Dosimetric properties of colloidal quantum dot-based systems for scintillation dosimetry

Area of Science:

• Materials Science
• Medical Physics
• Radiation Detection

Background:

• Colloidal quantum dots (cQDs) are emerging as materials for radiation detection, particularly in medical applications like scintillation dosimetry.
• Existing research often focuses on photoluminescence changes rather than the intrinsic scintillation signal properties of cQDs.

Purpose of the Study:

• To comprehensively investigate the scintillation properties of cQDs for radiation detection.
• To evaluate cQD-based detectors' linearity with dose, dose rate, and beam energy dependence for medical applications.

Main Methods:

• Utilized CdSe multishell cQDs in powder and liquid dispersion forms as sensitive volumes for dosimeters.
• Assessed signal linearity using R² coefficient across clinically relevant dose ranges and beam energies (kV and MV).
• Characterized dose rate and beam energy dependencies, comparing cQDs with commercial scintillators (BCF-60, Ultima Gold).

Main Results:

• Achieved excellent signal linearity (R² > 0.999) for cQD dosimeters across a clinically relevant dose range.
• Demonstrated good dose rate independence for cQDs, with minor variations (1-2%) in scintillation output.
• Observed varying beam energy dependence, with cQD powder showing higher dependence than liquid dispersions and commercial scintillators; cQD liquid dispersions exhibited minimal energy dependence (15% variation).

Conclusions:

• CdSe cQDs exhibit promising characteristics for scintillation dosimetry in radiation therapy, including high linearity and dose rate independence.
• cQD liquid dispersions offer a compelling alternative with minimal beam energy dependence, suitable for volumetric dosimetry.
• Further research into cQD scintillation properties can advance their application in medical radiation detection.