Optimizing the TLD-100 readout system for various radiotherapy beam doses using the Taguchi methodology

Area of Science:

• Medical Physics
• Radiation Dosimetry
• Materials Science

Background:

• Accurate radiation dosimetry is crucial in radiotherapy for effective cancer treatment.
• Thermoluminescent dosimeters (TLDs) are widely used for measuring radiation doses.
• Optimizing TLD readout parameters is essential for reliable and reproducible measurements.

Purpose of the Study:

• To optimize the TLD-100 readout system parameters for various radiotherapy beam doses.
• To enhance the linearity and reproducibility of TLD readings using the Taguchi method.
• To identify the most influential parameters affecting TLD readout accuracy.

Main Methods:

• Utilized the Taguchi method to systematically optimize four parameters: initial temperature, heating rate, preheat time, and maximum temperature.
• Employed a Varian 21EX linear accelerator (LINAC) to deliver 6MV radiotherapy beams at 50, 100, and 150 cGy doses.
• Averaged measurements from three TLD-100 chips for each dose group, analyzing nine parameter combinations.

Main Results:

• Determined optimal readout parameters: 50°C initial temperature, 3°C/s heating rate, 5 min preheat time, and 250°C maximum temperature.
• Identified initial temperature, heating rate, and maximum temperature as dominant parameters, with preheat time being minor.
• Found no significant interaction between initial temperature and heating rate or maximum temperature, but a complex interaction between heating rate and maximum temperature.

Conclusions:

• The Taguchi method effectively optimized the TLD-100 readout system for radiotherapy dosimetry.
• Initial temperature and heating rate are critical factors for achieving accurate and reproducible TLD measurements.
• Understanding parameter interactions is vital for further refining TLD readout protocols in clinical settings.