ultiplies exponentially at that moment. Purpose of this experiment is everyday and twice a week over a four month period (march~june) 2009 year to confirm maintenance of accuracy through Quality control of OBI. In short, measurement of exponentially multiplying accuracy of OBI and regular accuracy control was able to maintain accuracy from the center of treatment within 0.1 cm. Therefore, evaluation of exponentially multiplying accuracy using OBI accuracy control linear accelerator phantom on daily, weekly basis was confirmed.

• 장은성(고신대학교 복음병원 방사선종양학과) | Eunsun Jang
• 정봉재(한국국제대학교 방사선학과) | Bongjae Jeong
• 임인철(동의대학교 방사선학과) | Inchul Im
• 강수만(고신대학교 복음병원 방사선종양학과) | Suman Kang Corresponding Author