Medical X?band linear accelerator for high?precision radiotherapy

Purpose Recently, high-precision radiotherapy systems have been developed by integrating computerized tomography or magnetic resonance imaging to enhance the precision of radiotherapy. For integration with additional in a limited space, miniaturization and weight reduction linear accelerator (linac) system become important. The aim this work is develop compact medical linac based on 9.3 GHz X-band RF technology instead S-band typically used field. Methods accelerating tube was designed 3D finite-difference time-domain particle-in-cell simulations because frequency variation resulting from structural parameters processing errors relatively sensitive operating performance linac. Through simulation electric field distribution beam dynamics process, we an efficiently accelerate electron magnetron as source miniaturize entire In addition, side-coupled structure adopted design reduce power loss. To verify linac, diagnostic analyze characteristics quality assurance (QA) experimental environment including lateral water phantoms primary (energy, dose rate, flatness, symmetry, penumbra) QA process standard protocols AAPM TG-51, 106, 142 IAEA TRS-398. Results has high shunt impedance strength. Therefore, even though length 37 cm, could more than 6 MeV produce current 90 mA. transmission ratio measured be approximately 30% ~ 40% when gun operates constant emission region. percent depth at depths 10 20 cm 0.572, so verified that photon energy matched MV. maximum rate 820 cGy/min source-to-skin distance 80 cm. symmetry smaller flatness had higher value due flattening filter-free characteristics. case penumbra, it not sufficiently steep compared commercial equipment, but compensated improving devices such multileaf collimator jaw. Conclusions A for Since precise machining are required technology, performing ultraprecision machining. short volume, can generate validated therapeutic beam. flexibility coupled CT MRI bore size gantry. improve mechanical stiffness unit load.