Operation of Compact X-Band Linear Accelerator System Mounted on the Gantry for Radiation Therapy

Linear accelerators (LINAC) that generate high energy X-rays have been widely used for radiotherapy. With the combination of advanced imaging modalities, an image-guided radiation therapy (IGRT) has greatly improved the quality of radiotherapy by acquiring instant knowledge of changes in tumor volume, radiation dose distribution, and effective tumoricidal doses during treatment. In this study, we developed a compact 9.3 GHz X-band LINAC system and installed on the gantry for potential applications in IGRT. We confirmed X-ray generation using radio frequency transmission tests and measured the X-ray dose rates while the gantry was rotating, which demonstrates stable and reliable operation of the developed system. The field size of an X-ray beam was $\pmb{10.31}\ \mathbf{cm}\ \times \ \pmb{10.31}\ \mathbf{cm}$ at the solid water phantom (depth 0 cm) of the film, and the standard deviation of the Xray dose was 0.016 while rotating. Therefore, we describe the design and test results of the X-band LINAC system mounted on the O-arm gantry. We expect the use of our design for the fusion system that integrates a diagnostic imaging instrument with a radiation therapeutic device.