Thermal dose determination in cancer therapy

Area of Science:

• Oncology
• Biophysics
• Medical Physics

Background:

• Clinical hyperthermia is developing rapidly as a cancer treatment, often combined with other therapies.
• A standardized method for measuring thermal dose is needed for clinical relevance and to correlate with biological effects.
• Current methods lack a consistent way to quantify heat exposure in clinically meaningful units.

Purpose of the Study:

• To develop a clinically relevant method for calculating thermal dose in hyperthermia cancer treatment.
• To establish a relationship between temperature, time, and biological effect for thermal dose estimation.
• To provide a tool for real-time monitoring of accumulated thermal dose during patient treatment.

Main Methods:

• Empirically comparing published data to establish a basic time-temperature relationship.
• Defining a reference temperature (43°C) to calculate "equivalent-minutes" (t43) of thermal exposure.
• Developing a FORTRAN computer program to perform thermal dose calculations, including "degree-minutes" (tdm43).

Main Results:

• A method to calculate thermal dose as "equivalent-minutes" at a reference temperature (43°C) was established.
• The calculation method allows for adjustments to the reference temperature and Arrhenius "break" temperature.
• The approach considers factors like step-down heating and thermotolerance in thermal dose calculations.

Conclusions:

• The proposed thermal dose calculation provides a simple yet effective means for clinical hyperthermia applications.
• This method facilitates the evaluation of thermal dose in therapeutically useful units.
• Further efforts are stimulated to refine and validate thermal dose estimation for cancer treatment.