Laser interstitial thermotherapy of small breast fibroadenomas: numerical simulations.

Abstract

BACKGROUND:

Laser interstitial thermotherapy (LITT) is potentially a novel method to treat small breast fibroadenoma, without the need for surgical removal. Dosimetry planning and conformation of the treated area of tumor remain major issues, especially for a moving organ such as the breast. Pre-treatment simulation planning of this therapy is an effective method to predict the final thermal damage. In this study, a mathematical model is elaborated to simulate the heat distribution and the thermal damage.

METHODS:

The mathematical model was based on finite element method (FEM) to solve the light distribution, bioheat, and thermal damage equations. Six simulations were performed with the following powers: 5, 6, 7, 8, 9, and 10 W (λ = 980 nm), and for an irradiation time of 125 seconds, with a 50 °C iso-damage temperature. To validate these simulations, six turkey breast samples were irradiated with parameters used for simulations. Volumes of thermal damage were calculated by using formulas: spherical, Elliptical, and Carlsson volumes and compared to the simulated volumes.

RESULTS:

Differences between volumes were from 0.01 to 1 cm3. Interpolations between volumes from ex vivo experiments with corresponding powers were established. The relationship between the volume of the thermal damage and the laser power was described by a polynomial equation (R2  = 0.99). The power estimated by the interpolation to obtain 1 cm3 of thermal damage was 7.4 W (922 J) and the maximum corresponding temperature was 90 °C.

CONCLUSION:

In this study, a good correlation was established between simulation and ex vivo experiments of LITT for fibroadenoma breast cancer.

• Authors: Mohamad Feras Marqa, Serge Mordon, Nacim Betrouni
• Journal: Lasers in surgery and medicine (Lasers Surg Med) Vol. 44 Issue 10 Pg. 832-9 (Dec 2012) ISSN: 1096-9101 [Electronic] United States
• PMID: 23184405 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't, Validation Study)
• Copyright: Copyright © 2012 Wiley Periodicals, Inc.

Topics

• Animals
• Breast Neoplasms (surgery)
• Computer Simulation
• Female
• Fibroadenoma (surgery)
• Finite Element Analysis
• In Vitro Techniques
• Lasers, Semiconductor (therapeutic use)
• Models, Biological
• Turkeys