The idea behind this Briefing Meeting and also a brief introduction of both 1^<st> IDMC and 20^<th> IDRC will be presented. The 1^<st> IDMC was established this year and was arranged as a subject of this meeting instead of DMTC, which had been reported in previous years. 1^<st> IDRC was held in Seoul, Korea. IDRC is a regular conference being held in US, Asia, and Euorpe by rotation. The 20^<th> IDRC was held in Palm Beach, US.