2018 年 88 巻 3 号 p. 73-80
In recent years, technological innovations in radiotherapy have been remarkable, thanks to progress in computer technology and therapeutic equipment, and various high precision radiotherapy have been established.
Intensity-modulated radiation therapy (IMRT) can conduct complicated dose calculations by computer control and inverse planning and allows sufficient target dose applications while keeping the risk organs within the tolerance dose. Volumetric-modulated arc therapy (VMAT) is an irradiation technique that adds intensity-modulation to conformal radiotherapy, which shortens the treatment time. Image-guided radiotherapy (IGRT) is an irradiation technique that reproduces the irradiation position, which is determined by the treatment plan, by three-dimensional measurements.
Particle therapy is a form of high-precision radiotherapy that uses protons and heavy-particles (carbon-ion), which are obtained from large accelerators, such as cyclotrons and synchrotrons. Since the particle does not advance beyond a certain depth, called Bragg peak, it is possible to concentrate the dose onto the lesion. Particle therapy has the advantage of providing a low radiation dose to risk organs; thus, the risk of adverse events is low.
High-precision radiotherapy is expected to improve treatment outcomes and reduce side effects.
