Errors between two- and three-dimensional thermal model predictions of hyperthermia treatments

Area of Science:

• Biomedical Engineering
• Medical Physics
• Computational Biology

Background:

• Hyperthermia therapy requires precise temperature distribution modeling for efficacy.
• Anatomically realistic models are crucial for accurate simulation of heat transfer in biological tissues.
• Previous simulations often relied on simplified two-dimensional models, potentially limiting clinical applicability.

Purpose of the Study:

• To develop and validate a three-dimensional simulation program for hyperthermia.
• To compare the accuracy of 2D versus 3D simulations in realistic, inhomogeneous tissue models.
• To investigate the impact of tissue thermal conductivity on temperature distribution during hyperthermia.

Main Methods:

• Developed a simulation program using the bioheat transfer equation.
• Integrated anatomical data from serial computed tomography (CT) scans.
• Calculated power deposition patterns independently and performed parametric studies.

Main Results:

• Two-dimensional simulations produced significant temperature errors (up to tens of degrees) at tumor ends.
• Two-dimensional models showed acceptable accuracy in the central region of large tumors only with high blood perfusion (>1 kg/m3/s).
• Thermal conductivity values between 0.4-0.6 W/m/°C are suitable for most soft tissues, but bone and fat require specific values.

Conclusions:

• Three-dimensional simulations are necessary for accurate patient-specific hyperthermia treatment planning.
• Simplified 2D models are inadequate for precise temperature prediction in hyperthermia.
• Accurate thermal conductivity values for specific tissues like bone and fat are critical for simulation fidelity.