SU-E-I-85: Evaluation of a Solid-State Dosimeter Module for Measuring Nuclear Medicine Radionuclides

Area of Science:

• Medical Physics
• Radiation Detection and Measurement

Background:

• A new solid-state dosimeter module (UDOS001) offers portable radiation monitoring using external power.
• The dosimeter is designed for detecting various radiation types with a minimum energy of 100 keV.

Purpose of the Study:

• To evaluate the suitability of the UDOS001 dosimeter for measuring radiation doses from radionuclides commonly used in nuclear medicine.
• To assess the dosimeter's performance with specific isotopes like Fluorine-18 (F-18), Iodine-131 (I-131), and Technetium-99m (Tc-99m).

Main Methods:

• Three radionuclides (F-18, I-131, Tc-99m) were measured at one meter distance and varying angles.
• Dosimeter output was digitized using a battery-powered data logger and processed on a PC.
• Dose rates were calculated from the slope of cumulated dose versus time, using a manufacturer-provided calibration factor.

Main Results:

• Dosimeter measurements closely approximated published gamma ray dose rate constants for the tested radionuclides.
• Angular response varied, but a 90-degree acceptance angle provided uniform response across all tested radionuclides.
• A revised calibration factor of 0.154 urad/19.5 mV step is proposed for improved accuracy at relevant gamma ray energies.

Conclusions:

• The UDOS001 solid-state dosimeter is suitable for measuring doses from common nuclear medicine radionuclides.
• The device's portability and accuracy make it a valuable tool for radiation monitoring in clinical settings.
• Further calibration refinement can enhance measurement precision for specific gamma ray energies.