Imaging-therapy computed tomography with quasi-monochromatic X-rays.

Area of Science:

• Medical Physics
• Radiotherapy Technology
• Diagnostic Imaging

Background:

• Computed tomography (CT) operates at 50-100 keV, while radiotherapy requires MeV energies for optimal dose distribution.
• A gap exists between diagnostic imaging energies and therapeutic radiation energies.
• Heavy elements can act as photoelectric radiation enhancers for targeted therapy.

Purpose of the Study:

• To bridge the energy gap between CT diagnosis and radiotherapy.
• To enhance photoelectric radiation dose using targeted heavy elements.
• To combine diagnostic and therapeutic capabilities in a single clinical CT system.

Main Methods:

• An X-ray optical module was developed and mounted on a clinical CT scanner.
• The module modifies the X-ray beam into a high-intensity, monochromatized, and focused beam.
• Radiation characteristics and photoelectric enhancement were experimentally verified using specific elements.

Main Results:

• The X-ray optical module filters and focuses radiation to 59.3 keV (tungsten K alpha line), creating a steep dose gradient.
• The quasi-monochromatic radiation energy matches the peak photoelectric dose enhancement for gadolinium and iodine.
• The system achieves a dose gradient suitable for locoregional radiation therapy.

Conclusions:

• An optimized X-ray optical module enables targeted therapy and photoelectric dose enhancement.
• This technology allows for the integration of diagnosis and radiotherapy on a clinical CT platform.
• The developed system offers a novel approach to precision radiation medicine.