Rapid Multisite Remote Surface Dosimetry for Total Skin Electron Therapy: Scintillator Target Imaging

Area of Science:

• Medical Physics
• Radiation Oncology
• Dosimetry

Background:

• Total skin electron therapy (TSET) requires accurate surface dosimetry.
• Current methods can be time-consuming and require post-exposure processing.
• A need exists for rapid, real-time surface dose measurement in TSET.

Purpose of the Study:

• To develop and evaluate a rapid, wireless surface-dosimetry method for TSET.
• To enable accurate, remote skin dose measurement without post-processing.
• To improve the clinical workflow for TSET dosimetry.

Main Methods:

• Developed a wireless scintillator-based surface dosimetry system.
• Attached scintillator targets to patient skin during TSET.
• Imaged scintillators with an intensified, time-gated camera synchronized with the linear accelerator.
• Used optically stimulated luminescence dosimeters (OSLDs) for absolute dose reference.
• Employed real-time image processing and a custom fitting algorithm for dose conversion.

Main Results:

• Scintillator dosimetry reported dose with <3% difference in 88/99 sites and <5% difference in 98/99 sites compared to OSLDs.
• Linear regression analysis yielded an R² = 0.94, indicating strong correlation.
• The system demonstrated high accuracy, with scintillators reporting dose within <3% of OSLDs.

Conclusions:

• The intensified camera imaging of calibrated scintillator targets provides rapid, absolute surface-dosimetry measurements for TSET patients.
• This technique significantly reduces the time and effort for full-body dosimetry.
• The system is adaptable for any surface-dosimetry application with a visible treatment region.