Optimization in interstitial plasmonic photothermal therapy for treatment planning

Area of Science:

• Biomedical Engineering
• Nanotechnology
• Medical Physics

Background:

• Interstitial photothermal therapy (PPTT) shows promise for cancer treatment.
• Optimizing laser power, nanoparticle concentration, and exposure time is crucial for PPTT efficacy and safety.
• Simultaneous optimization of these parameters for deep-seated tumors remains an unmet need.

Purpose of the Study:

• To develop an optimization algorithm for interstitial PPTT.
• To simultaneously optimize laser power density, gold nanorod concentration, and exposure time.
• To achieve complete tumor destruction with a 1 mm margin in normal tissue for spherical tumors of varying sizes.

Main Methods:

• Numerical modeling using Pennes bioheat and Arrhenius damage equations.
• Simulation of temperature and thermal damage distributions in a tissue model with embedded tumors.
• Development of a novel objective function for simultaneous multi-parameter optimization.
• Assignment of sequential weights to parameters based on relative importance.

Main Results:

• Increased nanorod concentration elevates temperature but affects distribution uniformity and thermal damage.
• Optimization allows compensation between parameters to achieve desired tumor damage and margin.
• Demonstrated the critical role of optimization in interstitial PPTT outcomes.

Conclusions:

• The developed method effectively optimizes key parameters for interstitial PPTT planning.
• Enables simultaneous optimization of laser power, nanorod concentration, and exposure time.
• Offers clinical flexibility for personalized treatment planning for deep-seated tumors.