[Advances in brachytherapy--focusing on the permanent implant for early prostate carcinoma].

Even in the modern era of advanced external radiotherapy, brachytherapy is an important and useful modality of radiotherapy. In North America and Europe, it has been noted that the proportion of prostate cancer patients treated by HDR or LDR interstitial brachytherapy is rapidly increasing, as it offers several practical and theoretical advantages over external radiotherapy. HDR treatment with 192Ir remote afterloader provides an optimized dose distribution controlled by an accurate dwell time and position of 192Ir source. LDR brachytherapy is a simple, minimally invasive, and outpatient based procedure that avoids hospitalization and allows the patient an early recovery and rapid return to normal activities. It has produced good 10-year outcome with relatively low morbidity. Although in Japan this treatment was behind North America and Europe, the 125I-seed source was approved by the Japanese FDA and a rule for patient discharge was developed recently. The first case was treated in September 2003 and this treatment is expected to become an important option for early prostate cancer. Several areas of brachytherapy including treatment planning, choice of radionuclide, treatment procedure, and treatment outcome are discussed in this paper.