Digital Imaging For Radiation Therapy Verification

A linear diode array was used to scan a radiation field for pulsed high-energy x-ray imaging. With a signal of about 50 picocoulombs of charge from each diode for each beam pulse, the signal to noise ratio for an image of an open field was 119. An image of a porcine femur in a wax phantom was obtained by scanning the transmitted radiation. The resultant electronic image was superior in quality when compared to the standard radiotherapy port film. The simplicity of the detector system has demonstrated the feasibility of constructing an electronic portal imaging system for clinical use.