[192Ir brachytherapy].

Modern high technology has recently brought a precision treatment modality in the field of brachytherapy for cancer patients. Ir-192 manual afterloading (hair pin technique of Ir-192 wire) replaced the technique utilizing Ra-226 needles at our department in 1973. In May 1991, microSelectron-HDR (Ir-192 micro-source of 370 GBq) was installed in Osaka University Hospital. Preliminary analysis of phase I/II study resulted in no significant differences between the incidence of an acute mucosal reaction as well as early tumor response after high and low dose rate interstitial brachytherapy for oral cancer. Since April 1992, a phase III study has been under way to completely eliminate the problem of hospital personnel exposure to radiation in the field of brachytherapy. The introduction of remote after-loading of Ir-192 micro-source has resulted in improvements in elderly patient care during the interstitial brachytherapy for malignancies. The indications for HDR brachytherapy have been expanded, and new technology was developed to improve the local cure of the disease, such as linked double button technique for oral cancer, template interstitial brachytherapy for perineal cancer, and postoperative brachytherapy using intraoperative flexible catheter placement for locally unresectable disease or microscopically residual disease. Through these meticulous efforts, HDR interstitial brachytherapy will soon become a satisfactory substitute for traditional LDR interstitial brachytherapy.