and (2) Superparamagnetic particles. The amount of heat generated in case of former can be calculated by hysteresis loop while for the later Rosensweig has developed a model based on Debye theory for dielectric dispersion in polar fluids. It is shown that the amount of heat generated depends on square of the applied field and imaginary part of complex magnetic susceptibility which in turn depends on driving frequency of the field. So, one has to calculate the amount of heat generated at a give target in the body. For safety it is necessary to use types of magnetic particles that has a large pyromagnetic coefficient and Curie temperature around 43 degree Celsius.
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I am planning to do RT-PCR to evaluate the expression of HSP in human cancer cells. Please help me identify heat shock protein 70 and 90 primers.
Also you can measure the concentration via ELISA
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Different HIFU systems have different technical characteristics, so that the time required for treating a tumor may me heavily different. My statement refers to the system we used several years ago. Now the progress in the technology may have substantially reduced the treatment time. In addition, for the largest tumors, HIFU can be, eventually, administered in two or more session on overlapping regions to cover the whole diseased tissue. That may not feasible with RT, due to the dose limits in the surrounding structures where radiations doses add up and may reach a total value higher than clinically acceptable. In addition, tumors' regions already treated by HIFU need not to be treated again with radiations. In principle that would totally change the spatial distribution of concurrent RT, that can be restricted to a the relatively thin region where the tumor infiltrate the healthy tissue. But all that are speculations that should be compared with experimental data! I think that if you are interested in a deeper and more appropriate discussion I need to know better what kind of experiment you are planning. My best wishes,
Gianni
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Hi
For in-vivo hyperthermia, it depends on the method for inducing heat. for example for magnetic hyperthermia with superparamagnetic or ferromagnetic nanoparticles (as heating sources) coil that produce AC magnetic field and optical fiber (for heat measuring) are necessary and available. Also we can use RF generator instead of coil.
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