The effect of laser power, blood perfusion, thermal and optical properties of human liver tissue on thermal damage in LITT

Shibib, Khalid S.; Munshid, Mohammed A.; Lateef, Hind Ali

doi:10.1007/s10103-017-2321-8

Cited by 18 publications

(15 citation statements)

References 8 publications

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“…Therefore, if the laser is like a lancet, the average power is the amount of force used to operate the lancet. It has been confirmed that liver excision using laser entails the conversion of light energy into heat to coagulate liver tissue [29,30]. Higher heat energy leads to a better coagulation effect, resulting in better liver cutting speed and hemostasis effect; however, greater heat also worsens thermal damage.…”

Section: Discussionmentioning

confidence: 99%

Effects of Different 980‐nm Diode Laser Parameters in Hepatectomy

Chai

Zhu

et al. 2019

Lasers Surg Med

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Background and Objective: Despite the successful application of laser in animal experiments and clinics, the adjustment of laser parameters during surgery is still unclear. This study aimed to investigate the effect of different 980-nm diode laser parameters in hepatectomy. This could provide a clear protocol for using 980-nm diode laser in hepatectomy. Study Design/Materials and Methods: In total, 48 Sprague-Dawley rats were used to explore the effects of different 980-nm diode laser parameters in hepatectomy, by setting different parameter combinations. The rats were randomly divided into eight groups, including the continuous wave group and quasi-continuous wave group. The effects were assessed in terms of liver resection speed, extent of intraoperative bleeding, and thermal damage. Results: In the quasi-continuous wave group, there was a significant difference in resection speed at the different laser parameters (P < 0.001); however, there was no significant difference in intraoperative bleeding and thermal damage. In the continuous wave group, there was a significant difference in resection speed, intraoperative bleeding, and thermal damage at different parameters. Conclusion: The study showed that the average power determined hemostasis efficiency and thermal damage, and peak power determined the liver resection speed, whereas the pulse width and repetition frequency are not independent factors. When using 980-nm diode laser in hepatectomy, the average power should be decreased to prove hemostasis efficiency in delicate operations, and the peak power should be decreased to accelerate the procedure without worsening thermal damage. Lasers Surg. Med. 1--8, 2018.

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Section: Discussionmentioning

confidence: 99%

Effects of Different 980‐nm Diode Laser Parameters in Hepatectomy

Chai

Zhu

et al. 2019

Lasers Surg Med

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“…. As the Lagrangian is linear in p and ψ, we see that equations (8) and (9) of the optimality system are equivalent to the state equations (1) and (2) that constrain the optimization problem (5).…”

Section: Adjoint-based Identificationmentioning

confidence: 99%

“…The knowledge of the location of the blood vessels in the vicinity of tumorous tissue (and, thus, close to the applicator) is crucial for the performance of the therapy as well as for the reliability of a simulation model as e.g. discussed in [1][2][3][4][5]. Unfortunately, the location relative to the applicator varies for each patient and treatment.…”

Section: Introductionmentioning

confidence: 99%

Identification of the blood perfusion rate for laser-induced thermotherapy in the liver

et al. 2020

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Using PDE-constrained optimization we introduce a parameter identification approach which can identify the blood perfusion rate from MR thermometry data obtained during the treatment with laser-induced thermotherapy (LITT). The blood perfusion rate, i.e., the cooling effect induced by blood vessels, can be identified during the first stage of the treatment. This information can then be used by a simulation to monitor and predict the ongoing treatment. The approach is tested with synthetic measurements with and without artificial noise as input data.

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“…where A, E a , and R a are the frequency factor, activation energy, and universal gas constant, respectively. For liver thermal damage, A = 9.4 × 10 104 s −1 , E a = 6.68 × 10 5 J mol −1 , and R a = 8.31 J mol −1 K −1 [23]. The undamaged fraction of the tissue and the damaged fraction can be estimated by f u = exp(−Ω) and f d = 1 − f u , respectively [24].…”

Section: Thermal Energy Model For Tissue Heatingmentioning

confidence: 99%

“…where W b,0 is the constitutive blood perfusion rate, 18.2 Kg m −3 s −1 for liver, and f T is a dimensionless function that accounts for vessel dilation at slightly elevated temperatures, which can be approximated as [23,24]:…”

Section: Dynamic Tissue Propertiescmentioning

confidence: 99%

The Influence of Dynamic Tissue Properties on HIFU Hyperthermia: A Numerical Simulation Study

et al. 2018

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Accurate temperature and thermal dose prediction are crucial to high-intensity focused ultrasound (HIFU) hyperthermia, which has been used successfully for the non-invasive treatment of solid tumors. For the conventional method of prediction, the tissue properties are usually set as constants. However, the temperature rise induced by HIFU irradiation in tissues will cause changes in the tissue properties that in turn affect the acoustic and temperature field. Herein, an acoustic–thermal coupling model is presented to predict the temperature and thermal damage zone in tissue in terms of the Westervelt equation and Pennes bioheat transfer equation, and the individual influence of each dynamic tissue property and the joint effect of all of the dynamic tissue properties are studied. The simulation results show that the dynamic acoustic absorption coefficient has the greatest influence on the temperature and thermal damage zone among all of the individual dynamic tissue properties. In addition, compared with the conventional method, the dynamic acoustic absorption coefficient leads to a higher focal temperature and a larger thermal damage zone; on the contrary, the dynamic blood perfusion leads to a lower focal temperature and a smaller thermal damage zone. Moreover, the conventional method underestimates the focal temperature and the thermal damage zone, compared with the simulation that was performed using all of the dynamic tissue properties. The results of this study will be helpful to guide the doctors to develop more accurate clinical protocols for HIFU treatment planning.

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The effect of laser power, blood perfusion, thermal and optical properties of human liver tissue on thermal damage in LITT

Cited by 18 publications

References 8 publications

Effects of Different 980‐nm Diode Laser Parameters in Hepatectomy

Effects of Different 980‐nm Diode Laser Parameters in Hepatectomy

Identification of the blood perfusion rate for laser-induced thermotherapy in the liver

The Influence of Dynamic Tissue Properties on HIFU Hyperthermia: A Numerical Simulation Study

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