[How to select the treatment options in prostate cancer]

Radiation therapy (RT) for prostate cancer has been developing dramatically during the past 10 years in Japan as well as in USA. There are several ways to treat prostate cancer by RT. As for external-beam RT (EBRT), a more sophisticated technique beyond 3-dimensional conformal RT called intensity modulated RT was developed and has been in use in many Japanese RT centers. It can raise the total radiation dose and is expected to increase the biochemical control rate. As for brachytherapy, a low-dose-rate seed implant using iodine-125 was initiated in 2003 and has become widespread throughout Japan in only a few years. High-dose-rate brachytherapy using iridium-19 2 has also been used in more advanced cases combined with EBRT. Brachytherapy offers an ideal RT dose concentration and can avoid rectal complications. As for particle therapy, we have carbon and proton in several institutions in Japan. Particles have the merit of good dose distributions and for carbons, relative biological effectiveness. Furthermore, some centers are considering the stereotactic hypofractionated RT due to the relatively low alfa-beta ratio of prostate cancer. Recent reports showed that after a certain period of followup, the biochemical control rate was similar either with external beam high-quality RT, brachytherapy, heavy ion RT and surgery. Therefore, the choice of treatment should depend on the adverse effects, quality of life, medical costs, and the lifestyle of the patient. The merits and demerits of each treatment modality were discussed. Longer follow-up is still necessary and informed consent is mandatory when choosing a treatment modality.