High resolution small-scale inorganic scintillator detector: HDR brachytherapy application

Area of Science:

• Medical Physics
• Radiation Oncology
• Detector Technology

Background:

• Brachytherapy (BT) involves high-dose internal irradiation using sources near tumors.
• Clinical safety in BT requires precise dose verification for effective cancer treatment and healthy tissue sparing.
• Quality assurance is crucial for matching delivered doses to prescribed doses in brachytherapy.

Purpose of the Study:

• To evaluate the performance of a novel point-size inorganic scintillator detector (ISD).
• To assess the ISD's suitability for high dose rate brachytherapy (HDR-BT) quality assurance.
• To verify dose delivery accuracy in HDR-BT treatments.

Main Methods:

• Developed a dose verification system using scintillating dosimetry with an ¹⁹² Ir BT source.
• Measured dose rates in water phantoms according to TG43U1 recommendations.
• Assessed ISD performance including linearity, energy dependency, stability, SNR, and SBR, comparing results with TG43 reference data.

Main Results:

• The ISD demonstrated perfect linear behavior with dose rate (R²=1) and high SNR (>35) and SBR (>36).
• Achieved excellent stability (0.54%) and minimal afterglow (<1%).
• Measurements agreed with TG43 simulation data within 1.2% for distances >0.25 cm.

Conclusions:

• The proposed ISD system is suitable for dose verification in HDR-BT.
• The detector enables accurate dwell time estimation and high spatial resolution dose measurement.
• Further clinical investigations are recommended to promote the ISD for broader clinical use.