Radio-frequency lesioning in brain tissue with coagulation-dependent thermal conductivity: modelling, simulation and analysis of parameter influence and interaction

Johansson, Johannes; Eriksson, Olle; Wren, Joakim; Loyd, Dan; Wårdell, Karin

doi:10.1007/s11517-006-0098-1

Cited by 8 publications

(10 citation statements)

References 22 publications

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“…The pulse train over 30 seconds was modeled with a rectangular function depending on the frequency (20 Hz) and duty cycles (30% and 50%) of the laser output, and it was also multiplied to model the pulsed light stimulation. Thermal parameters used for the FEM simulation are summarized in Table 3 and the initial temperature was set to 36 °C for the entire domain [21][22][23][24][25]. Note that core diameter and NA of the fiber were set at 200 μm and 0.39 NA, respectively, for all temperature modeling cases (same as the experimental condition).…”

Section: ( )mentioning

confidence: 99%

Characterization of fiber-optic light delivery and light-induced temperature changes in a rodent brain for precise optogenetic neuromodulation

Shin

Yoo

Kim

et al. 2016

Biomed. Opt. Express

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Understanding light intensity and temperature increase is of considerable importance in designing or performing optogenetic experiments. Our study describes the optimal light power at target depth in the rodent brain that would maximize activation of light-gated ion channels while minimizing temperature increase. Monte Carlo (MC) simulations of light delivery were used to provide a guideline for suitable light power at a target depth. In addition, MC simulations with the Pennes bio-heat model using data obtained from measurements with a temperature-measuring cannula having 12.3 mV/°C of thermoelectric sensitivity enabled us to predict tissue heating of 0.116 °C/mW on average at target depth of 563 μm and specifically, a maximum mean plateau temperature increase of 0.25 °C/mW at 100 μm depth for 473 nm light. Our study will help to improve the design and performance of optogenetic experiments while avoiding potential over- and under-illumination.

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Section: ( )mentioning

confidence: 99%

Characterization of fiber-optic light delivery and light-induced temperature changes in a rodent brain for precise optogenetic neuromodulation

Shin

Yoo

Kim

et al. 2016

Biomed. Opt. Express

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“…Of these, RF lesioning became the method of choice, since it was considered that the size of the RF lesion was easiest and safest to be regulated, due to the physiological parameters which affected it [18,19,20,21]. The size of an RF lesion results from the balance between heat generation and heat loss, as well as from parameters such as electrode design, temperature setting, and tissue type and tissue conductivity [20,22,23]. …”

Section: Discussionmentioning

confidence: 99%

“…pallidum) and the proximity of the lamina medullaris interna to, or even its inclusion in, the lesion area in the posteroventral part of that nucleus. The presence of Virshow-Robin spaces, although not uncommon in the posteroventral putamen but rare in the pallidal target area, is likely to have some impact on the lesion volume, and on heat losses by diffusion, convection via circulation and low resistance shunting, all of which will contribute further to the difficulty to predict the lesion size [23,35]. Biological factors might also have influenced the lesion volume.…”

Section: Discussionmentioning

confidence: 99%

Impact of Parameters of Radiofrequency Coagulation on Volume of Stereotactic Lesion in Pallidotomy and Thalamotomy

Hirabayashi

Hariz²,

Wårdell

et al. 2012

Stereotact Funct Neurosurg

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Background: One of the many reasons why lesional surgery for movement disorders has been more or less abandoned may have been the difficulty in predicting the shape and size of the stereotactic radiofrequency (RF) lesion. Objectives: To analyse the contribution of various RF coagulation parameters towards the volume of pallidotomies and thalamotomies. Methods: The relationship between temperature of coagulation, length of coagulated area and duration of coagulation on the one hand, and lesion volume on the other was retrospectively evaluated. Lesion diameters were measured on stereotactic thin-slice CT and MRI scans, and volumes of lesions were calculated concerning 36 pallidotomies and 14 thalamotomies in 46 patients who were operated using the same RF generator and same RF electrode. Results: The coagulation temperature, length of coagulated area and duration of coagulation were all correlated to the lesion volume. However, for a given length of coagulated area, the lesion´s size was most strongly influenced by the temperature. Despite this clear correlation, and the relatively homogenous coagulation parameters, the lesions’ volumes were markedly scattered. Conclusions: The volume of the stereotactic RF lesions could be correlated with the coagulation parameters, especially the temperature, at a group level, but could not be predicted in individual patients based solely on the RF coagulation parameters.

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“…A previous developed model using coagulation dependent thermal conductivity [9] was improved in order to also include effects of the heat transfer from convective movements in fluid-filled cavities. Experiments in kidney tissue and corresponding computer simulations were carried out in order to investigate whether the convection is important and if the simulations give reasonable results.…”

Section: Methodsmentioning

confidence: 99%

“…Studied topics are e.g. coagulation of an albumin rich test solution [6], impact of thermocouple location [7], the influence on lesion size from electrode design [8], blood perfusion, target temperature and the electrical and the thermal properties of brain matter [9]. In the latter study coagulation dependent thermal conductivity was introduced.…”

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confidence: 99%

Impact of cysts during radiofrequency lesioning in deep brain structures—a simulation andin vitrostudy

et al. 2007

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Radio frequency lesioning of nuclei in the thalamus or the basal ganglia can be used in order to reduce symptoms caused by e.g. movement disorders such as Parkinson's disease. Enlarged cavities containing cerebrospinal fluid (CSF) are commonly present in the basal ganglia and tend to increase in size and number with age. Since the cavities have different electrical and thermal properties compared with brain tissue, it is likely that they can affect the lesioning process and thereby the treatment outcome. Computer simulations using the Finite Element Method (FEM) and in-vitro experiments have been used to investigate the impact of cysts on lesions' size and shape. Simulations of the electric current and temperature distributions as well as convective movements have been conducted for various sizes, shapes and locations of the cysts as well as different target temperatures. Circulation of the CSF caused by the heating was found to spread heat effectively and the higher electric conductivity of the CSF increased heating of the cyst. These two effects were together able to greatly alter the resulting lesion size and shape when the cyst was in contact with the electrode tip. Similar results were obtained for the experiments.

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Radio-frequency lesioning in brain tissue with coagulation-dependent thermal conductivity: modelling, simulation and analysis of parameter influence and interaction

Cited by 8 publications

References 22 publications

Characterization of fiber-optic light delivery and light-induced temperature changes in a rodent brain for precise optogenetic neuromodulation

Characterization of fiber-optic light delivery and light-induced temperature changes in a rodent brain for precise optogenetic neuromodulation

Impact of Parameters of Radiofrequency Coagulation on Volume of Stereotactic Lesion in Pallidotomy and Thalamotomy

Impact of cysts during radiofrequency lesioning in deep brain structures—a simulation andin vitrostudy

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